Comparing fixation location and stability in patients with neovascular age-related macular degeneration treated with or without Ranibizumab.

PURPOSE

To compare fixation location and stability in patients with neovascular age-related macular degeneration (AMD) treated with or without ranibizumab.

METHODS

Patients were recruited from the Macular Clinic of the King's College Hospital in London. Two groups of patients with neovascular AMD with at least 12 months of follow-up were included in the study. The treated group was treated with ranibizumab while the untreated group did not have any treatment. Best corrected visual acuity (BCVA) with modified ETDRS chart, fixation location and stability as measured with Nidek MP1, central retinal thickness as measured by Zeiss Cirrus SD-optical coherent tomography (OCT), and lesion size as measured by Topcon TRC-50IX camera were analysed and correlated.

RESULTS

In total, 102 eyes were included in the study with 76 in the ranibizumab-treated group and 26 in the untreated group. There were no significantly demographic differences between the two groups. However, as expected, the treated group has significantly better vision (48.5 vs 15.5 letters, P < 0.0001) and smaller lesions (10.8 vs 18.3 mm(2), P = 0.004), the central macular thickness as measured by OCT also showed a trend of normalised macular thickness (252 vs 282 microns, P = 0.07). The location of fixation was significantly more central in the ranibizumab-treated group (χ(2) 17.9, P < 0.0001) with over 50% of eyes with predominantly central fixation. Majority (84.6%) of the patients in the untreated group had predominantly eccentric fixation. Fixation stability was significantly better in the ranibizumab-treated group as compared with the untreated group, using both the software provided by the MP1 machine (χ(2) 21.8, P < 0.0001) and the mean log bivariate contour ellipse area calculated from the raw data obtained from the machine (3.64 vs 4.39 in treated and untreated group respectively, P < 0.0001).

CONCLUSION

Low vision rehabilitation strategy for this group of patients in the ranibizumab era will be very different from those used in untreated patients with dense central scotoma. Further studies on the visual rehabilitation in the ranibizumab-treated patients should consider fixation characteristics of the patients.