Correlation between macular structure and function in patients with age-related macular degeneration treated with intravitreal ranibizumab: 12-month-results.

PURPOSE: To determine the significance of the correlation between optical coherence tomographic (OCT) findings and focal macular electroretinograms (fmERG) at 12 months after beginning intravitreal injections of ranibizumab (IVR) in eyes with age-related macular degeneration (AMD).

STUDY

DESIGN

Prospective, clinical study.

METHOD: We studied 28 eyes of 28 patients with AMD treated with IVR at monthly intervals for the initial three months. Additional IVR was given according to a pro re nata (PRN) regimen. OCT and fmERGs were performed preoperatively and at 3 and 12 months postoperatively. The fmERGs were elicited by a 15° white stimulus spot centered on the fovea. The thickness of the inner, middle, and outer layers of the retina and also of the serous retinal detachment (SRD) and pigment epithelial detachment (PED) in the horizontal and vertical meridians at 1.2 mm from the fovea (parafoveal) were measured in the OCT images.

RESULTS

The b-wave amplitude at 12 months was significantly correlated with the thicknesses of the outer retinal layer, SRD, and PED (P=0.001-0.02). Multiple regression analyses showed that the outer retinal layer thickness was an independent determinant (P= 0.0001). The changes in the b-wave amplitude between the baseline and 12 months were significantly correlated with the changes in the SRD thickness (P=0.006). The changes in the b-wave amplitude during the PRN period were significantly correlated with the changes in the PED thickness (P=0.02).

CONCLUSIONS

At 12 months after beginning treatment, the reduction in the SRD thickness affects macular function recovery. As recurrences of the PED can occur during the PRN period, control of the PED is necessary to obtain good macular function for the long term.