Evaluation of In Vivo Human Retinal Morphology and Function in Myopes

Abstract

Purpose: To compare the retinal sensitivity, using Microperimeter and the morphological changes in retinal layers, using Spectral Domain Optical Coherence Tomography (SD-OCT), between myopes and age-matched emmetropes.

Methods: Twenty-nine myopic eyes and 29 emmetropic eyes were enrolled in this prospective case control study. All subjects underwent subjective refraction as part of the ophthalmic examination and in addition, SDOCT and Microperimetry were performed. Based on the reflectivity on the OCT cross sections, the thickness of the retinal layers was measured 2.5 mm on either side of the fovea.

Results: The mean retinal sensitivity was significantly (p = 0.001) reduced in myopes (17.31 ± 1.80 dB; mean ± SD) compared to that of emmetropes (18.61 ± 1.08 dB). SD-OCT did not show any significant difference in the photoreceptor layer and foveal thickness between myopes and emmetropes. The retinal pigment epithelium thickness was significantly reduced in myopes (35.03 ± 4.21 µm) compared to emmetropes (37.74 ± 4.30 µm) (p = 0.019). We found a significant positive correlation between refractive error and mean retinal sensitivity (r = 0.725, p = <0.001).

Conclusion: The retinal sensitivity was significantly reduced in myopes in spite of normal retinal morphology indicating that functional changes may precede structural changes.

Keywords::

• Myopia
• Microperimetry
• SD-OCT
• Retinal sensitivity
• Retinal thickness

Declaration of interest: The authors declare no conflict of interest.