Abstract
Introduction: It is known that there are alterations to the optical structures in eye in high myopia. Much attention has been placed on studying the retina in high myopia, however changes in the anterior segment, particularly the sclera, have also been noted. This study examines corneal nerves in high myopes, low myopes and hyperopes to determine if a relationship between nerve density and refractive error exists. Methods: Corneal nerves were imaged over the central cornea with a Nidek CS4 confocal microscope (460x345 μm field). Nerves were evaluated for density calculations using the ImageJ plugin NeuronJ (Meijering et al., 2004). Thirty subjects were included in this pilot and were divided into 8 high myopes (-5D to -11D), 16 low myopes (plano to -5D), and 6 hyperopes (plano to +3D). All patients were dilated and autorefracted using a Nidex OPD autorefractor. Results: There is a trend towards hyperopes having greater corneal nerve density than myopes. A regression of refraction and nerve density yields a significant slope (p<0.001). From the regression it appears nerve sums over the field double over our range of refractive errors. High myopes had significantly less corneal nerves than low myopes or hyperopes (p= 0.002). Conclusions: This pilot work indicates that high myopia may have greater effects on the cornea than previously found. This could have implications for corneal surgeries on these patients. More studies need to follow.