title: Evaluation of in vivo human retinal morphology and function in myopes.
abstract: OBJECTIVE
  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).
  
  
  CONCLUSIONS
  The retinal sensitivity was significantly reduced in myopes in spite of normal retinal morphology indicating that functional changes may precede structural changes.
authors.affiliation: Shri Bhagwan Mahavir Vitreoretinal Services, Sankara Nethralaya, Chennai, Tamil Nadu, India.
authors.forename: Laxmi
authors.initials: L
authors.lastname: Gella
authors.forename: Rajiv
authors.initials: R
authors.lastname: Raman
authors.forename: Tarun
authors.initials: T
authors.lastname: Sharma
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D009216:Myopia / Q000503:physiopathology*; D020419:Photoreceptor Cells, Vertebrate / Q000473:pathology; D011446:Prospective Studies; D012160:Retina / Q000503:physiopathology*; D055213:Retinal Pigment Epithelium / Q000473:pathology; D041623:Tomography, Optical Coherence; D058609:Visual Field Tests; D014794:Visual Fields / Q000502:physiology