Abstract
Purpose::
To evaluate baseline characteristics in glaucoma patients with distinct optic disc phenotypes.
Methods::
Open-angle glaucoma patients followed in the glaucoma clinic of the Eye Care Centre (Dalhousie University, Halifax, NS) with focal, diffuse or sclerotic types of optic disc damage were consecutively identified using optic disc photographs and eligible patients were invited to participate in this longitudinal study designed to evaluate rates of progression in the three groups. Patients were evaluated every 4 months with automated perimetry, scanning laser tomography, scanning laser polarimetry, optical coherence tomography and stereophotography of optic discs, among other tests (not all tests performed in every visit). In this study we report on the baseline characteristics and initial results of the study.
Results::
136 patients were enrolled (48 with focal, 44 with sclerotic and 44 with diffuse optic disc phenotypes). After a mean follow-up of 16 + 7 months, 4 patients were lost follow-up (attrition rate of 2.2%/year). Patients with diffuse disc damage were younger than the other two groups (63 years old, versus 69 and 72 for the focal and sclerotic groups respectively; p<0.05). There were more females in the focal group (62%, compared to 54% and 39% for sclerotic and diffuse groups respectively; p<0.05). Untreated IOP was higher in patients with diffuse disc damage (27+ 8 mmHg) than in patients with focal or sclerotic damage (25 + 8 and 23 + 8 mmHg respectively, p<0.05). The prevalence of self reported systemic diseases such as diabetes, hypertension, heart disease, stroke, sleep apnea and migraine did not differ significantly between the groups, although patients with sclerotic damage had the highest prevalence of ischemic heart disease (30%) and patients with focal damage had the highest prevalence of migraine (28%). The prevalence of optic disc haemorrhages identified on optic disc photographs at baseline was 10.4% in the focal group, 0% in the diffuse group and 6.8% in the sclerotic group.
Conclusions::
Several demographic and clinical characteristics differ among patients exhibiting different optic disc phenotypes followed in this prospective study, confirming previous findings from cross-sectional studies. These findings suggest possible distinct pathogenic mechanisms associated with these various optic disc phenotypes. This study will provide us the ability to evaluate progression rates in each of these groups as well as to better identify risk factors specific to each optic disc phenotype.
Keywords: optic nerve • clinical (human) or epidemiologic studies: outcomes/complications • intraocular pressure