# Choroidal thickness changes in patients with systemic lupus erythematosus treated with hydroxychloroquine using three dimensional maps

## TL;DR

This study found that patients with lupus treated with hydroxychloroquine have thicker choroids in certain eye regions compared to healthy people, but treatment duration had no effect.

## Contribution

The study introduces a novel method of analyzing choroidal thickness using 3D maps in SLE patients treated with hydroxychloroquine.

## Key findings

- Choroidal thickness in central nasal zones was significantly higher in SLE patients compared to healthy controls.
- Neither disease duration nor hydroxychloroquine treatment duration influenced choroidal thickness.
- Other choroidal regions showed no significant differences between SLE patients and healthy subjects.

## Abstract

To compare variations in choroidal thickness (CT) between patients with systemic lupus erythematosus (SLE) treated with hydroxychloroquine (HCQ) and healthy subjects for at least one year.

Cross-sectional study enrolling patients between 30 and 55 years of age with SLE and treated with HCQ for at least one year, and aged-matched healthy subjects. Exclusion criteria included any other ophthalmological disorder or previous treatment, and systemic treatment with immunosuppressive drugs or a dose of corticosteroids higher than 5 mg/d. Macular CT was measured automatically in a grid of 30 × 30 cubes using Triton swept-source optical coherence tomography (Topcon). These were merged into 25 zones (each one comprising 6 × 6 cubes). Three-dimensional (3D) CT maps were created using Microsoft Excel and mean CT values in the grid of 30 × 30 cubes. One eye of each patient was randomly selected for the study.

60 patients and 54 healthy subjects were recruited. Mean age was 45.16 ± 6.43 and 43.79 ± 8.98 years (p = 0.346), respectively. Mean axial length was 23.52 ± 0.96 and 23.67 ± 0.87 mm (p = 0.137), respectively. Mean SLE duration was 125.58 ± 63.10 months, and mean duration of HCQ was 87.87 ± 52.13 months. There were no differences in intraocular pressure (p = 0.271) or spherical equivalent (p = 0.219). Choroidal zones number 9, 14, 15, 19 and 20 (central nasal locations) were thicker in SLE patients. Neither SLE duration, nor HCQ duration had any influence on CT (p > 0.05).

Patients with SLE treated with HCQ for one or more years present higher CT values than healthy subjects. Nasal zones seem to be the most sensitive to these changes, while the other choroidal locations remain similar apparently. However, neither duration of SLE nor duration or dose of HCQ treatment seemed to have any influence on CT.