Abstract
Purpose: :
To assess clinical features and rates of visual field (VF) change in glaucoma patients with distinct optic disc phenotypes.
Methods: :
Retrospective observational cohort. Glaucoma patients with 8 or more 24-2 SITA VF tests (n=392) with baseline and final follow-up stereo photographs between January 1999 and July 2009 were reviewed by 2 investigators masked to all clinical and perimetric data. Each disc was classified by criteria described by Drance & Nicolela: focal ischemic (FI), myopic (M), senile sclerotic (SS), and generalized enlargement (GE). Disagreements were adjudicated after consensus. Discs that could not be classified into one of these categories were excluded from analysis. VF progression (defined as at least 2 adjacent test points in the same hemifield progressing >1/0 dB/yr at p<0.01) was evaluated using automated pointwise linear regression (PLR). Also reviewed were age, gender, race, central corneal thickness (CCT), intraocular pressure (IOP, mean, peak, and fluctuation), disc hemorrhage (DH) and beta-zone PPA (βPPA), and PSD and MD data from baseline VFs.
Results: :
127 GE, 41 FI, 54 M, and 42 SS discs were reviewed. 128 eyes could not be classified into any of the categories and were excluded from analysis. Patients with SS discs were significantly older than the other categorized patients (68.5±1.9 yrs, p<0.01). There were more men in the M group (52%, p=0.12). SS group showed worse baseline VF MD (-8.49±0.64 dB, p<0.01). IOP mean, peak, and fluctuation were significantly greater in the GE group (16.0±0.2; 20.9±0.4; and 2.6±0.1 mmHg, respectively, p<0.01). CCT differed significantly among groups, even though FI tended to show decreased values (536.7±6.1 µm, p=0.78). More DH were detected in the FI (17%) and SS (19%) groups (p=0.01). The percentage of βPPA was greater in the M (96%) and SS (100%, definition criterion) groups (p<0.01). The SS group showed more rapid but not significant global rates of VF change than the other groups (-0.5±0.1 dB/yr, p=0.72). After adjusting for co-variates, the number of eyes reaching a progression endpoint did not differ among groups (GE,30%; FI,29%; M,29%; SSE,28%, p=0.99).
Conclusions: :
Glaucomatous eyes with different optic disc phenotypes showed different clinical features. However, the 4 groups showed similar VF outcomes despite these differences. Optic disc phenotypes should not be considered independent risk factors for rapid VF progression.
Keywords: optic nerve • visual fields