Relationship between macular perfusion and lesion distribution in diabetic retinopathy.

BACKGROUND/OBJECTIVES: To assess the relationship between macular vessel density metrics and foveal avascular zone (FAZ) characteristics on optical coherence tomography angiography (OCTA) and lesion distribution in eyes with diabetic retinopathy (DR). SUBJECTS/METHODS: Patients with DR who underwent both Optos ultrawidefield (UWF) pseudocolor imaging and macular OCTA (Cirrus Angioplex, 6 × 6 mm) were included in this cross-sectional observational study. The distribution of DR lesions was assessed by comparing each of the peripheral ETDRS extended fields (3-7) against their corresponding ETDRS field, hence eyes were defined as either having predominantly peripheral lesions (PPL) or predominantly central lesions (PCL). En face OCTA images from the superficial and deep capillary plexuses (SCP and DCP) were then analysed using Image J software. Perfusion density (PD), vessel length density (VLD), and fractal dimensions (FD) were calculated following binarization and skeletonization of the images. RESULTS: Out of 344 eyes, 116 (33.72%) eyes had PPL and 228 (66.28%) eyes had PCL. For all DRSS levels, VLD, PD, and FD were not significantly different between eyes with PPL and PCL. The FAZ in eyes with PPL, however, was found to be more circular in shape compared to eyes with PCL (p = 0.037). CONCLUSION: Although the presence of PPL has been associated with a higher risk for diabetic retinopathy progression, the macular perfusion is similar in eyes with PPL and PCL. The FAZ is more circular in eyes with PPL, but the clinical relevance of this difference remains to be defined.

Internal limiting membrane separation and posterior vitreous hyperreflective dots: novel OCT findings in Purtscher-like retinopathy.

BACKGROUND: Purtscher or Purtscher-like retinopathy is diagnosed by retinal hemorrhages and areas of retinal whitening on fundus examination, as well as a reduction in visual acuity due to microvascular occlusion of the precapillary retinal arterioles. We describe novel optical coherence tomography (OCT) findings of internal limiting membrane (ILM) separation and posterior hyperreflective dots in a case of Purtscher-like retinopathy in this report. METHODS: A 33-year-old man with acute pancreatitis and alcohol-induced liver disease presented to the retina department complaining of four days of painless vision loss in both eyes. Both eyes' anterior segment examination and intraocular pressure were normal. Dilated fundus examination of both eyes revealed confluent areas of retinal whitening, hemorrhages, and cotton-wool spots over the posterior pole, indicating Purtscher-like retinopathy. OCT scans through the macula revealed dense inner retinal reflectivity, thickening, and loss of retinal layer stratification, as well as outer retinal layer shadowing and islands of ILM separation, posterior vitreous hyperreflective dots, and minimal subfoveal fluid, all of which corresponded to areas of retinal whitening on fundus photographs. The patient was given a brief course of systemic steroids. RESULTS: On the tenth day after the presentation, visual acuity in the right eye had improved to 6/18 and finger counting at 1 m in the left eye. The retinal findings had faded. The retina had reverted to its normal thickness on the OCT scans, with minimal hyperreflectivity remaining. The ILM separation and posterior vitreous hyperreflective dots were no longer present. CONCLUSION: Following Purtscher or Purtscher-like retinopathy, we believe inflammation could play a major role in the development of these two novel OCT findings. This case offers an additional perspective on the underlying mechanisms responsible for the retinal manifestations observed in Purtscher or Purtscher-like retinopathy.

Recommendations for diabetic macular edema management by retina specialists and large language model-based artificial intelligence platforms.

PURPOSE: To study the role of artificial intelligence (AI) in developing diabetic macular edema (DME) management recommendations by creating and comparing responses to clinicians in hypothetical AI-generated case scenarios. The study also examined whether its joint recommendations followed national DME management guidelines. METHODS: The AI hypothetically generated 50 ocular case scenarios from 25 patients using keywords like age, gender, type, duration and control of diabetes, visual acuity, lens status, retinopathy stage, coexisting ocular and systemic co-morbidities, and DME-related retinal imaging findings. For DME and ocular co-morbidity management, we calculated inter-rater agreements (kappa analysis) separately for clinician responses, AI-platforms, and the "majority clinician response" (the maximum number of identical clinician responses) and "majority AI-platform" (the maximum number of identical AI responses). Treatment recommendations for various situations were compared to the Indian national guidelines. RESULTS: For DME management, clinicians (ĸ=0.6), AI platforms (ĸ=0.58), and the 'majority clinician response' and 'majority AI response' (ĸ=0.69) had moderate to substantial inter-rate agreement. The study showed fair to substantial agreement for ocular co-morbidity management between clinicians (ĸ=0.8), AI platforms (ĸ=0.36), and the 'majority clinician response' and 'majority AI response' (ĸ=0.49). Many of the current study's recommendations and national clinical guidelines agreed and disagreed. When treating center-involving DME with very good visual acuity, lattice degeneration, renal disease, anaemia, and a recent history of cardiovascular disease, there were clear disagreements. CONCLUSION: For the first time, this study recommends DME management using large language model-based generative AI. The study's findings could guide in revising the global DME management guidelines.

Recommendations for initial diabetic retinopathy screening of diabetic patients using large language model-based artificial intelligence in real-life case scenarios.

PURPOSE: To study the role of artificial intelligence (AI) to identify key risk factors for diabetic retinopathy (DR) screening and develop recommendations based on clinician and large language model (LLM) based AI platform opinions for newly detected diabetes mellitus (DM) cases. METHODS: Five clinicians and three AI applications were given 20 AI-generated hypothetical case scenarios to assess DR screening timing. We calculated inter-rater agreements between clinicians, AI-platforms, and the "majority clinician response" (defined as the maximum number of identical responses provided by the clinicians) and "majority AI-platform" (defined as the maximum number of identical responses among the 3 distinct AI). Scoring was used to identify risk factors of different severity. Three, two, and one points were given to risk factors requiring screening immediately, within a year, and within five years, respectively. After calculating a cumulative screening score, categories were assigned. RESULTS: Clinicians, AI platforms, and the "majority clinician response" and "majority AI response" had fair inter-rater reliability (k value: 0.21-0.40). Uncontrolled DM and systemic co-morbidities required immediate screening, while family history of DM and a co-existing pregnancy required screening within a year. The absence of these risk factors required screening within 5 years of DM diagnosis. Screening scores in this study were between 0 and 10. Cases with screening scores of 0-2 needed screening within 5 years, 3-5 within 1 year, and 6-12 immediately. CONCLUSION: Based on the findings of this study, AI could play a critical role in DR screening of newly diagnosed DM patients by developing a novel DR screening score. Future studies would be required to validate the DR screening score before it could be used as a reference in real-life clinical situations. CLINICAL TRIAL REGISTRATION: Not applicable.

Abnormal retinal vessel filling in central retinal artery occlusion.

CLINICAL RELEVANCE: Central retinal artery occlusion (CRAO) is an ophthalmic emergency with a poor prognosis. Several initial CRAO presentation factors can influence the final visual outcome. Fluorescein angiography filling of retinal vessels in CRAO has not been studied in great detail. BACKGROUND: The aim of this paper is to study the aberrant filling of the retinal vessels on fluorescein angiography in patients with CRAO and understand its clinical relevance. METHODS: Cases of CRAO diagnosed between June 2017 and May 2022 and who had undergone a fundus fluorescein angiography were included. Comparisons were made between the cases with and without aberrant filling of the retinal vessel. RESULTS: Twenty-two eyes of 22 patients (14 males and 8 females) with CRAO underwent fluorescein angiography. Ages of the patients ranged from 18 to 73 years, while time interval between development of acute onset vision problems and presentation to the retinal clinic ranged from a minimum of 1 day to a maximum of 30 days. Snellen visual acuity at presentation ranged from perception of light (PL +) to 6/6. On fluorescein angiography, aberrant flow of the fluorescein dye into the retinal vein was observed in four of the 22 (18%) eyes with CRAO. All these cases showed a patient's temporal cilioretinal artery. The cases with aberrant filling of the retinal vessels showed a better presenting visual acuity (6/6-6/60), lesser severity of inner retinal damage and a better final visual acuity (6/6-6/60) compared to CRAO cases without aberrant filling. CONCLUSION: Aberrant filling of the retinal vein can be seen on fluorescein angiography in eyes with CRAO and a patent temporal cilioretinal artery. Such eyes with aberrant retinal vessel filling have a better visual prognosis.

Progressive retinoschisis and retinal detachment after uncomplicated macular hole repair surgery.

PURPOSE: To report a rare case of progressive retinoschisis and retinal detachment after uncomplicated macular hole (MH) surgery. CASE DESCRIPTION: A 67-year-old man with recent onset vision complaints in the right eye (visual acuity - 20/30), was diagnosed with a small idiopathic full-thickness MH. He underwent a 3-port 25G pars plana vitrectomy surgery with internal limiting membrane peeling and air endotamponade. RESULTS: MH closed with a normal foveal contour and intact retinal layers by the 1st post operative week and vision improved to 20/20. At the 7th week follow-up period, the patient complained of visual disturbances in his right eye for 2 days. Optical coherence tomography scans revealed development of peripheral retinoschisis which progressed towards the macula over the next 4 weeks. At the 13th week following the retinal surgery, patient developed sudden profound vision loss to hand motions and a total retinal detachment was noted. He underwent a second retinal surgery with retinectomy to the stiff retina and silicone oil endotamponade. At the last follow-up visit 8 weeks after the second surgery, the visual acuity had improved to 20/120 and the retina was well-attached with silicone oil in place. CONCLUSION: We present a rare case of progressive retinoschisis and retinal detachment caused by residual ILM contraction after MH repair surgery. To the best of our knowledge, no such complication after MH repair surgery has been reported in the literature.

Right-angled vessel characteristics in different stages of type 2 macular telangiectasia (MacTel).

PURPOSE: To study right-angled vessels (RAV) in disease progression and macular neovascularization in type 2 macular telangiectasia (MacTel) eyes. METHODS: This retrospective image analysis study examined type 2 MacTel patients' multicolour® and OCT imaging records from January 2015 to March 2023. Age, gender, laterality, visual acuity, systemic disease, and follow-up duration were recorded. RAV characteristics were assessed using OCT and multicolour® images. This study examined RAV characteristics and type 2 MacTel disease stage. RESULTS: In total, 270 eyes of 146 patients (97 females, 66%) with a mean age of 60.77 ± 9.34 years were studied. 153 (57%) eyes showed RAV. The non-proliferative stage of type 2 MacTel had either no RAV or a normal-calibre right-angled vein, while the proliferative stage had a right-angled artery and a dilated or normal-calibre RAV [p < 0.001]. RAV characteristics differed at the final follow-up (p < 0.001). 11 eyes transitioned from non-proliferative to proliferative after a median period of 26 months (range: 5-96 months). RAV characteristics changed from a normal calibre right-angled vein at presentation to a normal calibre vein and artery in 6 (55%) eyes and to a dilated vein and artery in 5 (45%) eyes respectively. CONCLUSION: RAV characteristics may indicate type 2 MacTel stages. A right-angled artery in type 2 MacTel may indicate proliferative disease.

Vitreomacular interface abnormalities in type 2 macular telangiectasia (MacTel).

PURPOSE: To describe the different types of vitreomacular interface abnormalities (VMIA) seen on optical coherence tomography (OCT) in type 2 macular telangiectasia (MacTel) and explain the possible reasons for its development. METHODS: In this retrospective cross-sectional study, type 2 MacTel eyes with macular volumetric OCT imaging protocol were included to identify different types of VMIA such as abnormal PVD, vitreomacular traction (VMT), ERM, and lamellar and full-thickness macular hole. The VMIA findings were then correlated with different MacTel disease stages and visual acuity. RESULTS: One thousand forty-three OCTs of 332 type 2 MacTel eyes from 169 patients at different visits were examined. VMIA was detected in 709 (68%) of those OCT scans in 216 (65%) eyes. There were 273 (39%), 31 (4%), 89 (13%), 7 (1%), and 381 (54%) OCT scans with vitreomacular adhesion, VMT, ERM, and inner and outer lamellar macular holes discovered respectively. VMIA eyes had a high frequency of abnormal PVD (p = 0.001) and retinal pigment clumps (RPCs) [p = 0.032]. Eyes with abnormal PVD (p = 0.034) and RPC (p = 0.000) had a higher rate of ERM development. RPC was linked to an increased risk of developing ERM (odd ratio 2.472; 95% CI 1.488-4.052). RPC and ERM contributed significantly to poor visual acuity (0.661 ± 0.416, 20/92). CONCLUSION: OCT reveals a high frequency of VMIA in advanced type 2 MacTel eyes. RPC could be responsible for the development of anomalous PVD, as well as subsequent VMIAs and ERM. Additional work is required to examine the long-term changes and surgical outcomes of these eyes.

Congenital versus acquired optic disc pit maculopathy: An OCT based study.

PURPOSE: The purpose of this study is to describe and compare the demographic, ocular, and imaging characteristics of a cohort of patients with congenital and acquired optic disc pit maculopathy (ODPM). METHODS: This retrospective case series included patients diagnosed with ODPM between June 2017 and April 2023. These patients' baseline demographics, ocular characteristics, and optical coherence tomography (OCT) imaging characteristics and follow up changes were analyzed. RESULTS: A total of 14 eyes with ODPM were identified (9 congenital and 5 acquired). Eyes with congenital ODP developed maculopathy at a younger age, presented commonly with visual symptoms, and exhibited an obvious pit at the temporal foveal margin as well as a high cup: disc ratio (p < 0.05). Primary open-angle glaucoma was identified in all five eyes with acquired ODPM. On OCT, eyes with acquired ODPM lacked the characteristic nerve fibre layer schisis, outer retinal layer hole, and foveal serous macular detachment (p < 0.05) unlike congenital ODPM. At the final follow-up visit, two cases from the congenital ODPM group and one case from the acquired ODPM group displayed complete resolution of maculopathy. The two cases of congenital ODPM were treated with pars plana vitrectomy and laser barrage to the optic disc margin, while the solitary case of acquired ODPM was treated with trabeculectomy surgery alone. CONCLUSION: Clinical examination and baseline OCT imaging reveal distinct differences between congenital and acquired ODPM eyes. These characteristics may help with accurate diagnosis and treatment planning for these two distinct clinical entities.

Central posterior hyaloid fibrosis: evolution and outcomes.

PURPOSE: To report contributory factors and clinical outcomes of central posterior hyaloid fibrosis (CPHF) associated with neovascular age-related macular degeneration (nAMD). METHODS: In this retrospective, single-center study, patients with CPHF and nAMD were included. Demographic and imaging characteristics, as well as the anatomical and functional outcomes, of these patients were analysed. RESULTS: We identified 530 eyes in 273 patients with chronic predominantly scarred macular neovascularisation (MNV), and 32 eyes in 29 patients revealed CPHF, representing a prevalence of 6%. Patients had a mean age of 72.76 years. Before and during the development of CPHF, Type 2 MNV was observed in all eyes. At the time of MNV diagnosis, mean logMAR visual acuity was 1.308 ± 0.559 (20/407). The average time to develop CPHF was 27.3 months since the diagnosis of MNV. At the time of CPHF identification, the mean logMAR visual acuity was 1.498 ± 0.374 (20/630). RPE tear was observed in 6% (n = 2) of CPHF eyes. The average number of intravitreal anti-VEGF injections administered prior to the diagnosis of CPHF was 2.4 and after the onset of CPHF was 0.9. The final visual acuity was not significantly different at the final follow-up visit [1.304 ± 0.42 (20/402); p = 0.646]. CONCLUSION: Rarely observed in eyes with predominantly scarred subfoveal type 2 MNVs and extensive subretinal fibrosis, CPHF is associated with poor visual outcomes. Its presence could possibly suggest a profibrotic effect of MNV on the posterior hyaloid. TRIAL REGISTRATION NUMBER: Not applicable.

Baseline demographic, clinical and multimodal imaging features of young patients with type 2 macular telangiectasia.

PURPOSE: Macular telangiectasia (MacTel) type 2 is observed in patients in their 5th-8th decades of life. The clinical and imaging findings in younger patients is unknown in larger cohorts. The study purpose is to report prevalence, baseline clinical and spectral domain optical coherence tomography (SDOCT) findings in young MacTel patients below 40 years. METHODS: This hospital-based, multicentre, retrospective, cross-sectional study included patients between 2011 and 2023. Retinal photographs from multiple imaging techniques were evaluated to diagnose and stage type 2 MacTel and describe their SDOCT findings. Imaging characteristics were correlated with clinical stages and visual acuity. RESULTS: Among all MacTel patients seen in hospital, prevalence of young MacTel cases less than age 40 was 1.77% (32/1806; 62 eyes). Youngest participant was 34 years, while mean age was 38.44 ± 1.795 years. Sixteen patients (50%) were diabetics. Perifoveal greying (n = 56, 90%) and perifoveal hyperreflective middle retinal layers (n = 47, 76%) were the most prevalent clinical and SDOCT imaging finding respectively. Less than 10% (n = 6) eyes had proliferative disease. Presence of retinal pigment clumps (RPC) (7% vs. 67%; p = 0.002) coincided with proliferative MacTel. Poor vision was associated with presence of outer retinal layer SDOCT findings like outward bending of inner retinal layers (p = 0.047), RPC (p = 0.007), subfoveal neurosensory detachment (p = 0.048) and subretinal neovascular membrane (p = 0.001). CONCLUSION: Type 2 MacTel before age 40 is rare, common in women and diabetics, and affects vision in advanced stage. Disease symmetry, comparison with older cases, and longitudinal SDOCT changes in such patients require further study.

Evaluation of baseline optic disc pit and optic disc coloboma maculopathy features by spectral domain optical coherence tomography.

PURPOSE: The aim of this study is to describe and compare the baseline demographic, ocular, and imaging characteristics of a cohort of patients with optic disc pit (ODP) or optic disc coloboma (ODC) maculopathy. METHODS: This retrospective study included patients diagnosed with ODP or ODC on clinical examination between June 2017 and December 2022. These patients' baseline demographics, ocular characteristics, and optical coherence tomography (OCT) imaging characteristics were analyzed. RESULTS: Fundus examination revealed 11 eyes of 11 patients with ODP and 14 eyes of 9 patients with ODC, respectively. On OCT, maculopathy was observed more frequently in ODP (n = 10) than in ODC (n = 4) [p = 0.004] cases. Eyes with ODP were more likely to exhibit retinoschisis and/or serous macular detachment [SMD] (n = 7, 70%), communication of the retinoschisis with the optic disc (p = 0.015), whereas the SMD did not communicate with the optic disc (p = 0.005), and significant outer retinal layer thinning (p = 0.015). In contrast, eyes with ODC exhibited only SMD (p = 0.005) and no retinoschisis on the non-colobomatous retina. SMD in ODC communicated with the margin of the optic disc. In both clinical entities, hyperreflective foci were observed in the SMD. CONCLUSION: In summary, baseline maculopathy characteristics on OCT, including its type, location, and relationship to the optic disc, are among the most distinguishing characteristics between an ODP and an ODC. TRIAL REGISTRATION NUMBER: Not applicable.

Mid-phase pinpoint hyperfluorescent spots on fundus fluorescein angiography in acute central retinal artery occlusion - a novel imaging finding.

PURPOSE: To describe the development and outcome of mid-phase pinpoint hyperfluorescent spots (MPHS) on fundus fluorescein angiography (FFA) in acute (< 7-day symptom onset) central retinal artery occlusion (CRAO) patients. METHODS: This retrospective study included acute CRAO patients who underwent multimodal imaging utilizing optical coherence tomography (OCT) and FFA between June 2017 and January 2023. The correlation of FFA images with the OCT images in various stages and severity of CRAO were studied. RESULTS: Twenty-three FFA studies on 23 patients with acute CRAO were included. In 11 (48%) cases, an important finding noted on FFA was the presence of single or multiple MPHS with adjacent minimal late vascular leakage. Of these 11 cases, eight (73%) were males and median age was 41 years (inter quartile range: 33-55 years). Visual acuity ranged from 'light perception' to 6/18, and these patients presented anytime on the same day to seven days after symptom onset. On OCT, three eyes had severe CRAO, seven eyes had moderate CRAO, and one eye had mild CRAO. MPHS were primarily observed at the posterior pole and more frequently observed in moderate CRAO severity. During follow-up, the MPHS and retinal vessel staining on FFA disappeared as the CRAO showed signs of resolution. CONCLUSION: MPHS at the posterior pole on FFA in acute CRAO patients could indicate a more severe occlusion and poor visual outcomes, even after treatment. This finding is most likely caused by red blood cell aggregation or rouleaux formation. TRIAL REGISTRATION NUMBER: Not applicable.

Retinal OCT findings in acute central retinal artery occlusion of varying severity at different disease stages - a retrospective, observational study.

PURPOSE: To study the optical coherence tomography (OCT) changes in eyes with acute central retinal artery occlusion (CRAO) of different severity and at different disease stages. METHODS: The study included acute CRAO cases of < 7 days duration, imaged on OCT at various time points. Based on the OCT findings at presentation, cases were classified into three severity groups: mild, moderate, and severe. OCT scans were evaluated and classified into four-time intervals based on symptom duration. RESULTS: There were 39 eyes from 38 patients with acute CRAO who underwent 96 OCT scans. At presentation, the study had 11, 16, and 12 cases of mild, moderate, and severe CRAO, respectively. Middle retinal layer opacification was more common in mild CRAO cases, which caused inner retinal layer thinning over time. Moderate CRAO cases had total inner retinal layer opacification, which resulted in retinal thinning over time. Prominent middle limiting membrane (p-MLM) sign was seen in mild and moderate CRAO eyes while were not visualised in severe CRAO. This sign gradually faded out over time. Other OCT findings in higher grades of CRAO included inner retinal fluid, neurosensory detachment, internal limiting membrane detachment, hyperreflective foci, and posterior vitreous opacities. Regardless of the CRAO grade, the final end-point seen was inner retinal layer thinning over time. CONCLUSION: OCT in CRAO is a useful for determining the severity of retinal ischemia, disease stage, tissue damage mechanism, and final visual outcome. More prospective studies analysing a larger number of cases at fixed time points will be required in the future. TRIAL REGISTRATION: Trial Registration Number: Not applicable.

Long-term follow-up of acute retinal necrosis with retinal detachment secondary to herpes simplex virus type 2 with a successful visual outcome.

A man in his early 20s presented with acute loss of vision in his only eye, the left eye (OS), and was on oral steroids. He had lost vision in his right eye during his childhood and the cause was unknown. There was no history of trauma. Best-corrected visual acuity (BCVA) in OS was 20/100 and in the right eye was hand movements. OS showed non-granulomatous keratic precipitates on the cornea, anterior chamber flare 1+ and cell 1+, early cataract, vitreous haze and cells 2+ with nasal retinal detachment and superior full thickness retinitis. He underwent pars plana vitrectomy with intravitreal ganciclovir and barrage laser away from the necrotic retina. PCR for herpes simplex virus 2 was positive from the aqueous and vitreous sample. He was started on oral valacyclovir 1 g three times a day and continued on tapering dose of oral steroids. BCVA in OS at 6-month follow-up was 20/25.

REal-world treatment outcomes after delayed intRavitreal therapy in center-involving diabetic macular edema - RETORT study.

PURPOSE: To compare real-life data on delayed intravitreal treatment of diabetic macular edema (DME) patients to early treatment. METHODS: In this single-centre, retrospective, interventional, comparative study, DME patients were divided into two groups based on when they received treatment: Group 1 - received treatment within 24 weeks and Group 2 - at or after 24 weeks from the time of treatment advice. Visual acuity and central subfield thickness (CSFT) changes were compared at various time points. Reasons for delaying treatment were noted. RESULTS: The study included 109 (Group 1-94; Group 2-15) eyes. When treatment was advised, demographic profile, diabetes duration, glucose control and VA between two groups were comparable. At this point, CSFT was higher in Group 1 than in Group 2 (p = 0.036). At injection time, Group 2 had better VA and lower CSFT than Group 1 (p < 0.05). Group 2's VA (53.4 ± 12.67) was significantly lower than Group 1's (57.38 ± 20.01) after 1-year treatment. At 1-year, CSFT decreased in Group 1 and increased in Group 2. Group 1 had mean improvement of + 7.6 letters and Group 2 had a decline of -6.9 letters. Group 2 required more intravitreal anti-VEGF (median - 3; IQR: 2-4), steroid injections (median - 4; IQR: 2-4) and focal laser sessions (median - 4; IQR: 2-4). CONCLUSION: Late-treated DME eyes needed more injections and focal laser sessions than early treated eyes. Adherence to early treatment of DME in real-life will help prevent long-term vision loss.

Post-vitrectomy delayed retinal breaks in proliferative diabetic retinopathy.

PURPOSE: To report a series of cases of post-operative new secondary retinal breaks following vitrectomy for proliferative diabetic retinopathy (PDR). METHODS: This retrospective case series included data of patients diagnosed with post-operative retinal breaks following uneventful vitrectomy surgery for PDR from January 2018 to December 2021. RESULTS: New post-vitrectomy retinal breaks in PDR were seen in 7% of eyes (n = 10/148 eyes; 10 patients). Age of study patients ranged from 45 to 69 years and there were 8 males. Vitreous surgery was performed for vitreous hemorrhage in six eyes, macular tractional retinal detachment in three eyes and epiretinal membrane in one eye. Tractional fibrovascular proliferation near the retinal break prior to its development was noted either pre- or intra-operatively in 8 eyes. Mean time interval between the vitreous surgery and secondary retinal break development was 6.4 months. Residual fibrous tissue post-surgery adjacent to the break was noted in 4 cases. Sclerosed retinal vessel was noted in 4 eyes and associated inner retinal thinning or schisis in 5 eyes. No retinal detachment was noted in any case. Prophylactic barrage was done in 4 eyes. Last follow-up interval ranged from 4 to 53 months and visual acuity ranged from 6/6 to 6/60. No subretinal fluid, traction or break enlargement was noted at the last visit. CONCLUSION: Delayed post-operative retinal breaks following vitrectomy are uncommon in PDR eyes. Careful preoperative evaluation of the retinal proliferations, intraoperative dissection of the membranes and regular post-operative reviews are vital in anticipating the development of delayed post-vitrectomy retinal breaks. Observation could be the management strategy for these breaks.

Incidence of post vitrectomy endophthalmitis in India - A multicentric study by VRSI study Group.

INTRODUCTION: The incidence of post vitrectomy endophthalmitis (PVE) is reported to be between 0.02 and 0.84%. Resterilization of single use instruments is a common practice amidst developing countries to make it more affordable to the patients by reducing the cost of the surgery and also reduce the environmental hazard. The aim of our study is to evaluate the incidence of PVE amidst existing sterilization practices of reused instruments in multiple vitreoretinal centres in India. METHODOLOGY: Centres with an endophthalmitis tracking system were invited to participate in a survey. Twenty-five centres were sent a questionnaire via email. The questionnaire included details about the institution, number of vitrectomies performed in a year, sterilization practices followed pre-operatively, intraoperatively and postoperatively, incidence of endophthalmitis and instrument reuse policies. RESULTS: A total of 29 cases of endophthalmitis were reported out of the 47,612 vitrectomies performed across various centres. The mean incidence of endophthalmitis was 0.06%. There was no difference in the rates of endophthalmitis based on various pre-operative, intraoperative or postoperative prophylactic measures. Nearly 80% of the centres change most of the instruments after every case, while the rest reused. The mean number of times a cutter was being reused until discarded was 4.7. Nearly 76% followed a performance-based protocol, and the remaining 24% had a fixed protocol for the number of times an instrument can be reused before discarding it. CONCLUSION: PVE rates are not significantly different in India despite the multiuse of single use instruments. The purpose of this paper is not to suggest an alternate protocol but to creating one in the future with these results in mind, to rationalise the use of single use instruments, make VR surgery more affordable and also have a positive impact on the carbon footprint of consumables in surgery.

Ocular blood vessel arrangement in choroidal coloboma.

OBJECTIVE: To describe the ocular blood vessel arrangement in choroidal coloboma eyes. METHODS: In this retrospective, observational cross-sectional study, fundus images from 69 coloboma eyes of 45 patients were classified as per Ida Mann's classification. The arrangement and distribution of retinal, choroidal, and episcleral vessels, as well as vortex veins, were observed in non-colobomatous, colobomatous, and extra-colobomatous regions. RESULTS: Seventy-eight colobomas were identified. There were 12 type 1, 13 type 2, 10 type 3, 13 type 4, 11 type 5, 4 type 6 and 15 type 7 colobomas respectively. In most cases of type 1 and 2 colobomas, origin of retinal blood vessels could not be determined. In colobomas type 3-7, retinal blood vessels originated either from the optic disc centre or, rarely, from the optic disc or coloboma margin. Eyes with large and deep type 1, 2, 3 and 7 colobomas showed prominent choroidal vessels in the non-colobomatous region and around the coloboma. Small choroidal colobomas lacked prominent choroidal vessels. Similarly, prominent extraocular episcleral vessels within the coloboma bed were observed in eyes with colobomas of types 1, 2, 3 and 7. Vortex veins were visible in 70% of coloboma eyes. They were more commonly seen with small focal colobomas and less frequently with large deep colobomas. CONCLUSION: Coloboma eyes have variations in the arrangement and distribution of ocular blood vessels. The position, size, and antero-posterior extent of the choroidal coloboma are the primary determinants of how these blood vessels are arranged. Future research would benefit from additional imaging with indocyanine green angiography.