Google Lens: A potential cost-effective screening tool for diabetic retinopathy

Background: Diabetic retinopathy (DR) is a major, sight-threatening complication of diabetes mellitus. Blindness from DR can be prevented by successful and proactive screening. However, DR is screened in less than half of the patients because of barriers in availability, affordability, accessibility, and awareness. Although artificial intelligence (AI)-based algorithms are being evaluated for DR screening, they have limitations of infrastructure, accessibility, training, and manpower cost. Therefore, simpler and more practical DR screening tools should be explored. Hypothesis: Google Lens, an easily available, vision- and AI-based application in most smartphones, is a potential tool for cost-effective DR screening. It recognises images through a visual analysis based on neural networking. Thus, it can recognize retinal disorders, such as DR, in images. The development and adoption of Google Lens-based DR screening would have several advantages over the conventional hospital/specialist/healthcare facility-based approach, including widespread accessibility, acceptable accuracy, reduction in the direct cost of healthcare for patients with diabetes mellitus, and active patient participation in self-care. Conclusions: DR screening, detection, and grading using Google Lens is a feasible and effective option. Despite current limitations, it could transform DR screening from a costly, hospital- and expert-based method to a cost-effective, self-applicable, and home-based one. However, diagnostic accuracy studies comparing the index test with Google Lens-based screening are required to determine the usability and validity of this proposed screening tool for DR

Hypo-angiogenesis: A possible pathological factor in the development of dry age-related macular degeneration and a novel therapeutic target

Background: Angiogenesis causes severe vision loss in patients with exudative or wet forms of age-related macular degeneration (AMD). The pathogenesis involves upregulation of several proangiogenic factors, particularly the vascular endothelial growth factor (VEGF). Contrary to the pathogenesis of exudative AMD, molecular events leading to the development of dry AMD remain unclear. Dry AMD is characterized by loss of the retinal pigment epithelium (RPE). The mechanism that triggers RPE cell loss remains unclear. Choriocapillaris development is absent in mice with RPE-specific deletion of VEGF. Moreover, in later life, background VEGF secretion promotes the survival of the RPE and maintains choriocapillaris integrity. Hypothesis: We hypothesized that reduced synthesis of VEGF (hypo-angiogenesis) or abnormalities in its receptors, VEGF receptor-1 (VEGFR1) and VEGFR2, may be involved in the pathogenesis of non-exudative AMD or dry AMD. If the concept of hypo-angiogenesis as a driver for dry AMD is proven, treatment with VEGF or induction of angiogenesis could be considered. Similar attempts at therapeutic angiogenesis have been actively investigated in cardiac and limb ischemia. Conclusions: The reasons for a patient developing exudative AMD or dry AMD remain poorly understood. Nevertheless, targeting increased VEGF production in patients with exudative AMD using anti-VEGF drugs is highly efficacious in preserving vision. Similarly, dry AMD may be a manifestation of reduced VEGF synthesis (hypo-angiogenesis) and subsequent decreased RPE cell survival. Experimental studies exploring the possibility of reduced VEGF secretion and/or increased receptor resistance/abnormality could pave the way for clinical trials of angiogenesis to treat dry AMD

Hypothetical proposal for the course of retinal blood vessels in the posterior pole—description and its clinical implications

Background: Branch retinal vein occlusion (BRVO) is the second-most common retinal vascular disorder. Arteriosclerotic changes at the site of obstruction and hemodynamic turbulence within the vessels are considered risk factors. Overcrossing of the vein by an artery has traditionally been considered to increase the risk of BRVO. Recent studies using optical coherence tomography and optical coherence tomography angiography have suggested a higher prevalence of vein-over-artery crossings in this disease. Nevertheless, uncertainty persists as to why some patients, even those with the same disease duration, have varying degrees of venous dilation and develop sufficient collaterals, while others develop substantial ischemia and its sequelae. Hypothesis: Herein, it is hypothesized that because retinal blood vessels are transparent, tubular, and collapsible conduits coursing over a hollow spherical surface, the changes related to AV crossings over the entire course of a vessel, rather than at any single isolated crossing, could contribute to the risk, natural progression, and outcomes of BRVO. The study analyzed color fundus photographs from two image datasets. The first dataset comprised 100 randomly selected images from the author’s own collection at the Rajendra Prasad Center for Ophthalmic Sciences. The second dataset comprised 100 images from the MESSIDOR database; three images were excluded owing to poor focus. Using 394 observations from 197 retinal photographs, four distinct patterns of AV crossing along the course of blood vessels were recognized: (A and B) wicker basket, (C) straight, (D) widely spaced, and (E) indeterminate. The percentages of tight wicker, loose wicker, straight, widely spaced, and indeterminate patterns in the two image sets were 19% (38/200) and 16.5% (32/194), 22.5% (45/200) and 27.8% (54/194), 16.5% (33/200) and 15.5% (30/194), 22.5% (45/200) and 28.4% (55/194), and 19.5% (39/200) and 11.9% (23/194), respectively. Hence, the wicker basket pattern was the most common AV crossing pattern in both image sets. Conclusions: The wicker basket pattern may provide structural stability and aid in maintaining pressure gradients within the retinal vascular bed. This observation of variable AV relationships at consecutive crossings may improve our understanding of the pathogenesis, natural history, and outcomes of BRVO. Future longitudinal studies including patients at risk of BRVO, or retrospective analyses of patients with BRVO who had ophthalmic examinations and archived fundus images before the vascular event, should verify the relevance of these observed vascular patterns

CFD simulation using FLUENT and RANS3D - A validation exercise

The present work involves two-dimensional numerical simulation of three benchmark problems like (i) Laminar flow in a lid driven cavity (ii) Turbulent flow past a backward facing step and (iii) turbulent flow past NACA0012 aerofoil, using in-house flow solution code RANS3D and the commercially available FLUENT code. The results obtained using these codes are compared with the available measurement data and/or other computations

Optical Coherence Tomography Angiography of Early Stage 1a Retinal Hemangioblastoma in Von-Hippel-Lindau

Von-Hippel-Lindau (VHL) syndrome is characterized by focal vasoproliferative tumors of retinal capillaries called retinal capillary hemangioblastomas (RCH). These tumors are initially small and can be easily missed if not looked for carefully. As they grow, these tumors are more demanding to treat and hence the importance of detecting them early and treating them. Herein, we describe and review the optical coherence tomography angiography (OCTA) of the early-stage lesion, which suggested the involvement of superficial and a deeper retinal capillary plexus. In addition, to helping us detect these lesions earlier, OCTA may also help to understand the in vivo changes occurring at an earlier phase

Giant Idiopathic Angioid Streaks

Purpose: To present a case of gigantic idiopathic angioid streaks. Case Report: A young male presented with macular choroidal neovascular membrane (CNVM) and peripheral retinal hemorrhages secondary to angioid streaks. Swept source optical coherence tomography (SSOCT) and ultrawide field imaging were performed. The latter revealed extension of the angioid streaks up to the equator in both eyes. SSOCT showed breaks in the retinal pigment epithelium-Bruch’s membrane complex in the area of peripheral retinal hemorrhages. The patient was extensively worked up for systemic associations, and the only significant finding was a long history of steroid abuse in the past. Conclusion: Advanced imaging techniques helped to diagnose angioid streaks in this patient. The possible role of steroid abuse in accentuating the presentation of angioid streaks may be explored further

Scleral abscess following posterior subtenon triamcinolone acetonide injection for diabetic macular edema

AbstractA 65-year-old male with uncontrolled diabetes, received posterior subtenon triamcinolone (PST) injection in the right eye for diabetic macular edema. Two days following PST, he developed scleral abscess at the injection site. The Gram stain showed Gram positive cocci in clusters. He responded favorably with systemic control of diabetes, topical concentrated cefazolin, concentrated tobramycin, and intravenous antibiotics. Possibility of infective complications should be considered when using periocular steroids, especially in diabetics. Strict control of diabetes and aggressive systemic antibiotics favor rapid healing in such cases

Ultrasound biomicroscopy findings of 25 G Transconjuctival sutureless (TSV) and conventional (20G) pars plana sclerotomy in the same patient

BACKGROUND: Transconjunctival Sutureless Vitrectomy (TSV) is a recent advancement in vitreo-retinal surgical techniques involving the use of 25 G instruments through self-sealing sclerotomies. It has been hypothesized that there may be less chance of vitreous and retinal herniation in the scleral wound as compared to conventional sclerotomy incision. However there are no reports on differences in 20 gauge and 25 gauge sclerotomies using ultrasound biomicroscopy (UBM). We report herein the differences in sclerotomies undertaken with 20 gauge (G) and 25 gauge instruments in the same patient. CASE PRESENTATION: Ultrasound biomicroscopy of the sclerotomy sites was done in the same patient in whom both 20 G and 25 G sclerotomies had to be constructed during pars plana vitrectomy and the differences were studied. On day 2, we observed a wide gape at the site that had been enlarged using a 20G MVR blade. In contrast, the other two sites made transconjunctivally using the 25G trocar showed only a mild gape. Significant gape continued to persist at the subsequent evaluations on day 7 and day 14 only at the port, which had been enlarged. CONCLUSION: Healing of a 25 G sclerotomy is expectedly quite rapid, with inability to detect the site of sclerotomy in a short duration of 2 weeks post-operatively. This is as opposed to conventional sclerotomies, which might take up to 6–8 weeks post-operatively for complete opposition

Comparative evaluation of diode laser versus argon laser photocoagulation in patients with central serous retinopathy: A pilot, randomized controlled trial [ISRCTN84128484]

BACKGROUND: To evaluate the efficacy of diode laser photocoagulation in patients with central serous retinopathy (CSR) and to compare it with the effects of argon green laser. METHODS: Thirty patients with type 1 unilateral CSR were enrolled and evaluated on parameters like best corrected visual acuity (BCVA), direct and indirect ophthalmoscopy, amsler grid for recording scotoma and metamorphopsia, contrast sensitivity using Cambridge low contrast gratings and fluorescein angiography to determine the site of leakage. Patients were randomly assigned into 2 groups according to the statistical random table using sequence generation. In Group 1 (n = 15), diode laser (810 nm) photocoagulation was performed at the site of leakage while in Group 2 (n = 15), eyes were treated with argon green laser (514 nm) using the same laser parameters. Patients were followed up at 4, 8 and 12 weeks after laser. RESULTS: The mean BCVA in group 1 improved from a pre-laser decimal value of 0.29 ± 0.14 to 0.84 ± 0.23 at 4 weeks and 1.06 ± 0.09 at 12 weeks following laser. In group 2, the same improved from 0.32 ± 0.16 to 0.67 ± 0.18 at 4 weeks and 0.98 ± 0.14 at 12 weeks following laser. The improvement in BCVA was significantly better in group 1 (p < 0.0001) at 4 weeks. At 4 weeks following laser, all the patients in group1 were free of scotoma while 6 patients in group 2 had residual scotoma (p < 0.05). The mean contrast sensitivity in group 1 improved from pre-laser value of 98.4 ± 24.77 to 231.33 ± 48.97 at 4 weeks and 306.00 ± 46.57 at 12 weeks following laser. In group 2, the same improved from 130.66 ± 31.95 to 190.66 ± 23.44 at 4 weeks and 215.33 ± 23.25 at 12 weeks. On comparative evaluation, a significantly better (p < 0.001) improvement was noted in group 1. CONCLUSION: Diode laser may be a better alternative to argon green laser whenever laser treatment becomes indicated in patients with central serous retinopathy in terms of faster visual rehabilitation and better contrast sensitivity. In addition, diode laser also has the well-recognized ergonomic and economic advantages