The Comparison of the Effects of the Pilocarpine Induced Accommodation with Regard to Cyloplegia on Lens Thickness Between Axial Myopia and Emmetropia

Purpose: To compare the effects of the pilocarpine induced accommodation with regard to cyloplegia on lens thickness between axial myopia and emmetropia. Methods: Twenty-seven subjects with unilateral axial myopia and more than 3 diopters of difference in spherical equivalent between two eyes of each subject were included in the study. The mean age of the subjects was 27.3 +/- 8.1 (range: 14 to 43) years. Both eyes of all subjects underwent axial length and lens thickness measurements with ultrasound biometry under cyclopentolate 1% and pilocarpine 2%, respectively. The eyes with axial myopia ( study group) were compared with same subjects fellow (control group) eyes with lower axial length. Results: The mean lens thickness under cyclopentolate was 3.78 +/- 0.08 mm and 3.76 +/- 0.10 mm in the axial myopia group and the control group, respectively. The mean lens thickness under pilocarpine was 3.96 +/- 0.08 mm and 4.00 +/- 0.08 mm in the axial myopia group and the control group, respectively. There was no statistically significant difference between the lens thickness of the axial myopia group and control group, under cyclopentolate (p>0.05) and pilocarpine (p>0.05), respectively. The mean increase in lens thickness after pilocarpine instillation with regard to cyloplegia was 0.20 +/- 0.10 mm in the axial myopia group and 0.21 +/- 0.10 mm in the control group. There was no statistically significant difference in increase in lens thickness after pilocarpine instillation with regard to cycloplegia between axial myopia and control groups (p>0.05). Conclusions: There is no statistically significant difference in the effects of the pilocarpine induced accommodation with regard to cyloplegia on lens thickness between axial myopia and emmetropia.