Risk factors and long term progression in open angle glaucoma patients

Aim: Investigation of perimetric progression rate and associated risk factors in open angle glaucoma, in clinical practice. Methods: Retrospective study based on clinical charts reviews of patients with primary open angle glaucoma (POAG) being followed for > 5 years with >/ = 5 SITA Standard visual fields. Demographics, visual acuity (VA), central corneal thickness (CCT), intraocular pressure (IOP) and IOP variation, treatment (number of medications), visual fields and associated systemic pathologies were recorded. Patients were followed at every 3-6 months, when identical tests were performed. VF progression rate was calculated as slope of mean deviation (MD) over time by Glaucoma Progression Analysis software. Results: 121 eyes of 121 patients with POAG were included in the study and were followed for a mean period of 68.81 months (SD +/ - 31.7). The mean MD at start was -3.55 dB (SD +/ -5.19)., with a mean number of VF tests of 9.3+/ -2.9. Progression rate reached -0.21 +/ -0.1 db/ year. Mean IOP of all visits decreased over time from 18.20 mmHg to 16.53 mmHg (p<0.05). Systemic factors like positive history of hypertension reached statistical relevance in terms of increased risk for glaucoma progression, but only after age and sex were corrected. MD slope was explained in ANOVA univariate analysis, by the level of MD at baseline, IOP baseline, number of topical medications and CCT in a proportion equal to 71.7% (p=0.004). Conclusion: Rate of visual field changes in POAG was correlated and dependent on the baseline MD level, IOP at baseline, number of topical medications and a thin CCT.