Implante laminar de drenagem para o tratamento cirúrgico de glaucoma refratário em olhos cegos dolorosos: técnica cirúrgica, efeitos sobre a pressão intraocular, sobre a dor e complicações pós-operatórias

Abstract

Introduction: Glaucoma drainage devices (GDD) have been used more frequently in recent years, as studies have proved that its efficacy and safety are comparable with those of trabeculectomy. Trying to achieve better results, a new device was used - Laminar Drainage Implant (LDI). Objective: To evaluate, in painful glaucomatous blind eyes, results of surgery using LDI, whose thickness is smaller than that of other GDD. Patients and Methods: From 2011 to 2016, a prospective non-controlled experimental study was conducted with 15 patients with absolute glaucoma (intraocular pressure - IOP30mmHg, despite maximal antiglaucoma medication) associated with ocular pain refractory to clinical therapy. LDI was used in the surgery of these patients. The study was approved by the institutional review boards at the Federal University of Minas Gerais (COEP/UFMG) and National Research Ethics Commission (CONEP), and was conducted at Hospital São Geraldo (Hospital das Clínicas/UFMG). Pre and postoperative variables were compared in each patient (IOP, ocular pain intensity, biomicroscopy findings and postoperative complications). Eight patients were evaluated postoperatively with anterior segment optical coherence tomography (OCT). Significance level considered was 0.05. Results: Follow-up time ranged from six to 24 months with a median of 24 months. Preoperative mean IOP was 53.6±5.3mmHg (n=15) and was reduced to 38.6±11.8mmHg (n=11) and to 37.0±15.5mmHg (n=10) at 12 (n=13) and at 24 (n=11) months after surgery, respectively, without glaucoma medication (p=0.002 and 0.003, respectively). Median of subjective pain intensity (in a scale from zero to 10) was 10 before surgery and lowered to zero at 12th and 24th months of follow-up (p=0.001 in both visits). In preoperative period, 80.0% (n=15) of patients presented conjunctival hyperemia, what was lowered to 23.1% (n=13) and to 33.3% (n=12), 12 and 24 months after surgery, respectively (p=0.031 in both visits). Corneal edema was present in 85.7% (n=14) of patients before surgery and its frequency reduced to 15.4% (n=13) and to 16.7% (n=12) at 12th and at 24th months after surgery, respectively (p=0.039 and p=0.016, respectively). There were no devastating intraoperative complications and no cases of LDI extrusion or endophthalmitis during postoperative follow-up. Images from anterior segment OCT showed probable liquid reservoir (hyporeflective spaces) between LDI plate and sclera in 100.0% of patients, and between LDI plate and conjunctiva in 37.5%. In scleral tunnel, image suggestive of liquid around LDI was present in 37.5% of patients. Conclusions: LDI surgery resulted in clinically significant IOP and pain reduction, rising as a new therapeutic option in patients with absolute glaucoma and painful eyes. There were no severe complications, suggesting that LDI might be tested in glaucoma eyes with vision. OCT images suggested LDI drains aqueous humor from anterior chamber to subconjunctival space.