Abstract
Purpose:
To assess and evaluate functional changes in fundus perimetry during the long-term follow-up of patients with Stargardt’s disease.
Methods:
Fundus perimetry with the SLO (Rodenstock, Gemany) and the Microperimeter 1 (MP1, Nidek, Italy) was performed in 101 eyes of 62 patients with Stargardt’s macular dystrophy. 61 eyes of 38 patients were followed for 1 to 13 years. Depth and size of central scotoma as well as location of fixation (preferred retinal locus, PRL) were documented during static or kinetic perimetry. We analyzed changes of scotoma and PRL in correlation with visual acuity as well as differences between both perimeters.
Results:
Fundus perimetry lasted for 2 to 20 minutes, with shorter times for the SLO for an identical number of locations (median 9.1 versus 11.9 minutes). During the baseline perimetric exam 86% showed an absolute central scotoma which was more precisely delineated using kinetic perimetry. However, remaining central visual field areas were not detected with kinetic technique. During follow-up the size of the central scotoma increased nearly linearly over time with movement of the corresponding PRL more peripherally. PRL showed a nearly pathognomonic vertical deviation and was located at the top of the scotoma in all but 6 eyes especially with markedly reduced visual acuity (≤20/100). Stability of fixation was better during kinetic erimetry and isolated fixation tasks compared with static perimetry. Visual acuity decreased from 20/100 during the follow-up to an end-stage of 20/160.
Conclusions:
Fundus perimetry represents an effective device to evaluate functional changes in Stargardt’s disease and allows documentation of visual deterioration over time more precisely than visual acuity testing alone. Although visual acuity showed only minor changes, the enlargement of the central scotoma with an upward movement of the PRL and varying PRL locations during different visual tasks were observed during fundus perimetry explaining the increasing problems during reading and visual performance over time.
Keywords: 642 perimetry •
585 macula/fovea •
552 imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)