Association between Chagas disease and changes in the optic nerve and retinal nerve fiber layer

To test the hypothesis that Chagas disease predisposes to optic nerve and retinal nerve fiber layer alterations. We conducted a cross-sectional study including 41 patients diagnosed with Chagas disease and 41 controls, paired by sex and age. The patients underwent ophthalmologic examinations, including intraocular pressure measurements, optic nerve and retinal nerve fiber layer screening with retinography, optical coherence tomography, and standard automated perimetry. All of the patients with Chagas disease had a recent cardiologic study; 15 (36.6%) had heart failure, 14 (34.1%) had cardiac form without left ventricular dysfunction, and 12 (29.3%) had indeterminate form. Optic nerve/retinal nerve fiber layer alterations were observed in 24 patients (58.5%) in the Chagas disease group and 7 controls (17.1%) (p£0.01). Among these, optic nerve pallor, optic nerve alterations suggestive of glaucoma, notch, peripapillary hemorrhage, and localized retinal nerve fiber layer defect were detected. Alterations were more prominent in patients with Chagas disease and heart failure (11 patients), although they also occurred in those with Chagas disease without left ventricular dysfunction (7 patients) and those with indeterminate form (6 patients). Optical coherence tomography showed that themean of the average retinal nerve fiber layer thickness measured 89 ± 9.7 mm, and the mean of retinal nerve fiber layer superior and inferior thickness measured 109 ± 17.5 and 113 ± 16.8 mm, respectively were lower in patients with Chagas disease. In controls, these values were 94 ± 10.6 (p=0.02); 117 ± 18.1 (p=0.04), and 122 ± 18.4 mm (p=0.03). Changes in optic nerve/ retinal nerve fiber layer were more prevalent in patients with Chagas disease.