Author: Professor Kyoko Ohno-Matsui
Purpose: To determine the early signs of posterior staphylomas in highly myopic eyes of younger subjects by swept-source ultra-widefield optical coherence tomography (WF-OCT).
Methods: This was an observational case series study. Highly myopic subjects younger than 20 years old who were examined consecutively by prototype WF-OCT were studied. High myopia was defined according to the Ministry of Health and Welfare, Japan classification. A posterior displacement of the sclera and two OCT features indicating the staphyloma edges were used as markers of a staphyloma.
Results: Fifty-five eyes of 30 patients with the mean age of 12.3 ± 4.0 years, and the mean axial length of 27.9 ± 1.6 mm were studied. Seven of the 55 eyes (12.7%) had a staphyloma by WF-OCT, and a posterior displacement of the sclera was observed in the staphylomatous area. Among the two OCT features of the staphyloma edges, a gradual thinning of the choroid toward the staphyloma edge and gradual re-thickening of choroid from the staphyloma edge toward the posterior pole were found in these 7 eyes. However, the other feature of an inward protrusion of the sclera at the staphyloma edge, was obvious in only 2 eyes. The subfoveal choroid and choroid nasal to the optic disc were significantly thinner in eyes with a staphyloma than those without it.
Conclusions: The changes of the choroidal thickness toward the staphyloma edge were considered an early sign which precedes an inward protrusion of sclera at the staphyloma edge.