Purpose: We determined structural retinal nerve fiber layer (RNFL) changes in schizophrenia patients and established if the structural changes were related to the duration of the illness using spectral-domain optical coherence tomography (SD-OCT).
Methods: We recruited a total of 30 schizophrenic patients and 30 age-matched controls in the study. The schizophrenic patients were subdivided further to acute (n = 5), chronic (n = 13), and long-term chronic (n = 12) subgroups depending on their duration of illness. Using SD-OCT, the peripapillary RNFL thickness, macula thickness, and macula volume measurements of schizophrenic patients and the control subjects were measured and compared at each location.
Results: Schizophrenic patients showed a statistically significant reduction in overall peripapillary RNFL thickness (cases, 94.70 ± 9.88 μm; controls, 103.53 ± 6.53 μm; P < 0.001), macula thickness (cases, 269.26 ± 12.59 μm; controls, 284.83 ± 9.76 μm; P < 0.001), and macula volume (cases, 9.61 ± 0.45 mm(3); controls, 10.17 ± 0.35 μm; P < 0.001). Chronic and long-term chronic schizophrenic patients were found to have significant peripapillary RNFL thinning, macula thinning, and reduction of macula volume when compared to controls (P < 0.001). There also was a statistically significant reverse correlation (P < 0.05) of peripapillary RNFL thickness (r = -0.36), macula thickness (r = -0.38), and macula volume reduction (r = -0.36) with the duration of schizophrenic illness.
Conclusions: These results indicate that RNFL and macula thickness, as well as macula volume measurements are reduced in schizophrenic patients. The degree of thinning and reduction was more significant in the chronic phase of the disease and correlated with the duration of illness. These findings demonstrate that SD-OCT can be a useful tool for the diagnosis and monitoring the progression of this disease.
Keywords: SD-OCT; duration of illness; retinal nerve fiber layer; schizophrenia.