Loratadine-associated cystoid macular edema: A case report

Yong Tang; Rui Dou; Yuyan Liu; Shiyong Xie; Quanhong Han

doi:10.1016/j.ajoc.2022.101477

Loratadine-associated cystoid macular edema: A case report

Am J Ophthalmol Case Rep. 2022 Mar 9:26:101477. doi: 10.1016/j.ajoc.2022.101477. eCollection 2022 Jun.

Authors

Yong Tang¹, Rui Dou¹, Yuyan Liu¹, Shiyong Xie¹, Quanhong Han¹

Affiliation

¹ Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Institute, Nankai University Affiliated Eye Hospital, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.

Abstract

Purpose: To report the first known case of bilateral cystoid macular edema in a patient undergoing long-term loratadine treatment.

Observations: A 49-year-old Chinese woman who had been undergoing treatment with loratadine for the past 6 years presented with decreased visual acuity and bilateral cystoid macular edema (CME). Upon cessation of loratadine, macular edema partially resolved, and visual acuity markedly improved. Fundus autofluorescence (FAF), optical coherence tomography (OCT), and fluorescence fundus angiography (FFA) were used to document the severity of CME and its subsequent resolution after cessation of loratadine therapy.

Conclusions and importance: Long-term use of loratadine might cause CME that partially resolves with discontinuation of the drug. The pathophysiology of drug-induced CME without leakage remains unclear. Dysfunction of histamine receptor1-expressed retinal neurons and the associated signal transduction, toxicity to Müller cells or RPE cells with subsequent intracellular fluid accumulation, and subclinical damage to the blood-retina barrier leading to leakage of extracellular fluid, have been proposed.

Keywords: Cystoid macular edema; Histamine; Loratadine; Optical coherence tomography.

Publication types

Case Reports