Progression of primary open angle glaucoma in asymmetrically myopic eyes.

PURPOSE

To compare progression of primary open angle glaucoma (POAG) in asymmetrically myopic eyes within the same subject and evaluate whether the degree of myopia is related to glaucoma progression.

METHODS

POAG patients with asymmetric myopia (axial length [AXL] ≥24 mm in both eyes, and the AXL difference between the right and left eyes to be ≥0.5 mm) were included. Glaucoma progression was determined either by optic disc/retinal nerve fiber layer (RNFL) photographs or by serial visual field (VF) data. The progression rates of VF mean deviation (dB/year) and spectral domain optical coherence tomography measured RNFL thickness (μm/year) were compared between the more myopic eye (MME) and the less myopic eye (LME) within the same subject.

RESULTS

A total of 55 patients (mean follow up period; 4.5 ± 1.0 years) were included. The mean AXL demonstrated a significant difference between MME and LME (26.3 ± 1.7 vs. 25.6 ± 1.7 mm; p = 0.036). The mean baseline VF MD (-3.8 ± 5.4 vs. -2.6 ± 4.7 dB; p = 0.21) and average RNFL thickness (77.5 ± 10.6 vs. 79.9 ± 12.3 μm; p = 0.36) did not differ between the MME and LME. Among the 55 patients, optic disc/RNFL photographic progression was noted in the MME in 15 patients, in the LME in 19 patients, and in both eyes in seven patients. VF progression was noted in the MME in seven patients, in the LME in seven patients, and in both eyes in four patients. The VF MD progression rates were -0.25 ± 0.34 dB/year in MME and -0.26 ± 0.34 dB/year in LME cases (p = 0.91). The mean progression rate of the average RNFL thickness also did not differ between the MME and LME (-0.59 ± 0.67 vs. -0.66 ± 0.72 μm/year, p = 0.68).

CONCLUSIONS

The degree of myopia was not associated with glaucoma progression when assessing the same patient using either the VF or optic disc/RNFL criteria in asymmetrically myopic patients.