The Relationship between Myopic Regression and the Progression of Normal-Tension Glaucoma after Refractive Correction Surgery

Purpose To investigate the relationship between the degree of myopic regression following refractive surgery and the progression of normal-tension glaucoma (NTG). Methods We retrospectively analyzed the age, axial length, corneal thickness, refractive error, and visual acuity, intraocular pressure, retinal nerve fiber layer (RNFL) thickness, ganglion cell inner plexiform layer thickness, and visual field test results at initial presentation and after follow-up in patients diagnosed with NTG following LASIK or LASEK surgery. We examined the factors that significantly differed between the groups with and without myopic regression and analyzed the relationship between the degree of myopic regression and glaucoma progression indicators using linear regression analysis. We also divided patients into groups with fast and slow RNFL thickness changes and analyzed the associated factors. Additionally, we identified the factors influencing the rate of RNFL thickness change using logistic regression analysis. Results Significant differences were observed between patients with and without myopic regression in initial visual acuity, axial length, post-follow-up visual acuity, RNFL thickness, mean deviation, visual field index, and the rate of RNFL thickness change. Linear regression analysis showed a significant relationship between the degree of myopic regression and the rate of RNFL thickness change (B = 0.333, p = 0.050). Patients with a slower rate of RNFL thickness change (average -0.23 µm/year) and those with a faster rate had significantly different degrees of myopic regression (-0.96 ± 0.72 D and -1.66 ± 1.22 D, respectively; p = 0.007). Logistic regression analysis indicated that the degree of myopic regression was the only significant factor influencing the rate of RNFL thickness change (Exp[B] = 0.469, p = 0.014). Conclusions The degree of myopic regression following refractive surgery is related to the rate of RNFL thickness change, an indicator of NTG progression.