PURPOSE: To assess the factors associated with malignant glaucoma (MG) following intraocular surgery. DESIGN: Retrospective case-control study. SETTING: Institutional. STUDY POPULATION: A total of 40 eyes with MG and 80 controls were included. METHODS: A total of 40 patients who developed malignant glaucoma following intraocular surgery between January 1995 and December 2013 were compared with 80 age- and gender-matched controls who underwent surgery during the study period. MAIN OUTCOME MEASURES: The associated factors for the development of malignant glaucoma following intraocular surgery. RESULTS: Diagnosis in cases included primary angle closure glaucoma (PACG: 31 [77.5%]), primary open-angle glaucoma (POAG: 2 [5%]), pseudoexfoliation glaucoma (PXFG: 4 [10%])
in controls included PACG 44 (55%) and POAG 36 (45%), (P <
0.001). Trabeculectomy was performed in 24 cases (50%) and 28 (35%) controls, phaco-trabeculectomy in 14 cases (35%) and 52 eyes (65%) in controls, and cataract surgery in 2 cases (5%) (P = 0.004). Factors associated on univariate analysis included PACG (odds ratio [OR]: 12.68, 95% confidence interval [CI]
2.84, 56.62, P <
0.001, synechial angle closure >
180° (OR: 10.1, 95% CI: 2.87, 35.44, P <
0.001, higher preoperative IOP >
22 mmHg (OR: 5.32, 95% CI: 2.64, 10.73, P <
0.001), trabeculectomy (OR: 3.05, 95% CI: 1.36, 6.83, P = 0.007) and axial length <
22 mm (OR: 6.80, 95% CI: 2.51, 18.46, P <
0.001. The use of postoperative cycloplegics was protective on univariate analysis (OR: 0.268, 95% CI: 0.12, 0.596), P <
0.001). Preoperative IOP >
22 mmHg (2.85, 95% CI: 1.11, 7.31, P = 0.02), and trabeculectomy (OR: 4.09, 95% CI: 1.48, 11.3, P = 0.007) remained significant on multivariate analysis. CONCLUSION: PACG eyes with higher preoperative IOP and eyes undergoing trabeculectomy surgery alone, increased the likelihood of developing MG.