Abstract
Purpose: :
A recently developed fundus microperimeter (MP–1) was used to evaluate fixation patterns in patients with various macular diseases
Methods: :
In an observational case series study, consecutive series of 64 patients with various macular diseases were studied by means of MP–1 microperimetry. Patients were divided into groups according to stability and position of fixation. The following parameters were documented: age, type of pathology, visual acuity, refractive power, presence or absence of age related macular degeneration, presence or absence of proliferative diabetic retinopathy, vitreomacular traction, and cystoid macular changes. All variables were compared in each group.
Results: :
Thirty–two eyes (50%) had predominantly central fixation, 20 eyes (31.3%) had poorly central fixation and 10 eyes (15.6%) had predominantly eccentric fixation. Thirty (46.9%) had stable fixation, 21 eyes (32.8%) had relatively unstable fixation and 13 eyes (20.3%) had unstable fixation. Thirty eyes (46.9%) showed both a stable and predominantly central fixation. There were significant differences in visual acuity between the groups of patients with poorly central fixation (0.5 ± 0.3) and predominantly eccentric fixation (0.9 ± 0.2), and the group with predominantly central fixation (0.2 ± 0.2) (P<0.05). Similarly, there were significant differences in visual acuity between the groups of patients with relatively unstable fixation (0.7 ± 0.4) and unstable fixation (0.9 ± 0.5), and the group with stable fixation (0.2 ± 0.2) (P<0.05). The prevalence of macular changes was significantly higher in the groups with poorly central fixation (75%) and predominantly eccentric fixation (100%) than in the group with predominantly central fixation (16.64%) (P<0.05). Presence of macular scotoma was significantly higher in patients having poorly central and predominantly eccentric fixation (7.0 ± 4 and 7.3 ± 3% respectively) (P<0.05) and in patients showing relatively unstable and unstable fixation (7.0 ± 4 and 7.2 ± 3%, respectively) (P<0.05).
Conclusions: :
In our sample patients who had large macular scotoma with decrease in retinal sensitivity from retinal pathology (Scar, atrophy, macular edema, choroidal neovascular membranes) showed deterioration of fixation. The univariate analysis suggested a link between density of macular scotoma, visual acuity, presence of cystoid macular changes, vitreo–macular adhesion and fixation patterns. Poor stability and centrality of fixation seem strongly related to the density of scotoma
Keywords: retina • perimetry • visual fields