The Macular Hole Coefficient - A Novel Optical Coherence Tomographic Predictive Factor For Macular Hole Closure

1. Anand Rajendran¹
2. Aditi Patwardhan¹
3. Kim Ramasamy¹

¹Aravind Eye Hospital, Madurai, India

Purpose: To evaluate a novel optical coherence tomographic (OCT) mathematical factor to predict type of macular hole (MH) closure post vitrectomy.

Methods: A retrospective, analytical review of macular holes surgeries performed was undertaken. 78 eyes with idiopathic MH that underwent pars plana vitrectomy, internal limiting membrane peeling and gas tamponade were included. Pre- and postoperative clinical, OCT features and acuity gains were analyzed. Zeiss Stratus OCT was used. The type of MH closure was assessed. A novel mathematical parameter, the Macular Hole Coefficient (MHC), ratio of the internal diameter (shortest distance between the edges of the macular hole) to the vertical height of the MH on OCT, was compared to MH closure type and clinical outcome.

Results: Of the 78 eyes, 69 had type 1 (closed without defect); 9 had type 2 (closed with defect) closure .Average MHC for type 1 was significantly lesser [1.73 (SD=0.52)] than those with type 2 closure [3.20 (SD=0.88)] [p< 0. 001] .Statistical analysis was done using STATA software (version 8.1). Visual acuity gain was more significant for type 1 (p<0.001) than type 2 cases (p=0.114) [Paired t-test].

Conclusion: The MHC is a useful mathematical predictor of type of macular hole closure. Macular holes with a lower MHC (< 2.0) had a better chance of attaining type 1 closure while those with a high MHC (> 3.0) were likely to result in type 2 closure. This may help surgeons preoperatively forecast the possibility of achieving a complete (type1) closure and an improved visual outcome.