Purpose. To determine retardation values of the retinal nerve fiber layer for healthy Mexican subjects using scanning laser polarimetry. Methods. We obtained scanning laser polarimetry images from normal eyes, defined as those with IOP £ 21 mmHg with no prior history of elevated IOP and normal slit lamp biomicroscopy of the anterior segment. This study was conducted at the Association to Prevent Blindness in México from March 1998 and February 1999. One randomly selected eye of 56 subjects was selected. 35(57.6%) female and 21 (42.4%) male. Mean age + S.D., 45.92+14.9 years. (Range 24 to 73 years).
Results. The scanning laser polarimetry results for this group were: In the peripapillary region, mean retardation in the superior and inferior regions was 12.0+2.50 and 12.6+2.6 respectively. Temporally and nasally retardation was lower 7.5+2.09 and 8.8+2.3 respectively. Average RNFL thickness was 80.09+15.96 µm. Average thickness in the superior and inferior regions was 89.32+18.55 µm and 89.26+19.93 µm respectively. Average thickness in the nasal and temporal region was 65.56+17.69 µm and 55.54+15.53 µm respectively. Conclusions. This study determined that normal distribution and thickness values of the retinal nerve fiber layer using the scanning laser polarimeter for a healthy Mexican population.