[Optical coherence tomography to evaluate peripapillary retinal nerve fiber layer in chloroquine patients]

To evaluated the retinal nerve fiber layer in chloroquine patients with optical coherence tomography (OCT).

Nerve fibers layer thickness was measured by a proprietary OCT Stratus through the fast retinal nerve fiber layer protocol in ninety-four eyes of 48 patients exposed to chloroquine for at least one year with no apparent macular disorder. Cumulative dose, maximum daily dose (mg/kg/day) and time of chloroquine use were correlated with the retinal nerve fiber layer thickness. Data were compared with a control group of 30 patients who did not use chloroquine. All patients underwent a complete ophthalmologic examination including visual acuity, refraction, intraocular pressure, fundoscopy, angiography and measurement of cup-to-disc ratio.

The average thickness of retinal nerve fiber layer between antimalaric users (107.60 +/- 13.25 microm) and the control group (99.05 +/- 13.08 microm) had a statistically significant difference (p=0.0137). Furthermore, a positive association of the peripapillary thickness measurements between temporal, upper and lower quadrants of both groups was found. Twelve clock hours retinal nerve fiber layer analysis detected at least one focal defect in more than 50% of the medication users. Particularly, a statistical correlation with the maximum daily dose was found in patients with focal defects (p=0.0120).

Optical coherence tomography is effective in detecting nerve fiber layer loss in chloroquine patients without apparent fundus changes. Thus, optical coherence tomography may contribute to the early diagnosis of chloroquine retinopathy.