Clinical features of primary and compound forms of wide macular posterior staphyloma in high myopia.

BACKGROUND

To compare the ocular features of highly myopic eyes with posterior staphyloma of wide macular type according to its morphological complexity.

METHODS

In this cross-sectional study, wide macular posterior staphyloma (WMPS) was classified into the primary (Curtin type I) and the compound (Curtin types VI to X) forms based on the configuration within the staphyloma. The grades of myopic maculopathy and the thicknesses of choroid and sclera were compared between the primary and compound forms of WMPS.

RESULTS

A total of 154 eyes (103 patients) with primary WMPS and 65 eyes (49 patients) with compound WMPS were included. Eyes with compound WMPS had worse visual acuity (P = 0.001) and greater axial length (P < 0.001) than those with primary WMPS. Compared to primary WMPS, compound WMPS had a higher grade of myopic macular degeneration (P < 0.001) and a higher frequency of lamellar or full-thickness macular hole associated with myopic traction (21.5% vs. 10.4%; P = 0.028) and active or scarred myopic choroidal neovascularization (33.8% vs. 20.1%; P = 0.030). On swept-source optical coherence tomography, eyes with compound WMPS had significantly thinner choroid and sclera.

CONCLUSIONS

The compound form of WMPS had more severe myopic macular changes and worse visual prognosis compared to the primary form of WMPS, and these were associated with more structural deformation in the posterior eyeball. Compound WMPS should be considered as an advanced form of staphyloma.