Virological and cytological changes in tears and conjunctiva of patients with COVID-19

Purpose: To analyze the presence of severe acute respiratory syndrome coronavirus 2 (SARS?CoV?2) in tears/conjunctival epithelium and assess the cytomorphological changes in the conjunctival epithelium of coronavirus disease 2019 (COVID?19) patients. Methods: In this pilot study, patients with moderate to severe COVID?19 were recruited from the COVID ward/intensive care unit of the institute. Tears and conjunctival swabs were collected from COVID?19 patients and sent to the virology laboratory for reverse transcription polymerase chain reaction (RT?PCR) testing. Conjunctival swabs were used to prepare smears, which underwent cytological evaluation and immunocytochemistry for SARS?CoV?2 nucleocapsid protein. Results: Forty?two patients were included. The mean age of participants was 48.61 (range: 5–75) years. Seven (16.6%) patients tested positive for SARS?CoV?2 ribonucleic acid in tears samples, four (9.5%) of which were positive on conjunctival swab by RT?PCR in the first test. Cytomorphological changes were observed significantly more in smears from patients with positive RT?PCR on tear samples, including bi?/multi?nucleation (p = 0.01), chromatin clearing (p = 0.02), and intra?nuclear inclusions (p < 0.001). One case (3.2%) showed immunopositivity for SARS?CoV?2; this patient had severe disease and the lowest Ct values for tear and conjunctival samples among all positive cases. Conclusion: Conjunctival smears from patients with COVID?19 revealed cytomorphological alterations, even in the absence of clinically significant ocular infection. However, viral proteins were demonstrated within epithelial cells only rarely, suggesting that although the conjunctival epithelium may serve as a portal for entry, viral replication is possibly rare or short?lived.

Rectus muscle pseudo-adherence syndrome

Purpose: To describe a clinical entity called “rectus muscle pseudo?adherence syndrome” following buckling surgery. Methods: A retrospective data review was undertaken to analyze the clinical profile of strabismus patients who had developed it following buckling surgery. Between 2017 and 2021, a total of 14 patients were identified. The demography, surgical details, and intraoperative challenges were reviewed. Results: The average age of the 14 patients was 21.71 ± 5.23 years. The mean pre?op deviation was 42.35 ± 14.35 prism diopters (PD) of exotropia, and the mean post?op deviation was 8.25 ± 4.88 PD of residual exotropia at 26.16 ± 19.53 months follow?up. Intraoperatively, in the absence of a buckle, the thinned?out rectus adhered to the underlying sclera with much denser adhesions along its margins. When there was a buckle, the rectus muscle adhered to the outer surface of the buckle again, but less densely, with marginal union into the surrounding tenons. In both scenarios, due to the absence of protective muscle coverings, the rectus muscles were naturally adsorbed onto the immediately available surface in the presence of active healing by the tenons. Conclusion: While correcting ocular deviations following buckling surgery, a false sense of an absent, slipped, or thinned?out rectus muscle is very much possible. This is due to active healing of the muscle with the surrounding sclera or the buckle in a single layer of tenons. This is the rectus muscle pseudo?adherence syndrome, where the culprit is the healing process and not the muscle

Evaluation of visual field changes with retinal nerve fiber layer thickness in primary congenital glaucoma

Purpose: To evaluate visual field changes in primary congenital glaucoma (PCG) with retinal nerve fiber layer thickness on optical coherence tomography. Methods: In this cross?sectional, observational study, consecutive PCG children who underwent combined trabeculotomy with trabeculectomy and on regular follow?up were enrolled. All patients were aged over four years and co?operative for RNFL OCT and visual field examination. Perimetry was done on Humphrey visual field (HVF) analyzer using 30?2 and 10?2 SITA standard algorithms as appropriate. If a reliable automated perimetry was not feasible, kinetic perimetry was done. The following were noted at baseline and every follow?up: age, sex, visual acuity, intraocular pressure (IOP), cup–disc ratio (CDR), corneal diameters, refraction, any topical antiglaucoma medications, surgeries underwent, age at surgery and duration between surgery and final examination. Results: Forty?eight eyes of 34 children operated for PCG and 19 eyes of 17 controls were analyzed. A statistically significant thinner average RNFL thickness of 87.2 ± 28 ?m was noted in PCG eyes as compared to controls with 100.6 ± 7.2 ?m (P = 0.04). The mean cup–disc area ratio on OCT in PCG eyes was 0.43 ± 0.2 (0.02–0.93) and in control eyes was 0.23 ± 0.07 (0.1–0.4) (P < 0.001). On RNFL OCT, there was significant focal RNFL loss in temporal superior (P = 0.003), nasal inferior (P = 0.037) and temporal inferior (P < 0.001) quadrants compared to controls. Among PCG eyes, 20/48 eyes (41.7%), had definitive, reproducible glaucomatous VF defects. Mean baseline IOP in PCG eyes with VF defect was 28.7 ± 5.7 mmHg and in eyes with normal VF was 24.6 ± 5.9 mmHg (P = 0.03). On univariate regression analysis, higher baseline IOP was significantly associated with both RNFL loss (odds ratio (OR): ?2.17) and VF defects (OR: 3.35). Fluctuation in follow?up IOP (OR: 3.33) was also significantly associated with the presence of VF defects. On multivariable regression analysis maximum, IOP was significantly associated with RNFL loss and VF defects. Conclusion: Peripapillary RNFL thickness could be used to identify PCG eyes having visual field loss and possibly poor visual function from PCG eyes without visual field defects. Baseline and follow?up IOP, significantly correlated with RNFL thickness in PCG eyes

Posterior corneal morphological changes in primary congenital glaucoma

Purpose: To compare posterior corneal morphology between older treated and younger untreated children with primary congenital glaucoma (PCG) using anterior segment optical coherence tomography (ASOCT) and intraoperative OCT (iOCT), respectively. Methods: In this comparative study, ASOCT of older PCG children were compared with iOCT of younger untreated PCG patients. Differences between the two groups with respect to posterior corneal morphology were studied. Results: Observed morphological patterns within posterior cornea in older treated (age: 72–300 months) children (87 eyes) included Descemet’s membrane (DM) excrescences (70%), thickened DM (35%), intracameral twin protuberances (92%), and DM detachment (26%). Changes within pre?Descemet’s layer (PDL) (28%) included thickening, breaks, and detachments. Extent of Haab’s striae was associated with thickness of DM/PDL complex (P = 0.008) when analyzed in the treated group. In contrast, in the untreated group (n = 53 eyes, age 1–63 months), posterior corneal changes were limited to diffuse hyper?reflectivity of the DM/PDL complex, with absence of DM tears. Conclusion: Posterior cornea thickens and Haab’s striae become more circumscribed in eyes of older treated children compared to untreated PCG eyes, probably reflecting a healing response of posterior cornea over time.

Validating the use of U-tool as a novel method for measuring the corneal diameter in infants screened for congenital glaucoma

Purpose: The Castroviejo caliper is routinely used for measuring the corneal diameter in patients with primary congenital glaucoma, but needs an examination under anesthesia (EUA) or sedation. A simple U?shaped tool was devised to aid in the estimation of the corneal diameters of patients in settings where an ophthalmic caliper is not available or EUA is not feasible. Methods: Infants presenting to the congenital glaucoma clinic posted for EUA were recruited. The demographic details of the patients such as age, sex, and diagnosis were noted. A simple U?shaped tool was devised using three Schirmer strips or a printable ruler. Before the patient underwent a EUA, the corneal diameters were measured using the U?tool. During EUA, corneal diameters were measured using the Castroviejo caliper. Results: The mean age of infants was 6.7 ± 3.39 months (R = 1–12). The mean corneal diameter measured using the U?tool was 13.29 ± 1.33 mm and with Castroviejo caliper was 13.18 ± 1.39 mm. The difference between the corneal diameters measured using the two techniques was ?0.114 mm with the Bland–Altman plot 95% Limits of agreement (LoA) from ?0.965 to 0.737 mm. Corneal diameters measured with both instruments had a good correlation (Pearson’s correlation coefficient = 0.95, P < 0.001). Conclusion: U?tool can be used for screening congenital glaucoma by first?contact physicians or optometrists. It can also be used by ophthalmologists when EUA is delayed