Scanning laser polarimetry in normal subjects and patients with myopia

Aims-To examine the changes in the retinal nerve fibre layer (NFL) thicknes s with age and myopia in normal population, Methods-Retinal nerve fibre layer thickness was measured with a scanning la ser polarimeter (NFA-I) in 180 normal subjects of varying age (range 7-83 y ears) and in 110 eyes of 85 patients with myopia of varying degrees (range -1.00 to -15.00D). They were all voluntary Anatolian people. Superior to na sal (S/N), inferior to nasal (I/N), and the superior to inferior (SII) rati os were used for the assessment of retinal NFL thickness. Results-The mean superior NFL ratio was 2.96 and the mean inferior NFL rati o was 2.93 in normal subjects. There was a gradual decrease in NFL ratio-wi th increasing age (simple regression analysis, p<0.05). The mean SII ratio was 1.01 with a large variation. In patients with myopia, the mean superior NFL ratio was 2.60 and the mean inferior NFL ratio was 2.72, Superior and inferior NFL retardations, and SII ratio in myopic patients were significan tly (15.5%, 10.8%, and 4.9% respectively) lower than that of age matched no rmals (t test, p<0.05). There was also a gradual decrease in NFL thickness with increasing degree of myopia (simple regression analysis, p<0.05). Conclusions-Nomograms we obtained for retinal NFL thickness may serve as re ference points for the assessment of normal Anatolian people and myopic pat ients in future studies. NFL thicknesses gradually decreased with increasin g age. Patients with myopia had significantly lower NFL thicknesses than no rmal subjects and, although weakened by wide age range of myopic group, the re is a linear relation between severity of myopia and NFL thickness in myo pic patients.