Abstract
Purpose :
To evaluate the macular function in highly myopic eyes using microperimetry, and to correlate macular sensitivity with axial length (AL), best corrected visual acuity (BCVA) and the severity of myopic macular degeneration (MMD).
Methods :
This is a clinic-based observational study of 49 eyes of 26 patients with AL ≥ 26.5 mm, enrolled from the high myopia clinic of the Singapore National Eye Centre. AL and anterior chamber depth (ACD) were measured with the IOLmaster. Myopic maculopathy (MMD) was graded from fundus photographs according to the META-PM Classification. Absence of MMD was defined as META-PM category <2, mild MMD as META-PM category 2 and severe MMD as META-PM category 3 or 4. Microperimetry was performed to measure macular sensitivity (MS) at central 6 degrees and 2 degrees. We analyzed the correlation of MS at these points to AL, logMAR BCVA and compared MS across different MMD categories.
Results :
The mean age was 64.2±10.1 years, mean AL was 29.2±3.0mm and mean logMAR BCVA was 0.55±0.65. 3 (6.1%), 6 (12.2%), 20 (40.8%), 14 (28.6%) and 6 (12.2%) eyes were graded as meta PM categories 0, 1, 2, 3 and 4 respectively. MS at 2 and 6 degrees were strongly correlated with AL (r=-0.52 and -0.59 respectively) and BCVA (r=-0.59 and -0.68 respectively). Compared to eyes with no MMD (26.7±1.9), MS at 2 degrees was significantly worse in eyes with mild (22.0±1.3, p=0.05) and severe MMD (19.8±1.5, p=0.007). MS at 6 degrees was significantly worse in eyes with mild (22.8±1.1, p=0.04) and severe MMD (19.1±1.3, p=0.001) compared to eyes with no MMD (26.9±1.6). In contrast, logMAR BCVA was significantly different only between eyes with severe and mild MMD (0.75±0.15 vs 0.32±0.15, p=0.05).
Conclusions :
Macular sensitivity decreased with increasing axial length and worsening severity of MMD. Macular function as measured by microperimetry may be a more sensitive marker of visual function than visual acuity in eyes with MMD.
This is a 2020 ARVO Annual Meeting abstract.