Comparison of ganglion cell layer thickness and pattern electroretinography among glaucoma suspects and healthy controls.

PURPOSE: To evaluate the difference in ganglion cell layer (GCL) thickness on optical coherence tomography (OCT) and waveform on pattern electroretinography (PERG) among glaucoma suspects and healthy controls. METHODS: An analytical, cross-sectional study was done on 100 eyes of 50 subjects, equally divided in the glaucoma suspect and control group. Subjects with an asymmetrically increased vertical cup-to-disc ratio and without any perimetric change were taken as suspects, and subjects with normal findings were taken as controls. GCL thickness was evaluated on spectral domain OCT at 3 mm, 3.45 mm, and 6 mm centering the foveola, and P50, N95 wave forms were recorded according to the standard PERG protocol. RESULTS: In this study, we observed that the average GCL thickness is significantly less in glaucoma suspects at 3.45 mm (p = 0.045) and at 6 mm (p < 0.001) circle zone. On PERG, P50 amplitude was significantly low in glaucoma suspects in comparison to controls (p = 0.007). There was significantly increased implicit time for both P50 and N95 in glaucoma suspects (p < 0.001). For N95 amplitude, a non-significant (p = 0.127) difference was observed among the two groups. At 3.45 mm, average GCL thickness showed a weak negative correlation with N95 implicit time (r = - 0.286, p = 0.044), a weak positive correlation with P50 amplitude (r = 0.349, p = 0.013), and at 6 mm, a weak positive correlation with P50 amplitude (r = 0.311, p = 0.028) in glaucoma suspects. CONCLUSIONS: Analysing GCL thickness can help in the structural assessment of preperimetric glaucoma. PERG can be used as a valuable tool for the detection of ganglion cell dysfunction, even before cell loss.

Visual Outcomes in Malignant Hypertensive Retinopathy Cases: A Clinical and Spectral Domain Optical Coherence Tomography Study.

Objective The objective is to correlate visual outcomes in malignant hypertensive retinopathy with changes in systemic causative factors and spectral domain optical coherence tomography (SD OCT) morphologic parameters. Materials and methods This is a prospective observational study including patients presenting within two weeks of acute rise of systolic blood pressure (SBP) ≥ 180 mm Hg or diastolic blood pressure (DBP) ≥ 120 mm Hg and with posterior segment involvement in both eyes. Baseline SBP, DBP, mean arterial pressure (MAP), best corrected visual acuity (BCVA), and SD OCT parameters such as central macular thickness (CMT), subfoveal choroidal thickness (SCT), and sub-retinal fluid (SRF) height were measured at presentation and followed monthly up to three months. These variables at baseline and three months were compared and correlated. Results Thirty-three patients (66 eyes) having malignant hypertension were included in the study. Diverse clinical presentations noted among patients were optic disc edema, hard exudates in the macula, peripapillary splinter hemorrhage, cotton wool spots, Elschnig spots, exudative retinal detachment, optic neuropathy, and severe exudative retinopathy. SD OCT shows hyperreflective dots and intraretinal fluid with or without SRF. At three months, the mean SBP, DBP, MAP, CMT, SRF, and SCT all decreased significantly from baseline (p<0.001). Changes in SBP, DBP, MAP, and SCT correlated significantly with changes in BCVA (p<0.001). Conclusion In malignant hypertensive retinopathy, macular edema with SRF is the major cause of mild-to-moderate decrease BCVA at presentation, but macular ischemia, exudative RD, and optic neuropathy can cause a significant decrease in vision. A decrease in SBP, DBP, MAP, and SCT correlate significantly with visual outcomes.

Survival benefit of exenteration in COVID-19-associated rhino-orbital mucormycosis.

PURPOSE: There has been a sudden increase in the number of rhino-orbital mucormycosis cases, primarily affecting patients recovering from COVID-19 infection. The local health authorities have declared the current situation an epidemic. In this study, we assess the role of exenteration in preventing disease progression and improving survival in patients with rhino-orbital mucormycosis. METHODS: The patients undergoing exenteration were grouped into the exenteration arm and those denying exenteration were grouped into the nonexenteration arm. The patients were followed at 1 month and 3 months. The 6-month survival data were collected telephonically. Continuous data were presented as Mean ± SD/Median (IQR) depending on the normality distribution of data, whereas the frequency with percentages was used to present the categorical variables. Kaplan-Meier survival curves were created to estimate the difference in survival of patients with exenteration in rhino-orbital mucormycosis versus those without exenteration. RESULTS: A total of 14 patients were recruited for our study based on the inclusion and exclusion criteria. All the patients were qualified for exenteration; however, only eight patients underwent exenteration and six patients did not consent to exenteration. At the end of 3 months in the exenteration group, four (50%) patients died. Two patients died within a week of exenteration, whereas two patients died after 2 weeks of exenteration. The deaths in the first week were attributed to septic shock and the deaths happening beyond 2 weeks were attributed to severe meningitis. The Kaplan-Meier survival analysis showed the cumulative probability of being alive at 1 month in the exenteration arm to be 85%, and it decreased to 67% by 53 days and subsequently remained stable until the end of 3 months. CONCLUSION: The Kaplan-Meier survival analysis did not show a survival benefit of exenteration at 3 months and 6 months in COVID-associated rhino-orbital mucormycosis.

Role of tenon advancement in treating limbal ischemia in acute chemical injury.

Background: In acute chemical injury, damage can range from ocular surface epithelial defects to limbal and scleral ischemia. This may subsequently progress to corneal or scleral melting and perforation and finally result in phthisis bulbi. Thus, acute chemical injury is a potentially blinding condition and warrants attention. The accurate technique to assess the damage incurred should be practiced to avoid undertreatment and subsequent complications. Surgical intervention wherever needed should be appropriately timed and should be performed. The primary aim of medical or surgical intervention in acute chemical injury is to attain a stable and epithelized ocular surface. Even a conjunctival phenotype over the cornea is a desirable outcome. Purpose: This video discusses the nuances involved in the assessment and planning of Tenon advancement with amniotic membrane grafting for treating limbal ischemia in acute chemical injury. Synopsis: The video demonstrates the technique of restoration of limbal vascularization by performing Tenon advancement with amniotic membrane grafting and its outcome. Highlights: Ocular surface painting with fluorescein dye is essential to assess the areas of surface involvement. Merely instilling the fluorescein dye in the cul-de-sac will underestimate the extent of the damage. Tenon advancement should ideally be planned between 7 and 10 days following an injury when actual limbal blanching is obvious. A stable and epithelized ocular surface is the desirable outcome irrespective of the epithelial phenotype. Video Link: https://youtu.be/06XhwLKnsIA.