Retinal arcades in posterior microphthalmos: biometric correlation.

CLINICAL RELEVANCE: Posterior microphthalmos (PM) is a rare developmental disorder characterised by high hyperopia, short axial length, presence of retinal papillomacular fold and relatively normal anterior segment findings.

BACKGROUND

The purpose of the study was to compare the retinal arcade distance from fovea between PM cases and to correlate axial shortening in PM eyes with imaging findings.

METHODS

This retrospective, comparative case series included 24 eyes of 12 patients with PM as cases and an equal number of age- and sex-matched controls. Retinal findings on optical coherence tomography (OCT), OCT-angiography, Multicolour® image, axial length and corneal biometry were computed, compared and correlated between two groups.

RESULTS

Retinal papillomacular fold was noted in all 24 PM eyes. Retinal arcade narrowing was noted in PM (p < 0.001). The central retina (p < 0.001) and choroid (p = 0.003) was thick in PM. Corneal biometry showed shorter axial length (p < 0.001), high keratometry readings (p < 0.001) and small corneal diameters (p = 0.011) in PM. Vessel density (p = 0.031) on OCTA was denser and foveal avascular zone area (p = 0.033) reduced in PM. Strong negative correlation of axial length with spherical equivalent (r = > -0.804;p < 0.001), vessel density (r = > -0.803; p = <0.001) and K1 (r = > -0.76; p < 0.001) and K2 (r = > -0.67; p = 0.001) keratometry readings was noted in PM. Significant positive correlation was noted between axial length and anterior chamber depth (r = 0.75; p < 0.001), foveal avascular zone area (r = 0.56; p = 0.033) and corneal diameter (r = 0.65; p = 0.001). Vessel density on OCT-angiography correlated positively with central corneal thickness (r = 0.552;p = 0.005) and corneal powers K1 (r = 0.709; p = 0.001) and K2 (r = 0.56; p = 0.004) and negatively with corneal diameter (r = > -0.521; p = 0.033).

CONCLUSION

Increased choroidal thickening and retinal vascular arcade narrowing were two important, interesting observations noted with PM. Intercorrelation between the axial length, OCT, OCT-angiography and corneal biometry helped in understanding the pathogenesis and the structural and vascular changes in PM eyes.