Diabetic retinal neurodegeneration as a form of diabetic retinopathy.

PURPOSE: To review the evidence supporting diabetic retinal neurodegeneration (DRN) as a form of diabetic retinopathy. METHOD: Review of literature. RESULTS: DRN is recognized to be a part of retinopathy in patients with diabetes mellitus (DM), in addition to the well-established diabetic retinal vasculopathy (DRV). DRN has been noted in the early stages of DM, before the onset of clinically evident diabetic retinopathy. The occurrence of DRN has been confirmed in animal models of DM, histopathological examination of donor's eyes from diabetic individuals and assessment of neural structure and function in humans. DRN involves alterations in retinal ganglion cells, photoreceptors, amacrine cells and bipolar cells, and is thought to be driven by glutamate, oxidative stress and dysregulation of neuroprotective factors in the retina. Potential therapeutic options for DRN are under evaluation. CONCLUSIONS: Literature is divided on the temporal relation between DRN and DRV, with evidence of both precedence and simultaneous occurrence. The relationship between DRN and multi-system neuropathy in DM is yet to be evaluated critically.

Predictors of visual outcome in post-fever retinitis: a retrospective analysis.

PURPOSE: To identify the predictors of final visual outcome in cases with post-fever retinitis (PFR). METHODS: This is a retrospective study of cases with diagnosis of post-fever retinitis. Colour fundus photograph and optical coherence tomography (OCT) parameters at presentation and final visit were analysed. Various factors at presentation [age, systemic illness, best-corrected visual acuity (BCVA), area of retinitis and hard exudates, OCT parameters], at final visit (OCT parameters) and the treatment modalities used were correlated with BCVA at final visit. RESULTS: Twenty-four eyes of 16 patients with PFR were included in the study. Median BCVA at presentation was 6/60 and at final visit was 6/9. By multiple linear regression after adjusting for other variables, for every 1 unit increase in height of subretinal fluid (SRF) at fovea at presentation, the value of final BCVA decreased by 0.001 unit. For every 1 unit increase in extent of ellipsoid zone (EZ) loss and subfoveal deposit height, the value of final BCVA decreased by 0.0001 unit and 0.004 unit, respectively. The baseline OCT parameters that had negative correlation with final BCVA included central macular thickness (r: - 0.5182, p: 0.02), maximum SRF height (r: - 0.5539, p < 0.01) and SRF height at fovea (r: - 0.582, p < 0.01). The OCT parameters at final visit which had a negative correlation with final BCVA included disorganisation of retinal inner layers (DRIL) within 1000 microns from centre of fovea (r: - 0.6494, p < 0.01), height of subfoveal deposit (r: - 0.7627, p < 0.01), horizontal extent of subfoveal deposit (r: - 0.6695, p < 0.01) and extent of EZ loss (r: - 0.8216, p < 0.01). CONCLUSION: Height of SRF at presentation, extent of EZ loss and subfoveal deposit height at final visit were associated with poor final BCVA in PFR.

Diabetic Retinopathy Screening Using Smartphone-Based Fundus Imaging in India.

PURPOSE: Early detection and treatment can prevent irreversible blindness from diabetic retinopathy (DR), which is the leading cause of visual impairment among working-aged adults worldwide. Some 80% of affected persons live in low- and middle-income countries, yet lack of resources has largely prevented DR screening implementation in these world regions. Smartphone-based fundus imaging (SBFI) allows for low-cost mobile fundus examination using an adapter on a smartphone; however, key aspects such as image quality, diagnostic accuracy, and comparability of different approaches have not been systematically assessed to date. DESIGN: Evaluation of diagnostic technology. PARTICIPANTS: A total of 381 eyes of 193 patients with diabetes were recruited at outreach eye clinics in South India. METHODS: We compared 4 technically different approaches of SBFI (3 approaches based on direct and 1 approach based on indirect ophthalmoscopy) in terms of image quality and diagnostic accuracy for DR screening. MAIN OUTCOME MEASURES: Image quality (sharpness/focus, reflex artifacts, contrast, and illumination), field-of-view, examination time, and diagnostic accuracy for DR screening were analyzed against conventional fundus photography and clinical examination. RESULTS: Smartphone-based fundus imaging based on indirect ophthalmoscopy yielded the best image quality (P < 0.01), the largest field-of-view, and the longest examination time (111 vs. 68-86 seconds, P < 0.0001). Agreement with the reference standard (Cohen's kappa 0.868) and sensitivity/specificity to detect DR were highest for the indirect SBFI approach (0.79/0.99 for any DR and 1.0/1.0 for severe DR, 0.79/1.0 for diabetic maculopathy). CONCLUSIONS: Smartphone-based fundus imaging can meet DR screening requirements in an outreach setting; however, not all devices are suitable in terms of image quality and diagnostic accuracy. Smartphone-based fundus imaging might aid in alleviating the burden of DR screening in low- and middle-income countries, and these results will allow for a better selection of SBFI devices in field trials for DR screening.

Patterns of uveitis at the Apex Institute for Eye Care in India: Results from a prospectively enrolled patient data base (2011-2013).

The purpose of the study was to identify the clinical and etiological profile of uveitis at the apex institute for eye care in India. This is a prospective, prevalence study. 980 consecutive patients with uveitis referred to uvea clinic, Dr. RP Centre for Ophthalmic Sciences (Ophthalmology division, All India Institute of Medical Sciences). Demographic data of each patient were noted and a thorough ocular examination including slit lamp examination and dilated fundus evaluation was carried out. OCT and fluorescein angiography were undertaken whenever indicated. Uveitis was classified based on the anatomic location of inflammation (IUSG classification). Relevant serological and radiological investigations were obtained based on systemic symptomatology, and if the uveitis was recurrent (even in the absence of systemic symptoms). The presence of a systemic disease was confirmed by obtaining an internist consultation. The main outcome measures include pattern of uveitis according to anatomical classification and the etiology. Out of 980 patients with uveitis, 413 (42.14 %) patients had anterior uveitis, 131 (13.36 %) had intermediate uveitis, 165 (16.83 %) had posterior uveitis, 91 (9.2 %) had panuveitis, 47 (4.7 %) had retinal vasculitis, 22 (2.24 %) had scleritis, 17 (1.7 %) had masquerade syndromes, 8 (0.8 %) had keratouveitis, 22 (2.24 %) had sclerokeratouveitis, 19 (1.9 %) had endophthalmitis and 45 (4.5 %) had other causes of inflammation including trauma and intraocular surgery. Out of all uveitic patients definite etiological correlation could be made out in 225 (23 %) patients; thus 77 % were categorised as idiopathic. Only 9 % of all patients were found to have uveitis with an infectious etiology. Amongst infectious causes of uveitis tuberculosis was the leading cause, accounting for sixty percent of all infectious uveitis (approximately 5 % of overall uveitis). Non-infectious uveitis etiology accounted for more than 90 % of all cases with ankylosing spondylitis being the most common followed by sarcoidosis and juvenile rheumatoid arthritis. Amongst known uveitic syndromes serpiginous like choroidopathy was the most common and was followed by acute posterior placoid pigmented epitheliopathy and Fuch's heterochromic iridocyclitis. Infection, including tuberculosis, is an infrequent cause of uveitis in the study population. Multicentric, collaborative efforts are required to improve levels of clinical evidence and evolve consensus in establishing stringent guidelines for labelling uveitis as being of infectious etiology.

Exudative vascular anomalous complex-like lesion of the peripapillary area.

PURPOSE: Perifoveal exudative vascular anomalous complex is an uncommon retinal lesion of idiopathic origin characteristically described as an isolated, aneurysmal lesion of the perifoveal region. We report an unusual presentation of an exudative vascular anomalous complex-like lesion affecting the peripapillary area. CASE DESCRIPTION: A 69-year-old diabetic woman presented with blurred vision in her left eye for two months. Fundus examination of the left eye showed a small, reddish-orange lesion just supratemporal to the optic disc with perifoveal hard exudates and retinal thickening. Fundus fluorescein angiography demonstrated a peripapillary hyperfluorescent lesion with minimal leakage. Ocular coherence tomography showed an oval structure extending throughout the outer and inner plexiform and nuclear layers with a hyper-reflective wall accompanied by subfoveal and intraretinal fluid suggestive of an eVAC-like lesion in the peripapillary area. Intravitreal anti-vascular endothelial growth factor injection was given, and the lesion persisted even three weeks after the injection. Later, focal laser photocoagulation of the aneurysmal lesion was done. At 6 weeks follow-up, a complete resolution of the aneurysmal lesion with a marked decrease in retinal edema and an improvement of the visual acuity was observed. CONCLUSION: Exudative intraretinal aneurysmal lesions can occur in areas other than perifoveal area. OCT is an useful investigation for knowing their characteristics and the response to treatment. These aneurysmal lesions irrespective of their location can be called by the name eVAC-like or more aptly retinal capillary macro aneurysms (RCM).

Role of multimodal imaging in coexistent pachychoroid spectrum disease.

PURPOSE: To describe the role of multimodal imaging in a case of coexisting pachychoroid diseases. CASE DESCRIPTION: We report a case of a 43 year old lady with coexistent central serous chorioretinopathy (CSC) and pachychoroid neovasculopathy (PNV) in the same eye which posed a diagnostic challenge. Fundus examination showed neurosensory detachment (NSD) at the macula along with retinal pigment epithelial alterations. Optical coherence tomography (OCT) showed a shallow pigment epithelial detachment and OCT angiography showed the presence of vascular network in outer retina choriocapillaris slab suggesting a diagnosis of PNV. However, fundus fluorescein angiography (FFA) showed a smoke stack leak adjacent to the site of vascular network. Focal laser photocoagulation of the leaky point resulted in resolution of NSD pointing towards a diagnosis of CSC. CONCLUSION: This case emphasises the role of multimodal imaging in identifying the source of leak in coexistent pachychoroid spectrum diseases.

Role of optical coherence tomography angiography in retinal tumors: A narrative review.

Intraocular tumors constitute a small subset of cases in ophthalmologic practice. Proper diagnosis of intraocular tumors is crucial because some pose threat to vision and life, while others may indicate underlying systemic disorders. Intraocular tumors comprise benign and malignant lesions affecting the retina, choroid, optic disc, iris, and ciliary body. Retinal tumors can be classified as vascular, neural, glial, and retinal pigment epithelial tumors. Optical coherence tomography angiography (OCTA) is a noninvasive imaging modality employed in diagnosis and management of retinal and choroidal vascular diseases, and has enhanced our knowledge in better understanding of the vascular physiology and pathology. Multiple case reports and small series evaluating the role of OCTA in retinal tumors are published in literature. OCTA helps in better understanding of the vascularity of intraocular tumors. In addition to this, OCTA has its role in clinical practice. It helps in identification of small retinal capillary hemangioblastoma (RCH), assessment of treatment response, and identification of tumor recurrence in RCH. It aids in identification of retinal astrocytic hamartoma missed on clinical examination and differentiating retinal astrocytic hamartoma and presumed solitary circumscribed retinal astrocytic proliferation. It helps in assessment of risk of tumor recurrence in retinoblastoma. It helps in differentiating tumors of retinal pigment epithelium (RPE) origin from pigmented tumors of the choroid. It also helps in detection of choroidal neovascular membrane in combined hamartoma of the retina and RPE.

Efficacy of peribulbar bupivacaine at the end of surgery in the management of postoperative pain after scleral buckling.

PURPOSE: To compare the efficacy of peribulbar bupivacaine with routine analgesics for pain management in patients undergoing scleral buckling. METHODS: In total, 72 patients undergoing scleral buckling or combined with vitrectomy were enrolled in this study. Patients were randomized into two groups, each containing 36 patients. Patients of group A received 5 mL of bupivacaine (0.5%) injection at the end of surgery, whereas group B patients received routine analgesics. The postoperative pain score was assessed in the first 24 hours of the postoperative period with the visual pain analog score. RESULTS: Maximum postoperative pain scores were lower in patients receiving bupivacaine block (median: 3; range: 3-7) than in the control group (median: 5; range: 3-9). Pain scores in group A were lower than in the control group both at 3 and 6 hours after surgery, which was statistically significant ( P < 0.001). Four patients in group A and 17 patients in group B needed additional analgesia in the first 24 hours of the postoperative period. In addition, two patients in group A and seven patients in group B experienced episodes of nausea and vomiting in the first 24 hours of surgery. CONCLUSION: The results of this study suggest that the postoperative experience of patients undergoing scleral buckling surgery can be made more comfortable with the use of bupivacaine block at the end of surgery.

Evaluation of agreement in macular vascular density measured by different protocols: 4.5 mm × 4.5 mm and 6 mm × 6 mm.

PURPOSE: To evaluate the agreement in the macular vascular density (MVD) measured by two protocols: 4.5 mm × 4.5 mm and 6 mm × 6 mm. DESIGN: Cross-sectional observational study. METHODS: Healthy volunteers between the age group of 19 and 39 years were recruited. Topcon DRI OCT Triton plus (Topcon Corporation, Tokyo, Japan) was used to acquire the fovea-centered optical coherence tomography angiography (OCTA) image using two protocols: 4.5 mm × 4.5 mm and 6 mm × 6 mm. MVD was measured by the manufacturer software in the superficial capillary plexus slab in five regions: central, superior, nasal, inferior, and temporal subfields of early treatment diabetic retinopathy study grid in each protocol. RESULTS: The study included 79 eyes of 40 healthy volunteers. The difference in the mean MVD between two protocols was 3.84% in right eye and 4.2% in left eye in central subfield, 0.93% in right eye and 1.13% in left eye in superior subfield, 0.06% in right eye and 1.45% in left eye in nasal subfield, 1.65% in right eye and 0.7% in left eye in inferior subfield, 0.4% in right eye and 0.54% in left eye in temporal subfield. The measurements were significantly higher in 6 mm × 6 mm in central subfield in both the eyes and in nasal field in the left eye. Whereas, the measurements were significantly higher in 4.5 mm × 4.5 mm in superior and inferior subfield in both the eyes and in temporal subfield in the left eye. CONCLUSION: The protocols should not be used interchangeably and it is necessary to include recommendation of the field of view to measure MVD while standardizing OCTA reporting.

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.

Fundus Autofluorescence in Posterior and Panuveitis-An Under-Estimated Imaging Technique: A Review and Case Series.

Fundus autofluorescence (FAF) is a prompt and non-invasive imaging modality helpful in detecting pathological abnormalities within the retina and the choroid. This narrative review and case series provides an overview on the current application of FAF in posterior and panuveitis. The literature was reviewed for articles on lesion characteristics on FAF of specific posterior and panuveitis entities as well as benefits and limitations of FAF for diagnosing and monitoring disease. FAF characteristics are described for non-infectious and infectious uveitis forms as well as masquerade syndromes. Dependent on the uveitis entity, FAF is of diagnostic value in detecting disease and following the clinical course. Currently available FAF modalities which differ in excitation wavelengths can provide different pathological insights depending on disease entity and activity. Further studies on the comparison of FAF modalities and their individual value for uveitis diagnosis and monitoring are warranted.

Subhyaloid hypopyon as a diagnostic cue in syphilitic necrotizing retinitis.

PURPOSE: To describes one case of syphilitic necrotizing retinitis and one case of presumed syphilitic necrotizing retinitis with presence of subhyaloid hypopyon. CASE DESCRIPTION: We report two cases of necrotizing retinitis, which were noted to have yellow boat-shaped lesions at the inferior edge of retinitis resembling subhyaloid hypopyon. The subhyaloid location was confirmed on optical coherence tomography in one case. Both the cases were positive for venereal disease research laboratory test (VDRL) and Treponema pallidum hemagglutination (TPHA). But in one case, polymerase chain reaction (PCR) of the aqueous humor was positive for Pseudomonas aeruginosa and responded well to piperacillin. As piperacillin is effective against Pseudomonas and the efficacy of piperacillin in the management of syphilis is not studied, we may have to consider it as a case of presumed syphilitic retinitis. DISCUSSION: Subhyaloid hypopyon is an uncommon presentation and is reported in two cases of syphilitic necrotizing retinitis in literature. Severe infection and necrosis confined to the inner retina leads to collection of white blood cells and necrotic material in the subhyaloid space and would settle down resulting in subhyaloid hypopyon. Two cases of subhyaloid hypopyon reported in literature and 2 cases reported in our article are syphilitic retinitis and is not reported in other entities. CONCLUSION: It is possible that subhyaloid hypopyon may serve as a diagnostic cue in syphilitic necrotizing retinitis.

Laser photocoagulation of a hypofluorescent perifoveal exudative vascular anomalous complex/capillary macroaneurysm.

PURPOSE: To report successful treatment of a hypofluorescent perifoveal exudative vascular anomalous complex (PEVAC)/capillary macroaneurysm. CASE DESCRIPTION: A 63 year old healthy gentleman had a perifoveal isolated aneurysmal lesion with white rim. Optical coherence tomography (OCT) showed cystoid macular edema (CME) with neurosensory detachment. The aneurysmal lesion was seen in the inner retina as a hyperreflective intraretinal structure with a heterogenous lumen suggestive of PEVAC/capillary macroaneurysm. OCT angiography showed a capillary loop and a slightly hyperreflective lesion at the tip of the loop in the superficial capillary plexus slab. Minimal reduction in edema was noted following one dose of intravitreal triamcinolone (2 mg). Fundus fluorescein angiography performed at 6 weeks demonstrated the capillary loop, but the aneurysmal lesion remained hypofluorescent with no definite leak in the late phase. Few perifoveal microaneurysms were seen in both the eyes. Six weeks later, focal laser photocoagulation of the aneurysmal lesion was performed, which resulted in complete resolution of macular edema at 1 month. There was no recurrence of macular edema till his recent follow up, which is 4 month post laser. DISCUSSION: PEVAC is typically described as unifocal lesion and is not associated with other retinal vascular abnormalities. But in this case, in addition to the lesion, perifoveal microaneurysms were seen in both the eyes. Despite the absence of leak on fundus fluorescein angiography, targeted focal laser photocoagulation resulted in complete resolution of macular edema at 1 month. CONCLUSION: Laser photocoagulation would be helpful even in hypofluorescent PEVAC/capillary macroaneurysms.

Targeted laser photocoagulation of larger capillary aneurysms with rim in diabetic macular edema.

This is a retrospective series of five eyes of four cases with diabetic macular edema (DME) secondary to large capillary aneurysms. Larger capillary aneurysms were identified noninvasively based on the presence of white rim in color photograph. On optical coherence tomography (OCT), the larger capillary aneurysms were seen as vertically oval structures with heterogeneous lumen and hyperreflective margin. Two of the four eyes were treated with intravitreal therapy with poor response before considering laser photocoagulation. In one eye, laser photocoagulation was considered as primary therapy in view of the poor response to intravitreal therapy in the fellow eye. In one eye, intravitreal steroid with prompt laser was considered. In one eye, laser was considered as primary therapy. Complete obliteration of the capillary lumen was noted on OCT in all the five eyes after laser photocoagulation. Complete resolution of macular edema was noted in all the five eyes with no recurrence over a follow-up period of 4-18 months. DME secondary to larger capillary aneurysms responds well to targeted laser photocoagulation. These larger capillary aneurysms can be identified on clinical examination and color photograph by the presence of white rim and can be confirmed on OCT.

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.

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.

"HOURGLASS COLOBOMA": A CASE REPORT AND REVIEW OF ETIOPATHOGENESIS.

PURPOSE: To report a rare case of multiple fundal colobomata and to review the possible etiopathogenic factors involved in its genesis. METHOD: Case report. RESULT: A 21-year-old myopic lady was noted to have 2 fundal colobomata-one in the inferior and the other in superior hemisphere of globe in a mirror-image fashion resembling an "hourglass" in the right eye and a typical Type 3 coloboma in the left eye. The iris was normal in both the eye. Multiple fundal colobomata have not been described in the literature. The presence of "accessory embryonic fissure" in the developing eyeball is the only probable mechanism that can explain this presentation. This case is an evidence for the possibility of presence of accessory embryonic fissure in developing eyeball in human. The eponym "hourglass coloboma" or "mirror-image colobomata" best describes this condition. CONCLUSION: This report of multiple fundal colobomata is the first of its kind. This case is an evidence for possibility of presence of accessory embryonic fissure in developing eyeball in human.