Microglia activation and neuronal alterations in retinas from COVID-19 patients: correlation with clinical parameters.

BACKGROUND: Different ocular alterations have been described in patients with coronavirus disease 2019 (COVID-19). Our aim was to determine whether COVID-19 affected retinal cells and establish correlations with clinical parameters. METHODS: Retinal sections and flat-mount retinas from human donors with COVID-19 (n = 16) and controls (n = 15) were immunostained. The location of angiotensin-converting enzyme 2 (ACE2) and the morphology of microglial cells, Müller cells, astrocytes, and photoreceptors were analyzed by confocal microscopy. Microglial quantification and the area occupied by them were measured. Correlations among retinal and clinical parameters were calculated. RESULTS: ACE2 was mainly located in the Müller cells, outer segment of cones and retinal pigment epithelium. Cell bodies of Müller cells in COVID-19 group showed greater staining of ACE2 and cellular retinaldehyde-binding protein (CRALBP). The 81.3% of COVID-19 patients presented disorganization of honeycomb-like pattern formed by Müller cells. Gliosis was detected in 56.3% of COVID-19 patients compared to controls (40%) as well as epiretinal membranes (ERMs) or astrocytes protruding (50%). Activated or ameboid-shape microglia was the main sign in the COVID-19 group (93.8%). Microglial migration towards the vessels was greater in the COVID-19 retinas (P < 0.05) and the area occupied by microglia was also reduced (P < 0.01) compared to control group. Cone degeneration was more severe in the COVID-19 group. Duration of the disease, age and respiratory failure were the most relevant clinical data in relation with retinal degeneration. CONCLUSIONS: The retinas of patients with COVID-19 exhibit glial activation and neuronal alterations, mostly related to the inflammation, hypoxic conditions, and age.

Streptococcus vestibularis atypical infectious keratits after intracorneal ring segment implantation.

PURPOSE: To report the first case of an atypical infectious keratitis caused by Streptococcus vestibularis after ICRS implantation. CASE REPORT: A 65-year-old man underwent intracorneal ring segments (ICRS) implantation for the treatment of a pellucid marginal corneal degeneration (PMCD) in his both eyes (OU). Three weeks after the surgery of the right eye (OD), the patient presented with pain, redness, and vision loss in his OD. BCVA was 20/100 Snellen equivalent in the OD. Slit-lamp examination revealed punctate whitish infiltrates along the ring segment with associated corneal stromal edema in the OD. Corneal scrapings were obtained for gram satins and bacterial and fungal cultures, and topical treatment with hourly ciprofloxacin was started. Two days later, corneal stromal edema worsened with involvement of the ring channel. Thus, the ring segment was removed and sent for cultures, and the ring channel was irrigated with vancomycin. Culture from ring segment came back positive for Streptococcus vestibularis, so topical targeted antiobiotherapy with vancomycin and erythromycin was applied. At 3 weeks of follow-up, BCVA was of 20/40 Snellen equivalent in the OD and a subtle corneal leucoma in the OD was observed in the slit-lamp examination. CONCLUSION: Although infectious keratitis is a rare and serious disorder associated with ICRS implantation, its early recognition and management is essential in order to avoid sight-threatening complications. Thus, a prompt obtainment of corneal curettage samples and removal of ring segment becomes decisive to initiate a targeted antiobiotherapy.

Case Report: Tapioca Iris Melanoma: An Uncommon Presentation of an Uncommon Tumor.

SIGNIFICANCE: Iris tumors are rare conditions, and there is a relative paucity of recent published data on its broad clinical spectrum. Tapioca iris melanoma is a rarer yet devastating form with wide and challenging differential diagnoses because of its amelanotic nodular appearance. PURPOSE: This study aimed to report the challenging presentation of an uncommon iris melanoma, describing the clinical and histological findings and comparing them with the existing published data. CASE REPORT: An uncommon clinicopathological report on the tumor unusual localization, patient age, absence of elevated IOP and heterochromia, and negative S-100 stain that caused diagnostic uncertainty is presented. The patient remains free of metastatic disease 7 years after a complete tumor full-thickness excision. CONCLUSIONS: Tapioca iris melanomas are uncommon tumors with a presentation/surgical management that differs from other malignant tumors. Ophthalmologists should consider it among the vast differential diagnoses when observing amelanotic lesions, even without the hallmark signs being evident.

Endoftalmitis en paciente con queropatía bullosa y uso de lente de contacto terapéutica / Endophthalmitis in patients with bullous keratopathy and therapeutic contact lenses wear

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