Macular Gradient Measurement in Myopic Posterior Staphyloma Using Optical Coherence Tomography

ABSTRACT

PURPOSE: To evaluate clinical characteristics and the macular gradient in myopic posterior staphyloma with time domain (TD) optical coherence tomography (OCT). METHODS: Sixty-four staphyloma eyes of 40 patients were examined. Macular gradient (tangent theta) and the location of staphyloma were assessed with OCT imaging. The macular gradient was measured at points 1 mm and 2 mm distant from the fovea. The relationships of the macular gradient with age, axial length, and spherical equivalent were analyzed. RESULTS: In 8 eyes (12.5%), the bottoms of the staphylomas were in the fovea, and there was no macular gradient. However, in the other 56 eyes (87.5%), the bottoms of the staphylomas were not in the foveal area, and macular gradients existed. Staphylomas were commonly located in the infero-nasal retinal area. The mean macular gradient (tangent theta) was 0.26 +/- 0.08 at 1 mm distance from the fovea and 0.28 +/- 0.10 at 2 mm. No significant relationships were observed between macular gradient and axial length, patient age, or spherical equivalent. CONCLUSIONS: TD OCT reveals staphyloma location. If the location is outside of the fovea, a macular gradient exists and can be measured by OCT. Axial length measurement error may occur in eyes with poor visual fixation and steep macular gradients.