Influence of Clinically Active Graves' Ophthalmopathy on Spherical Equivalent and Visual Acuity

Purpose: Clinical experience regarding the fluctuations of the refractive error of the eye during the different stages of Graves' ophthalmopathy observed through outpatient clinic frequent check-ups points towards an underestimated and often overlooked problem. Published data about it are sparse. The clinical manifestations of Graves' ophthalmopathy can be understood from the perspective of "compartment syndrome" and literature implies how such changes can affect the refractive error and consequently, the visual acuity. The purpose of the study was to explore how the clinical activity score of Graves' ophthalmopathy affects refractive error and visual acuity.

Patients and methods: The study was prospective and observational, including 60 eyes of 30 patients with clinically active Graves' ophthalmopathy. All the patients were monitored and evaluated over a period of 36 months by the clinical activity score, spherical equivalent and visual acuity. All the observed parameters were statistically analyzed.

Results: The mean values of spherical equivalent and visual acuity throughout the observed period showed continuous fluctuation. Repeated measure analysis of variance showed statistically significant differences in visual acuity and spherical equivalent over the observed period. There was a statistically significant positive correlation between visual acuity and clinical activity score. The correlation between spherical equivalent and clinical activity score was also positive but not statistically significant.

Conclusion: A decrease in the clinical activity score is either the result of a spontaneously resolving course of Graves' ophthalmopathy or a consequence of treatment, so lowering in fluctuation of refractive error and improved visual acuity may be associated with a reduction in orbital inflammation.