Purpose:
To investigate the rates of visual field (VF) and optic disc (OD) progression in patients with open angle glaucoma (OAG) and different patterns of optic disc damage.
Methods:
136 patients with OAG were enrolled in a prospective longitudinal study after having the study eyes classified as focal, diffuse or sclerotic optic disc damage. They were examined every 4 months with standard automated perimetry (SAP, 24-2 SITA Standard test) and Heidelberg Retinal Tomography (HRTII) for a period of 4 years. Patients were treated according to a predefined study protocol to achieve a target intraocular pressure (IOP). Mean Deviation (MD) and point-wise linear regression of total deviation/age were used to assess VF progression (MD slope worse than -0.5 dB/year [P<0.05] or at least a two-cluster point in the same hemifield with a slope worse than -1.0 dB/year [P<0.01]). Linear regression of global and sectoral rim area/age was used to assess HRT progression (global rim area slope worse than -10.0 mm2 x 10-3/y [P<0.05] or 2 sectors with a slope worse than zero [P<0.05]). Due to differences among the groups in baseline age (P=0.001), MD (P=0.001), and rim area (P=0.008), these covariates were included as predictors in a multivariate logistic regression analysis.
Results:
121 eyes from 121 patients with focal (40), diffuse (40) and sclerotic (41) qualified for this analysis. Mean (SD) baseline age, MD and rim area was 68.2 (11.2) yrs, -4.4 (3.2) dB, and 1.17 (0.29) mm2, respectively. IOP reduction from untreated levels and mean IOP during the follow-up were similar among the 3 groups (P=0.57 and P=0.06). Forty-seven (39%) patients met the criteria for SAP or HRT progression overall, 18 (38%) in SAP only, 23 (49%) in HRT only and 6 (13%) in both. Figure 1 shows progression in VF and OD among the groups. The differences in progression among the groups were not significantly influenced by the covariates analyzed.
Conclusions:
Patients with focal optic disc damage were more likely to present progression in both VF and OD. Moreover, the focal group had more agreement between SAP and HRT analysis of progression.
Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • imaging/image analysis: clinical • visual fields