Objective: To evaluate the efficacy and safety of Phacoemulsification-deep sclerectomy modified by trabeculum microperforations and anterior lens capsule as autologous scleral implant (mPDS) for open-angle glaucoma.
Research design and method: A case series study comprised 127 patients and 127 eyes after mPDS. The applied modification of deep sclerectomy consisted in creating microperforations within the posterior trabeculum and in fixing the anterior lens capsule, removed during phacoemulsification, in the scleral lake as an autologous intrascleral implant. Primary open-angle glaucoma without satisfying intraocular pressure (IOP) control (>or=21 mmHg) despite maximally tolerated medications or with progression of visual field and cataract was the indication for surgery. For statistical analyses paired Student's t-test, the Wilcoxon signed rank test and one-dimensional ANOVA with repeated measures were used; survival analysis was performed using the Kaplan-Meier method.
Main outcome measures: IOP, number of medications and best corrected visual acuity (BCVA) were examined. On the basis of the assessment of the anterior and posterior segments of the eye, the character and also the degree of intensification of postoperative complications were established. Follow-up examinations were performed on days 1 and 7, and at 1, 3, 6, 12, 18 and 24 months and thereafter every 6 months. The complete success rate was defined as IOP <or= 18 mmHg without, and the qualified success rate as IOP <or= 18 mmHg with and without antiglaucoma medications.
Results: The mean follow-up was 32.2 +/- 9.1 months. Mean IOP decreased by 30.4%. Mean IOP decreased from 20.1 +/- 5.1 to 14.0 +/- 2.9 mmHg (p < 0.001). The mean number of medications was reduced from 2.2 +/- 0.7 to 0.6 +/- 0.8 (p < 0.001). Complete and qualified success rates were 74.4 % and 93.3 %, respectively. Mean logMAR of BCVA changed from 0.52 +/- 0.40 to 0.16 +/- 0.16 (p < 0.001). Subconjunctival 5-FU injections together with suturolysis because of bleb fibrosis were performed in 20 eyes, which represented 15.7% of the cases operated on. 5-FU-induced complications involved corneal epitheliopathy in nine eyes (7.1 % of cases) and irregular astigmatism in one eye (0.8% of cases). Among early complications the most frequent was transient hypotony observed in 55 eyes (41.7% of cases).
Limitations: The explanation of the role of the anterior capsule in the mechanism of mPDS requires inclusion into the study of histological observations of surgeries performed on an animal model as well as prospective ultrasound biomicroscopy (UBM) examinations performed in humans.
Conclusions: Phacoemulsification-deep sclerectomy modified by trabecular microperforations and anterior capsule as a scleral implant lead to an effective decrease in the IOP in medium-term follow-up. The profile of the observed complications indicates that it can be a safe procedure. However, a larger group of patients should be observed to confirm this.