Visualization of the trabeculo-Descemet membrane in deep sclerectomy after Nd:YAG goniopuncture: an in vivo confocal microscopy study.

Objectives: To evaluate the morphologic characteristics of the trabeculo-Descemet membrane (TDM) by in vivo confocal microscopy (IVCM) after deep sclerectomy with collagen implant and to correlate the findings with the intraocular pressure (IOP)-lowering effect of goniopuncture.

Methods: Twenty eyes of 19 patients were evaluated in a prospective, observational case series. Examination using IVCM and measurement of IOP were performed 15 minutes before and 15 minutes after Nd:YAG goniopuncture.

Results: Two groups could be distinguished on the basis of morphologic characteristics of the TDM before goniopuncture. In group 1 (13 eyes), the TDM was characterized by the presence of an area of epithelial cells in the deep stromal level. After goniopuncture, an opening at the TDM with dispersed epithelial cells was visible. In group 2 (7 eyes), fibrotic tissue overlying the TDM was observed in all cases, and no openings were visible after goniopuncture. Group 1 had a statistically significant decrease in mean (SD) IOP after goniopuncture (21.6 [4.8] mm Hg before and 13.5 [4.6] mm Hg after, P = .008); there was no significant change in group 2 (19.2 [4.3] mm Hg before and 20.8 [7.5] mm Hg after, P = .30). There was a strong correlation between the presence of fibrous tissue and percentage of IOP lowering after goniopuncture (ρ = -0.89, P < .001).

Conclusions: The presence of fibrotic tissue covering the TDM is associated with failure of goniopuncture. Use of IVCM may be valuable in predicting the efficacy of goniopuncture in patients with elevated IOP after deep sclerectomy with collagen implant.