Assessment of Foveal Microstructure and Lucencies Using High Density Radial Scanning Protocol On SD-OCT and Correlation with Visual Recovery following Macular Hole Surgery

Abstract

Purpose: To evaluate the foveal microstructures using high density radial SD-OCT scans and their correlation with visual recovery following macular hole (MH) surgery with or without internal limiting membrane (ILM) peeling for idiopathic full thickness MH (FTMH).

Methods: Retrospective series of 25 eyes of 24 patients with ≥6 months follow-up and registered serial 24-line radial Spectralis SD-OCT scans. Individual B scans were analyzed to evaluate preop MH minimum linear diameter (MLD), height, basal hole diameter (BHD), inner opening diameter (IOD) and postop foveolar lucency zone (FLZ) horizontal and vertical size, external limiting membrane (ELM) and ellipsoid zone (EZ) recovery.

Results: Mean age was 69.6±7.4 years, 18 patients (75%) were female and 6 eyes (24%) were pseudophakic preop. 23/25 eyes (92%) underwent ILM peel and all received 30% SF6 tamponade. All holes closed. Average preop BHD was 633.5±355.6µ, MLD 266.9±140µ, height 377.8±123.7µ and IOD was 379.6±126.2µ<br /> Visual acuity (logMAR) improved from 0.66±0.16 preop to 0.43±0.24 at 3, 0.40±0.23 at 6 and 0.32±0.21 at 12 months (all p<0.001).<br /> Mean postop FLZ size was 117.7±110.2µ (horizontal) and 35.2±21.2µ (vertical) at 1 month, reducing to 95.0±6.3 (p=0.03) and 29.5±13.6µ (p=0.02) at 3, 77.9±35.5 (p=0.003) and 25.2±7.4µ (p=0.04) at 6 and 39±11.4 (p=0.04) and 22±7.8µ (p=0.02) respectively at 12 months. Preop BLD was predictive (p<0.05) of horizontal FLZ size at 1 (r=0.5), 3 (r=0.83) 6 (r=0.71) and 12 months (r=0.63). ELM recovered in all cases at 1 month. Mean percentage EZ recovery defined as proportion of radial scans with intact EZ was 61.5±36.5% at 1 month, 86.7±23.3% at 3 (p<0.001), 87.7±23.8% at 6 (p<0.001) and 88.3±26 % at 12 months (p<0.001). Mean EZ defect was 167.6±208.2µ at 1 month, 120.8±166.3µ at 3 (p=0.03), 54.7±43.9µ at 6 (p=0.02) and 42.8±47.1µ at 12 months (p=0.03). EZ defect at 6 (r=0.43) and 12 months (r=0.70) moderately correlated with vision. Horizontal and vertical FLZ sizes at 1 month were moderately predictive of vision at 6 (r²=0.33 and 0.27) and 12 months (r²=0.11 and 0.11).

Conclusions: 76% of eyes showed FLZ at 1 month and its size was moderately predictive of visual outcomes. FLZ decreased in size and incidence over 12 months. Preop BLD was predictive of FLZ size. EZ defect significantly improved postop and correlated with visual recovery.