Abstract
Purpose:
To evaluate the visual function and architecture of macula and peripapillary retina in patients with inactive toxoplasmic retinochoroiditis sparing macular and peripapillary regions (zones 2 and 3).
Methods:
Cross-sectional study of 20 eyes of 18 patients with inactive ocular toxoplasmic retinochoroiditis (≥3 months remission) involving zones 2 and 3 with visual acuity ≥20/25. Patients underwent clinical examination, Humphrey 10-2 perimetry, contrast sensitivity (Mars test, expressed as LogCS) and color vision testing [L'Anthony desaturated D-15, expressed as a color confusion score (CCS)]. Retinal nerve fiber layer (RNFL) and macular thicknesses were determined by spectral-domain optical coherence tomography (OCT).
Results:
The mean age of patients was 27.05 years [standard deviation (SD): 10.62 years], and mean period of retinochoroiditis remission was 6.15 months (SD: 5.19 months). Lesions involved zone 2 in 6 eyes (30%) and zone 3 in 14 eyes (70%). Seven eyes (35%) had >1 retinochoroidal scar and the largest scar was >1 disc diameter (DD) in 11 eyes (55%). Mean logCS was 1.64 (SD: 0.13), and mean CCS was 1.41 (SD: 0.61). The prevalence of abnormal contrast sensitivity and abnormal color vision was, respectively, 15.0% (3 eyes) and 20.0% (4 eyes). Mean perimetric foveal sensitivity was 30.0dB (SD: 9.29), mean MD was -4.33 dB (SD: 3.93), and mean PSD was 1.91 (SD: 1.73). Mean peripapillary RNFL thickness was 116.17µm (SD: 13.76µm), and mean foveal thickness was 255.90µm (SD: 23.64µm). Macular and RNFL measurements were within normal limits in all eyes. Foveal sensitivity was lower in eyes with retinochoroiditis in zone 2 than in zone 3 (23.00dB vs. 33.31dB, p=0.041). Eyes with lesions >1 DD also had lower foveal sensitivity, however, statistical significance was not reached (26.60 vs. 33.88, p=0.55). Eyes with longer periods of retinochoroiditis inactivity had higher MD (r=0.575, p=0.013) and lower PSD (r=-0.593, p=0.010).
Conclusions:
Eyes with inactive zones 2 and 3 toxoplasmic retinochoroiditis and VA ≥20/25 had a high prevalence of abnormal color, contrast and macular perimetric sensitivity. However, no OCT changes of macular structure and peripapillary RNFL were observed in these eyes. Zone 2 retinochoroiditis was associated with lower foveal sensitivity. Longer duration of ocular toxoplasmosis remission was associated with improvement of perimetric parameters.
Keywords: 734 toxoplasmosis •
471 color vision •
758 visual fields