OPTICAL COHERENCE TOMOGRAPHY FINDINGS IN PRESUMED VETERINARY ANTHELMINTIC DRUG-INDUCED RETINAL TOXICITY: A Glimpse into Underlying Mechanism.

PURPOSE: To report optical coherence tomography findings of presumed veterinary anthelmintic drugs (VADs)-induced retinal toxicity that may aid in understanding potential pathogenic mechanisms. METHODS: This is a retrospective observational case series analysis of patients with vision abnormalities following the accidental or intentional consumption of veterinary anthelmintic drugs. All cases underwent a thorough ophthalmological examination. Moreover, medical records, as well as the initial and follow-up optical coherence tomography images, were thoroughly scrutinized. RESULTS: Four patients were identified (3 men; mean [range] age, 36.5 [22-52] years). Each patient overdosed on one or two of the following VADs: closantel, triclabendazole, praziquantel, pyrantel pamoate, and niclofolan. The most characteristic optical coherence tomography finding was diffuse, granular, hyperreflective lesions throughout the outer retina, which were initially identified in the ellipsoid zone in two cases. At follow-up, optical coherence tomography exhibited regression of hyperreflective lesions and extensive loss of the outer retinal elements in two patients. In addition, the subfoveal outer retinal layers may be partially preserved. CONCLUSION: Some veterinary anthelmintic drugs could be detrimental to the human retina if overdosed, resulting in visual disturbances. Optical coherence tomography revealed the mitochondria-enriched ellipsoid zone where outer retinal damage first appeared on, implying that these medications may harm the retina by inhibiting mitochondrial energy metabolism, as they do to eliminate parasites.

Vitreoretinal Lymphoma with Intraretinal Infiltration, Simulating Retinal Necrosis.

PURPOSE: To describe the clinical features and outcomes of vitreoretinal lymphoma (VRL) with intraretinal infiltration, a pseudonecrotic variant. DESIGN: Retrospective, comparative analysis. SUBJECTS: Patients with biopsy-proven VRL at a single center from August 2016 to April 2022. METHODS: A retrospective record review was conducted for clinical, imaging, and laboratory data. MAIN OUTCOME MEASURES: Clinical features, visual, and survival outcomes. RESULTS: We included 67 eyes of 40 patients with biopsy-proven VRL. Pseudonecrotic retinal lesions (PRLs) were found in 24 (35.8%) eyes of 19 patients; these eyes were classified as a pseudonecrotic variant, whereas the remaining 43 (64.2%) eyes were classified as nonnecrotic. Comparison (pseudonecrotic vs. nonnecrotic) revealed that eyes with PRLs at presentation had a worse median best-corrected visual acuity (BCVA; 2.4 vs. 0.5 logarithm of the minimum angle of resolution [logMAR], P < 0.0001) and severe ocular manifestations (P < 0.0001), including optic disc swelling (79.2% vs. 0%), retinal vasculitis (93.8% vs. 4.7%), retinal hemorrhage (83.3% vs. 0%), and retinal detachment (RD) (79.2% vs. 0%). Follow-up data were available for 20 eyes (17 patients) in the pseudonecrotic group and 43 eyes (21 patients) in the nonnecrotic group. An equally worse median BCVA was noted in pseudonecrotic eyes at 6 months after treatment and the final follow-up as compared with nonnecrotic eyes (2.4 vs. 0.3 logMAR, P < 0.0001). The median follow-up period did not differ significantly (16.6 vs. 18.4 months, P = 0.47). Initial BCVA (ß = 0.300, P = 0.003), presence of anterior chamber cell (ß = 0.472, P = 0.013), and RD (ß = 1.137, P < 0.0001) were significantly associated with poor visual outcomes in multivariate linear regression analysis (adjusted R2 = 0.693). There were no significant differences in survival outcomes. CONCLUSION: Vitreoretinal lymphoma can present as pseudonecrotic retinopathy, with more advanced clinical presentations and worse final visual outcomes. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.