Purpose
The aim of the current study is to investigate the adoption of microperimetry in the follow-up of patients with Stardgardt disease.
Methods
One hundred patients with ABCA4-related Stardgardt disease were followed up for a median time of 2 yrs (range 1 - 3 yrs) by performing the following examinations: ophthalmoscopic exam, best corrected visual acuity (BCVA) and microperimetry. BCVA was measured with Early Treatment Diabetic Retinopathy Study (ETDRS) charts. The fundus lesion were classified according to Fishman stages. Microperimetry was performed by an automatic fundus-related perimeter (MP1 Microperimeter, Nidek Technologies, Padova, Italy). The following parameters were used: a fixation target of 2° in diameter consisting of a red ring; a white, monochromatic background with a luminance of 4 abs; and a Goldman III-size stimulus with a projection time of 200 ms. The following MP parameters were assessed: mean sensitivity, the percentage of fixation points within 2° and within 4° circle.
Results
The patients had the following demographic characteristics: age 8-71 yrs (32 ± 13 yrs), disease length 1-46 yrs (10±8 yrs), age of onset 4 - 51 yrs (21 ± 11). The BCVA ranged from 0.16 to 1 (0.20 ± 0.23). Fundus lesions were classified as Fishman stage I, II and III in 63, 12 and 25 patients, respectively. We observed significant differences of BCVA and mean sensitivity (p<0.05) over the three years: BCVA decreased from 0.27 ± 0.31 to 0.23 ± 0.28 and the mean sensitivity decreased from 9.7 ± 0.31 to 8.4 ± 5.7 dB. In particular, the differences of mean sensitivity occurred earlier (between first year follow-up time-point and baseline) than those of BCVA (between the second year follow-up time-point and the first year follow-up time-point).
Conclusions
The results of this study revealed significant reductions in BCVA and mean sensitivity over a three follow-up of Stardgardt patients. Moreover, the reductions in mean sensitivity assessed by microperimetry appeared to precede the reductions in BCVA up to one year. Our findings suggest that the microperimetry could be an useful tool to follow-up disease progression in Stardgardt disease. Further studies with shorter intervisit interval (i.e. six months) could provide additional information.
Keywords: 494 degenerations/dystrophies •
696 retinal degenerations: hereditary •
642 perimetry