Study design
We performed a single center, retrospective review of all patients undergoing combined ELT and phacoemulsification from January 2017 to October 2021. The study followed the tenets of the Declaration of Helsinki. Every participant signed an IRB-approved informed consent before the surgery was performed. Sixty-two eyes of 44 patients were included. All the surgeries were performed by 3 experienced surgeons (EA, LP, SF).
Eligibility criteria for treatment was medically controlled mild glaucoma or ocular hypertension and presence of a visually significant cataract.
Before surgery, all patients had a complete ophthalmologic examination. The evaluation included manifest refraction, slit-lamp biomicroscopy, Goldmann applanation tonometry, binocular indirect ophthalmoscopy through a dilated pupil, corneal topography, (Orbscan II; Bausch & Lomb, Rochester, NY, USA), pachymetry (ultrasound pachymetry; Corvis ST; OCULUS, Wetzlar, Germany), optic nerve and macular optical coherence tomography (OCT) (CIRRUS HD-OCT 5000; Carl Zeiss Meditec, Jena, Germany) and visual field assessment (Humphrey Field analyzer 3; Carl Zeiss Meditec, Jena, Germany). Optic biometry was performed to every patient before surgery (IOL master 700; Carl Zeiss Meditec, Jena, Germany).
Data collection was performed through individual chart review and registered into a standardized study spread sheet by one investigator (R.P). Collected variables were the following: age, gender, eye, preoperative and postoperative (3-months, 1-year and at final visit in cases with ≥ 1 year of follow-up) corrected distance visual acuity (CDVA), manifest refraction, type of glaucoma, cup to disc ratio, IOP, glaucoma medication requirements (preoperative, 1-day, 1-week, 1-month, 3-months, 6-months, 1-year and > 1-year). Preoperative and postoperative RNFL thickness, preoperative and postoperative visual field mean defect (MD) and visual field index (VFI).
Surgical procedure
After sub-Tenon anesthesia and patient preparation, a standard phacoemulsification through a clear corneal 2.4-mm incision and posterior chamber intraocular lens implantation was performed. Acetylcholine was injected, to achieve a better visualization of the trabecular meshwork. The laser treatment (ExTra Laser System, MLase AG, Germany) was performed under viscoelastic stabilization in the anterior chamber. With direct gonioscopic visualization, the ELT probe was advanced bevel up, through the anterior chamber and placed in direct contact with the trabecular meshwork. A foot pedal system was used to apply the laser energy. Ten microchannels were created over 90 degrees, 500 μm apart at the inferior-nasal or at the inferior-temporal quadrant.
After the procedure, patients were instructed to either stop all or continue some of their glaucoma medications as per surgeon preference. Typically, patients used a combination of antibiotic and steroid drops 3 or 4 times a day while awake and tapered over 2–4 weeks.
Statistical analysis and outcome parameters
Outcome variables were tested for normality with Shapiro-Wilk and Kolmogorov Smirnov tests. Descriptive analyses were performed for all variables. Comparison of continuous variables was made with Paired t-test or Wilcoxon signed-rank test according to data distribution. Repeated measurement analysis of variance (ANOVA) was performed to compare the mean IOP at different follow-up time points with baseline. Comparison of categorical variables was made with chi-squaretest. Kaplan-Meier survival analysis was performed and a univariate and multivariate binary logistic regression was performed to selected variables. A p value < 0.05 was considered statistically significant. Analyses were made with IBM SPSS Statistics version 25 (IBM Corp).
Outcome parameters:
Complete success was defined as a reduction ≥20% from baseline IOP or an IOP ≤14 mmHg without glaucoma medication.
Qualified success was defined as a reduction ≥20% from baseline IOP, or an IOP ≤14 mmHg with the same or less glaucoma medication requirements, or a reduction in glaucoma medication requirements with an IOP equal or lower than the preoperative IOP.
Failure was defined as an IOP reduction <20% from baseline, no reduction in glaucoma medication requirements, or the need of other surgical or laser procedure to control IOP.