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Continuous intraocular pressure (IOP) monitoring for improving glaucoma diagnosis and treatment has remained a challenge for the past 60 years because glaucoma is the second leading cause of irreversible blindness worldwide. Several devices with different measurement principles and recently developed biosensors with semiconductor materials offer exciting properties. However, none of these devices for continuous IOP monitoring have been fully integrated into clinical practice, primarily due to technical problems. This review summarizes state-of-the-art biosensors developed for IOP monitoring by explaining their basic functions and applications, the main technology (pressure transductors, piezoresistive sensors, capacitive sensors, and resonant sensors), measurement approach (noninvasive, minimally invasive or invasive (surgically implantable)), and telemetry characteristics. To provide updated information for clinicians and researchers, we also describe the advantages and limitations of the application of these new sensors to eye care management. Despite significant improvements in IOP biosensor technology, the accuracy of their measurements must be improved to obtain a clear equivalence with actual IOP (measured in units of mmHg) to facilitate their clinical application. In addition, telemetry systems may be simplified to prevent adverse outcomes for patients and to guarantee the safety of stored data.

Telehealth has become a viable option for glaucoma screening and glaucoma monitoring due to advances in technology. The ability to measure intraocular pressure without an anesthetic and to take optic nerve photographs without pharmacologic pupillary dilation using portable equipment have allowed glaucoma screening programs to generate enough data for assessment. At home, patients can perform visual acuity testing, web-based visual field testing, rebound tonometry, and video visits with the physician to monitor for glaucomatous progression. Artificial intelligence will enhance the accuracy of data interpretation and inspire confidence in popularizing telehealth for glaucoma.

Michael Smith,1 Marco Bresolin,1 Rose McCabe2 1Glaucoma Unit, West of England Eye Unit, Exeter, UK; 2School of Health Sciences, City, University of London, London, UKCorrespondence: Michael Smith Email Michael.smith26@nhs.netPurpose: This pilot study was undertaken to examine the feasibility of a larger scale trial examining the effect of interventions to improve patient-clinician collaboration. The primary outcome was the extent of clinician-patient collaboration during glaucoma consultations. The secondary outcomes were the results of the Patient Experience Questionnaire and the patients’ opinion of how involved they were in decisions about their care and how keen they would be to increase this involvement.Methods: This is an observational study of clinician-patient communication involving 9 glaucoma clinicians and 37 patients attending a glaucoma monitoring clinic. Consultations were videotaped and later assessed for the degree of collaboration. Patients completed a validated Patient Experience Questionnaire and a questionnaire designed to collect the patients’ opinion of how involved they were in decisions about their care.Results: The consultations were largely “clinician centred” with clinicians speaking 58% of the sentences and asking a mean of 8.1 questions compared to the patients 2.6. Glaucoma medications were discussed in 97% of consultations. When a treatment change was recommended in 53% of cases different options were discussed. Patients had an overall positive opinion of the consultations. Although 80% of patients indicated they were happy with how involved they were in decisions about their care 44% said they would like to be more involved, and 47% would welcome written information or information sessions on how to be more involved in decisions about their care.Conclusion: Glaucoma consultations remain “clinician-centred” and, in view of the evidence of the benefits of good clinician-patient collaboration, further studies to examine interventions to improve clinician-patient collaboration may be of benefit to glaucoma patients. These interventions could target both clinicians and patients, and many patients in this study indicated they would like to be more involved in decisions about their care and would welcome support in achieving this.Keywords: glaucoma, communication, ophthalmology

Technological advances provide a number of options for glaucoma monitoring outside the office setting, including home-based tonometry and perimetry. This has the potential to revolutionize management of this chronic disease, improve access to care, and enhance patient engagement. Here, we provide an overview of existing technologies for home-based glaucoma monitoring. We also discuss areas for future research and the potential applications of these technologies to telemedicine, which has been brought to the forefront during the ongoing COVID-19 pandemic.

In the management of glaucoma, recent and upcoming innovations have the potential to contribute to both the efficacy of intraocular pressure (IOP) monitoring and the number of available treatment options. These new devices and procedures have two things in common: they are part of the trend in medicine towards miniaturization, and they require a limited surgical procedure to become effective. This review focuses on the Eyemate (Argos) intraocular sensor, which offers a new way to reliably measure 24 h IOP, and on intraocular sustained release systems for pharmacological glaucoma therapy. It also briefly reflects on the miniature implants currently used in minimally invasive glaucoma surgery (MIGS).

The article reviews historical aspects of direct and indirect (by reducing intraocular pressure (IOP)) neuroprotective effect of brimonidine in terms of modern views on glaucoma monitoring and treatment. Brimonidine, a selective alpha-adrenergic receptor agonist, is the first-line treatment choice for glaucoma. This agent reduces IOP by decreasing aqueous humor production and improving uveoscleral outflow. The result is the achievement of target IOP. Brimonidine prevents ganglionic cell death in glaucomatous optic neuropathy. Several in vitro and in vivo studies describe the mechanism of preventing mitochondrial dysfunction and excitotoxic retinal cell damage in ischemia. Brimonidine affects NMDA receptors, inhibits proapoptotic protein expression, activates neurotrophic processes, and normalizes oxidative phosphorylation thus preventing mitochondrial dysfunction. According to the modern concept, the aim of glaucoma treatment is to avoid vision loss by preventing ganglionic cell death. Therefore, lifelong visual field monitoring and neuroprotective therapy are required. Brimonidine provides target IOP and prevents retinal cell death thus preserving vision in glaucoma. Keywords: glaucoma, intraocular pressure, neuroprotection, visual field, monitoring, brimonidine, Luxfen. For citation: Erichev V.P., Petrov S.Yu., Volzhanin A.V. et al. Alpha-adrenergic receptor agonists in terms of modern views on glaucoma monitoring and treatment. Russian Journal of Clinical Ophthalmology. 2019;19(2):87–91. About the authors: 1Valery P. Erichev — MD, PhD, Professor, Head of Glaucoma Department, ORCID iD 0000-0001-6842-7164; 1Sergey Yu. Petrov — MD, PhD, Leading Research Associate of Glaucoma Department, ORCID iD 0000-0001-6922-0464; 1Andrey V. Volzhanin — postgraduate, ORCID iD 0000-0002-1421-8882; 1Darya M. Safonova — MD, PhD, Junior Research Associate of Modern Treatmen in Ophthalmology, ORCID iD 0000-0002-5082-1494; 2Tamara V. Yaremenko — postgraduate, ORCID iD 0000-0002-3094-1958; 3Serzh A. Kazaryan — resident, ORCID iD 0000-0003-2258-2964. 1Reseach Institute of Eye Diseases. 11A Rossolimo str., Moscow, 119021, Russian Federation. 2Sechenov University. 8 Trubeckaya Str., Moscow, 119146, Russian Federation. 3Mkhitar Heratsi Yerevan State Medical University. 2 Koryuna str., Erevan, 0025, Republic of Armenia. Contact information:Andrey V. Volzhanin, e-mail:avolzhanin@mail.ru.Financial Disclosure:no author has a financial or property interest in any material or method mentioned. There is noconflict of interests. Received11.04.2019.

Purpose To characterize anatomical dimensions of a disc notch using novel methods using spectral domain optical coherence tomography (SD-OCT). Participants All age- and severity-matched glaucoma patients with disc notch (defined as complete loss of neural rim with no residual rim between disc and cup) seen from 2014 to 2015 who underwent enhanced depth imaging with SD-OCT (Cirrus HD-OCT version 6.5, Carl Zeiss, USA) were included for this retrospective observational study. Methods Using known dimensions of the 200 * 200 optic disc cube (6 * 6 mm), the notch width was calculated from the margins of the notch on either side using ImageJ software. The height was calculated from the lowest margin of the cup to the lowest point of the defect on the optic disc. These were compared with the quadrant retinal nerve fiber layer (qRNFT) and sectoral retinal nerve fiber layer (sRNFLT) thickness in notch and the sector 2 clock hours adjacent to the notch region (SaRNFLT). Results The height and width of the notch in 31 eyes of 27 patients were 2.6 ± 0.48 mm and 2.23 ± 0.31 mm. The RNFL thickness in the same sector as that of the notch was 41 ± 21.06 µm while the adjacent two sectors measured 62 ± 26.5 and 64 ± 26.5 µm on either sides of the sector of the notch. The difference between the sRNFLT and saRNFLT ranged from -9 to 67 and -13 to 50 µm, respectively. This difference was significantly associated with height of the notch (R2 = 20.8, p = 0.01). Conclusion Automated analysis of a notch and RNFL thickness in that sector can help in precise glaucoma monitoring in the region of interest.

The present review casts a critical eye on intraocular pressure (IOP) monitoring and its value in current and future glaucoma care. Crucially, IOP is not fixed, but varies considerably during the 24-h cycle and between one visit and another. Consequently, a single IOP measurement during so-called office hours is insufficient to characterize the real IOP pathology of a patient with glaucoma. To date IOP remains the principal and only modifiable risk factor for the development and progression of glaucoma. Only by evaluating IOP characteristics (mean, peak and fluctuation of IOP) at diagnosis and after IOP-lowering interventions can we appreciate the true efficacy of therapy. Unfortunately, a major limiting factor in glaucoma management is lack of robust IOP data collection. Treatment decisions, advancement of therapy and even surgery are often reached on the basis of limited IOP evidence. Clearly, there is much room to enhance our decision-making and to develop new algorithms for everyday practice. The precise way in which daytime IOP readings can be used as predictors of night-time or 24-h IOP characteristics remains to be determined. In practice it is important to identify those at-risk glaucoma patients for whom a complete 24-h curve is necessary and to distinguish them from those for whom a daytime curve consisting of three IOP measurements (at 10:00, 14:00 and 18:00) would suffice. By employing a staged approach in determining the amount of IOP evidence needed and the rigour required for our monitoring approach for the individual patient, our decisions will be based on more comprehensive data, while at the same time this will optimize use of resources. The patient’s clinical picture should be the main factor that determines which method of IOP monitoring is most appropriate. A diurnal or ideally a 24-h IOP curve will positively impact the management of glaucoma patients who show functional/anatomical progression, despite an apparently acceptable IOP in the clinic. The potential impact of nocturnal IOP elevation remains poorly investigated. The ideal solution in the future is the development of non-invasive methods for obtaining continuous, Goldmann equivalent IOP data on all patients prior to key treatment decisions. Moreover, an important area of future research is to establish the precise relationship between 24-h IOP characteristics and glaucoma progression.

Glaucoma is a leading cause of irreversible blindness worldwide, which is estimated to affect approximately 112 million people by 2040. Elevated intraocular pressure (IOP) is the most important risk factor for glaucoma, as well as the primary target for the treatment. Current therapies aim at IOP reduction to prevent the disease progression. The accurate and real-time measurement of IOP is therefore critical to evaluate treatment response and guide medical decisions. However, IOP fluctuates throughout the 24-hour cycle with different patterns from day to day in the same individual and also different patterns among individuals. The current clinical practice typically captures a single IOP measurement during “in-office hours”, and this is insufficient for disease monitoring. With the development of wearable electronic devices, a variety of IOP monitoring devices provide a unique potential for continuous IOP monitoring. In addition to IOP monitoring for glaucoma management, this mini-review also summarizes novel drug delivery devices for treating glaucoma. Because certain types of glaucoma do not show elevated IOP, we also discuss the potential to incorporate biomarker detection with IOP measurement for more accurate and reliable glaucoma diagnostics and therapies.

As the number of individuals developing glaucoma is increasing, researchers and ophthalmologists are exploring new approaches to monitor intraocular pressure, which is a critical measurement for glaucoma detection. Current monitoring methods, such as implantable pressure sensors and wearable contact lenses with sensors, are being explored in eye research clinics. However, these systems currently lack in providing 24 hours data through a practical platform for large-scale use. This paper presents a novel method that provides constant measurements of the scleral strain, which is correlated with the change of intraocular pressure, using a nanofabricated discrete resistor array implant sensor. A preliminary bench-top test was performed using the sensor, and it showed that the nanofabricated 1.6 mm by 2.7 mm resistor array exhibits discrete sensing levels at increments of 41 ohms as a fixture needle traversed approximately half of the array. Though the nanosensor is in the prototype developing stage, it promises a new modality for constant, remote, and around the clock glaucoma monitoring.

PReCIS:: The C3 fields analyzer (CFA) is a moderately reliable perimeter preferred by patients to standard perimetry. While it does not approximate the gold standard, it was sensitive and specific for clinically defined glaucoma (area under the receiving operator characteristic curve=0.77 to 0.86). PURPOSE Testing the visual field is a vital sign for diagnosing and managing glaucoma. The current gold standard, the Humphrey visual field analyzer (HFA), is large, expensive and can be uncomfortable for some patients. The current study investigated the CFA, a virtual reality head-mounted visual field testing device, as a possible subjective field test for glaucoma screening and eventually glaucoma monitoring. PATIENTS AND METHODS The CFA presented stimuli in the same 54 positions as the HFA 24-2 SITA Standard test using a suprathreshold algorithm approximating an 18 dB deficit. A total of 157 patients (both controls and glaucoma patients) at the Aravind Eye Hospital, Pondicherry, India, were tested with both devices. RESULTS The number of stimuli missed on the CFA correlated with HFA mean deviation (r=0.62, P

BACKGROUND: To generate a practical and clinically useful consensus definition of ‘stable glaucoma’ to aid provision of glaucoma services in the UK and to provide guidance for the criteria that should be used for monitoring of glaucoma patients in primary care services. METHODS: A Delphi exercise was undertaken to derive consensus through an online questionnaire. Participants were asked to score their strength of agreement for a series of clinical parameters. Results and comments from each round were used to inform subsequent rounds. A total of 3 rounds were undertaken. RESULTS: Thirty-two glaucoma experts participated in the study with over 90% completion rate achieved over three rounds. The consensus was reached for the following parameters: IOP levels to be used for defining stability, visual field-testing techniques to define stability, the number of medication changes acceptable to define stability and the number of treatment medications allowed to define stability. No consensus was reached on the period of time over which stability was defined, however, there was considerable agreement that longer durations of follow up (36–48 months) were required. A combination of optic disc photos and ocular coherence topography (OCT) retinal nerve fibre layer (RNFL) assessment/ OCT disc structural evaluation are the preferred imaging methods for the assessment of structural stability. Oversight by a glaucoma consultant was considered important for glaucoma monitoring schemes. CONCLUSION: The consensus definition of glaucoma stability generated through this Delphi exercise provides guidance for allocation of patients suitable for monitoring in primary care glaucoma monitoring schemes.

PURPOSE Glaucoma specialists and optometrists who work in a team model at a single institution utilize a common definition of glaucoma progression and treatment algorithm. The purpose of this study was to assess the consistency of agreement in identifying glaucoma progression among glaucoma specialists and optometrists of 1 team. METHODS In total, 399 eyes of 200 patients age 18 or older with glaucoma were enrolled over 2 years. Clinical data, disc photographs, optical coherence tomography (OCT), and visual fields were independently reviewed by 2 masked optometrists and 2 masked fellowship-trained glaucoma specialists. Each eye was judged as progression or no progression of glaucomatous disease. The following were assessed: (1) agreement among optometrists; (2) agreement among glaucoma specialists; and (3) agreement among optometrists and glaucoma specialists. The frequency of use of testing modality to determine progression was also studied. κ statistics were used to evaluate agreements. RESULTS Optometrists agreed with each other for 74.2% of the eyes assessed (κ=0.42), whereas glaucoma specialists agreed with each other for 78.7% of eyes (κ=0.39). All 4 providers agreed with each other for 54.4% of the eyes evaluated (κ=0.37). Providers had the highest agreement when the progression decision was based on disc hemorrhage (92%) and the lowest agreement when based on OCT progression analysis (36%). Compared with optometrists, glaucoma specialists used OCT (P≤0.01) more frequently to determine disease progression. CONCLUSIONS Fair to moderate agreement levels were found among providers in their assessment of glaucoma progression, suggesting that a team approach to glaucoma management may be effective. Further work is needed to investigate ways to optimize consistency within the glaucoma team.

Automated perimetry still represents the gold standard in long term glaucoma monitoring. On a daily practice basis, glaucoma progression analysis could be difficult due to the long time needed to detect, confirm, and quantify the progression rate. Moreover, "trend" and "event" analysis require a good theoretical basis to perform and interpret. Aim of study was to present an alternative method to conventional Glaucoma Progression Analysis (Humphrey Visual Field Analyzer, Carl Zeiss® Inc.) applied for the early detection of glaucoma progression. Such an "event" analysis orients the clinician in a fast manner on the progression profile in glaucoma patients and might adapt the follow up visits accordingly. Method and material: 41 eyes from 41 patients with open angle glaucoma were studied in a longitudinal manner, over a 24 months' time interval from diagnosis. Results: in the GPA analysis, a positive "event" (progression) was detected in 11/ 41 eyes (26.82%). Non-parametric analysis confirmed progression in all GPA cases, and additionally found 8 more eyes with positive progression (46.34% studied eyes). Mc Nemar concordance analysis between tests was good and relevant (kappa index k=0.596, p=0.000), with positive correlation (r=0.652, p=0.008). In conclusion, NPA tends to overestimate the number of progression cases in a cohort, but it can easily orient the clinician on the profile of the followed patients. In the first years, the GPA analysis can be highly inaccurate, but there is a great need to detect which patients are at significant risk for vision loss (fast progressors). Yet, combining the two methods of detection of glaucoma progression, the practitioners might direct their selected interest and attention towards observing a larger than expected number of patients who are at risk for vision loss over time due to glaucoma, but not necessarily in a fast manner.

AimTo assess the equivalence of measurement outcomes between patients attending a standard glaucoma care service, where patients see an ophthalmologist in a face-to-face setting, and a glaucoma monitoring service (GMS).MethodsThe average mean deviation (MD) measurement on the visual field (VF) test for 250 patients attending a GMS were compared with a ‘big data’ repository of patients attending a standard glaucoma care service (reference database). In addition, the speed of VF progression between GMS patients and reference database patients was compared. Reference database patients were used to create expected outcomes that GMS patients could be compared with. For GMS patients falling outside of the expected limits, further analysis was carried out on the clinical management decisions for these patients.ResultsThe average MD of patients in the GMS ranged from +1.6dB to −18.9dB between two consecutive appointments at the clinic. In the first analysis, 12 (4.8%; 95% CI 2.5% to 8.2%) GMS patients scored outside the 90% expected values based on the reference database. In the second analysis, 1.9% (95% CI 0.4% to 5.4%) GMS patients had VF changes outside of the expected 90% limits.ConclusionsUsing ‘big data’ collected in the standard glaucoma care service, we found that patients attending a GMS have equivalent outcomes on the VF test. Our findings provide support for the implementation of virtual healthcare delivery in the hospital eye service.

Central corneal thickness (CCT) can be a promising source of glaucoma monitoring and diagnosis. This study evaluated changes in CCT according to experimental adjustment of intraocular pressure (IOP) in canine eyes. To adjust and measure IOP, each eye was cannulated with two 26-gauge needles under inhalant anesthesia. One needle was connected to a pressure transducer, and the other was connected to an adjustable bag of physiologic saline. IOP was stepwise increased from 10 mmHg to 70 mmHg in 10 mmHg increments (Group T). IOP was maintained at 15 mmHg (Group C15), 30 mmHg (Group C30), 45 mmHg (Group C45), 60 mmHg (Group C60) and 75 mmHg (Group C75) during the experiment. CCT was measured with an ultrasonic pachymeter every 10 min after cannulation. There was a significant difference in the effect of time on CCT (P

AIM: To determine the relevance of the objective parameters addressing the altered biomechanical properties of cornea for glaucoma monitoring in patients with mild or moderate thyroid associated orbitopathy (TAO), and in healthy individuals. METHODS: Twenty-five patients with TAO (group 1) and 25 healthy adults (group 2) were included to the study. Both groups were of a similar age and the ratio women:man. For each patient, the following parameters of both eyes were measured with ocular response analyzer (ORA): corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann correlated intraocular pressure (IOPg) and corneal compensated intraocular pressure (IOPcc). In both groups participating in our study, all measurements were performed within minutes to reduce the diurnal effects. RESULTS: The mean age in group 1 was 56±11y and 76% were women, 24% were men. The mean age in group 2 was 64±11y and 68% were women, 32% were men. CH correlated negatively with IOPg in group 1 (r2=0.10, P0.05) and also no significant correlation in group 2 (r2=0.04, P>0.05). CRF mean value in group 2 (11.51±1.72 mm Hg) was higher than in group 1 (10.85±1.45 mm Hg) (P

This work was part of the Surveillance for Ocular Hypertension study funded by the National Institute for Health Research (NIHR) Health Technology Assessment Programme (07/46/02) . Objective: To assess the efficiency of alternative monitoring services for people with ocular hypertension (OHT), a glaucoma risk factor. Design: Discrete event simulation model comparing five alternative care pathways: treatment at OHT diagnosis with minimal monitoring; biennial monitoring (primary and secondary care) with treatment if baseline predicted 5)year glaucoma risk is ≥6%; monitoring and treatment aligned to National Institute for Health and Care Excellence (NICE) glaucoma guidance (conservative and intensive). Setting: UK health services perspective Participants: Simulated cohort (IOP) 24.9mmHg (SD 2.4). Main outcome measures: Costs, glaucoma detected, quality adjusted life years (QALYs). Results: Treating at diagnosis was the least costly and least effective in avoiding glaucoma and progression. Intensive monitoring following NICE guidance was most costly and effective. However, considering a wider cost)utility perspective, biennial monitoring was less costly and provided more QALYS than NICE pathways, but was unlikely to be cost)effective compared with treating at diagnosis (£86,717 per additional QALY gained). The findings were robust to risk thresholds for initiating monitoring but were sensitive to treatment threshold, NHS service costs and treatment adherence. Conclusions: For confirmed ocular hypertension, glaucoma monitoring more frequently than every two years is unlikely to be efficient. Primary treatment and minimal monitoring (assessing treatment responsiveness [IOP]) could be considered, however further data to refine glaucoma risk prediction models and value patient preferences for treatment are needed. Consideration to innovative and affordable service redesign focused on treatment responsiveness rather than more glaucoma testing is recommended. Postprint

Objectives: To investigate the views and experiences of patients regarding their glaucoma follow-up, particularly towards the type and frequency of visual field (VF) testing.\ud \ud Design: A qualitative investigation using focus groups. The group discussion used broad open questions around the topics in a prompt guide relating to experiences of glaucoma follow-up, and in particular, VF monitoring. All the groups were taped, transcribed and coded using manual and computer-aided methods.\ud \ud Setting: Three National Health Service (NHS) hospitals in England; two focus groups took place at each hospital.\ud \ud Participants: 28 patients (mean (SD) age: 74 (9) years; 54% women) diagnosed with glaucoma for at least 2 years. Each focus group consisted of 3–6 patients.\ud \ud Primary and secondary outcomes: (1) Attitudes and experiences of patients with glaucoma regarding VF testing. (2) Patients’ opinions about successful follow-up in glaucoma.\ud \ud Results: These patients did not enjoy the VF test but they recognised the importance of regular monitoring for preserving their vision. These patients would agree to more frequent VF testing on their clinician's recommendation. A number of themes recurred throughout the focus groups representing perceived barriers to follow-up care. The testing environment, waiting times, efficiency of appointment booking and travel to the clinic were all perceived to influence the general clinical experience and the quality of assessment data. Patients were also concerned about aspects of patient–doctor communication, and often received little to no feedback about their results.\ud \ud Conclusions: Patients trust the clinician to make the best decisions for their glaucoma follow-up. However, patients highlighted a number of issues that could compromise the effectiveness of VF testing. Addressing patient-perceived barriers could be an important step for devising optimal strategies for follow-up care.

Several modes of non-standard automated perimetry have been introduced for the detection and the follow-up of glaucoma, with some techniques described over 30 years ago. The objective of these techniques was to allow clinicians to monitor glaucoma more effectively than standard automated perimetry. In spite of dozens of studies that report apparently favourable results with these techniques, their use has not become widespread, and arguably is decreasing. This presentation will review the evidence for the merit of non-standard automated perimetry and argue that given that the frequency of standard automated perimetry is well below practice standards, non-standard perimetric techniques have a limited role in glaucoma.

Implanted biomedical devices have been potentially used in many applications to make a better medical environment. Various diseases are being detected, monitored and treated by the help of implantable bio-devices. Currently, there are several implantable devices that have been proposed in medical applications, such as retinal prosthesis, glaucoma monitoring, cochlear implants, cardiac pacemaker and implantable cardiac defibrillators. This project deals with the design of antenna for teeth implantable device, which performs the measurement and monitor of temperature by sensing the basal body temperature (BBT). This work focuses mainly on the design of an implantable novel antenna for a bio-device that is fully wireless and implantable. This simple architecture provides a hybrid design that involves a high-efficiency antenna, which is used to send the signal wirelessly by means of MedRadio band. The resonant frequency for the Archimedean spiral antenna has been acquired at 314 MHz, to obtain a broadband design. The above frequency of the antenna obtained for the implantable bio-device is simulated and verified through our results.

We propose a 2D continuous-time Hidden Markov Model (2D CT-HMM) for glaucoma progression modeling given longitudinal structural and functional measurements. CT-HMM is suitable for modeling longitudinal medical data consisting of visits at arbitrary times, and 2D state structure is more appropriate for glaucoma since the time courses of functional and structural degeneration are usually different. The learned model not only corroborates the clinical findings that structural degeneration is more evident than functional degeneration in early glaucoma and the opposite is observed in more advanced stages, but also reveals the exact stages where the trend reverses. A method to detect time segments of fast progression is also proposed. Our results show that this detector can effectively identify patients with rapid degeneration. The model and the derived detector can be of clinical value for glaucoma monitoring.

Objective: To compare prospectively 2 perimetric progression detection algorithms for glaucoma, the Early Manifest Glaucoma Trial algorithm (glaucoma progression analysis [GPA]) and a nonparametric algorithm applied to the mean deviation (MD) (nonparametric progression analysis [NPA]). Methods: Patients with a reproducible glaucomatous visual field defect at baseline in at least 1 eye were followed up prospectively using perimetry (Humphrey field analyzer 30-2 Swedish interactive thresholding algorithm). Classifications by GPA and by NPA at the end of the follow-up period were compared. Results: Two hundred twenty-one patients met the inclusion criteria; 1 eye per patient was analyzed. On average, 7.1 reliable fields were available after a mean follow- up period of 5.3 years. The mean MD at baseline was -9.4 dB; the mean MD slope during the follow-up period was -0.25 dB/y. Fifty-six eyes showed progression by GPA and 89 eyes by NPA ( P

To assess potential problems in monitoring glaucoma status in pseudophakic patients in whom the intraocular lens (IOL) has undergone varying degrees of opacification. Data was collected by retrospective review of the notes of such patients, who had received a hydrophilic acrylic IOL, SC-60B-0UV, after primary cataract extraction by phacoemulsification. At first, among these, patients with glaucoma were identified and notes were reviewed to identify problems with patients in whom the IOL had undergone varying degrees of opacification. A total of 32 eyes with glaucoma were identified to have received the SC-60B-0UV IOL. Of these, 13 IOLs (40.6%) had undergone varying degrees of opacification. Eyes with the opacified IOLs showed decreased visual acuity (2.5 lines of Snellen acuity on average). For these eyes, visual field performance (as determined on automated field analyzers) and optic disc assessments were adversely affected giving a false impression of advanced glaucomatous field loss. In our experience, glaucoma monitoring is made comparatively more difficult in pseudophakic patients with cloudy IOLs. Problems are encountered during assessment of the glaucomatous optic disc due to poor view of the optic disc. On standard static automated visual fields, these opacified IOLs produce artefactual visual field defects making monitoring glaucoma and subsequent management more difficult.

We have measured the force required to depress the palpebrum over the center of the cornea in human patients and found that the curve is linear to within the accuracy of our measurements (R-value=0.9991). The motivation of this measurement is its clinical relevance to the development of a device to measure the intra ocular pressure in patients at risk for glaucoma without touching the cornea. This class of device has promise for patient-operated tonometry, including glaucoma monitoring in third-world counties. We find that non-linearity in the compressibility develops proportional to the distance of the center of the point of application of force from the center of the cornea. We show that this non-linearity can give rise to uncertainty in determination of the compressibility, with values up to 30% as compared to the well-aligned case with values typically 4%. We show that the compressibility value varies from subject to subject because of its three sources: the palpebrum, the cornea supported by the intra ocular pressure and the retropulsive structures. We find that the linearity of the compressibility of the compound structure and therefore of each of its constituents is intrinsic. We conclude that the understanding of the linearity of the compressibility indicates feasibility of this class of tonometer for glaucoma monitoring.