Volume measurement of the vitrectomised eye and its applications in practice.

PURPOSE: To estimate the vitreous cavity replacement volume after pars plana vitrectomy and analyze its correlation with axial length and refractive error. METHODS: Observational cross-sectional study on 103 eyes undergoing vitrectomy. Fluid-air exchange was performed using a soft-tip cannula connected to a PVC tubing, the distal end of which opened into a 10-cc syringe without the plunger. The collected fluid was measured (and correction factors applied) to estimate the vitreous cavity volume. RESULTS: The mean axial length of 103 eyes was 23.43 ± 1.54 mm. The mean vitreous cavity volume was 4.46 ± 0.83 mL (2.8-8.1 mL). There was a strong positive correlation between axial length and vitreous volume, which was stronger for pseudophakic and aphakic groups than for phakic groups. CONCLUSION: Accurate assessment of vitreous cavity volume can enable precise quantification of tamponade, intravitreal drugs, and intravitreal chemotherapeutic agents. This will allow better surgical outcomes, decreased toxicity, and increased cost-effectiveness due to lesser wastage. OBJECTIVE: To estimate the vitreous cavity replacement volume after pars plana vitrectomy and analyze its correlation with axial length and refractive error.

Efficacy, Safety and Immunogenicity of Sun's Ranibizumab Biosimilar in Neovascular Age-Related Macular Degeneration: A Phase 3, Double-Blind Comparative Study.

INTRODUCTION: The study aimed to evaluate comparability in terms of efficacy, safety and immunogenicity of Sun's ranibizumab biosimilar with reference ranibizumab in patients with neovascular age-related macular degeneration (nAMD). METHODS: This prospective, randomised, double-blind, two-group, parallel-arm, multicentre, phase 3 comparative study included patients with nAMD ≥ 50 years, randomised (in a 2:1 ratio) in a double-blind manner to receive 0.5 mg (0.05 mL) intravitreal injection of either Sun's ranibizumab or reference ranibizumab in the study eye every 4 weeks until week 16 (total of four doses). RESULTS: Primary endpoint results demonstrated equivalence in the proportion of patients who lost fewer than 15 letters from baseline best-corrected visual acuity (BCVA) to the end of week 16 (99% of patients in Sun's ranibizumab and 100% in reference ranibizumab; p > 0.9999), with the proportional difference (90% confidence interval) at -1% (-2.51, +0.61) lying within a pre-specified equivalence margin. Visual acuity improved by 15 or more letters in 43% of Sun's ranibizumab group and 37% of the reference ranibizumab group (p = 0.4267). The mean increase in BCVA was 15.7 letters in Sun's ranibizumab group and 14.6 letters in the reference ranibizumab group (p < 0.001 within both groups and p = 0.5275 between groups). The mean change in central macular thickness was comparable between groups (p = 0.7946). Anti-ranibizumab antibodies were found in one patient of the reference ranibizumab group, while neutralising antibodies were not found in any patients. Both products were well tolerated. CONCLUSION: Sun's ranibizumab biosimilar is found to be therapeutically equivalent to reference ranibizumab in patients with nAMD. There were no additional safety or immunogenicity concerns. TRIAL REGISTRATION: CTRI/2020/09/027629, registered on 07 September 2020.

Inter-Rater Reliability of Proliferative Diabetic Retinopathy Assessment on Wide-Field OCT-Angiography and Fluorescein Angiography.

Purpose: To assess inter-rater reliability in the detection of proliferative diabetic retinopathy (PDR) changes using wide-field optical coherence tomography angiography (WF-OCTA) versus fluorescein angiography (FA). Methods: This retrospective, cross-sectional study included patients with severe nonproliferative and PDR. Images were acquired with 12 × 12 mm WF-OCTA and FA with a 55° lens. Images were cropped to represent the exact same field of view. Qualitative (detection of neovascularization at the disc [NVD] and elsewhere [NVE], enlarged foveal avascular zone [FAZ], vitreous hemorrhage [VH]) and quantitative analyses (FAZ area, horizontal, vertical, and maximum FAZ diameter) were performed by 2 masked graders using ImageJ. Inter-rater reliability was calculated using unweighted Cohen's kappa coefficient (κ) for qualitative analyses and intraclass correlation coefficients (ICC) for quantitative analyses. Results: Twenty-three eyes of 17 patients were included. Inter-rater reliability was higher for FA than for WF-OCTA in qualitative analyses: κ values were 0.65 and 0.78 for detection of extended FAZ, 0.83 and 1.0 for NVD, 0.78 and 1.0 for NVE, and 0.19 and 1 for VH for WF-OCTA and FA, respectively. In contrast, inter-rater reliability was higher for WF-OCTA than for FA in the quantitative analyses: ICC values were 0.94 and 0.76 for FAZ size, 0.92 and 0.79 for horizontal FAZ diameter, 0.82 and 0.72 for vertical FAZ diameter, and 0.88 and 0.82 for maximum FAZ diameter on WF-OCTA and FA, respectively. Conclusions: Inter-rater reliability of FA is superior to WF-OCTA for qualitative analyses whereas inter-rater reliability of WF-OCTA is superior to FA for quantitative analyses. Translational Relevance: The study highlights the specific merits of both imaging modalities in terms of reliability. FA should be preferred for qualitative parameters, whereas WF-OCTA should be preferred for quantitative parameters.

Creatively tiding over the crisis.

Background: A patient with a retained intraocular metallic foreign body post-trauma was taken up for vitrectomy and intraocular foreign body removal. Unfortunately, the intraocular magnet was not available at the moment on the table! How a little bit of creativity and innovative thought helped us tide over this crisis is the content of this video. Purpose: To demonstrate magnetization of a metallic surgical instrument for temporary use in the event of unavailability of the intraocular magnet for intraocular foreign body removal. Synopsis: A ferromagnetic substance can be magnetized temporarily using an existing magnet. We obtained a general-purpose magnet and wrapped it in sterile plastic, using which we magnetized normal intraocular forceps and a Micro Vitreo Retinal (MVR) blade by giving about 20-30 strokes over the magnet in a single direction. This aligned the magnetic domains in the metal in a parallel fashion. These Do It Yourself (DIY)- magnetic instruments were then effectively utilized to remove the metallic intraocular foreign body. Highlights: The video showcases effectively harnessing the available resources and tiding over the dearth of a necessary instrument, with the right use of an innovative idea and some creativity!. Video link: https://youtu.be/QtRC-AK5FLU.

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.

The Masquerading Retinopathy of Revesz Syndrome.

Revesz syndrome is a rare telomeropathy characterized by bone marrow failure and exudative retinopathy. We report the case of a 2-year-old male child, initially treated with bilateral laser photocoagulation for retinopathy of prematurity. He developed exudative changes in the right eye, presumed to be Coats disease. Later, the left eye developed a total vitreous hemorrhage. Proliferative retinopathy was noted intraoperatively. Systemic features of bone marrow failure, growth retardation, and nail pigmentation were present. Genetic testing confirmed the diagnosis of Revesz syndrome. We describe our approach to diagnosis and surgical management of the case. [Ophthalmic Surg Lasers Imaging Retina 2022;53(6): 346-348.].

Acceptability of artificial intelligence-based retina screening in general population.

Purpose: A deep learning system (DLS) using artificial intelligence (AI) is emerging as a very promising technology in the future of healthcare diagnostics. While the concept of telehealth is emerging in every field of medicine, AI assistance in diagnosis can become a great tool for successful screening in telemedicine and teleophthalmology. The aim of our study was to assess the acceptability of AI-based retina screening. Methods: This was a prospective non-randomized study performed in the outpatient department of a tertiary eye care hospital. Patients older than 18 years who came for a regular eye check-up or a routine retina screening were recruited in the study. Fundus images of the posterior pole were captured on fundus on a phone camera (REMIDIOTM, India) with a built-in AI software (Netra.AI) that can identify normal versus abnormal retina. The patients were then given an 8-point questionnaire to assess their acceptance and willingness toward AI-based screening. We recruited 104 participants. Results: We found that 90.4% were willing for an AI-based fundus screening; 96.2% were satisfied with AI-based screening. Patients with diabetes (P = 0.03) and the male population (P = 0.029) were more satisfied with the AI-based screening. The majority (i.e., 97.1%) felt that AI-based screening gave them a better understanding of their eye condition and 37.5% felt that AI-based retina screening prior to a doctor's visit can help in routine screening. Conclusion: Considering the current COVID-19 pandemic situation across the globe, this study highlights the importance of AI-based telescreening and positive patient approach toward this technology.

Coats' disease - Prognostic factors for globe and vision salvage in children, a long-term experience.

PURPOSE: Coats' disease is associated with poor outcomes, and there are limited studies on long-term outcomes of Coats' disease. The purpose of our study is to identify various predictive factors to help in prognosticating the treatment outcomes in advanced Coats' disease in children. METHODS: This is a retrospective case series from a single tertiary eye care center of children (<18 years) diagnosed with coat's disease. Sixty-seven patients with Coat's disease were identified from the medical records from 2009 to 2020. Patients' demographic data, clinical presentation, stage, extent of involvement, detailed treatment history, clinical sequelae post-treatment (including complications and anatomical and functional outcomes) were noted. Binary logistic regression was performed to correlate the predictive factors for anatomical and functional improvement. RESULTS: Of the 67 patients, 51 eyes of 51 patients were included in the study. The male to female proportion was 2.2. Mean age at presentation was 4.98 ± 3.55 years (range: 2 months-15 years). Mean duration of follow-up was 31.53 ± 26.38 months. Overall, our globe salvage rate was 92.2%. We found that vitreoretinal fibrosis (P < 0.001), subretinal gliosis (P < 0.001), vitreous hemorrhage (P = 0.02), tractional or combined retinal detachment (P < 0.001), foveal scar (P < 0.006), and cataract (P < 0.001) to be important factors to affect the outcome. CONCLUSION: Advanced stage of presentation (stage 3B and above), diffuse involvement, cataract, vitreoretinal fibrosis (preretinal and subretinal), vitreous hemorrhage, tractional or combined retinal detachment, and anterior hyaloid proliferation are poor prognostic factors for globe salvage in advanced disease. Subretinal gliotic nodule or scar and lack of visual rehabilitation suggest poor functional outcomes.

Impact of systemic parameters before commencing anti-vascular endothelial growth factor therapy for diabetic macular edema - Pan-Indian survey of retina specialists.

PURPOSE: Intravitreal anti-vascular endothelial growth factor (VEGF) injection therapy has emerged as the mainstay of treatment in the management of diabetic macular edema (DME) today. Various systemic risk factors have to be considered before initiating anti-VEGF therapy. The aim of our study was to form a consensus on various systemic factors to consider before starting anti-VEGF therapy for DME. METHODS: A questionnaire was created and sent across to various retina specialists across India. A GoogleTM form with various questions pertaining to what systemic parameters would one consider before giving anti-VEGF therapy for DME was sent to each of them by email/WhatsAppTM/direct telephonic interview. RESULTS: Of the 650 retina specialists contacted, 322 responded to the questionnaire. There was no difference in responses between private and institutional practitioners. The majority would consider RBS (85%), HbA1c (61%), blood pressure (63%), and renal function (57%) as a routine before administering the anti-VEGF injection, while the majority would not consider hemoglobin (63%) or lipid profile (55%) of the patient as a routine practice prior to administering the injection. CONCLUSION: In our study, most VR specialists prefer to consider RBS, HbA1c, BP, and renal profile (creatinine) routinely prior to anti-VEGF injection. We suggest that it is important to consider blood pressure control, glycemic control, HbA1c, Hb, lipid profile, and renal profile (UACR, eGFR, and creatinine) prior to anti-VEGF therapy in all diabetic patients and to discuss the need for statins in patients with dyslipidemias with the physician.

A questionnaire-based assessment of Safe Eye Examination (SEE) technique.

PURPOSE: This study aims to assess the novel and innovative method of Safe Eye Examination (SEE) technique using the model eye for the purpose of teaching, training, and resident examination. METHODS: A questionnaire-based study (Descriptive Data) with 53 participants, including ophthalmology residents, fellows in various subspecialties, and trainee optometrists was used. In our study, we used the Reti Eye model, but instead of the usual retina template sheet, we used prominent pathological fundus photographs loaded into the model eye. The study participants were asked to view prominent pathological fundus images printed on a matte finish paper. A circular image was cut and was placed in the Reti Eye model. The candidates were made to perform indirect ophthalmoscopy with a + 20D lens and to fill up a Google image assessment scale questionnaire with characteristics, including pixelation, sharpness, contrast, reflexes, blotchy appearance, and diagnostic confidence, which were then analyzed and depicted. Association between categorical variables was analyzed using Fisher exact test and Chi-square test. A P value of less than 0.05 was considered statistically significant. All data were analyzed with a statistical software package (SPSS, Version 16.0 for Windows). RESULTS: The number of positive responses (>90%) obtained for the pixelation, sharpness, contrast, reflexes, blotchy appearance, and diagnostic confidence of the image viewed were statistically more significant than the negative responses (P < 0.05). CONCLUSION: The SEE technique of using the model eye can be incorporated for teaching, training, and skill assessment in the examinations in these difficult times of COVID-19 (coronavirus disease 2019) pandemic.

Comparison of standard and "innovative wide-field" optical coherence tomography images in assessment of vitreoretinal interface in proliferative diabetic retinopathy: A pilot study.

Purpose: To compare the standard and "innovative wide-field" optical coherence tomography images in assessment of vitreoretinal interface in proliferative diabetic retinopathy. Methods: Fifty consecutive eyes of 25 patients with proliferative diabetic retinopathy underwent 12 × 12 mm radial swept source-optical coherence tomography (OCT) imaging using standard technique and innovative wide-field (+90D) technique. The image expansion ratio was calculated using Image J software. Results: Out of the 50 eyes, only in four eyes with +90 D were minimally misaligned or were having quality less than grade 2 as compared to standard OCT. The mean age group was 51 ± 4.5 years. The expansion ratio (scan length) increased by a factor of 1.65 ± 0.67 when obtained using +90 D technique. Conclusion: Innovative wide-field technique provides us with the widest of available OCT scans with the presently available machine and the software.