Clinical Predictors of the Region of First Structural Progression in Early Normal-tension Glaucoma

ABSTRACT

Purpose@#This study aimed to compare the clinical characteristics of patients who showed structural progression in the peri-papillary retinal nerve fiber layer (RNFL) first against those who showed progression in the macular ganglion cell-inner plexi-form layer (GCIPL) first and to investigate clinical parameters that help determine whether a patient exhibits RNFL or GCIPL damage first. @*Methods@#A retrospective review of medical records of patients diagnosed with early-stage normal-tension glaucoma was performed. All eyes underwent intraocular pressure measurement with Goldmann applanation tonometer, standard auto-mated perimetry, and Cirrus optical coherence tomography at 6-month intervals. Structural progression was determined using the Guided Progression Analysis software. Blood pressure was measured at each visit. @*Results@#Forty-one eyes of 41 patients (mean age, 52.6 ± 16.7 years) were included in the study. In 21 eyes, structural pro-gression was first detected in the RNFL at 54.2 ± 14.8 months, while structural progression was first observed at the macular GCIPL at 40.5 ± 11.0 months in 20 eyes. The mean intraocular pressure following treatment was 13.1 ± 1.8 mmHg for the RNFL progression first group and 13.4 ± 1.8 mmHg for the GCIPL progression first group (p = 0.514). The GCIPL progression first group was older (p = 0.008) and had thinner RNFL at baseline (p = 0.001). The logistic regression analyses indicated that both age and follow-up duration until first progression predicted the region of structural progression (odds ratio, 1.051; 95% confidence interval, 1.001–1.105;p= 0.046 for age; odds ratio, 0.912; 95% confidence interval, 0.840–0.991; p = 0.029 for time until progression). @*Conclusions@#Age of glaucoma patients and time until progression are associated with the region of the first structural pro-gression in normal-tension glaucoma. Further studies exploring the association between glaucomatous progression and the location of damage are needed.