Comparison of efficacy and early surgery-related complications between one-quadrant and two-quadrant microhook ab interno trabeculotomy: a propensity score matched study.

PURPOSE

We compared the 1-year outcomes and early surgery-related complications between 1-quadrant and 2-quadrant microhook ab interno trabeculotomy (TLO).

METHODS

Medical chart extraction was performed on 47 consecutive patients with 1-quadrant incision and 37 consecutive patients with 2-quadrant incision of trabecular meshwork. Logistic regression analysis was conducted to calculate the propensity score to create a 1:1 match for a comparative analysis of 1-year postoperative success. Success was defined as postoperative intraocular pressure (IOP) between 5-21 mmHg, >20% IOP reduction from baseline, and no additional glaucoma surgery. Outcome-related covariates were age, glaucoma type, mean deviation of visual field tests, preoperative IOP, the number of preoperative glaucoma eye drops and the presence of combined cataract surgery. Thirty eyes from each group were compared.

RESULTS

The median preoperative IOP was not different between the 1-quadrant and 2-quadrant groups (28.5 mmHg, quartile range 23-33.5 versus 27 mmHg, 23.3-30.0, p = 0.47). There was no difference in median postoperative IOP at 1 year (15 mmHg versus 16 mmHg, p = 0.80). The success rate was 73% in the 1-quadrant group versus 70% in the 2-quadrant group (p = 1.00). The 2-quadrant group had a significantly higher proportion of patients with transiently elevated IOP (47%) than the 1-quadrant (17%; Fisher's exact test, p = 0.02). There was no difference of hyphema formation (Fisher's exact test, p = 0.18).

CONCLUSION

The 1-year success rate was not significantly different between 1- and 2-quadrant incisions of microhook TLO. However, the 2-quadrant TLO showed significantly higher proportion of post-surgical transient IOP elevation.