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When laser coagulation of eye retina is carried out, the laser beam is directed to target retinal areas selected by an ophthalmologist. The exposure to laser light produces a photocoagulate. When using laser coagulation, the main problem is selecting both the laser exposure areas that would cover all pathological zones and the laser exposure parameters to prevent retina damage. Any patient has an individual fundus structure. The individual structure of pathological and anatomical elements must be taken into account to achieve the desired therapeutic effect. The formation of coagulates in all hemorrhage-affected areas results in the desired therapeutic effect. The vascular layer must be heated to a sufficient temperature to form a coagulate. Such an effect can be predicted using mathematical modeling of laser exposure. In this paper, we consider methods of mathematical modeling of laser exposure based on the solution of a heat equation. The methods are compared in terms of their computational complexity and solution stability. An analysis of the possibility of predicting the therapeutic effect using methods of mathematical modeling of laser exposure is carried out.

INTRODUCTION Retinopathy of prematurity (ROP) is a condition that affects preterm infants, being the second leading cause of childhood blindness worldwide. The most commonly used treatments are cryotherapy or laser photocoagulation, but over the last few years, anti-vascular endothelial growth factor (anti-VEGF) drugs have gradually gained more adherents, mainly in the treatment of patients with type 1 retinopathy of prematurity (ET- ROP) Therefore, it is important to summarize the existing evidence to evaluate the efficacy and safety of anti-VEGF drugs in type 1 retinopathy of prematurity. METHODS We searched in Epistemonikos, the largest database of systematic reviews in health, which is maintained by screening multiple information sources, including MEDLINE, EMBASE, Cochrane, among others. We extracted data from the systematic reviews, reanalyzed data of primary studies, conducted a meta-analysis and generated a summary of findings table using the GRADE approach. RESULTS AND CONCLUSIONS We identified six systematic reviews including 15 studies overall, of which five were randomized trials. We conclude that the use of anti-VEGF compared to laser photocoagulation, probably reduces the risk of refractive errors. On the other hand, the use of anti-VEGF may result in little or no difference in the mortality at hospital discharge, lens or corneal opacity requiring surgery, and complete or partial retinal detachment, but the certainty of the evidence is low. Finally, it is not possible to clearly establish whether anti-VEGF compared with laser photocoagulation, increases the recurrence of retinopathy of prematurity, because the certainty of the existing evidence has been assessed as very low.

Purpose: To describe 6 cases of acute central serous chorioretinopathy (CSCR) and the response to laser treatment, focusing on the underlying pathogenic mechanism., Methods: Multimodal imaging from 6 eyes of 6 patients with acute and recurrent CSCR were reviewed, including fundus autofluorescence (FAF), fluorescein angiography (FA), indocyanine green angiography (ICGA), and optical coherence tomography (OCT) at baseline and after laser therapy., Results: In 3 of the 6 cases with acute CSCR, the hyporeflective lucency sign was identified with cross-sectional and en face OCT and co-localized with an intense active inkblot retinal pigment epithelium (RPE) leak on FA. The development of this sign was suggestive of active leakage into the subretinal space displacing overlying subretinal hyperreflective material (SHRM) and suggestive of a reversal of RPE pump function. All 6 cases were treated with focal laser to directly target the intense leakage points with remarkable resolution of the fluid due to destruction of the RPE cells mediating reversal of pump function., Conclusions: Unlike chronic CSCR in which degenerative changes of the RPE lead to oozing of fluid into the subretinal space, in acute forms of CSCR including bullous CSCR, there are focal leaks of the RPE that actively drive fluid into the subretinal space suggestive of RPE pump reversal. We propose that pachychoroid disease causes increased hydrostatic pressure and increased resistance to the RPE pump, thereby triggering a reversal in pump function. Understanding this concept can have therapeutic implications., (Published by Elsevier Inc.)

AimTo determine the effect of alpha-2-agonist (AA) premedication (PM) on intraocular pressure (IOP) following selective laser trabeculoplasty (SLT).MethodsRetrospective cohort study of all patients undergoing 360° SLT at an institution with two prevalent practice patterns consisting of SLT performed with PM and without premedication (NPM) with AA. The association between pre- and post-operative IOP was evaluated using a linear regression model in 49 (59%) PM and 34 (41%) NPM eyes.ResultsThe prevalence of IOP elevations up to 5 mmHg 1 h postoperatively was similar in both groups, occurring in 18% of PM and in 15% of NPM. Elevations above 5 mmHg were seen in 4% of PM and 8% of NPM (P = 0.732). After correcting for age, gender, diagnosis, number of medications, and preoperative IOP, the presence or absence of AA PM had no significant association with any postoperative IOP (P > 0.5).ConclusionThe practice of using AAs before SLT and measuring IOP at 1 h has not been validated yet adds to expenses and workflow burden. Our retrospective study showed no significant correlation between PM and postoperative or longer-term IOP. IOP at 1 h should be measured in patients who cannot tolerate transient pressure elevations. Further studies are needed to elucidate this relationship.

Copyright of Der Ophthalmologe is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The objective of this study was to describe the dynamics of water heating carried out by continuous laser radiation with wavelengths 1.47, 1.55, and 1.94 μm with different types of fibers used for endovenous laser coagulation. The study was conducted in water using high-speed surveying of the heating process through the shadow optical method. It has been shown that in the case of highly water-absorbed laser radiations, convection and boiling play a major role in the process of heat transfer. It has been shown that in the case of radiation with λ = 1.94 μm that is heavily absorbed by water, effective heat transfer begins at significantly lower levels of power compared to the weaker-absorbed radiations with λ = 1.47 and 1.55 μm. Mathematical models based only on thermal conductivity inadequately describe the process of real heat transfer during endovenous laser coagulation. It has been established that heat transfer is sharply asymmetrical and is directed mainly up-and-forward (bare-tip fiber) or upward ("radial" and "two-ring" fibers). Heat transfer for laser light with wavelength 1.94 μm is most effective than for 1.47 and 1.55 μm. [ABSTRACT FROM AUTHOR]

Purpose. Experimental study the morphological changes of the retina and choroid, providing adhesion of the detached retina in the first 72 hours after laser coagulation.Material and methods. A clinical and morphological study of 12 eyes of 12 Chinchilla rabbits with experimentally simulated retinal detachment was performed 12, 24, 48 and 72 hours after the operation of transciliary vitrectomy with laser coagulation.Results. Due to local destruction and exudative effects in the field of laser coagulation of the retina (increasing to 24 hours and decreasing to 72 hours) detected the formation of a tight adhesive contact between the shells resulting from the destruction of exudative fibrinogen and deposition fibrin. Histological changes in the retina and choroid in the area of laser coagulation in the first two days corresponded to the growing destructive-exudative phase of fibrinoid’s inflammation moderate with maximum cases in the period of 48 hours with the attenuation of exudative effects and proliferative phase after 72 hours.Conclusion. In the period from 24 to 48 hours of the adhesive after laser coagulation is formed of a dense chorioretinal contact by deposits of fibrin, which serves as a fibrinogen serum, part extravasal exudate area of laser coagulation. Based on the studied morphological processes, it can be assumed that chorioretinal adhesion in the LC area becomes strong enough to independently hold the retina in place 48 hours after surgery.

The paper proposes a method for selection the region of diabetic macular edema in fundus images using OCT data. The relevance of the work is due to the need to create support systems for laser coagulation to increase its effectiveness. The proposed algorithm is based on a set of image segmentation methods, as well as searching for specific points and compiling their descriptors. The Canny method is used to find the boundary between the vitreous body and the retina in OCT images. The segmentation method, based on the Kruskal algorithm for constructing the minimum spanning tree of a weighted connected undirected graph, is used to select the retina to the pigment layer in the image. Using the results of segmentation, a map of the thickness of the retina of the eye and its deviation from the norm were constructed. In the course of the research, the optimal parameter values were selected in the Canny and graph segmentation algorithms, which allow to achieve a segmentation error of 5 %. SIFT, SURF, and AKAZE methods were considered for super-imposing calculated maps of the retina thickness and its deviation from the norm on the fundus image. In cases where a picture from the fundus camera of the OCT apparatus is provided along with OCT data, using the SURF method, it is possible to accurately combine with the fundus image.

Diabetic retinopathy (DR) is a serious complication of diabetes mellitus (DM). As DR progresses, it could be complicated with a significant decrease or complete loss of vision. It is the leading cause of blindness in the working-age population and, according to global estimates, occurs in one in every three patients with diabetes. DR has been studied for more than 160 years, and the implementation of retinal laser coagulation into clinical practice in the 20th century, and then vascular endothelial growth factor (VEGF) inhibitors in the 21th century, allowed us to influence vascular proliferation in DR and reduce the risk of vision loss from diabetic macular oedema (DME). However, these tools can only stop the progression of DR at the stages with risk of complications with vision loss, and prevention – screenings and the impact on risk factors (hyperglycaemia, arterial hypertension, and dyslipidemia) – remains as the main method of management of DR. Possible new risk factors (hypodynamy, obesity, body weight deficiency, and obstructive sleep apnoea syndrome) attract a lot of attention, and there is ongoing research for early markers of DR in the fundus, which could allow more active influence on the pathological process in its early stages. This review focuses on epidemiology, history of research, proven and possible risk factors, and current and promising approaches to the prevention and treatment of DR, including accurate, less traumatic laser techniques (PASCAL, NAVILAS, and D-MPL), and intravitreal antiangiogenic drugs in studies.

Laser hemorrhoidoplasty (LHP) is a new technique for treatment of hemorrhoids. The exact extent of coagulation is not visible at the time of the procedure. There currently is no experimental or clinical data on the subject.

Background: Oculocutaneous albinism (OCA) is a group of autosomal recessive hereditary disorders that affect melanin biosynthesis, resulting in abnormalities in hair, skin, and eyes. Retinopathy of prematurity (ROP) is a proliferative retinopathy mainly observed in premature infants with low birth weight and early gestational age, but it can also affect full-term infants or children with normal weight, particularly in developing countries. The coexistence of ROP and OCA is rare. There is limited documentation regarding treatment approaches, with few studies reporting positive outcomes with laser treatment due to the absence of melanin pigment. This study discusses the treatment challenges in a female infant diagnosed with ROP and OCA, and underscores the importance of genetic analysis in guiding therapeutic decisions for this rare comorbid condition., Case Presentation: The study presents a case of ROP occurring concurrently with OCA. Genetic testing revealed two variants, c.727C > T (p.R243C) and c.1832 T > C (p.L611P), in the OCA2 gene, inherited from the patient's mother and father, respectively. The identified mutations were consistent with a diagnosis of OCA2, classified as a subtype of OCA. The patient initially received intravitreal anti-vascular endothelial growth factor (anti-VEGF) injection, followed by laser photocoagulation therapy for a recurrent event. A favorable outcome was observed during the 2-month follow-up period., Conclusions: The co-occurrence of ROP and OCA is a rare phenomenon, and this is the first recorded case in the Chinese population. The current case supports the use of laser as the primary treatment modality for ROP in OCA2 patients with partial pigmentation impairment. Furthermore, genetic analysis can aid in predicting the effectiveness of laser photocoagulation in this patient population., (© 2024. The Author(s).)

Purpose: To analyze changes in demographic parameters and retreatment patterns over a 10-year period in a clinical routine setting of infants with retinopathy of prematurity (ROP) requiring treatment documented in the German Retina.net ROP registry., Design: Multicenter, noninterventional, observational registry study recruiting patients treated for ROP., Subjects: A total of 692 eyes of 353 infants treated for ROP were documented in the Retina.net ROP registry over a 10-year period between 2011 and 2020. These cases cover about 15% of all infants treated for ROP in Germany., Methods: The Retina.net ROP registry was established in 2012 to jointly collect information on infants treated for ROP. The database collects information on demographic parameters (gestational age [GA], birth weight, neonatal comorbidities) as well as treatment parameters (type of treatment, weight and age at treatment, and stage of ROP). A total of 19 centers contributed to the analysis. This is the 10-year analysis of data from 2011 to 2020, in which we focus on changes over time regarding the respective parameters., Main Outcome Measures: Changes over time in demographic parameters and treatment patterns for ROP in Germany., Results: The overall incidence of treatment requiring ROP was 3.5% of all infants screened for ROP at participating centers. Gestational age, weight at birth, and weight at treatment remained stable over the 10-year period, whereas postmenstrual and postnatal age at treatment increased moderately but statistically significantly over the years. The most prevalent ROP severity stage at treatment was stage 3+ in zone II (76.6% of all treated eyes). Treatment patterns changed considerably from predominantly laser treatments in 2011 (75% of all treated eyes) to predominantly ranibizumab treatments in 2020 (60.9% of all treated eyes). The overall retreatment rate was 15.6%. Retreatment rates differed between initial treatment modalities (14.1% after laser coagulation, 12% after bevacizumab and 24.5% after ranibizumab). Treatment-associated systemic or ophthalmic complications were rare., Conclusions: This data analysis represents one of the largest documented cohorts of infants treated for ROP. The data on demographic parameters and treatment patterns provide useful information for further improvement of ROP management., Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article., (Copyright © 2023 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.)

Objective: To describe a case of bilateral retinal vasculitis due to presumed sarcoidosis and rickettsial retinitis complicated with neovascularization with tear biomarker analysis., Methods: A retrospective case report., Results: A 16-year-old male presented with bilateral retinal vasculitis and retinitis in both eyes with inferotemporal quadrant neovascularization in the right eye. Multimodal imaging revealed the presence of active inflammation in both eyes. Weil Felix test was positive with raised ACE levels. This patient was treated with local and systemic steroids, doxycycline, and laser photocoagulation followed by oral methotrexate therapy which resulted in clinical resolution with recovery of visual acuity. Tear biomarker analysis showed raised sICAM-1 and MMP-9 levels in both eyes which significantly reduced following treatment., Conclusion: Ocular sarcoidosis with rickettsial infection is a rare association. Tear biomarkers correlated well with clinical and imaging manifestations. High index of suspicion and aggressive anti-inflammatory therapy can help control inflammation and restore good vision., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

We present a case of Takayasu's arteritis in a woman in her 30s, who exhibited visual symptoms and ophthalmic manifestations of the disease, specifically Takayasu's retinopathy stage 4, in both eyes. Despite severe narrowing of all branches of the aortic arch and compromised perfusion in both upper limbs, she had no history of intermittent claudication. Doppler study and CT angiography revealed diffuse circumferential wall thickening of bilateral common carotid, subclavian and axillary arteries. Treatment involved retinal laser photocoagulation and immune suppression. This case underscores that advanced Takayasu's retinopathy can be an initial presentation of Takayasu's arteritis even in a state of severely compromised peripheral limb circulation., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Purpose: To determine timing and rates of reactivation and retreatment of type 1 retinopathy of prematurity (ROP) after treatment with either 0.125 mg, 0.250 mg, or 0.500 mg of intravitreal bevacizumab (IVB)., Methods: Retrospective data, including demographic information, past medical history, and ROP characteristics were analyzed for babies with type 1 ROP treated with IVB at Riley Hospital for Children for the perioed 2014-2021., Results: A total of 84 patients met inclusion criteria: 29 patients received 0.125 mg of IVB; 39, 0.250 mg; and 16, 0.500 mg. Of the 84, 67 (80%) had additional laser treatment because of late reactivation (n = 52) or persistent avascular retina (PAR) (n = 15). Subsequent laser treatment was more common with lower doses: 0.125 mg (n = 27 [93%]); 0.250 mg (n = 31 [80%]); 0.500 mg (n = 9 [57%]) (P = 0.012). There was no difference between groups with regard to reason for subsequent laser treatment (reactivation vs PAR). The 0.125 mg group required retreatment because of reactivation 3.8 weeks sooner than the other dosing groups (P = 0.047)., Conclusions: The outcomes comparing three doses of IVB for severe ROP showed a difference in the timing of secondary treatment, with the lower dosing group requiring laser for reactivation earlier., (Copyright © 2024 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.)

Purpose: To investigate the 5-year treatment outcomes of retinopathy of prematurity in infants <500 g birth weight and compare laser and anti-vascular endothelial growth factor therapies., Methods: A multicenter retrospective study comprised 24 eyes of 13 patients treated for Type 1 retinopathy of prematurity, followed for 5 years. Initial treatment was laser and anti-vascular endothelial growth factor in 13 and 11 eyes, respectively. Data collected included sex, birth characteristics, retinopathy of prematurity characteristics at the time of treatment, best-corrected visual acuity (BCVA), spherical equivalent, and astigmatism at 5 years posttreatment., Results: Median BCVA was 0.15 logarithm of the minimum angle of resolution (interquartile range, 0.0-0.5). Snellen BCVA was ≥20/40 in 73% and ≥20/20 in 27% of eyes. Median spherical equivalent was -2.37 (interquartile range, -6.1 to -0.1); 75% had myopia (≤-0.5 D), and 25% had high myopia (≤-6.0 D). Median astigmatism was 1.25 (interquartile range, 0.9-3.0); 46% had ≥1.5 D. Anti-vascular endothelial growth factor-treated eyes showed less myopia ( P < 0.009), with no BCVA or astigmatism difference ( P = 0.997, P = 0.271) compared with laser-treated eyes., Conclusion: One-quarter of the eyes exhibited good visual acuity (Snellen BCVA of ≥20/20) 5 years after retinopathy of prematurity treatment. Refractive errors were common. Anti-vascular endothelial growth factor therapy may be superior to laser therapy in myopic refractive error.

Background: Limited data have shown that, compared to uncomplicated twin pregnancies, pregnancies complicated by twin-twin transfusion syndrome (TTTS), a life-threatening condition, are associated with higher maternal serum levels of both human chorionic gonadotropin (hCG) and thyroid hormones. With the continuing expansion of assisted reproductive technologies, the rate of twin pregnancies, including those complicated by TTTS and associated hyperemesis gravidarum, is expected to increase further. Therefore, detailed descriptions of the maternal and fetal clinical outcomes of maternal thyrotoxicosis linked to TTTS can be useful for timely diagnosis and management. However, such descriptions are currently lacking in the literature. Case Presentation: We report the case of a 30-year-old woman carrying a monochorionic twin pregnancy complicated by TTTS that induced a relapse of severe hyperemesis gravidarum with overt non-autoimmune hyperthyroidism at 17 weeks of gestation. Following fetoscopic laser coagulation (FLC), both hyperemesis and hyperthyroidism improved within 1 week. Conclusions: The present experience contributes to the knowledge base on maternal thyrotoxicosis linked to TTTS and can be useful in the diagnosis and treatment of future cases; it also emphasizes the need for a high degree of clinical suspicion and for close collaboration between endocrinologists and obstetricians. Another key point is that TTTS-associated hyperemesis gravidarum and maternal hyperthyroidism should be considered in the differential diagnosis of refractory or relapsing hyperemesis gravidarum in women with monochorionic twin pregnancy, because this condition may require more stringent supportive treatment before and during the FLC procedure when the mother is overtly hyperthyroid. [ABSTRACT FROM AUTHOR]

Diabetic retinopathy is one of the dangerous fundus diseases that leads to irreversible loss of vision. In the case of untimely or incorrect treatment, blindness occurs. Currently, laser coagulation is a common treatment method. An ophthalmologist uses a laser to apply a series of burns to the retina. The success of the operation depends entirely on the experience of the doctor. The automatic formation of a preliminary plan of coagulates allows us to solve a number of problems related to the operation, such as long manual placement of coagulates or adjustment of laser power. Thus, the probability of a doctor's error is reduced, and the preparation time for the operation is significantly reduced. One of the key stages in the formation of the plan is the segmentation of the fundus image. This stage is carried out with the help of texture features, the calculation of which takes a long time. In relation to this, this study proposes high-performance algorithms for the segmentation of fundus images using CUDA technologies, which significantly speed up sequential versions and outperform parallel algorithms. [ABSTRACT FROM AUTHOR]

PurposeDevelopment of nongenetic animal models of local retinal degeneration is essential for studies of retinal pathologies, such as chronic retinal detachment or age-related macular degeneration. We present two different methods to induce a highly localized retinal degeneration with precise onset time, that can be applied to a broad range of species in laboratory use.MethodsA 30-μm thin polymer sheet was implanted subretinally in wild-type (WT) rats. The effects of chronic retinal separation from the RPE were studied using histology and immunohistochemistry. Another approach is applicable to species with avascular retina, such as rabbits, where the photoreceptors and RPE were thermally ablated over large areas, using a high power scanning laser.ResultsPhotoreceptors above the subretinal implant in rats degenerated over time, with 80% of the outer nuclear layer disappearing within a month, and the rest by 3 months. Similar loss was obtained by selective photocoagulation with a scanning laser. Cells in the inner nuclear layer and ganglion cell layer were preserved in both cases. However, there were signs of rewiring and decrease in the size of the bipolar cell terminals in the damaged areas.ConclusionsBoth methods induce highly reproducible degeneration of photoreceptors over a defined area, with complete preservation of the inner retinal neurons during the 3-month follow-up. They provide a reliable platform for studies of local retinal degeneration and development of therapeutic strategies in a wide variety of species.

Objective: Due to the increased risk of antenatal brain lesions, we offer a third-trimester magnetic resonance imaging (MRI) scan to all patients who underwent an in utero intervention for twin-twin transfusion syndrome (TTTS). However, the usefulness of such a policy has not been demonstrated yet. Therefore, we determined the prevalence of antenatal brain lesions detected on third-trimester MRI and the proportion of lesions detected exclusively on MRI.Materials and Methods: We conducted a retrospective cohort study of monochorionic diamniotic twin pregnancies complicated by TTTS that underwent laser coagulation of the vascular anastomoses or fetal reduction by umbilical cord occlusion between 2010 and 2017. We reviewed the third-trimester MRI findings and compared those with the prenatal ultrasonography.Results: Of the 141 patients treated with laser coagulation and 17 managed by cord occlusion, 112/141 (79%) and 15/17 (88%) patients reached 28 weeks. Of those, 69/112 (62%) and 11/15 (73%) underwent an MRI between 28 and 32 weeks. After laser coagulation, MRI detected an antenatal brain lesion in 6 of 69 pregnancies (9%) or in 6 of 125 fetuses (5%). In 4 cases (67%), the lesion was detected only on MRI. In the 11 patients treated with cord occlusion, no brain lesions were diagnosed.Conclusion: The prevalence of brain lesions detected by third-trimester MRI is higher compared to prenatal ultrasonography alone, making MRI a useful adjunct to detect antenatal brain lesions in twin pregnancies after in utero treatment for TTTS.Key Points: • In utero interventions for twin-to-twin transfusion syndrome (TTTS) do not prevent the occurrence of antenatal brain lesions. • Fetal magnetic resonance imaging (MRI) has high accuracy in detecting anomalies of cortical development and can be a useful adjunct to ultrasonography in diagnosing certain brain abnormalities. • After laser coagulation of the anastomoses for TTTS, third-trimester MRI diagnosed a brain lesion that was not detected earlier on ultrasound scan in 6% of pregnancies. [ABSTRACT FROM AUTHOR]

Copyright of Arquivos Brasileiros de Oftalmologia is the property of Arquivos Brasileiros de Oftalmologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Amniotic band syndrome is a rare condition. There have been few cases reported of fetoscopic band dissection. The aim of this case series is to report 3 cases of fetoscopic treatment for amniotic band syndrome, including indication for surgery, technical aspects, complications and outcomes. Fetoscopic treatment was performed respectively at 23 5/7, 26 5/7 and 18 3/7 weeks' gestation. Two procedures were performed with a laser fiber through a single trocar whereas one surgery was performed with scissors. In conclusion, fetoscopic release of the amniotic bands in case of amniotic band syndrome is feasible with encouraging results in order to prevent amputation and dysfunction of the extremities. [ABSTRACT FROM AUTHOR]

AimTo evaluate the efficacy of a standardised combination therapy for clinically significant diabetic macular oedema using bevacizumab injections followed by navigated laser photocoagulation to stabilise retinal thickness.MethodsIn this pilot study we retrospectively reviewed charts and imaging of 23 eyes treated with the standardised combination regimen. Eyes initially received monthly bevacizumab injections, followed by navigated laser photocoagulation when central retinal thickness (CRT) was

PurposeTo compare laser photocoagulation plans for diabetic macular edema (DME) using fluorescein angiography (FA) versus optical coherence tomography (OCT) thickness map superimposed on the retina.MethodsFourteen eyes with DME undergoing navigated laser photocoagulation with navigated photocoagulator had FA taken using the same instrument. Optical coherence tomography central retinal thickness map was imported to the photocoagulator and with same magnification aligned onto the retina. Three retina specialists placed laser spot marks separately on FA and OCT image in a masked fashion. The spots placed by each physician were compared between FA and OCT and among physicians. The area of dye leakage on FA and increased central retinal thickness on OCT of the same eye were also compared.ResultsThe average number of spots using FA and OCT template was 36.64 and 40.61, respectively (P = 0.0201). The average area of dye leakage was 7.45 mm, whereas the average area of increased central retinal thickness on OCT of the same eye was 10.92 mm (P = 0.013).ConclusionThere is variability in the treatment planning for macular photocoagulation with a tendency to place more spots when guided by OCT than by FA. Integration of OCT map aligned to the retina may have an impact on treatment plan once such information is available.

The purpose of the study is to increase the efficiency of delivering high-tech eye care to the infants of Orenburg and the Orenburg region.Material and methods. An algorithm has been developed to deliver specialized care for retinopathy of prematurity. Recently purchased «RetCam3» pediatric retinal camera made it possible to conduct dynamic screening and monitoring of preterm infants who were prematurely born at risk of retinopathy. The examination was prescribed to children at risk (gestation age up to 35 weeks, birth weight up to 2500 g). The time frame for fundoscopy varied from 3 to 7 weeks after birth depending on the infant physical condition. The number of examinations at 3th–4th weeks of life was 63 %, at 5th–6th weeks – 29 %, at 6th–7th weeks – 8 %. Screening examinations were carried out in the perinatal centre with intervals, depending on the stage of retinopathy of prematurity: preretinopathy, stage I and II from 1 to 2 weeks, III and more severe stages from several days to a week. 60 initial examinations were performed in 6 months, laser treatment was provided for 13 patients (21.7 %).Results and discussion. For 6 months, 60 initial examinations were performed; laser treatment was performed in 13 patients (21.7 %). We observed positive changes for all the infants after laser treatment, which proves high efficiency of the developed algorithm of treatment premature infants with retinopathy, which is the prevention of blindness and low vision from infancy. Repeated monitoring after laser coagulation was carried out after 2, 4 and 8 weeks.Conclusions. Thus, screening contributes to the identification of this pathology at an early stage, dynamic monitoring of the fundus changes is carried out using retinal camera, which contributes to timely laser treatment. The developed algorithm improves the quality of specialty care for premature infants at risk of developing retinopathy of prematurity, and, accordingly, improves the quality of their life.

AIM: To investigate the efficacy and safety of conbercept intravitreal injection combined with selective laser photocoagulation for central retinal vein occlusion(CRVO).METHODS: A retrospective study was performed on 66 patients with CRVO in our department of ophthalmology. Among them, 30 patients received only conbercept's intravitreal injection and served as a control group. On this basis, another 36 patients were combined with selective laser photocoagulation and as an observation group. The differences of central macular thickness(CMT), BCVA(LogMAR)and complication rate after treatment were compared between the two groups.RESULTS:The CMT and BCVA of the two groups were significantly improved after treatment(Pth month after treatment(PPP>0.05).CONCLUSION: The combination therapy has a more significant effect on CRVO and is safe.

The paper proposes a technology for effective feature selection to localize individual characteristics of anatomical and pathological structures in the human eye fundus. Such an approach allows the intellectual analysis of features to be conducted using color subspaces and the regions of interest to be identified. This problem is relevant because in this way the efficiency of laser coagulation surgery can be improved. The technology is based on the texture analysis of certain image patterns. The initial textural attributes are derived from different statistical image descriptors calculated using the MaZda library (image histogram, image gradient, series length and adjacency matrices). The analysis of the feature space informativity and selection of the most effective features are carried out using the discriminant data analysis. The best-size image fragmentation windows for eye fundus clustering and sets of features that provide the necessary accuracy in identifying the regions of interest were derived via analyzing the following four image classes: exudates, thick vessels, thin vessels, and healthy areas. The feature selection technology was based on clustering using a K-means method, with the Euclidean and Mahalanobis distance used as a similarity measure. The required minimum size of the fragmentation window and the similarity measure were chosen from a criterion of the minimum clustering error among all the smallest window sizes. The article also presents a system for automatically forming a coagulate plan, expected to be used to support the decision-making during laser retinal coagulation surgery in the treatment of diabetic macular edema. This system is currently being developed based on the proposed technology.

The article describes a determination method of the laser radiation with specific parameters effect on the eye tissues based on optoacoustic probing. Low-power probing laser with 7-10 ns pulses generates acoustic waves at the aiming point. The waves propagate through the medium (saline in a cuvette) to acoustic receiver. The characteristics of the acoustic wave give basis for estimation of optical absorption coefficient - a parameter that determines temperature in the affected area after applying therapeutic laser. Calculation of the temperature pattern was performed using a three-dimensional thermal conductivity model that enabled determination of temperature distribution at any local point during coagulation and immediately after. To compare the results with pre-calculated temperature field values, direct temperature measurement was taken from the surface of the absorbing layer. The experiment was performed on six human chorioretinal tissue samples in vitro; the obtained optical absorption coefficient values did not exceed 120-300 cm-1 with maximum error margin of 20 %. The computational model was seen to be in good agreement with experimental thermocouple measurements.

OBJECTIVE: To study changes in retinal nerve fiber layer (RNFL) measured on optical coherence tomography (OCT) after panretinal photocoagulation (PRP) in patients with proliferative diabetic retinopathy (PDR). METHODS: This quasi experimental study was conducted at Department of Ophthalmology, Lahore General Hospital, Lahore from 1-4-2017 to 30-3-2018. All patients (n=38) diagnosed with PDR requiring PRP were included. Patients having any coexisting ocular pathology hindering the OCT measurement were excluded. Pre-operatively, RNFL thickness in four quadrants and signal strength was measured on OCT and visual acuity (VA) on Snellen’s chart. Post-operatively, patients were followed-up after one-month and three-months and VA was measured and OCT performed. RESULTS: The mean age of patients was 60.66±5.51years with 23(60.5%)males. PRP was performed in right-eye of 22 patients. Pre-laser VA in 28 patients was 6/60. Pre-laser total RNFL was 84.32±4.78µm reduced to 83.74±4.61µm one-month and 81.89±4.40µm three-months post-laser (p

ABSTRACT Introduction: twin-to-twin transfusion syndrome (TTTS), defined by combination of polyhydramnios-oligohydramnios, is the most prevalent (5%-35%) of the abnormalities due to placental vascular anastomoses and the most lethal (80%-100% mortality) if untreated. Fetoscopic laser ablation of abnormal vasculature using the Solomon technique is the gold standard approach. It consists of interrupting the intertwin blood flow. Objectives: to present our initial experience at the Fetal Surgery Service of the Hospital de Clinicas of the Federal University of Parana (HC-UFPR) and to compare our results with those reported in the literature. Methods: we conducted a retrospective analysis of pregnancies who had undergone laser ablation, assessing data on Quintero’s staging, gestational age at diagnosis and at the time of the procedure, placental position, immediate post-procedure survival, and survival after the neonatal period. We then compared these data with the most recent data available in the literature. Results: we analyzed ten TTTS cases. The diagnosis was performed before the 26th week of pregnancy (median 20.8 weeks) and treatment occurred in a median of 9.5 days later. The distribution by the Quintero’s staging was of three cases in stage II, five in stage III, and two in stage IV. In 50% of the gestations, at least one of the fetuses survived through the neonatal period. Conclusion: the treatment of TTTS in the HC-UFPR had a positive impact in the survival of the affected fetuses, although the results were worse than the ones reported in the literature, probably due to the delay in referencing the patients to our service, leading to a prolonged interval between diagnosis and treatment.

Background: Endolaser probes have been designed and sold for single-use only. However, in Brazil, they are not included in the list of single-use medical products that are prohibited from being reprocessed and could potentially be reused if safety requirements are accomplished. Therefore, this study aimed to determine and compare the quality, safety and costs of reprocessed versus original single-use endolaser probes of a specific brand and model. Methods: The study, conducted at a university hospital in Sao Paulo, Brazil, was divided in two phases. The first one tested the feasibility, sterility and physical integrity of ten reprocessed laser probes. In the second phase, all vitrectomy procedures using endolaser probes (reprocessed and original ones) from August 2017 to October 2019 were evaluated. The operated cases were followed for any signs of infection and number of defective probes for each group were counted. The cost of acquiring a new probe and for all reprocessing stages were evaluated and quantified in US dollars($). Results: Microbiologic, residual ethilen oxide and microscopic evaluation of integrity of reprocessed laser probes were all within acceptable range. The second phase of this study included 590 endolaser probes, of which 375 were original and 215 were reprocessed. Functionality rates differed significantly between groups. Among the original probes, 373 (99.47%) were functioning and 2 (0.53%) were non-functioning. Among the reprocessed ones, 201 (93.5%) were functioning and 14 (6.5%) were non-functioning (p <.001). The average cost of one reprocessing was $3.00, and the average cost of an original probe was $150.00. Considering the loss rates, potential savings were $147.60 for each once-reprocessed probe. The frequency of infectious endophthalmitis was null in both groups. Conclusions: Our study showed that a single cycle endolaser probe reprocessing was safe and efficient, not associated with increase in endophthalmitis rate and proved to be significantly cost-effective, even considering a greater malfunction rate when compared to the original devices. [ABSTRACT FROM AUTHOR]

The purpose of this study was to evaluate the efficacy of a 980-nm diode laser coagulation in women with radiation-induced hemorrhagic cystitis (RHC). We conducted a retrospective study of 21 RHC patients treated with a 980-nm diode laser between July 2014 and December 2017 at our institution. Data was collected with regard to age, sex, lower urinary tract symptoms, use of transfusions, a drop in hemoglobin levels, indication of radiotherapy, median time between radiation therapy and presentation, previous treatments, operative time, mean energy used, number of coagulated areas, catheterization time, discharge time after treatment, hospital stay, and surgical outcome. All 21 patients were women with a median age of 52 years (range 36–68 years). Eighteen patients complained of frequency and urgency, four patients had dysuria, and one patient developed urinary retention. Radiation therapy was primarily indicated in the treatment of cervical cancer in 18 patients (85.7%) and endometrial cancer in three patients (14.3%). Nine patients (42.8%) received blood transfusion before surgery and three patients (14.3%) needed blood transfusion after the procedure. The mean decrease in hemoglobin prior to the procedure was 4.08 ± 2.04 g/dL. The median length of time from completion of radiotherapy to the presentation of hematuria was 38 months (range 8–65 months). All patients had failed an adequate trial of conservative treatment which included adequate hydration, hemostatics, continuous bladder irrigation (CBI), and clot evacuation at the bedside. Eleven patients (52.4%) had previously been treated with endoscopic electrocoagulation; the mean number of procedures was 1.73 ± 0.78 (range 1–3 sessions). Six patients (28.6%) underwent HBO, and sodium hyaluronate solution irrigation was administered to 3 patients (14.3%). The mean number of HBO sessions was 26.3 ± 16.8 (range 8–50), and the mean number of sodium hyaluronate solution irrigation procedures was 4.33 ± 1.53 (range 3–6). All operations were successful. The mean operative time was 45.6 ± 12.3 min, the mean number of coagulated areas was 11.7 ± 4.4, the mean energy used was 2.74 ± 1.14 kJ, the mean catheterization time was 6.2 ± 0.9 days, the mean discharge time after treatment was 6.8 ± 1.2 days, and the average length of a hospital stay was 7.4 ± 1.3 days. In 16 patients (76.2%), hematuria was completely resolved after one session of diode laser coagulation. Four patients (19.0%) underwent multiple sessions of laser treatment due to recurrent gross hematuria (three patients required two sessions and one patient required three sessions). Only one patient (4.8%) who had persistent gross hematuria after diode laser treatment (two sessions) underwent a radical cystectomy, which resolved the hematuria. The median hematuria-free interval of patients who had multiple procedures was 9 months (range 1–13 months). In total, 21 patients underwent 27 sessions of diode laser coagulation, and the median hematuria-free interval was 16 months (range 1–45 months) with a median follow-up of 25 months (range 7–48 months). Our study shows promising results for the management of patients with RHC; however, further evaluation with a larger cohort is required to confirm the efficacy of this treatment. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study is to assess the effectiveness and safety of intrafetal vascular laser ablation (VLA) for fetuses with bronchopulmonary sequestration (BPS) with hydrops.Methods: First, we present 3 cases of fetuses with BPS and hydrops treated by VLA. Second, we aimed to conduct a narrative review to identify all reported cases of fetuses with BPS treated by intrafetal VLA.Results: The review of the literature identified 41 fetuses treated by VLA for BPS with hydrops. The median gestational age of the VLA was 27+0 weeks' gestation [25+0-31+0] with an associated procedure at the same time in 43% of the cases (pleuroamniotic shunt, thoracentesis, and amniodrainage). A second procedure was required in 25% of cases for residual flow in the feeding vessel. No stillbirth or neonatal death was reported. The complications reported were a fetal thoracic hematoma complicated by fetal anemia and 4 preterm deliveries with a rate of 9%.Conclusion: VLA of the feeding vessel can be an effective treatment but is not without complications. In cases demonstrating cardiac output failure, intrafetal VLA should be considered as a treatment for BPS. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to investigate and compare the efficacy and safety of retinal laser photocoagulation (PRP) alone, PRP with aflibercept 3+PRN, and PRP with aflibercept 5+PRN in patients with both high-risk proliferative diabetic retinopathy (PDR) and diabetic macular edema (DME)., Methods: Overall, 170 patients with high-risk PDR and DME (170 eyes from 170 patients) who visited our ophthalmology clinic from December 2018 to December 2020 were divided into the PRP (n=58), aflibercept 5+PRN with PRP (n=53), and aflibercept 3+PRN with PRP (n= 59) groups. General information, such as age, sex, and eye category, was obtained. Moreover, best-corrected visual acuity (BCVA), baseline central macular foveal thickness (CFT), microaneurysm (MA), area of neovascularization (NV), area of hard exudate (HE), and cytokine levels in atrial fluid before and after treatment, were assessed. The χ 2 test was used for comparison between groups for statistical data. Analysis of variance was used for the statistical description of measurement data, independent samples were analyzed using Student's t -test, and Student-Newman-Keuls test was used for group comparisons. Differences were considered statistically significant at P < 0.05., Results: After treatment, no significant improvement in the BCVA (logMAR) of patients in the PRP group was observed. The BCVA (log MAR) decreased from 0.72 ± 0.17 and 0.74 ± 0.17 to 0.50 ± 0.13 and 0.53 ± 0.17 in PRP with aflibercept 5+PRN and PRP with aflibercept 3+PRN groups, respectively, with a statistically significant difference compared to those in the PRP group (P<0.05 in all cases). However, no statistically significant difference was observed between the combined treatment groups (P>0.05). The CFT in the PRP-only group decreased slightly from 361.80 ± 36.70 μm to 353.86 ± 40.88 μm, with no statistically significant difference (P>0.05), whereas the CFT in the aflibercept 5+PRN with PRP and aflibercept 3+PRN with PRP groups decreased from 356.57 ± 37.57 μm and 358.17 ± 44.66 μm to 284.87 ± 31.52 μm and 303.19 ± 37.00 μm, respectively, with statistically significant differences before and after treatment (P<0.05 for both groups). Statistically significant differences were observed in CFT between the three groups after treatment (P<0.05 in all cases). The number of MA (pcs) in the PRP, aflibercept 5+PRN with PRP, and aflibercept 3+PRN with PRP groups decreased from 118.34 ± 27.96, 118.60 ± 33.34, and 116.59 ± 28.95 to 92.95 ± 29.04, 44.60 ± 20.73, and 54.26 ± 25.43, respectively. The two-way comparison of the three groups revealed statistically significant differences in MA (P<0.05 in all cases). In the three groups, NV decreased from 1.00 ± 0.21 mm², 1.01 ± 0.18 mm², and 0.98 ± 0.20 mm² before treatment to 0.49 ± 0.17 mm², 0.31 ± 0.16 mm², and 0.38 ± 0.14 mm², respectively, with statistically significant differences (P<0.05 in all cases). After 12 months of treatment, 13, 18, and 18 patients had reduced HE area in the PRP-only, aflibercept 5+PRN with PRP, and aflibercept 3+PRN with PRP groups, respectively, with statistically significant differences (P<0.05 in all cases). After 12 months of treatment, vascular endothelial growth factor, monocyte chemoattractant protein-1, and glial fibrilliary acidic protein levels (pg/mL) in the aqueous humor decreased in both combined treatment groups compared with that at baseline, with statistically significant differences; however, no significant difference was observed between the two combined treatment groups (P>0.05)., Conclusion: Aflibercept 5+PRN combined with PRP was safe and effective in treating patients with high-risk PDR and DME, and was more effective than PRP-only and aflibercept 3+PRN with PRP in improving CFT and MA., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Li, Tao, Yang, Zhao, Si, Cui and Wang.)

This Quasi Experimental study was conducted at Major Eye Clinic, Gujranwala, from January to December 2022, to study the effect of muting the sound of Argon Laser machine on patient compliance and the pain felt during pan-retinal photocoagulation (PRP). Eighty patients were included in the study with proliferative diabetic retinopathy (PDR), retinal breaks, lattice and myopic fundus degenerations for which PRP was performed. A total of 80 patients were enrolled, who were divided in two groups with 40 patients in each group. Group A patients received muted machine settings, while group B underwent regular PRP. The mean age was 54.6±3.4 years. Sixty-eight (85%) cases were of PDR, 4 (5%) of retinal breaks, 3 (3.75%) of lattice degenerations associated with breaks, and 5 (6.25%) of laser barrage. In group A, 28 (70%) patients had grade 1 and grade 2 pain score, while in group B, 26 (65%) had grade 3 and grade 4 pain score. It was concluded that by eliminating machine sound, noise anxiety can be greatly reduced ensuring better patient cooperation.

Prcis: Both micropulse (MP-CPC) and continuous wave (CW-CPC) cyclophotocoagulation exhibited short-term effectiveness in lowering IOP, followed by reversion to near baseline levels 12 months after laser treatment., Objective: To determine and compare the effectiveness and safety of MP-CPC and CW-CPC in patients diagnosed with pediatric glaucoma., Methods: A retrospective cohort study was conducted on a total of 28 patients (81 eyes) diagnosed with pediatric glaucoma either undergoing MP-CPC or CW-CPC. Intraocular pressure (IOP) measurements, number of glaucoma medications, and the onset of complications were collected at baseline, 1-month, 3-month, 6-month, and 12-month intervals. Success rate (SR) was defined as eyes achieving IOP ≤21 mm Hg and ≥5 mm Hg and a 20% reduction in IOP at the last follow-up visit., Results: All patients either undergoing MP-CPC or CW-CPC were matched for age (mean ± SD; 1.76 ± 1.69 vs 1.56 ± 2.49 y). Patients undergoing MP-CPC had significant decreases in IOP from baseline IOP at 1, 3, and 6 months with a 22% SR at 12 months. CW-CPC had a significant decrease in IOP from baseline IOP at all follow-ups, with a 27% SR at 12 months. At the 12-month follow-up, the CW-CPC cohort exhibited a significantly larger overall drop in IOP when compared with the MP-CPC cohort, (7.99 ± 7.95 vs 1.78 ± 6.89, P < 0.05); however, the difference in SR between treatment groups (27% vs 22%) at 12 months was not significant ( P > 0.05). Complications were minimal for both groups., Conclusion: Both MP-CPC and CW-CPC exhibited short-term effectiveness in lowering IOP, followed by reversion to near baseline levels 12 months after laser treatment. Both MP-CPC and CW-CPC exhibited similar SR at 12 months, 22% and 27% respectively., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: To report the surgical success and response to treatment for children undergoing cyclophotocoagulation (CPC) for refractory pediatric glaucoma., Methods: The medical records of children with a diagnosis of glaucoma who underwent a first CPC between May 2000 and May 2020 were reviewed retrospectively. The cumulative probability of success was assessed. For definition 1, treatment success was defined as IOP ≤21 mm Hg at all the visits after the first 3 months without the need for additional glaucoma surgery or repeat CPC. For definition 2, repeat CPC did not constitute failure., Results: Of 300 eyes that underwent CPC, we identified 262 eyes eligible for inclusion. The mean age at time of first treatment was 5.33 ± 5.03 years, with a mean follow-up of 4.3 ± 4.2 years (31 eyes having at least 10 years of follow-up). The success rates for definitions 1 and 2 were 26.7% (95% CI, 21.7%-32.4%) and 46.2% (95% CI, 40.2%-52.3%), respectively. Older age was associated with a lower risk of failure after both single CPC (HR, 0.92; 95% CI, 0.88-0.96; P < 0.001) and multiple CPCs (HR, 0.95; 95% CI, 0.90-1.00, P = 0.073). Of the 262 eyes, 107 (41%) had sustained IOP-lowering with a single treatment and 56 (21%) with multiple treatments; 35 (13%) had a transient response, and 64 (24%) had no response., Conclusions: Glaucoma control through CPC often requires multiple treatments, with around a quarter of children responding suboptimally. Older children are more likely to exhibit successful IOP lowering., (Copyright © 2024 American Association for Pediatric Ophthalmology and Strabismus. Published by Elsevier Inc. All rights reserved.)

Purpose: To investigate recent trends in the cumulative incidence and treatment patterns of retinopathy of prematurity (ROP) in Japan., Methods: A retrospective multicenter cohort was conducted from 2011 to 2020 using the Diagnosis Procedure Combination inpatient database. Preterm newborns with birth weight <2,500 g were categorized by birth weight. The cumulative incidence of ROP, treatment patterns, and association between treatment and birth weight were investigated., Results: A total of 82,683 preterm infants were identified, of whom 9,335 (11.3%) were diagnosed with ROP. The cumulative incidence of ROP increased by 15% in those with birth weight <500 g over the study period. Among the ROP infants, 20.2% received treatment, including laser photocoagulation (94.8%), intravitreal injection (3.8%), or both (1.8%). The proportion receiving laser photocoagulation decreased followed by an increase in intravitreal injection. This shift in intervention pattern was most conspicuous for those with birth weight 750 to 1,249 g. The risk ratio of receiving laser and intravitreal injection for those weighing <500 g was 24.7 (95% confidence interval, 10.5-58.2) and 28.4 (5.8-138.1), respectively, as compared with infants weighing >1,500 g., Conclusion: The cumulative incidence of ROP increased in infants with birth weight <500 g. A shift from laser photocoagulation to intravitreal injection was observed in the more recent years.

Fetoscopic Laser Coagulation (FLC) for Twin to Twin Transfusion Syndrome is a challenging intervention due to the working conditions: low quality images acquired from a 3 mm fetoscope inside a turbid liquid environment, local view of the placental surface, unstable surgical field and delicate tissue layers. FLC is based on locating, coagulating and reviewing anastomoses over the placenta's surface. The procedure demands the surgeons to generate a mental map of the placenta with the distribution of the anastomoses, maintaining, at the same time, precision in coagulation and protecting the placenta and amniotic sac from potential damages. This paper describes a teleoperated platform with a cognitive-based control that provides assistance to improve patient safety and surgery performance during fetoscope navigation, target re-location and coagulation processes. A comparative study between manual and teleoperated operation, executed in dry laboratory conditions, analyzes basic fetoscopic skills: fetoscope navigation and laser coagulation. Two exercises are proposed: first, fetoscope guidance and precise coagulation. Second, a resolved placenta (all anastomoses are indicated) to evaluate navigation, re-location and coagulation. The results are analyzed in terms of economy of movement, execution time, coagulation accuracy, amount of coagulated placental surface and risk of placenta puncture. In addition, new metrics, based on navigation and coagulation maps evaluate robotic performance. The results validate the developed platform, showing noticeable improvements in all the metrics., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Purpose of the study: To examine the cause of treatment failures in Type 1 retinopathy of prematurity (ROP). Patients and Methods: The medical charts of all infants with disease persistence after laser treatment at Uppsala University Hospital, Sweden, during a 10‐year period (2009–2019) were reviewed. RetCam photography and angiography were used to document the retinal appearance before and after retreatment. Results: Ten infants (18 eyes), of whom nine were referred from other hospitals, had persistence of Type 1 ROP in zone I or zone II despite previous laser treatment. Their mean gestational age was 24 weeks and their mean birth weight was 618 g. Seven eyes were diagnosed as stage 3 plus, eight eyes as stage 4A and three eyes as stage 4B. In eight infants (14 eyes), inadequate laser coagulation was suspected to be the cause for persistence of type 1 disease. Two infants (four eyes) were appreciated to have persistence of plus disease because of presence of zone I disease. For persistence of Type 1 ROP, five infants (seven eyes) were treated with vitrectomy, two infants (three eyes) with laser photocoagulation and anti‐vascular endothelial growth factor (VEGF), two infants (four eyes) with anti‐VEGF alone and finally two infants (four eyes) with laser photocoagulation alone. The anatomical outcome was good in 14 eyes and poor in four eyes (three infants). Conclusions: Inadequate laser coagulation is an important cause of treatment failure of ROP Type 1. Another cause is laser coagulation in zone I. To minimize remaining visual disability, some kind of centralization of the ROP treatment is suggested. [ABSTRACT FROM AUTHOR]

Background/objectivesCurrent laser therapy of port wine stain (PWS) birthmarks with a single laser pulse (SLP) does not produce complete lesion removal in the majority of patients. To improve PWS therapeutic efficacy, we evaluated the performance of an approach based on multiple laser pulses (MLP) to enhance blood vessel photocoagulation.Study designThe hamster dorsal window chamber model was used. Radiant exposure (RE), pulse repetition rate (f(r)), total number of pulses (n(p)), and length of vessel irradiated were varied. Blood vessels in the window were irradiated with either SLP with RE of 4-7 J/cm(2) or MLP with RE per pulse of 1.4-5.0 J/cm(2), f(r) of 0.5-26.0 Hz, and n(p) of 2-5. The laser wavelength was 532 nm and pulse duration was 1 ms. Either a 2 mm vessel segment or entire vessel branch was irradiated. Digital photographs and laser speckle images of the window were recorded before and at specific time points after laser irradiation to monitor laser-induced blood vessel structural and functional changes, respectively.ResultsWe found that: (1) for a SLP approach, the RE required to induce blood vessel photocoagulation was 7 J/cm(2) as compared to only 2 J/cm(2) per pulse for the MLP approach; (2) for MLP, two pulses at a repetition rate of 5 Hz and a RE of 3 J/cm(2) can induce photocoagulation of more than 80% of irradiated blood vessel; and (3) irradiation of a longer segment of blood vessel resulted in lower reperfusion rate.ConclusionsThe MLP approach can induce blood vessel photocoagulation at much lower RE per pulse as compared to SLP. The 5 Hz f(r) and the need for two pulses are achievable with modern laser technology, which makes the MLP approach practical in the clinical management of PWS birthmarks.