Clinical Characterization of Young Chinese Myopes With Optic Nerve and Visual Field Changes Resembling Glaucoma

Purpose: To clinically characterize young Chinese myopic patients with optic disc changes suggestive of glaucoma. Methods: In this prospective study, patients <= 50 years of age who had myopia and suspected glaucomatous optic neuropathy (group A) were compared with established glaucoma patients (group B) and normals (group C). Risk factors such as family history of glaucoma and history of vasospasm and ischemic risk factors were compared. Ophthalmic examination included optic disc assessment and static automated perimetry. Peak diurnal intraocular pressure (IOP) and fluctuation were measured for groups A and C. Results: Ninety-two patients were enrolled (32 patients in group A, 43 in group B, and 21 in group C). Mean refractive error differed between group A [-6.59 Diopter sphere (DS); 95% CI, -8.51 to -4.68] and group B (-0.92 DS; 95% CI, -2.05 to 0.19) (P < 0.0001) and C (-0.17 DS; 95% CI, -0.48 to 0.14) (P < 0.0001). Optic disc tilt was more common in group A (31.3%) compared with group B (16.3%, P = 0.01); both groups had comparable vertical cup-to-disc ratios (P = 0.58). The visual field mean pattern standard deviation was higher for group A compared with group B (P = 0.03), whereas mean deviation was similar (P = 0.42); group A had less frequent hemifield defects (P = 0.02). Mean peak diurnal IOP in group A (19.0 mm Hg; 95% CI, 17.3-20.7) was significantly higher than group C (15.8 mm Hg; 95% CI, 14.6-17.0, P = 0.007); mean IOP fluctuation showed no difference (P = 0.19). Ischemic risk factors were more common in group B compared with A (P < 0.0001). Conclusions: Although the clinical features of myopia and glaucoma-like optic nerve changes in young Chinese individuals may allow differentiation from older glaucoma patients of the same ethnicity, such a distinction is not reliable enough to make definitive differential management recommendations for these groups in all circumstances at the present time. A prospective observational study with matching of groups on potentially confounding variables is necessary to better assess and compare the natural history of glaucomatous disease in such groups of patients.