Evaluation of the effect of unilateral late blindness on the retina, optic nerve and choroid parameters in the sighted eye

Abstract

To investigate whether unilateral late blindness alters the peripapillary retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), central macular thickness (CMT) and choroidal thickness (CT). The 17 healthy eyes of 17 monocular patients with late blindness due to isolated eye trauma in one eye and the 19 eyes of 19 healthy individuals were evaluated in this retrospective study. Patients with at least 10years of monocular blindness, a refractive error between + 1.5 and -1.5 D in the sighted eye, a best-corrected visual acuity of at least 20/20 and an axial length (AL) < 25mm were included in the study. Following ophthalmologic examination, the RNFL, GCC, CMT and CT values were measured with spectral domain optic tomography (SD-OCT). Those with ocular, systemic or neurological disease that could influence the measured parameters were excluded from the study. A total of 17 (14 males, 3 females) monocular patients [mean age 41.00 ± 11.95 (24-64)] and 19 (16 males, 3 females) healthy individuals [mean age 39.79 ± 6.74 (30-56)], similar in age and gender (p = 0.949 and p = 0.881), were included in the study. The mean duration of being monocular was 22.76 ± 11.76 (10-49) years. No difference was present between the RNFL, GCC, CMT and CT measurements of the monocular patients and the healthy individuals (p = 0.692, p = 0.294, p = 0.113, p = 0.623, respectively). No significant correlation was found between the duration of monocularity and the retinal and optic nerve parameters. The results of our study indicate no difference in the optic nerve, retina and choroid OCT findings in the sighted eyes of subjects with long-term monocular blindness compared to subjects with bilateral normal eyes. Although functional and volumetric neuroimaging studies suggest the possibility of compensation in these patients, our findings indicate that this is not at the ocular level.