Optical coherence tomography retinal nerve fiber layer analysis in eyes with long axial lengths.

Purpose: To evaluate the relationship between axial length (AL) and retinal nerve fiber layer (RNFL) profile and to characterize differences in optical coherence tomography RNFL of myopic glaucomatous eyes compared to nonglaucomatous eyes.

Methods: Retrospective chart review of 170 eyes of 89 subjects with optical biometry and optical coherence tomography RNFL assessment was conducted.

Results: Temporal RNFL thickness showed no association with AL in either glaucomatous or nonglaucomatous eyes. Nasal thinning was most strongly associated with glaucoma in myopic eyes. Both myopic glaucomatous and nonglaucomatous eyes had a mean RNFL thickness of 16-22 µm thinner than mean RNFL thickness of normal AL eyes.

Conclusion: An average of 16-22 µm thinning of RNFL compared to nomogram can be tolerated in patients with long AL. Prominent nasal thinning likely represents changes from axial elongation. Temporal RNFL thinning in those with long AL tends to be mild, and significant thinning should raise suspicion for glaucoma.