Comparing Trabeculectomy Outcomes between First and Second Operated Eyes: A Multicenter Study

MicroShunt versus Trabeculectomy for Surgical Management of Glaucoma: A Retrospective Analysis

This case-control study aims to compare the efficacy, safety, and postoperative burden of MicroShunt versus trabeculectomy. The first consecutive cohort of MicroShunt procedures (n = 101) was matched to recent historical trabeculectomy procedures (n = 101) at two London hospital trusts. Primary endpoints included changes in intraocular pressure (IOP) and glaucoma medications. Secondary outcome measures included changes in retinal nerve fibre layer (RNFL) thickness, rates of complications, further theatre interventions, and the number of postoperative visits. From the baseline to Month-18, the median [interquartile range] IOP decreased from 22 [17–29] mmHg (on 4 [3–4] medications) to 15 [10–17] mmHg (on 0 [0–2] medications) and from 20 [16–28] mmHg (on 4 [3–4] medications) to 11 [10–13] mmHg (on 0 [0–0] medications) in the MicroShunt and trabeculectomy groups, respectively. IOP from Month-3 was significantly higher in the MicroShunt group (p = 0.006), with an increased number of medications from Month-12 (p = 0.024). There were greater RNFL thicknesses from Month-6 in the MicroShunt group (p = 0.005). The rates of complications were similar (p = 0.060) but with fewer interventions (p = 0.031) and postoperative visits (p = 0.001) in the MicroShunt group. Therefore, MicroShunt has inferior efficacy to trabeculectomy in lowering IOP and medications but provides a better safety profile and postoperative burden and may delay RNFL loss.

Bilateral Nonpenetrating Deep Sclerectomy: Difference in Outcomes Between First- and Second-Operated Eyes at 24 Months

BACKGROUND/AIM

The aim of this study was to assess the difference in outcome between the first-operated and the second-operated eyes after nonpenetrating deep sclerectomy (DS), and to identify potential success predictors for the second eye.

METHODS

This single-surgeon, retrospective study analyzed the outcomes of all bilateral nonsimultaneous DS with at least 24 months of follow-up. Its main outcome measure was surgical success, defined as unmedicated intraocular pressure (IOP) ≤15 mm Hg associated with a relative reduction ≥20%.

RESULTS

In all, 104 eyes of 52 patients who underwent bilateral (standalone or combined) DS, within a mean of 344.3±526.3 days of each other, were analyzed. Postoperatively, the mean medicated IOP decreased from 20.7±7.9 (first-operated eyes) and 19.3±6.6 mm Hg (second-operated eyes) at baseline (P=0.107) to 13.8±4.8 [(-33.3%; P<0.001) first-operated eyes) and 12.7±3.8 mm Hg [(-34.2%; P<0.001) second-operated eyes] after 2 years (P=0.619). Postoperative IOP and treatment reduction, respectively, showed fair (r=0.53) and good (r=0.71) levels of correlation between fellow eyes. The rates of complete success were comparable between first-operated and second-operated eyes (32.7% and 40.4%, respectively; P=0.364). At 2 years, among patients whose first-operated eyes were considered a success, 82.4% of surgeries in second eyes were successful (P=0.001). The odds ratio of a second-operated eye experiencing complete success were 6.32 (P=0.011) if the first-operated eye experienced complete success.

CONCLUSIONS

The present study demonstrated a strong association between first-operated and second-operated eyes after DS, in terms of surgical outcomes and IOP reduction. In effect, surgical success in the first-operated eye increases the odds of success in the second eye by 6-fold.

Predictability of ab-interno trabeculectomy success in the subsequent eye: A contralateral eye comparison study

BACKGROUND

To determine whether the outcome of the first eye may serve as a predictor for intraocular pressure (IOP)-lowering effectiveness in the second eye following bilateral ab interno trabeculectomy.

METHODS

This retrospective single-centre study included 168 eyes from 84 participants, who underwent combined Trabectome surgery with phacoemulsification cataract surgery in a hospital setting. The clinical endpoint was defined as either 'success' or 'failure' based on four separate scores at the longest follow-up time point: IOP at follow-up <21 mm Hg (Score A) or IOP < 18 mm Hg (Score B), without re-surgery and IOP reduction >20%; IOP ≤15 mm Hg without re-surgery and IOP reduction ≥40% (Score C); and the sole absence of re-surgery according to the discretion of the surgeon (Score D).

RESULTS

No significant difference was observed between the outcomes of first and second eyes. The frequency of success in the second eye after effective surgery in the first eye significantly exceeded that after prior failure. Within our analysis, the probability calculations determined a 75% chance of success following prior success for Score A. If surgery in the first eye failed, the chance of success in the subsequent eye was 37%. The corresponding probabilities were 79% and 32% for Score B, 56% and 9% for Score C, and 99% and 50% for Score D.

CONCLUSION

The results of our study offer a useful tool to assess the success of subsequent eye surgeries based on the outcome in the initial eye, owing to the high predictive potential.

Secondary surgical intervention after primary glaucoma filtration surgery: an Ontario population-based study

OBJECTIVE

To identify factors associated with secondary surgical intervention after glaucoma filtration surgery.

DESIGN

Population-based retrospective cohort.

METHODS

Patient records with billing claims for a primary glaucoma filtration surgery occurring between April 2003 and March 2015 were identified. Each identified record was examined for instances of secondary glaucoma surgeries within the patient's first postoperative year. Baseline characteristics of patients who required secondary surgical intervention were compared with those who did not. A multivariable Cox proportional hazards model was used to calculate hazard ratios.

RESULTS

Within a cohort of 10,097 patients, 349 (3.46%) underwent a secondary surgical intervention within the first postoperative year. Interventions were less frequent after surgeries that included an indwelling drainage device (HR=0.58 95% CI, 0.37-0.89), phacoemulsification (HR=0.33, 0.21-0.52), or both (HR=0.09, 0.03-0.31). Patients with preoperative aminoglycoside and mydriatic exposure had significantly increased risk of secondary surgical intervention (HR=3.19, 1.89-5.36) and (HR=2.32, 1.49-3.61). Patients who underwent surgery on their contralateral eye experienced secondary surgical interventions more frequently: 7.44 per 10,000 person-days (versus 1.18 per 10,000 person-days, p < 0.0001). No significant differences in the rates of secondary surgical intervention were observed for patients taking different classes of glaucoma medications or those exposed to higher amounts of benzalkonium chloride.

CONCLUSIONS

In Ontario, the overall rates of secondary surgical interventions in the first postoperative year are low but significantly higher in certain patient populations. Further work is required to address the higher rate of secondary surgical intervention in patients with a history of certain perioperative eye drop medications and those who require sequential-bilateral procedures.