Quantitative measurements of the ciliary body in eyes with malignant glaucoma after trabeculectomy using ultrasound biomicroscopy

Purpose: To evaluate and compare the structural differences of the ciliary body in eyes with and without malignant glaucoma.

Design: Cross-sectional study.

Participants: Twenty-seven consecutive patients diagnosed with malignant glaucoma in 1 eye after trabeculectomy were recruited. They were all originally diagnosed with primary angle closure (PAC) or PAC glaucoma (PACG). Twenty-seven PAC/PACG eyes of 27 patients who had undergone uneventful trabeculectomy in the same period were also recruited. They were comparable with the fellow eyes of the malignant glaucoma patients in terms of surgical type, glaucoma type, and stage.

Methods: A-scan ultrasonography and ultrasound biomicroscopy measurements were performed on the eyes with malignant glaucoma, the fellow eyes of the patients with malignant glaucoma, and the matched eyes.

Main outcome measurements: Ciliary body parameters included maximum ciliary body thickness (CBTmax), ciliary body thickness at the point of the scleral spur (CBT0) and 1000 μm from the scleral spur (CBT1000), anterior placement of the ciliary body (APCB), and the trabecular-ciliary process angle (TCA). Biometric measurements including axial length, central anterior chamber depth (ACD), pupil diameter (PD), anterior chamber width, and lens vault (LV) were also recorded.

Results: Average CBTmax were 0.545±0.088 (mean ± standard deviation), 0.855±0.170, and 0.960±0.127 mm in eyes with malignant glaucoma, their fellow eyes, and the matched eyes, respectively. Average APCB were 0.860±0.176, 0.608±0.219, and 0.427±0.139 mm, respectively. Average TCA were 18.49±4.12, 41.79±17.27, and 48.53±10.38 degrees, respectively. The CBTmax, CBT0, CBT1000, and TCA were smaller, whereas APCB was larger in eyes with malignant glaucoma compared with their fellow eyes (P < 0.01). The fellow eyes had larger APCB and smaller CBTmax and CBT0 than the matched eyes (P < 0.05). The ACD, anterior chamber width, and PD were smaller, whereas LV was larger in eyes with malignant glaucoma compared with their fellow eyes (P < 0.05). No differences were found in the ACD, anterior chamber width, PD, or LV between the fellow eyes of malignant glaucoma and matched eyes (P > 0.1).

Conclusions: The ciliary bodies were thinner and more anteriorly rotated in eyes with malignant glaucoma as well as in their fellow eyes, which may be the predisposing factor for malignant glaucoma.