Macular Ectasia (Maculoconus) in Myopic Posterior Staphyloma

1. Sung Soo Kim MD, PhD¹
2. Hyoung Eun Kim MD¹
3. Won Kyung Song MD²

¹Department of Ophthalmology, Yonsei University College of Medicine, Gangnam Severance Hospital, Seoul, Korea
²Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Republic of Korea

Purpose: To describe posterior staphyloma involving the center and inferior part of the macula (Macular Ectasia) detected by Spectral Domain Optical Coherence Tomography (SD-OCT) and to investigate the effect of angle between optical axis and foveal center axis (AOF) on visual acuity in macular ectasia without complication.

Methods: The study enrolled 11 eyes with macular ectasia (ME group) and sixteen normal controls (control group). Best corrected visual acuity (BCVA), ocular axial length, and the macular configuration including 5 line raster scan (Horizontal and Vertical) and macular cube scan was obtained by SD-OCT. The AOF were calculated by ImageJ software.

Results: ME group showed significantly poorer Snellen BCVA (0.69 vs. 0.96) and wider AOF (9.04° vs. 4.26° in horizontal plane) compared to control. (p<0.001) The AOF of ME group was wider in vertical plane (Mean 31.69°, p<0.001) than in horizontal plane (Mean 9.04°, p=0.014) compared to control. The degree of AOF was not correlated with BCVA in macular ectasia group at vertical and horizontal plane(r=0.084, p=0.817 and r=0.414, p=0.235, respectively).

Conclusions: Macular ectasia may be a cause of unexplained visual impairment in myopia patients without other macular complications. Difference in AOF between horizontal and vertical plane in macular ectasia may induce irregular astigmatism similar to keratoconus. (Maculoconus) SD-OCT can detect subclinical macular ectasia and macular cube scan may be useful to screen macular ectasia in posterior staphyloma.