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AimTo investigate the safety and performance of a telemetric suprachoroidal intraocular pressure (IOP) sensor (EYEMATE-SC) and the accuracy of its IOP measurements in open angle glaucoma (OAG) patients undergoing simultaneous non-penetrating glaucoma surgery (NPGS).MethodsProspective, multicentre, open-label, single-arm, interventional clinical trial. Twenty-four eyes of 24 patients with OAG regularly scheduled for NPGS (canaloplasty or deep sclerectomy) were simultaneously implanted with an EYEMATE-SC sensor. Six-month follow-up on the sensor's safety and performance as well as on the level of agreement between the EYEMATE-SC measurements and IOP measurements with Goldmann applanation tonometry (GAT).ResultsThe eyes underwent canaloplasty (n=15) or deep sclerectomy (n=9) and achieved successful implantation of the sensor. No device migration, dislocation or serious device-related complications occurred. A total of 367 comparisons were included in the IOP agreement analysis. The overall mean difference between GAT and EYEMATE-SC measurements was 1.31 mm Hg (lower limit of agreement (LoA) 7.55 mm Hg; upper LoA -4.92 mm Hg). The maximum difference of 2.5 mm Hg ±3.96 (LoA 0.30-2.29) was reached on day 10 and continuously improved to an agreement of -0.15 mm Hg ±2.28 (LoA -1.24 to 0.89) after 6 months. Accordingly, the percentage of eyes within an IOP difference of ±5 mm Hg improved from 78% (day 3) to 100% (6 months).ConclusionsAfter 6 months, the EYEMATE-SC sensor was safe and well tolerated, and allowed continual IOP monitoring.Trial registration numberNCT03756662.

In the present study, it was aimed to investigate the effects of α-2 agonists used for sedation in cats, namely medetomidine hydrochloride and dexmedetomidine, on intraocular pressure. Two study groups, each containing 17 animals, were formed. One of the groups was treated with 80 µg/kg medetomidine hydrochloride, and the other group with 40 µg/kg dexmedetomidine, via IM route. The animals underwent intraocular pressure measurement before sedative agent administration (T), at the time of vomiting (T1), after vomiting (T2), at 40th minute (T3), at 60th minute (T4), and 20 minutes after atipamezol administration (T5). There was no significant difference between intra-group intraocular pressure measurements taken at different times and inter-group IOP mesaurements taken at the same time points (P>0.05). A numerical increase occurred in intraocular pressure after vomiting, and intraocular pressure was found to be lower during sedation than at the baseline. In conclusion, it was determined that the administration of medetomidine hydrochloride and dexmedetomidine via intramuscular route for sedation reduced intraocular pressure but the levels remained within reference range.

Purpose: To evaluate the influence of atmospheric pressure changes on the behavior of intraocular pressure of healthy military individuals-students and instructors of the National Navy’s Diving & Rescue School at the “ARC BOLÍVAR” naval base-during a simulated immersion in the hyperbaric chamber of the Naval Hospital of Cartagena. Methods: A descriptive exploratory study was performed. The intraocular pressure was measured at different atmospheric pressures during 60-min sessions in the hyperbaric chamber while breathing compressed air. The maximum simulated depth was 60 feet. Participants were students and instructors of the Naval Base’s Diving and Rescue Department. Results: A total of 48 eyes from 24 divers were studied, of which 22 (91.7%) were male. The mean age of the participants was 30.6 (SD=5.5) years, ranging from 23 to 40. No participant had a history of glaucoma or ocular hypertension. The mean base intraocular pressure at sea level was 14 mmHg, which decreased to 13.1 mmHg (decreased by 1.2 mmHg) at 60 feet deep (p=0.0012). However, during the safety stop at 30 feet, the mean IOP kept decreasing until reaching 11.9 mmHg (p

Pulse arrival times (PATs) are time intervals between the electrocardiogram (ECG) and an arterial pulse wave (APW) widely used to obtain cuffless blood pressure (BP). Although some distal APWs can be easily measured using, for example, a photoplethysmography (PPG) sensor on a finger, proximal APWs, such as the one of the carotid in the neck, are much more difficult to obtain for unskilled users. To overcome this, we propose an impedance-based sensor using only two electrodes in contact with each upper extremity (one to inject current and one to measure voltage at each hand or wrist), which can measure both ECG and an APW [an impedance plethysmogram, (IPG)] to obtain the PAT. Since the injected current flows from hand to hand across the upper torso, we hypothesize that the measured IPG should be sensitive to the arrival of the APW near the heart and, therefore, that the obtained PAT could be used as a surrogate of a proximal PAT even when measured on the hands. We have verified this by comparing the hand-to-hand impedance PAT obtained with the sensor with a gold-standard proximal PAT obtained in the carotid by tonometry in a cohort of 84 volunteers aged 20-61 years, showing a correlation of r=0.90 between the two. These results support the feasibility of future inclusion of these proximal PAT measurements in easy-to-use devices to obtain cuffless BP or other cardiovascular information with improved performance by nonspecialist users outside clinical settings.

Current glaucoma treatments aim to lower intraocular pressure, often with topical ocular hypotensive medications. Unfortunately, the effectiveness of these medications depends on sustained patient adherence to regimens which may involve instilling multiple medications several times daily. Patient adherence to glaucoma medications is often low. Recent innovations in digital sensor technologies have been leveraged to confirm eyedrop medication usage in real-time and relay this information back to providers. Some sensors have also been designed to deliver medication reminders and notifications as well as assist with correct eyedrop administration technique. Here, we review recent innovations targeted at improving glaucoma medication adherence and discuss their limitations.

This study aimed to determine the association between the echogenicity of Dupuytren’s disease nodules and myofibroblast load, and between echogenicity and nodule hardness. Thirty-eight nodules were assessed sonographically. The echogenicity of nodules was measured objectively with Image J (grey-value) and subjectively by visual inspection (hypo-, mixed and hyper-echogenicity). These findings were compared with myofibroblast load measured by histopathological analysis. In a different cohort, 97 nodules were assessed for grey-value and nodule hardness using a tonometer. There was a moderate, significant, negative association between grey-value and myofibroblast load and the subjective visual measurements corresponded to this finding. There was also a moderate, significant, negative association between grey-value and nodule hardness. Ultrasound and tonometry may be useful in the selection of patients for possible future preventive treatments.

The aim of this work is to emphasize the need to take into account several important biomechanical factors (biometrical parameters of patient, s eyes accuracy of tonometers) as well as the design of the procedure when interpreting clinical data of immediate IOP elevation after intravitreal injections

Glaucoma is the second leading cause of blindness in India. Despite advances in diagnosing and managing glaucoma, there is a lack of India-specific clinical guidelines on glaucoma. Ophthalmologists often refer to the European Glaucoma Society (EGS) and Asia-Pacific Glaucoma Society (APGS) guidelines. A group of glaucoma experts was convened to review the recently released EGS guideline (fifth edition) and the APGS guideline and explore their relevance to the Indian context. This review provides the salient features of EGS and APGS guidelines and their utility in Indian scenario. Glaucoma diagnosis should be based on visual acuity and refractive errors, slit-lamp examination, gonioscopy, tonometry, visual field (VF) testing, and clinical assessment of optic nerve head, retinal nerve fiber layer (RNFL), and macula. The intraocular pressure target must be individualized to the eye and revised at every visit. Prostaglandin analogues are the most effective medications and are recommended as the first choice in open-angle glaucoma (OAG). In patients with cataract and primary angle-closure glaucoma (PACG), phacoemulsification alone or combined phacoemulsification and glaucoma surgery are recommended. Trabeculectomy augmented with antifibrotic agents is recommended as the initial surgical treatment for OAG. Laser peripheral iridotomy and surgery in combination with medical treatment should be considered in high-risk individuals aged

Rabbits have played an important role in ophthalmological research processes, however in the environment there has been a deficiency of sensitive equipment in measurement of intraocular pressure for this species. To compare intraocular pressure (IOP) measured with rebound (TONOVET Plus®) and applanation (TONO-PEN VET®) tonometry in healthy New Zealand rabbits treated with Amlodipine. Twelve healthy male New Zealand white rabbits, 5 months old; two groups with 6 individuals were used in this study. The experimental group was given Amlodipine® at a dose of 5 mg/kg, once a day for a month. Blood pressure and intraocular pressure were measurement before treatment and 6 h after treatment in a period of one month. A trend is noted where the group of animals treated with amlodipine® presents lower values than the control group, both in systolic and diastolic pressure. The systolic pressure of the control group showed an average of 116.5 ± 7.9 mmHg and 117.4 ± 8.9 mmHg and the treatment group showed an average of 113.6 ± 7.9 mmHg and 111.8 ± 10.0 mmHg (pretreatment and posttreatment respectively). Tonometry: the values obtained using the TONOVET Plus® (19 ± 3 mmHg) are on average higher than the values obtained using the TONO-PEN VET® (17 ± 3 mmHg). It was possible to demonstrate the relationship between systemic blood pressure and intraocular pressure in New Zealand white rabbits. Rebound tonometry showed less variability in results than applanation tonometry. This study confirmed that both tonometers are reliable for measuring IOP in rabbits. Resumen Los conejos han jugado un papel importante en los procesos de investigación oftalmológica, sin embargo, en el medio ha existido una deficiencia de equipos sensibles en la medición de la presión intraocular para esta especie. Para comparar la presión intraocular (PIO) medida con la tonometría de rebote (TONOVET Plus®) y aplanación (TONO-PEN VET®) en conejos Nueva Zelanda sanos y tratados con Amlodipino, fueron usados doce conejos Nueva Zelanda, machos, sanos, de 5 meses de edad y distribuidos en dos grupos con 6 individuos cada uno. El grupo experimental recibió Amlodipino® en una dosis de 5 mg/kg, una vez al día durante un mes. La presión arterial y la presión intraocular se midieron antes del tratamiento y 6 h después del tratamiento en un período de un mes. Se observa una tendencia donde el grupo de animales tratados con amlodipino® presenta valores más bajos que el grupo control, tanto en presión sistólica como diastólica. La presión sistólica del grupo control mostró un promedio de 116,5 ± 7,9 mmHg y 117,4 ± 8,9 mmHg y el grupo de tratamiento mostró un promedio de 113,6 ± 7,9 mmHg y 111,8 ± 10,0 mmHg (pretratamiento y postratamiento respectivamente). Tonometría: los valores obtenidos con el TONOVET Plus® (19 ± 3 mmHg) son en promedio superiores a los valores obtenidos con el TONO-PEN VET® (17 ± 3 mmHg). Fue posible demostrar la relación entre la presión arterial sistémica y la presión intraocular en conejos blancos Nueva Zelanda. La tonometría de rebote mostró menos variabilidad en los resultados que la tonometría de aplanamiento. Este estudio confirmó que ambos tonómetros son confiables para medir la PIO en conejos. Resumo Os coelhos têm desempenhado um papel importante nos processos de pesquisa oftalmológica, porém no meio tem havido uma deficiência de equipamentos sensíveis na medida da pressão intraocular para esta espécie. Comparar a pressão intraocular (PIO) medida com tonometria de rebote (TONOVET Plus®) e de aplanação (TONO-PEN VET®) em coelhos saudáveis da Nova Zelândia tratados com Amlodipina®. Foram utilizados neste estudo doze coelhos brancos da Nova Zelândia, machos saudáveis, 5 meses de idade; distribuído em dois grupos com 6 indivíduos cada um. O grupo experimental recebeu Amlodipina® na dose de 5 mg / kg, uma vez ao dia durante um mês. A pressão arterial e a pressão intraocular foram medidas antes do tratamento e 6 horas após o tratamento em um período de um mês. Nota-se uma tendência onde o grupo de animais tratados com amlodipina® apresenta valores inferiores ao grupo controle, tanto na pressão sistólica quanto na diastólica. A pressão sistólica do grupo controle apresentou média de 116,5 ± 7,9 mmHg e 117,4 ± 8,9 mmHg e o grupo tratamento apresentou média de 113,6 ± 7,9 mmHg e 111,8 ± 10,0 mmHg (pré-tratamento e pós-tratamento, respectivamente). Tonometria: os valores obtidos com o TONOVET Plus® (19 ± 3 mmHg) são em média superiores aos valores obtidos com o TONO-PEN VET® (17 ± 3 mmHg). Foi possível demonstrar a relação entre a pressão arterial sistêmica e a pressão intraocular em coelhos brancos da Nova Zelândia. A tonometria de rebote mostrou menos variabilidade nos resultados do que a tonometria de aplanação. Este estudo confirmou que ambos os tonômetros são confiáveis para medir a PIO em coelhos.

Cilj: Ciljevi istraživanja bili su utvrditi postoji li razlika u mjerenju intraokularnog tlaka (IOT) Goldmanovom aplanacijskom tonometrijom (GAT) i air-puff tonometrijom (APT) te usporediti osjećaj ugode prilikom mjerenja IOT-a objema metodama. Ispitanici i metode: Ovom presječnom studijom obuhvaćena su 133 ispitanika kojima je učinjen standardni oftalmološki pregled. Ispitanici su na pregled dolazili zbog korekcije refrakcijske greške od listopada 2017. do travnja 2018. godine na Polikliniku za oftalmologiju „Oculus“ u Osijeku. Isključni kriteriji bili su dob manja od 18 godina, liječenje od glaukoma, operativni zahvat na prednjem ili stražnjem segmentu oka, degenerativne promjene na prednjem segmentu oka ili teži poremećaj suznog filma. Svim ispitanicima izmjeren je IOT objema metodama, nakon čega su ispitanici dobrovoljno ispunili anketu u kojoj su se prikupljali sljedeći podatci: dob, spol, nošenje leća, broj pregleda mjerenja IOT-a te procjena ugodnosti pregleda GAT-om i APT-om. Rezultati: Presječna studija uključila je 133 pacijenta (83 žene, 50 muškaraca). Medijan dobi ispitanika bio je 51 godina. Utvrđena je statistički značajna razlika između izmjerenog IOT-a desnog i lijevog oka GAT-om i APT-om (t-test za zavisne uzorke, P < 0,001). Nije bilo statistički značajnih razlika u ocjeni ugode mjerenja IOT-a GAT-om i APT-om (Fisherov egzaktni test, P = 0,180). Zaključci: Iako APT ima određene prednosti u odnosu na GAT, GAT daje preciznije rezultate mjerenja IOT-a te se s razlogom danas smatra zlatnim standardom u mjerenju IOT-a., Aim: The objectives of the study were to determine whether there is any difference in the measurement of intraocular pressure (IOP) by Goldmann applanation tonometry (GAT) and air-puff tonometry (APT) and to compare the feeling of comfort when measuring the IOP by both methods. Participants and methods: This cross-sectional study included 133 participants, who underwent standard ophthalmic examination. Participants were examined for correction of refractive error from October 2017 to April 2018 at the Ophthalmology polyclinic “Oculus”, Osijek. Exclusion criteria were age under 18 years, glaucoma treatment, operative surgery at the anterior or posterior eye segment, degenerative changes in the anterior eye segment, or tear film disorder. IOP was measured in all participants by both methods, after which participants voluntarily completed a questionnaire in which the following data were collected: age, gender, data on wearing lenses, number of IOP measures, and evaluation of the comfort level of GAT and APT. Results: This cross-sectional study included 133 patients (83 women, 50 men). The median of the participants’ age was 51. There was a statistically significant difference between the measured IOP of the right and left eye with the GAT and APT (t-test, P < 0.001). There was no significant difference in the comfort level of IOP measured with GAT and APT (Fisher’s exact test, P = 0.180). Conclusions: Although APT has some advantages over GAT, GAT provides more accurate results for IOP measurement and is therefore considered a gold standard for IOT measurement today.

Purpose. To analyze the outcomes of the national polymer microshunt implantation in refractory glaucoma surgery and to show its efficacy and safety. Patients and methods. We analyzed the results of treatment of 90 patients (90 eyes) with refractory glaucoma. All patients were divided into two groups: main group and comparison group. The patients in the main group (44 eyes) were implanted with the national polymer microshunt (Reper-NN). The patients in the comparison group (46 eyes) were implanted with Ex-PRESS. Control criteria in the postoperative period included visometry, tonometry by Maklakov, computed perimetry. The examinations were performed preoperatively, at discharge, in a month, in six months and later postoperatively.Results. When implanting the national polymer microshunt we reached the significant decrease in the intraocular pressure in the postoperative period in comparison with the preoperative level. The implantation outcomes of the national polymer microshunt and Ex-PRESS were comparable in efficacy and safety. The easy implantation and special construction of the national polymer microshunt provided with the sufficient efficacy and safety in refractory glaucoma surgery and allowed recommending its further application in the clinical practice.Conclusion. The use of Reper-NN microshunt is effective and safe method of treating refractory glaucoma. The implantation of this shunt may be the method of choice both in primary and secondary refractory glaucoma surgery. The least price of Reper-NN microshunt in comparison with the foreign analogue allows this surgery to be more available for patients with refractory glaucoma.

This paper corresponds to the results of an experimental research that to led to the design of a useful prototype for quality control of measurements in the field of tonometry to diagnose and check glaucoma. All tonometry techniques are based on Goldmann´s tonometers (GT) and the Imbert-Fick principle. Taking into account the principles and techniques of industrial metrology, the prototype could be used as a standard to calibrate the pressure readings of this class of tonometers. The developed protoype eliminates the indirect measurement that is required with current standards and facilitates a greater control of the sources of error in the measurement. The model is based on the integration of a sensor to a hydraulic model to measure pressures from 0 to 80 mmHg range, whose precision was validated through R&R studies. The precision of the prototype was validated according to the Rigel UNI-SIM standard and was complemented by calibrating 15 tonometers. Resumen Este artículo corresponde a los resultados de una investigación experimental que derivó en el diseño de un prototipo útil para el control de calidad de las mediciones en el campo de la tonometría para diagnosticar y controlar el glaucoma. Todas las técnicas de tonometría se basan en los tonómetros de Goldmann (TG) y en el principio de Imbert-Fick. Teniendo en cuenta los principios y técnicas de la metrología industrial, el prototipo podría usarse como un estándar para calibrar las lecturas de presión de esta clase de tonómetros. El prototipo desarrollado elimina la medición indirecta que se requiere con los patrones actuales y facilita un control mayor de las fuentes de error en la medición. El modelo se basa en la integración de un sensor a un modelo hidráulico para medir presiones de 0 a 80 mmHg de alcance, cuya precisión se validó a través de experimentos R&R. La precisión del prototipo fue validada según el estándar Rigel UNI-SIM y se complementó mediante la calibración de 15 tonómetros.

(1) Purpose: This study aimed to investigate the changes in Reichert Ocular Response Analyzer (ORA) parameters, corneal endothelium parameters, central corneal thickness (CCT), and intraocular pressure (IOP) before and after the transsphenoidal resection of pituitary adenoma in patients with acromegaly. (2) Methods: This was a single-center, prospective, interventional study. Twenty patients with newly diagnosed acromegaly were examined before and 19 ± 9 months after transsphenoidal resection. The participants underwent a comprehensive ophthalmological examination including pneumatic IOP (IOP air puff), Goldmann applanation tonometry (IOP GAT), CCT measured using the iPac pachymeter (CCTUP), IOP value corrected for CCTUP using the Ehlers formula (IOPc) ORA measurements included corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated IOP (IOPcc), and Goldmann-correlated IOP (IOPg). CCT from non-contact specular microscopy (CCTNSM), the number of endothelial cells (CD) per mm2, and average cell size (AVG) were determined with non-contact specular microscopy. (3) Results: A statistically significant decrease was observed in CCTUP (p = 0.007), and IOP air puff (p = 0.012) after surgery. Moreover, we noted a statistically significant increase in CD (p = 0.001), and a statistically significant decrease in AVG (p = 0.009) and CCTNSM (p = 0.004) after surgery. A statistically significant decrease was also observed in IOPg (p = 0.011), CH (p = 0.016), and CRF (p = 0.001) after surgery. The mean value of IOP GAT and IOPc was lower after the surgery. However, the difference was not statistically significant. (4) Conclusions: Our study revealed significant changes in biomechanics, corneal endothelium, CCT and IOP after pituitary adenoma resection in patients with acromegaly. It proves that the eye might be sensitive to long-term overexposure to growth hormone (GH) and insulin-like growth factor-1 (IGF-1). We suggest that disease activity be taken into consideration on ophthalmological examination.

Tonometry is commonly used to provide efficient and good diagnostics for cardiovascular disease (CVD). There are many advantages of this method, including low cost, non-invasiveness and little time to perform. In this study, the effort was undertaken to check whether tonometry data hides valuable information associated with different stages of chronic kidney disease (CKD) and end-stage renal disease (ESRD) treatment. For this purpose, six groups containing patients at different stages of CKD following different ways of dialysis treatment, as well as patients without CKD but with CVD and healthy volunteers were assessed. It was revealed that each of the studied groups had a unique profile. Only the type of dialysis was indistinguishable a from tonometric perspective (hemodialysis vs. peritoneal dialysis). Several techniques were used to build profiles that independently gave the same outcome: analysis of variance, network correlation structure analysis, multinomial logistic regression, and discrimination analysis. Moreover, to evaluate the classification potential of the discriminatory model, all mentioned techniques were later compared and treated as feature selection methods. Although the results are promising, it could be difficult to express differences as simple mathematical relations. This study shows that artificial intelligence can differentiate between different stages of CKD and patients without CKD. Potential future machine learning models will be able to determine kidney health with high accuracy and thereby classify patients. ClinicalTrials.gov Identifier: NCT05214872.

The purpose of this study was to highlight the impact of biomechanical corneal response in available in vivo tonometry methods for glaucoma management. Systematic review of non-contact air-puff tonometers that analyzes the corneal deformation response, with special focus on the investigation of the correlation of derived parameters with intraocular pressure measurements. The two actual and commercially available in vivo corneal tonometers provide promising information about biomechanical characteristics of the cornea and its relation to glaucoma, allowing the development of new protocols to evaluate, diagnose, and manage this disease. RESUMO O objetivo deste estudo é destacar o impacto da resposta biomecânica corneana em métodos de tonometria in vivo disponíveis para o manejo do glaucoma. Trata-se de revisão sistemática de tonômetros de ar que analisa a resposta à deformação corneana, com foco especial na investigação da correlação dos parâmetros derivados com as medições da pressão intraocular. Os dois tonômetros mais recentes e comercialmente disponíveis fornecem informações promissoras sobre as características biomecânicas da córnea e sua relação com o glaucoma, permitindo o desenvolvimento de novos protocolos para avaliar, diagnosticar e controlar a doença.

PurposeTo compare the effects of the Ahmed glaucoma valve (AGV; New World Medical, Rancho Cucamonga, CA) with sulcus versus anterior chamber (AC) tube placement on the corneal endothelial density and morphology over time.DesignNonrandomized, interventional study.ParticipantsThis study included 106 eyes from 101 pseudophakic patients who had the AGV tube placed in the AC (acAGV) and 105 eyes from 94 pseudophakic patients who had the AGV tube placed in the ciliary sulcus (sAGV).MethodsAll patients underwent preoperative specular microscopy, which was repeated postoperatively in 2019. The patients' demographic information, glaucoma diagnoses, and basic ocular information were obtained on chart review. Anterior segment OCT was conducted for patients who underwent sAGV to evaluate the sulcus tube position. Gonioscopy was performed to document peripheral anterior synechiae (PAS). Linear mixed-effects models were used to compare the different ocular and endothelial measurements between the 2 groups and to identify risk factors for endothelial cell density (ECD) loss over time.Main outcome measuresMonthly change in corneal endothelial measurements, including ECD and coefficient of variation (CV), calculated as the difference between preoperative and postoperative measurements divided by the number of months from the time of surgery to postoperative specular microscopy.ResultsThe acAGV and sAGV groups were comparable in all baseline characteristics except that the acAGV group had longer follow-up (37.6 vs. 20.1 months, respectively, P < 0.001). Mean monthly loss in central ECD was significantly more in the acAGV group (mean ± standard deviation: 29.3±29.7 cells/mm2) than in the sAGV group (15.3±20.7 cells/mm2, P < 0.0001). Mean monthly change in CV was similar between the 2 groups (P= 0.28). Multivariate analyses revealed that younger age and tube location in the AC were associated with faster central ECD loss (P= 0.02, P < 0.0001, respectively). For patients with sAGV, while PAS was associated with faster central ECD loss (P= 0.002), a more forward tube position tenting the iris was not (P > 0.05).ConclusionsCompared with anterior segment placement, ciliary sulcus tube implantation may be a preferred surgery approach to reduce endothelial cell loss in pseudophakic patients.

Lymphedema can develop after treatment for breast cancer (BCRL). Lymphedema of the breast is not well studied. Currently, the main techniques used to diagnose and monitor the effectiveness of treatment are subjective clinician assessment and patient reports. Eighty-nine women who had undergone breast cancer treatment were recruited with and without breast lymphedema. Blinded clinical assessment determined the presence or absence of breast lymphedema. Measurement of skin thickness by ultrasound scanning, local tissue water by tissue dielectric constant (TDC) and tissue indentation by tonometry was recorded. Breast cancer treatment and demographic details were documented. Descriptive statistics were undertaken to compare sample characteristics, including the Chi-squared test, Odds Ratio (OR) and Relative Risks (RR) calculated. Increased body mass index (BMI), larger bra size, increased number of positive lymph nodes, axillary surgery, chemotherapy and increased Nottingham Prognostic Index (NPI) were all associated with breast lymphedema (p < 0.05). Ultrasound and TDC measurements were significantly higher in the lymphedema group (p < 0.05). Receiver Operator Characteristic (ROC) curves demonstrated that ultrasound and TDC measurements could distinguish between edematous and non-edematous breasts. Threshold levels were produced, which demonstrated good levels of sensitivity and specificity. These findings have the potential to improve the diagnosis of breast lymphedema.

Intraocular pressure (IOP) is checked using tonometry, which helps in the diagnosis of diseases that lead to hypotension or ocular hypertension. Being, uveitis and glaucoma, the main eye diseases that alter IOP and generate the need for an early diagnosis and treatment for more satisfactory results and patient comfort. It is known that this test is still little used in the routine of production animals, because, in the literature, there are few data on the subject. For a reliable diagnosis of diseases that cause changes in IOP, it is necessary to have knowledge of the normal values of this parameter and its physiological variations at different times of the day. The objective of the test was to analyze the IOP values during a period of 24 hours, obtaining data for the elaboration of the daily tension curve (CTD) and mini curve of the sheep species. In addition, compare the IOP with the cortisol levels of the studied species, in each hour during a period of one day, in order to correlate the data of these two variables. This study was carried out with the number of animals suitable for this proposal, being 12 Texel ewes, under minimal restraint and in their natural habitat, aiming at minimal external interference in the data presented. With this, it was possible to affirm that there is no statistically significant difference between the IOPs of the right eye (OD) and left eye (LE), considering the 24 measurements performed over 24 hours. However, in the values of the IOPs of both eyes, every hour, there was a statistically significant difference between different times of the day. Furthermore, the maximum and minimum IOP peaks during the 24 hours of the day followed the cortisol levels at the same times. In addition, these variables were correlated with the daily luminosity rate. After analyzing the data obtained, it was possible to determine the physiological CTD of Texel sheep, noting a positive feedback relationship between IOP and blood cortisol rates. Then, a mini daily tension curve was proposed, with IOP measurements at 04:00h (average IOP value), at 12:00h (maximum IOP peak) and at 22:00h (minimum IOP peak). A pressão intraocular (PIO) é verificada por meio da tonometria, que auxilia no diagnóstico das doenças que cursam com hipotensão ou hipertensão ocular. Sendo, uveíte e glaucoma, as principais enfermidades oculares que alteram a PIO e geram a necessidade de um diagnóstico e tratamento precoce para resultados mais satisfatórios e conforto do paciente. Sabe-se que este exame ainda é pouco empregado na rotina de animais de produção, pois, na literatura, são escassos dados referentes ao assunto. Para um diagnóstico fidedigno das doenças que provocam alterações da PIO, é necessário ter o conhecimento dos valores normais deste parâmetro e suas variações fisiológicas nos diferentes períodos do dia. O objetivo teste trabalho foi analisar os valores da PIO durante um período de 24h, obtendo-se dados para elaboração da curva tensional diária (CTD) e mini curva da espécie ovina. Além disso, comparar a PIO com os níveis de cortisol da espécie estudada, em cada hora durante um período de um dia, a fim de correlacionar os dados dessas duas variáveis. Este estudo foi realizado com o número de animais adequados para tal proposta, sendo 12 ovelhas da raça Texel, sob mínima contenção e em seu habitat natural, objetivando-se mínima interferência externa nos dados apresentados. Com isso, foi possível afirmar que não há diferença estatística significativa entre as PIOs do olho direito (OD) e olho esquerdo (OE), considerando as 24 medições realizadas ao longo de 24h. Entretanto, nos valores das PIOs de ambos os olhos, a cada hora, constatou-se uma diferença estatisticamente significante entre diversos momentos do dia. Ademais, os picos máximos e mínimos da PIO durante as 24 horas do dia, acompanharam os níveis de cortisol nos mesmos momentos. Além disso, essas variáveis foram correlacionadas com a taxa de luminosidade diária. Após a análise dos dados obtidos, foi possível determinar a CTD fisiológica de ovinos da raça Texel, constatando uma relação de feedback positivo da PIO com as taxas de cortisol sanguíneo. Em seguida, propôs-se uma mini curva tensional diária, com aferições da PIO às 04:00h (valor médio da PIO), às 12:00h (pico máximo da PIO) e às 22:00h (pico mínimo da PIO).

Glaucoma is the leading cause of irreversible blindness, affecting around 80 million people worldwide. Glaucoma is a multifactorial disease of poorly understood pathogenesis, with intraocular pressure being the most significant risk factor. Currently there are different methods of intraocular pressure measurement, based on different physical principles, some of which are continuous measurement methods and others which are only measured in the medical office. The importance of the corneal biomechanical properties in intraocular pressure measurement is becoming increasingly clear. With the development of new instruments that can measure them, it will become possible to obtain more accurate intraocular pressure measurements within a short period of time. In the future, glaucoma patients will be better monitored with instruments capable of measuring intraocular pressure 24 hours a day., FCT -Fundação para a Ciência e a Tecnologia(UIDB/04650/2020)

Background The purpose of this study is to describe measurements using a newly developed modified Goldmann convex tonometer (CT) 1 year after myopic laser refractive surgery. Intraocular pressure (IOP) measurements were compared with IOP values obtained by Goldmann applanation tonometer (GAT), and Ocular Response Analyzer (ORA). Methods Prospective double-masked study performed on thirty eyes of thirty patients that underwent laser in situ keratomileusis (LASIK; n = 19) or photorefractive keratectomy (PRK; n = 11). IOP was measured before and 3 and 12 months after surgery. Intraclass correlation coefficient (ICC) and Bland-Altman plot were calculated to assess the agreement between GAT, CT, IOPg (Goldmann-correlated IOP) and IOPcc (corneal-compensated IOP) from ORA. Results Twelve months after LASIK, IOP measured with CT showed the best correlation with IOP measured with GAT before surgery (GATpre) (ICC = 0.886, 95% CI: 0.703–0.956) (15.60 ± 3.27 vs 15.80 ± 3.22; p p p p Conclusions Twelve months after LASIK, IOP measured with CT strongly correlated with GAT before surgery and could therefore provide an alternative method for measuring IOP after this surgery. More studies regarding this new convex prism are needed to assess its accuracy.

The field related to the visual system of wild animals is deeply scarce. Settling anatomical and physiological parameters for these animals is still a descriptive vision for Bradypus variegatus (Schinz, 1825). Thus, our research aimed to determine patterns of normal eye for this species. For this purpose, eight eye bulbs were dissected from the carcasses obtained by natural death, and then performed an overview of ocular anatomical. Rebound tonometry (RBT) and ocular B-mode ultrasonography were also applied for eight eyes in four animals from “Parque Estadual Dois Irmãos”, situated in the city of Recife, state of Pernambuco (PE), to estimate the intraocular pressure and ocular ecobiometry. The ocular morphology of sloth is similar as described for other species, however, with some peculiarities. They present a third eyelid emerging in the nasal region of the inferior conjunctival sac and retina and also contain little differentiated blood vessels. Medium the intraocular pressure (IOP) was 4.25mmHg with no difference for both eyes. Ultrasonography of ocular anatomy is also similar regarding other species. Ecobiometric patterns were evaluated to determine the anterior chamber depth, lens width, vitreous chamber depth, and axial length (AL) of ocular globe and the averaged as shown 0.63±1.11mm, 3.73±0.24mm, 6.15±0.41mm, 3.70±0.27mm, and 8.48±0.22mm, respectively. There was no difference between the right and left eyes. The RBT and ocular B-mode ultrasonography are fast exams and easy for animal testing. This study contributed to the characterization of ocular anatomy as well as settling medium values of IOP and intraocular measures; however, further research on physiology and histology is necessary to better understand the visual function of the species. RESUMO: O campo de estudo relacionado ao sistema visual de animais silvestres é muito escasso. Estabelecer parâmetros anatômicos e fisiológicos para estes animais ainda está restrito a uma visão descritiva, assim ocorre em Bradypus variegatus (Schinz, 1825). Diante deste fato, objetivou-se com este estudo determinar padrões de normalidade oftálmica nesta espécie. Para isto foram dissecados oito bulbos oculares de cadáveres obtidos por morte natural e realizada a descrição anatômica ocular. Além disso, foram realizadas tonometria de rebote (TonoVet®) e ultrassonografia em modo B em oito olhos de quatro animais provenientes do Parque Estadual Dois Irmãos, Recife/PE, para avaliação da pressão intraocular e realização da ecobiometria ocular. A anatomia ocular do bicho-preguiça é semelhante à descrita para outras espécies com algumas particularidades. Apresentam uma terceira pálpebra emergindo na região nasal do saco conjuntival inferior e retina com vasos sanguíneos pouco diferenciados. A pressão intraocular média foi de 4,25mmHg não havendo diferença entre os olhos direito e esquerdo. A anatomia ocular ultrassonográfica é semelhante à encontrada para outras espécies. Os padrões ecobiométricos obtidos foram: profundidade da câmara anterior, espessura do cristalino, diâmetro do cristalino, profundidade da câmara vítrea e comprimento axial do bubo ocular com tamanhos médios de 0,63±1,11mm, 3,73±0,24mm, 6,15±0,41mm, 3,70±0,27mm e 8,48±0,22mm, respectivamente. Não houve diferença entre os olhos direito e esquerdo. A tonometria de rebote e a ultrassonografia ocular em modo B são exames de rápida e fácil execução, sendo bem tolerados pelos animais. Este estudo contribuiu para a caracterização anatômica ocular e para o estabelecimento de valores médios da pressão intraocular e das medidas intraoculares, no entanto são necessárias outras pesquisas na área da fisiologia e histologia para melhor compreensão da função visual da espécie.

This paper focuses on the problematic of intraocular pressure (IOP) measurements, performed by non-invasive methods. More specifically, the devices that are connected with the presented finding are non-contact tonometers that use concentrated air stream and optical sensors to determine the IOP within a human’s eye. The paper analyzes various influential factors that have an effect on the determination of the IOP values originating from the patients themselves and from the non-contact tonometer devices. The paper furthermore elaborates on the lack of independent methods of calibration and control of these devices. In order to fill this gap a measurement standard device that is capable of calibrating and testing these devices with traceability to the basic SI unit is presented. A detailed characterization and the determination of the expected uncertainty of the device are provided. By introducing an independent and traceable calibration method and control of non-contact tonometers into the clinical practice, the reliability of the measured IOP that is the primary indicator of glaucoma can be improved.

Précis: Micropulse trans-scleral cyclophotocoagulation (TSCPC) is an effective and safe IOP-lowering treatment for patients with primary or secondary glaucoma.Purpose: To investigate the 1-year and 2-year effect on intraocular pressure (IOP) and safety profile of micropulse TSCPC in patients with glaucoma.Methods: Patients with glaucoma underwent a standardized micropulse TSCPC (MicroPulse P3 probe, Iridex cyclo G6 laser system, Mountain View, CA) at the University Eye Clinic Maastricht from November 2016 to May 2018. Patients with at least 12 months of follow-up were included.Results: A total of 141 eyes of 136 patients were included. The mean age was 67.2±14.5 years, and 56.6% of patients were male individuals. The glaucoma subtypes treated were primary glaucoma (n=99) and secondary glaucoma (n=42). Prior glaucoma surgery was performed in 59 of 141 eyes (41.8%). The mean preoperative IOP was 23.5±9.4 mm Hg. The mean postoperative IOP dropped to 16.8±8.4, 17.0±7.8, and 16.8±9.2 mm Hg, after 12, 18, and 24 months, respectively. The mean number of IOP-lowering medications used preoperatively was 3.3±1.4. The mean number of medications used at 12, 18, and 24 months was respectively 2.6±1.5, 2.5±1.4, and 2.2±1.5. Postoperative complications included cystic macular edema (n=2), hypotony maculopathy (n=1), fibrinous/uveitic reaction (n=1), and rejection of corneal graft (n=1), all reversible after treatment. One patient developed persisting hypotony in the late postoperative period.Conclusions: Micropulse TSCPC is a safe and effective treatment for lowering both IOP and the number of IOP-lowering medications. Micropulse TSCPC can also be considered as a good alternative treatment option for patients after failed incisional glaucoma surgery or patients who are at high risk for incisional surgery.

Background/Aims: Both eyes of a same person are not completely independent entities. The purpose of this study was to assess the difference in outcome between the first-operated eye and the fellow-operated eye following bilateral XEN surgery, and to identify potential success predictors for the fellow eye. Methods: This single-site, prospective, nonrandomized interventional study investigated bilateral nonsimultaneous XEN gel stent implantation over 24 months. Its main outcome measure was surgical success, defined as unmedicated intraocular pressure (IOP) = 20%. Results: Of 149 enrolled eyes, 74 eyes of 37 patients who underwent bilateral (standalone or combined) XEN implantation, within a mean of 50.5 +/- 74.3 days of each other, were analyzed. Postoperatively, mean medicated IOP decreased from 19.0 +/- 6.6 (first-operated) and 18.2 +/- 5.2 mm Hg (fellow) at baseline (P=0.209) to 13.7 +/- 4.0 (-27.9%;P

This review focuses on best practices and recommendations for hygiene and disinfection to limit exposure and transmission of infection in outpatient glaucoma clinics during the current COVID-19 pandemic.

Precis Central corneal thickness (CCT) may increase over time in children affected by primary congenital glaucoma and treated with latanoprost for at least 30 months. Purpose The purpose of this study was to investigate CCT modification over time in a population of primary pediatric glaucoma (PPG) patients prescribed a monotherapy of latanoprost. Materials and methods The present paper reports the results of a post hoc analysis on patients enrolled in the Glaucoma Italian Pediatric Study (GIPSy). Children affected by PPG, with a postsurgical intraocular pressure between 22 and 26 mm Hg and treated with latanoprost monotherapy for at least 30 months were eligible for the analysis. CCT variation from baseline was investigated over the follow-up using univariable and multivariable longitudinal linear mixed models. The impact of age, sex, and intraocular pressure on CCT variation were evaluated taking into account the interaction of each variable with time. Results Twenty-seven eyes (20 patients) were included in the analysis. Mean duration of latanoprost treatment was 36.6 months (SD 2.5) and mean CCT at baseline was 551 μm (SD 37.7). A significant increase of CCT over time was revealed by multivariable analysis, taking into account the impact of age at baseline and its interaction with time (P=0.03). The interaction between age and time was significant (P=0.04), indicating that older age at baseline was associated with lower increase of CCT over time. No variation of CCT was found in univariable analysis (P=0.28). Conclusion In this population of PPG patients treated with latanoprost for at least 30 months, CCT significantly increased over time, when the impact of age and its interaction with time were considered.

BACKGROUND Primary angle-closure glaucoma affects 20 million people worldwide. There is a significantly high incidence of PACG in India, which forms almost half of all adult primary glaucoma seen in a hospital setting. The primary angle closure suspects (PACS) are defined as patients with narrow angles with no evidence of glaucoma or damage to the angle. Half of those blind from glaucoma are due to angleclosure disease. Not all PACS need LPI, as the incidence of acute angle closure in angle closure suspects is not very high according to a few studies. Some studies have shown that LPI may not necessarily widen the angle following iridotomy. We wanted to study the completeness of the pre- and post-procedure evaluation of PACS in terms of gonioscopy and tonometry and the prescription and treatment rate of Nd YAG LPI and its complications in a tertiary hospital. METHODS This is a retrospective analysis of medical case records of patients with angle closure suspects. Data was retrieved from hospital EMR and also from the glaucoma speciality clinics registry. Only PACS were included where at least two quadrants of posterior trabecular meshwork were not visible with normal IOP and with no peripheral anterior synechiae. PAC, PACG, secondary angle closures and all open angle glaucomas were excluded. RESULTS 61 records were included for analysis. 38 (62%) were females and 56 (92%) were bilateral. The pre- and post-procedure IOP performed were 82% and 90% respectively, and gonioscopy performed were 87% and 77% respectively. 53 (86%) were advised LPI and 25 (71.5%) underwent the same immediately. CONCLUSIONS The pre-procedure tonometry and post procedure gonioscopy rates confirming the state of angle anatomy and patency of iridotomy were not satisfactory. The rate of LPI prescription was high. Majority of patients underwent LPI immediately on prescription. Hyphema was the only complication documented.

Author(s): Nguyen, Tran; Kim, Han; Mielke, Christy; Momont, Anna C; Brandt, James D; Liu, Yao | Abstract: PrecisAt 1-year postoperative follow-up, concurrent placement of a dexamethasone intravitreal implant and glaucoma drainage device effectively controlled intraocular pressure (IOP) and inflammation in eyes with uveitic glaucoma with no changes in systemic immunomodulatory therapy.PurposeThe purpose of this study was to assess 1-year postoperative outcomes in eyes with uncontrolled uveitic glaucoma following concurrent placement of a dexamethasone intravitreal implant and glaucoma drainage device.Materials and methodsThis is a retrospective, observational case series of patients with chronic, noninfectious uveitis and uveitic glaucoma uncontrolled on maximal tolerated medical therapy with at least 1-year postoperative follow-up. The main outcomes were visual acuity, IOP, number of glaucoma medications, recurrent inflammation, frequency of topical steroids, systemic immunomodulatory therapy, and adverse events. Success was defined as IOP l21 mm Hg and IOP reduced by g20% from baseline on at least 2 consecutive visits after 3 months either with or without glaucoma medications (ie, partial or complete success, respectively).ResultsEight eyes in 6 patients met the inclusion criteria. The average age was 44.1±19.7 years (range: 10 to 68 y) and 50% were female. At 1-year, there was no significant change in visual acuity. No eyes lost ≥3 lines of vision. The majority of eyes (87.5%) achieved complete (n=2) or partial success (n=5) with a decrease in average IOP from 36.5 to 11.8 mm Hg (P=0.002). Glaucoma medication use decreased from 3.0 to 1.3 medications (P=0.04). There was a significant decrease in the number of episodes of recurrent inflammation in the 6 months following surgery compared with the 6 months before surgery (P=0.004).ConclusionIn this small case series, dexamethasone intravitreal implant combined with Ahmed glaucoma drainage device appears to be an effective approach for the management of uncontrolled uveitic glaucoma.

This study aimed to compare values of intraocular pressure (IOP) by different tonometers and evaluators (veterinary ophthalmologist specialist and veterinary not a specialist). For this, 30 rabbits were used, and in all (n = 60 eyes), the IOP was initially measured with a rebound tonometer (model TD - 8000 portable, Apramed Indústria e Comércio de Equipamentos Médicos Ltda) and, subsequently, with an applanation tonometer (portable model Tono-Pen AviaTM®, Reichert Technologies®, USA). With the two devices, the measurements in mmHg were performed in the central region of the corneas, always performed in the same period, by a professional veterinary ophthalmologist (specialist) and a professional veterinary (not a specialist). Data were statistically compared using the simple analysis of variance test. With the rebound tonometer, IOP ranged from 7 to 14 mmHg when measured by both evaluators; while with the applanation tonometer, from 9 to 15 mmHg by the specialist and from 8 to 16 mmHg by the non-specialist. In the right eyes, the IOP measured by the applanation tonometer by the non-experienced evaluator was statistically lower than the specialist's values; yet, the results of the two evaluators were higher in these same eyes when compared with those of the rebound tonometer. In the left eyes, the IOP measured by the applanation tonometer by the non-experienced evaluator was statistically higher than the specialist's values with the rebound tonometer. Thus, it was possible to infer that, regardless of experience in the area, the applanation tonometer indicated higher mean values of IOP in both eyes and, about the evaluators, the means of the measurements performed by the specialist were higher compared to the non-professional specialist. Resumo Este estudo teve como objetivo comparar os valores da pressão intraocular (PIO) por diferentes tonômetros e avaliadores (veterinário oftalmologista especialista e veterinário não especialista). Para isso, foram utilizados 30 coelhos, em todos (n = 60 olhos), a PIO foi medida inicialmente com um tonômetro de rebote (model TD - 8000 portable, Apramed Indústria e Comércio de Equipamentos Médicos Ltda) e, posteriormente, com um tonômetro de aplanação (portable model Tono-Pen AviaTM®, Reichert Technologies®, USA). Com os dois aparelhos, as medidas em mmHg foram realizadas na região central das córneas, sempre no mesmo período, por um profissional oftalmologista veterinário (especialista) e um profissional veterinário (não especialista). Os dados foram comparados estatisticamente por meio do teste de análise de variância simples. Com o tonômetro de rebote, a PIO variou de 7 a 14 mmHg quando medida por ambos os avaliadores; enquanto com o tonômetro de aplanação, de 9 a 15 mmHg pelo especilista e de 8 a 16 mmHg pelo não especialista. Nos olhos direitos, a PIO medida pelo tonômetro de aplanação pelo avaliador não experiente foi estatisticamente inferior aos valores do especialista; ainda, os resultados dos dois avaliadores foram maiores nestes mesmos olhos quando comparados com os do tonômetro de rebote. Nos olhos esquerdos, a PIO medida pelo tonômetro de aplanação pelo avaliador não experiente foi estatisticamente superior aos valores do especialista com o tonômetro de rebote. Assim, foi possível inferir que, independente da experiência na área, o tonômetro de aplanação indicou maiores valores médios de PIO em ambos os olhos e, em relação aos avaliadores, as médias das medidas realizadas pelos especialistas foram maiores em relação ao não especialista.

Background: Chronic mesenteric ischaemia (CMI) is a vastly underdiagnosed condition that typically leads to postprandial abdominal pain and weight loss. The aim of the study was to explore the involvement of various mesenteric vessels in total splanchnic blood flow (SBF) and hepatic vein oxygenation. Methods: Single-blinded comparative trial of 476 patients clinically suspected of CMI. Routine investigation included measurement of hepatic vein oxygen saturation, indirect measurement of the total splanchnic blood flow (SBF), using Fick's principle and the tracer [ 99mTc]Mebrofenin, before and after a meal, and digital subtraction angiography. Results: A total of 176 of the 476 patients (36%) had at least one angiographically significant stenosis (lumen reduction ≥70%). In patients with a significant one-vessel disease, the percentage having CMI according to SBF was 10% for a celiac trunk stenosis (n = 60), 50% for a superior mesenteric stenosis (n = 24) and 6% for an inferior mesenteric artery stenosis (n = 34). In patients with a significant two-vessel disease, the percentage with CMI according to SBF response was 92%, 18% and 79%, for no significant stenosis of the celiac trunk (n = 13), superior mesenteric artery (n = 17) and inferior mesenteric artery (n = 19), respectively. Conclusion: Patients with significant one- or two-vessel stenosis involving the superior mesenteric artery have a higher likelihood of CMI according to flow criteria and a greater postprandial decrease in hepatic vein saturation on average than patients with no involvement of the superior mesenteric artery.

Purpose: To assess intraocular pressure and ocular pulse amplitude changes in obese children and adolescents using dynamic contour tonometry. Methods: 137 cases, 64 obese and 73 healthy children, who were both age-matched and gender-matched, comprised the study population in this cross-sectional study. Children with body mass index values >95% for sex and age were regarded as obese. Participants underwent detailed ophthalmological examinations, including intraocular pressure measurement using a Pascal dynamic contour tonometer. Relationships between intraocular pressure and ocular pulse amplitude measurements and age, sex, obesity, pubertal status, and insulin resistance were investigated. Results: Bilateral ocular pulse amplitude was lower while intraocular pressure was higher in the obese group than in the control group (p0.005). No correlation was determined between systolic and diastolic blood pressure, homeostasis model assessment for insulin resistance, or blood lipid levels and intraocular pressure and ocular pulse amplitude. Conclusion: Our results show that obesity caused an increase in intraocular pressure and a decrease in ocular pulse amplitude independently of insulin resistance in children and adolescents. Prospective studies involving long-term follow-up of cases are now needed to assess the probable adverse effects of these ocular findings in obese children.

The purpose of this study was to highlight the impact of biomechanical corneal response in available in vivo tonometry methods for glaucoma management. Systematic review of non-contact air-puff tonometers that analyzes the corneal deformation response, with special focus on the investigation of the correlation of derived parameters with intraocular pressure measurements. The two actual and commercially available in vivo corneal tonometers provide promising information about biomechanical characteristics of the cornea and its relation to glaucoma, allowing the development of new protocols to evaluate, diagnose, and manage this disease.

Introduction: Corneal integrity has long been a preoccupation of glaucoma surgeons considering glaucoma drainage device surgery or antimetabolite-enhanced trabeculectomy. Despite having demonstrated a good safety profile and significant intraocular pressure-lowering capacities, the impact of XEN gel stents on endothelial density was never specifically investigated. The purpose of this study is to assess the effect of XEN gel stents on central endothelial cell density (ECD) over 24 months. To achieve this, we compared the effect on ECD of combined XEN surgery with that of a standard phacoemulsification procedure. Methods: This was an investigator-initiated, retrospective study, conducted at a single tertiary glaucoma center. Patients with primary or secondary open-angle glaucoma who underwent XEN implantation combined with phacoemulsification between January 2015 and June 2016 were retrospectively enrolled. Patients who had undergone standalone phacoemulsification over the same period of time were enrolled to form the control group of this comparative study. The primary outcome measure was the ECD. Patients who had undergone standalone XEN implantation and patients for whom both a baseline and 24-month ECD could not be obtained were excluded from the analysis. Percentages of ECD reductions were calculated for each studied eye, and the mean of ECD reductions was calculated for each group as well as for subgroups. Results: Thirty-two eyes of 23 patients (mean age=76.0 +/- 7.9 y, 60% female) underwent standalone phacoemulsification (n=15) or combined XEN surgery (n=17) and had an ECD both at baseline and 24-month postoperatively. Mean baseline ECDs were 2568 +/- 491 versus 2379 +/- 335 cells/mm(2), respectively (P=0.21). In the combined XEN surgery group, 58.8% of eyes (n=10) required at least 1 mitomycin C (MMC)-enhanced needling revision to maintain their target intraocular pressure. In the standalone phacoemulsification group, ECD decreased by a mean 14.5%, from 2567.7 +/- 491.2 to 2196.1 +/- 591.9 cell/mm(2) (P=0.072). In the combined XEN surgery group, ECD decreased by a mean 14.3%, from 2378.8 +/- 334.7 to 2039.6 +/- 451.1 cell/mm(2) (P=0.018). The difference in percentage reduction of ECD between the 2 groups was not statistically significant (P=0.226). Within the combined XEN surgery group, the ECD decreased by a mean of 15.4% in patients who did not undergo needling revisions and by 13.1% in patients who underwent the MMC-augmented procedure (P=0.485). In the 3 patients who underwent >1 needling revision, a 21.3% reduction in ECD was observed, but the difference was not statistically significant (P=0.653). Neither the time of the first needling (P=0.452), the patients' age (P=0.285), or sex (P=0.308) was statistically associated with ECD loss. Discussion: The present study demonstrated that the XEN gel implant combined with phacoemulsification produces 24-month ECD loss of a similar magnitude to that observed following standalone phacoemulsification. MMC-augmented needling revisions do not appear to have an impact on ECD.

Purpose. To analyze the daily dynamics and the parameters of intraocular pressure circadian rhythm (IOP CR) in patients with primary open-angle glaucoma (POAG) (stable and progressive forms) and determine chronobiological regularities of glaucoma progression depending on the patterns of restructuring the daily dynamics of IOP CR and body temperature.Material and methods. The study included 75 POAG patients, of which 35 had a stable form (S-POAG) and 40 had a rapidly progressing form (P-POAG). The control group was composed of 80 subjects without POAG. The index of retinal ganglion cell loss measured by optical coherence tomography (OCT) was used as a criterion of POAG progression. IOP was measured by the patients themselves for 72 hours at 7 time points (3 am, 8 am, 11 am, 2 pm, 5 pm, 8 pm, and 11 pm, who used an Icare ONE portable intraocular pressure tonometer for individual use.Results. IOP daily dynamics was distributed differently in the different groups. In S-POAG, the peak values were mainly reached in the morning hours, while the minimum values were observed at night. In P-POAG, the peak values of IOP were contrariwise recorded at night. In both POAG groups, an increase of irregular fluctuation share was noted, which indicated a decrease of the CR contribution to the IOP CR. Moreover, in POAG, a change in the phase ratio between the IOP CR and CR of body temperature was observed. For IOP CR phase violation manifestations, the threshold value of GCS global loss index was determined at 10–15 % according to OCT data.Conclusion. IOP daily dynamics were shown to differ in S-POAG and P-POAG patients. In both groups. Signs of desynchronization were detected. The ganglion retinal cell global loss index can be used to determine phase disturbances of IOP CR.

The leading cause of health loss and deaths worldwide are cardiovascular diseases. A predictor of cardiovascular diseases and events is the arterial stiffness. The pulse wave velocity (PWV) can be used to estimate arterial stiffness non-invasively. The tonometer is considered as the gold standard for measuring PWV. This approach requires manual probe fixation above the artery and depends on the skills of the operator. Electrical impedance plethysmography (IPG) is an interesting alternative using skin surface sensing electrodes, that is miniaturizable, cost-effective and allows measurement of deeper arteries. The aim of this pilot study was to explore if IPG can be a suitable technique to measure pulse wave velocity in legs as an alternative for the tonometer technique. The PWV was estimated by differences in the ECG-gated pulse arrival times (PAT) at the a. femoralis, a. popliteal, a. tibialis dorsalis and a. dorsalis pedis in nine healthy young adults using IPG and the SphygmoCor tonometer as a reference. The estimated PWV results from bioimpedance and the tonometer were fairly in agreement, and the beat-to-beat variability in PAT was similar. This pilot study indicates that the use of IPG may be a good alternative for estimating PWV in the legs.

Objectives: We aim to investigate the involvement of the choroid and retinal nerve fiber layer (RNFL) in COVID-19 patients using spectral domain optical coherence tomography. Methods: This cross-sectional study was conducted between April and June 2020. 40 patients (23 female and 17 male) with COVID-19 and 42 healthy individuals (26 female and 16 male) were included in the study. The OCT scans were performed 4 weeks after the COVID-19 diagnosis. Results: In the COVID-19 group, in the right eyes, the mean nasal choroidal thickness was 295.70 ± 7,046 μm ( p = 0.017), mean subfoveal choroidal thickness was 333.25 ± 6,353 μm ( p = 0.003), mean temporal choroidal thickness was 296.63 ± 6,324 μm ( p = 0.039), and mean RNFL was 89.23 ± 1.30 μm ( p = 0.227). In the left eyes, mean nasal choroidal thickness was 287.88 ± 9,033 μm ( p = 0.267), mean subfoveal choroidal thickness was 333.80 ± 9,457 μm ( p = 0.013), mean temporal choroidal thickness was 298.50 ± 9,158 μm ( p = 0.079), and mean RNFL was 89.48 ± 1,289 μm ( p = 0.092). Compared with the control group, the patient group had significant thickening of the choroidal thickness in all quadrants of the right eyes, and significant thickening of the subfoveal choroidal thickness in the left eyes. There was no significant difference in the RNFL thickness between groups ( p > 0.05). Conclusion: COVID-19 may cause a subclinical involvement in the choroidal layer.

OBJECTIVE To compare intraocular pressures (IOPs) estimated by rebound and applanation tonometry for dogs with lens instability. ANIMALS 66 dogs. PROCEDURES Medical records of dogs examined between September 2012 and July 2018 were reviewed for diagnoses of anterior (ALL) or posterior (PLL) lens luxation or lens subluxation. RESULTS Estimates of IOP obtained with rebound and applanation tonometry significantly differed from each other for all types of lens instability considered collectively (mean ± SE difference between tonometric readings, 8.1 ± 1.3 mm Hg) and specific types of lens instability considered individually (mean ± SE difference between tonometric readings: ALL, 12.8 ± 2.5 mm Hg; PLL, 5.9 ± 1.7 mm Hg; subluxation, 2.8 ± 0.8 mm Hg). Median (range) differences between rebound and applanation tonometer readings for dogs with ALL was 5 mm Hg (–9 to 76 mm Hg), with PLL was 3 mm Hg (–1 to 19 mm Hg), and with lens subluxation was 3 mm Hg (–9 to 18 mm Hg). In eyes with ALL, rebound tonometer readings exceeded applanation tonometer readings on 44 of 60 (73%) occasions. CONCLUSIONS AND CLINICAL RELEVANCE Rebound tonometry yielded higher estimates of IOP than did applanation tonometry in eyes with ALL and with all types of lens luxation considered collectively. Estimates of IOP in eyes with lens instability should ideally be obtained with both rebound and applanation tonometers. Veterinarians with only one type of tonometer should interpret results for dogs with lens instability concurrent with physical examination findings.

Author(s): Mikula, Eric; Holland, Guy; Srass, Hadi; Suarez, Carlos; Jester, James V; Juhasz, Tibor | Abstract: PurposeThis study investigated the initial feasibility of using femtosecond laser trabeculotomy (FLT) to create open channels through the trabecular meshwork into Schlemm's canal to lower intraocular pressure (IOP) in a perfused anterior segment model.MethodsHuman anterior segments (12 eyes) were assigned to either treatment (n = 6) or sham treatment (n = 6) groups. Both groups were perfused until a baseline IOP was recorded upon which a direct FLT treatment or a sham treatment was administered. IOP was recorded before and after the treatment. Spectral domain optical coherence tomography and second harmonic generation imaging we used to investigate the FLT channels.ResultsIn the FLT group, there was a significant mean decrease in the IOP of 22% compared with the pre-FLT IOP (7.13 ± 2.95 mm Hg to 5.34 ± 1.62 mm Hg; P l 0.05). In the control group, the post-sham IOP remained relatively unchanged compared with the pre-sham IOP (6.39 ± 3.69 mm Hg to 6.67 ± 4.12 mm Hg).ConclusionsThe results of this study indicate that FLT treatment can significantly decrease the IOP in a perfusion model and may provide a potential noninvasive treatment option for primary open angle glaucoma.Translational relevanceInvestigating the use of femtosecond lasers for photodisrupting the trabecular meshwork can lead to a clinically relevant alternative to current glaucoma procedures.

Intraocular pressure (IOP) is an important measurement that needs to be taken during ophthalmic examinations, especially in ocular hypertension subjects, glaucoma patients and in patients with risk factors for developing glaucoma. The gold standard technique in measuring IOP is still Goldmann applanation tonometry (GAT); however, this procedure requires local anesthetics, can be difficult in patients with scarce compliance, surgical patients and children, and is influenced by several corneal parameters. Numerous tonometers have been proposed in the past to address the problems related to GAT. The authors review the various devices currently in use for the measurement of intraocular pressure (IOP), highlighting the main advantages and limits of the various tools. The continuous monitoring of IOP, which is still under evaluation, will be an important step for a more complete and reliable management of patients affected by glaucoma.

Author(s): van den Bosch, Jacqueline JON; Pennisi, Vincenzo; Invernizzi, Azzurra; Mansouri, Kaweh; Weinreb, Robert N; Thieme, Hagen; Hoffmann, Michael B; Choritz, Lars | Abstract: PurposeTo explore the effect of gaze direction and eyelid closure on intraocular pressure (IOP).MethodsEleven patients with primary open-angle glaucoma previously implanted with a telemetric IOP sensor were instructed to view eight equally-spaced fixation targets each at three eccentricities (10°, 20°, and 25°). Nine patients also performed eyelid closure. IOP was recorded via an external antenna placed around the study eye. Differences of mean IOP between consecutive gaze positions were calculated. Furthermore, the effect of eyelid closure on gaze-dependent IOP was assessed.ResultsThe maximum IOP increase was observed at 25° superior gaze (mean ± SD: 4.4 ± 4.9 mmnHg) and maximum decrease at 25° inferonasal gaze (-1.6 ± 0.8 mmnHg). There was a significant interaction between gaze direction and eccentricity (P = 0.003). Post-hoc tests confirmed significant decreases inferonasally for all eccentricities (mean ± SEM: 10°: -0.7 ± 0.2, P = 0.007; 20°: -1.1 ± 0.2, P = 0.006; and 25°: -1.6 ± 0.2, P = 0.006). Eight of 11 eyes showed significant IOP differences between superior and inferonasal gaze at 25°. IOP decreased during eyelid closure, which was significantly lower than downgaze at 25° (mean ± SEM: -2.1 ± 0.3 mmnHg vs. -0.7 ± 0.2 mmnHg, P = 0.014).ConclusionsOur data suggest that IOP varies reproducibly with gaze direction, albeit with patient variability. IOP generally increased in upgaze but decreased in inferonasal gaze and on eyelid closure. Future studies should investigate the patient variability and IOP dynamics.

Intraocular pressure (IOP) is known to have a definite circadian rhythm and its fluctuation correlates well with glaucoma progression. Twenty-four hour monitoring of IOP is an important indicator intraocular pressure fluctuation, as well as its peaks and spikes. However, Diurnal variation in IOP is well recognized but many decisions in glaucoma management are taken after one or two IOP measurements. Patient directed self-tonometry can be preformed through the twenty-four cycle, and has been the subject of an ongoing debate. In this review, we studied the history of self-tonometry devices and the present technologies for future. The results of various techniques studied revealed that a standardized method of conducting diurnal variation is yet to be ascertained, and for this, a proper research method is required.

Mohammad-Reza Sedaghat,1 Hamed Momeni-Moghaddam,2,3 AbbasAli Yekta,3–5 Ahmed Elsheikh,6–8 Mehdi Khabazkhoob,5,9 Renato Ambrósio Jr,10 Nasim Maddah,3 Zeynab Danesh3 1Eye Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; 2Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran; 3Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran; 4Refractive Errors Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; 5Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran; 6School of Engineering, University of Liverpool, Liverpool, UK; 7School of Biological Science and Biomedical Engineering, Beihang University, Beijing, China; 8NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK; 9Department of Medical Surgical Nursing, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 10Federal University of the State of Rio de Janeiro, Rio de Janeiro, BrazilCorrespondence: Hamed Momeni-MoghaddamDepartment of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Parastar 2 Str., Ahmadabad Blvd., Mashhad 9189754151, IranTel +98 511 9155337952Email hmomeni_opt@yahoo.comPurpose: To compare the biomechanically-corrected intraocular pressure (bIOP) measured by the Corvis ST (Oculus, Wetzlar, Germany) with IOP measurements made by other commonly used tonometers; and to test the correlations between IOP measures and central corneal thickness.Methods: One randomly-selected eye from each of 94 healthy subjects was assessed. The bIOP was determined by the CorVis ST and compared with the IOP measurements made by standard Goldmann Applanation Tonometer (GAT: Haag-Streit AG, Bern, Switzerland), the Icare (Icare Finland Oy, Vantaa, Finland), and the Ocular Response Analyzer (ORA-IOPcc: Reichert, New York, USA). Corneal thickness was assessed by the Oculus Pentacam. The correlation between bIOP and the other devices and between CCT were assessed using the Pearson correlation test or Spearman’s rho test accordingly to the distribution of these values. The Bland-Altman method and intraclass correlation coefficients (ICC) were used to assess the agreement of bIOP results with IOP obtained with other techniques. The limits of agreement (LoA) were determined as the mean difference ±1.96 SD of the mean differences. In all tests, the significance level was considered to be 0.05.Results: Mean and SD of the bIOP were 16.11±1.66 mmHg. Significant differences were found between the bIOP and other IOP measurements (GAT, 3.02±2.60 mmHg, p

Mohammad-Reza Sedaghat,1 Hamed Momeni-Moghaddam,2,3 AbbasAli Yekta,3–5 Ahmed Elsheikh,6–8 Mehdi Khabazkhoob,5,9 Renato Ambrósio Jr,10 Nasim Maddah,3 Zeynab Danesh3 1Eye Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; 2Health Promotion Research Center, Zahedan University of Medical Sciences, Zahedan, Iran; 3Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran; 4Refractive Errors Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; 5Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran; 6School of Engineering, University of Liverpool, Liverpool, UK; 7School of Biological Science and Biomedical Engineering, Beihang University, Beijing, China; 8NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK; 9Department of Medical Surgical Nursing, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran; 10Federal University of the State of Rio de Janeiro, Rio de Janeiro, BrazilCorrespondence: Hamed Momeni-MoghaddamDepartment of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Parastar 2 Str., Ahmadabad Blvd., Mashhad 9189754151, IranTel +98 511 9155337952Email hmomeni_opt@yahoo.comPurpose: To compare the biomechanically-corrected intraocular pressure (bIOP) measured by the Corvis ST (Oculus, Wetzlar, Germany) with IOP measurements made by other commonly used tonometers; and to test the correlations between IOP measures and central corneal thickness.Methods: One randomly-selected eye from each of 94 healthy subjects was assessed. The bIOP was determined by the CorVis ST and compared with the IOP measurements made by standard Goldmann Applanation Tonometer (GAT: Haag-Streit AG, Bern, Switzerland), the Icare (Icare Finland Oy, Vantaa, Finland), and the Ocular Response Analyzer (ORA-IOPcc: Reichert, New York, USA). Corneal thickness was assessed by the Oculus Pentacam. The correlation between bIOP and the other devices and between CCT were assessed using the Pearson correlation test or Spearman’s rho test accordingly to the distribution of these values. The Bland-Altman method and intraclass correlation coefficients (ICC) were used to assess the agreement of bIOP results with IOP obtained with other techniques. The limits of agreement (LoA) were determined as the mean difference ±1.96 SD of the mean differences. In all tests, the significance level was considered to be 0.05.Results: Mean and SD of the bIOP were 16.11±1.66 mmHg. Significant differences were found between the bIOP and other IOP measurements (GAT, 3.02±2.60 mmHg, p

Precis: This study confirms the safety and efficacy of XEN gel stents in the management of pseudoexfoliative glaucoma 2 years after implantation, with success rates similar to primary open-angle glaucoma regardless of the definition of success. Purpose: To compare the long-term safety and efficacy of XEN gel implant surgery (Allergan Inc., Irvine, CA) in patients with pseudoexfoliative glaucoma (PEXG) and primary open-angle glaucoma (POAG). Setting: Prospective, interventional study in a tertiary glaucoma center. Methods: A total of 110 eyes of 85 patients with POAG (57 eyes) or PEXG (53 eyes) and uncontrolled intraocular pressure (IOP) despite medical treatment underwent combined XEN+cataract surgery or standalone XEN surgery. Mean IOP, mean number of medications, needling rates, and incidence of adverse effects were compared between the 2 groups. Complete surgical success was defined as an unmedicated IOP

Monitoring intraocular pressure in patients with open-angle glaucoma at different stages of the development of the disease using self-measurement by a portable Icare HOME tonometer. In study, patients were divided into 3 groups depending on the treatment prescribed. With the help of near-day monitoring, hidden IOP elevations that are not recorded during a single IOP measurement on an outpatient appointment with a doctor were detected. Perspective possibilities of prescribing drugs and regulating the mode of instillation on the basis of individual time periods of increasing intraocular pressure on the example of one of the patient. Assessment of the convenience of the method from the personal experience of using the device by patients.

We present a numerical model of a contactless test commonly used to assess the biomechanics of the human cornea. The test, consisting in a rapid air jet applied to the anterior surface of the cornea, is controversial. Although the numerous studies documented in the literature have not been able yet to clarify its relevance as a diagnostic tool, the test has the potential to be combined with inverse analysis procedures to characterize the parameters of numerical models of the cornea. With the final goal of employing the air puff test in advanced material identification algorithms, here we propose to model the cornea with standard finite elements and the fluids filling the anterior chamber of the eye with a meshfree discretization. The interaction between moving fluids and deforming cornea is accounted for by modifying the interface boundary conditions of both fluid and solid. The proposed model represents the first fully 3D example of an aqueous-cornea fluid-solid interaction analysis which uses a robust meshfree approach for the fluid. Although we restrict our scope to isotropic nonlinear materials, numerical results confirm the undeniable importance of including internal fluids in the simulation of the air puff test. Thus the proposed approach stands as a procedural paradigm for the identification of the mechanical parameters of the human cornea.

Objective: The primary objective was to find an agreement of intraocular pressure (IOP) assessed by Goldmann applanation tonometry (GAT) and Corvis in healthy, ocular hypertension (OHT) and primary open-angle glaucoma (POAG). The secondary objective was to find a reliability of intra-examiner and inter-examiner IOP measurement by GAT and Corvis. Methods: Fifty three eyes from 53 participants were included and were divided into healthy (N=20), OHT (N=13) and POAG group (N=20). Only right eyes were selected for further statistical analysis except one patient with only left eye eligible. The eyes with corneal pathologies, greater than 2.5 diopters astigmatism, or recent ocular surgery were excluded. Randomized examining sequence between GAT and Corvis was applied. To minimize an after measurement IOP fluctuation, five minutes and two minutes gap between measurements were strictly applied for Corvis and GAT respectively. The first ten patients had 3 measurements per measurer and two measurers were assigned per machine to evaluate intra-examiner and inter-examiner reliability. Intraclass correlation coefficient was used to analyze the reliability of the IOP measuring machine. Bland & Altman plot was used to analyze an agreement between the machines. Results: High ICCs were found in both measurers using GAT (ICC of measurer 1 = 0.954, measurer 2 = 0.977) and Corvis (ICC of measurer 1 = 0.920, measurer 2 = 0.927) which indicated excellent intra-examiner reliability. High ICCs were found when comparing IOP between 2 measurers who used the same machine (GAT ICC = 0.928, Corvis ICC = 0.915) which indicated excellent inter-examiner reliability. GAT tends to yield higher IOP reading. The mean IOP were 13.93±3.849 by GAT and 12.15±4.030 by Corvis. The mean IOP differences were 1.8, 1.7, 1.4 and 2.2 mmHg in total, healthy, OHT and POAG group respectively. POAG had highest mean difference and widest standard deviation which might result from poor agreement between 2 machines. According to Bland & Altman plot the values were scattered and no trend was found indicating higher or lower average IOP would result in higher or lower difference between the two machines. From the clinical point of view, 71.7% and 47.2% fall into IOP difference range of ±3 and ±2 mmHg respectively. Conclusion: Corvis-IOP is a good parameter with excellent intra-examiner and inter-examiner reliability. In clinical practice, the usefulness of Corvis-IOP is limited especially in POAG patients according to the poor agreement with gold standard GAT-IOP.

The early vascular adaptation to indoor cycling, a popular activity at many fitness centres, is incompletely evaluated. Forty two healthy women (21-45 years) underwent measurements of arterial wall properties and geometry as well as a maximal bicycle exercise test before and after a 3 months period during which 21 of the women joined indoor cycling classes at a gym 2-3 times per week, while 21 women served as time controls. Peak work load increased by in average 16% (pamp;lt;0.001) and ascending aortic diameter by 4% (pamp;lt;0.01) in the exercise group, while unchanged in control group. The exercise intervention had no significant influence on the local intima-media thickness, blood pressure or the pulse pressure wave configuration while the carotid artery distensibility (pamp;lt;0.05) was higher after the intervention. There was a positive correlation between change in () peak work load and -diameter of tubular ascending aorta (r=0.42, pamp;lt;0.01) in the exercise group. In conclusion, after only 3 months of bicycle exercise training, signs of central arterial remodelling were seen in premenopausal women, which was associated to improvement in exercise capacity. Funding Agencies|Futurum-academy for Health and Care Region Jonkoping County, Sweden; FORSS-the Research Council of South-East Sweden; Linkoping University Hospital; Swedish Research Council [12161]; Swedish Heart-Lung Foundation

PurposeClinically evaluate intraocular pressure (IOP) measurements taken with a Goldmann applanation tonometer (GAT) prism and a modified surface Goldmann prism examining measurement differences correlated to central corneal thickness (CCT) and corneal hysteresis (CH) values.DesignProspective, open-label, randomised, controlled, multicentre reference device accuracy analysis.MethodsA GAT and a modified surface GAT prism measured IOP on 243 unique eyes. The study design and methodology complied with International Standard Organization (ISO) tonometer evaluation guidelines, except the inclusion of thin (600 µm) corneas. All eyes were randomised to IOP measurement by one of five standard Goldmann prisms and five modified prisms. Pressures were measured by six investigators, two times with each prism for a total of 1936 IOP measurements. Analysis included a multiple linear regression including CCT and CH correlation.ResultsThe difference in IOP measurements of the standard and modified Goldmann prisms correlated well to CCT particularly in thin (600 µm) corneas (R2=0.404, p=0.007). Corneal hysteresis (CH) also significantly correlated to the difference in prism measurements (R2=0.125, p=0.039). There was no significant overall mean IOP bias between the two prisms (+0.43 mm Hg in modified, p=0.19).DiscussionThe paired IOP measurement difference between GAT and a modified surface Goldmann replacement prism indicated a statistically significant correlation to CCT and CH. A simple modified replacement prism for any Goldmann-type tonometer may significantly improve IOP measurement accuracy by minimising corneal biomechanical errors associated with CCT and CH.Trial registration numberNCT02990169 and NCT02989909.