Simultaneous use of amniotic membrane and Mitomycin C in trabeculectomy for primary glaucoma

Abstract

Purpose: This study aimed to propose the role of amniotic membrane transplantation (AMT) as an additional modulator in primary Mitomycin C (MMC)-augmented trabeculectomy.

Methods: This was a randomized prospective interventional study. Forty eyes of 39 adult patients with uncontrolled primary glaucoma were randomly divided into two equal groups. Control group underwent trabeculectomy augmented with MMC while the study group underwent additional AMT. Patients were followed up for 12 months and outcomes measured were intraocular pressure (IOP), need for additional intervention, and bleb morphology.

Results: Complete success (defined as IOP <16 mmHg on no medication) could be achieved in 85% eyes in study group while it was 60% in control group (P = 0.04). IOP reduced by 71.1% in study group from 41.9 ± 10.6 to 12.1 ± 2.7 mmHg and from 40.5 ± 8.5 to 12.8 ± 4.5 mmHg in control group, a decline of 68.29%. Blebs in AMT group showed better bleb morphology in terms of significantly better extent (E3) on day 1 (P = 0.03) and better height (H2 and H3) (P = 0.04), according to the Indiana Bleb Appearance Grading Scale, at all follow-up visits along with normal vascularity. The study group required significantly lesser (P = 0.03) bleb needlings as compared to control group.

Conclusion: Amnion enhanced the efficacy of MMC-modulated trabeculectomy in terms of eyes with complete success and lesser interventions such as bleb needling. This reiterates the role of amnion as a safe and effective bleb modulator. A diffusely elevated bleb with healthier conjunctiva can go a long way in predicting better health and longevity of the bleb.

Figure 1

Mean intraocular pressure at follow-up visits

Figure 2

Height of blebs in Groups A and B postoperatively at day 1, 6 months, and 12 months. H0: Flat bleb without visible elevation, H1: Low bleb elevation, H2: Moderate bleb elevation, H3: High bleb as compared to standard images

Figure 3

Three-month postoperative photograph of a patient in Group A showing a bleb with normal vasculature, diffuse bleb, and glistening conjunctiva

Figure 4

Three-month postoperative photograph of a patient in Group B showing a pale bleb

Figure 5

Extent of blebs in Groups A and B postoperatively at day 1, 6 months, and 12 months. E0: No visible bleb extent or <1 clock hour, E1: Extent ≥1 clock hour but <2 clock hours, E2: Between 2 and 4 clock hours, E3: Extent ≥4 clock hours

Figure 6

Vascularity of blebs in Groups A and B postoperatively at day 1, 6 months, and 12 months. V0: Avascular/white (no microcysts visible on slit-lamp examination), V1: Avascular/polycystic (microcysts of the conjunctiva visible on slit-lamp examination), V2: Mild vascularity, V3: Moderate vascularity, V4: Extensive vascularity (vascular engorgement)