Impact of glaucoma medications on the ocular surface and how ocular surface disease can influence glaucoma treatment

Ten-Year Effectiveness and Safety of Trabecular Micro-Bypass Stent Implantation with Cataract Surgery in Patients with Glaucoma or Ocular Hypertension

INTRODUCTION

This study evaluated 10-year results of implanting one iStent trabecular micro-bypass stent during cataract surgery in eyes with open-angle glaucoma (OAG) or ocular hypertension.

METHODS

This retrospective, non-randomized study examined 10-year outcomes of iStent trabecular micro-bypass stent implantation with cataract surgery by one surgeon in eyes with OAG [including primary OAG (POAG) and pseudoexfoliative glaucoma (PXG)] or ocular hypertension at a multi-specialty German ophthalmology center. Study visits were conducted preoperatively and at 2.5, 3, 5, and 10 years postoperatively; examinations included intraocular pressure (IOP), medications, corrected-distance visual acuity (CDVA), and adverse events.

RESULTS

A total of 63 eyes of 45 patients with OAG (n = 60 eyes) or ocular hypertension (n = 3 eyes) and data through 10 years were analyzed. Mean preoperative IOP was 18.6 ± 4.4 mmHg on 1.83 ± 1.03 mean medications. At study visits through 10 years postoperative, mean IOP reduced by 12.9-19.0% (p < 0.005 at all points), and mean medication burden reduced by 37.8-51.4% (p ≤ 0.006 at all points). At 10 years postoperatively, 77.8% of eyes had IOP ≤ 18 mmHg and 47.6% had IOP ≤ 15 mmHg (vs. 50.8% and 25.4% preoperatively, respectively; p = 0.016). One-third (33.3%) of eyes were medication-free vs. 3.2% preoperatively (p < 0.001); 17.5% were on 2-5 medications (vs. 55.6% preoperatively, p = 0.005); and 93.7% of eyes were on the same or fewer medications vs. preoperative. Post-phacoemulsification CDVA improvement was maintained; no filtering surgeries were completed over 10-year follow-up.

CONCLUSIONS

Significant and safe IOP and medication reductions were observed through 10 years after iStent implantation with cataract surgery in patients with OAG or ocular hypertension.

Topical glaucoma medications - Possible implications on the meibomian glands

One of the most common causes of blindness on a global scale is glaucoma. There is a strong association between glaucoma and increased intraocular pressure (IOP). Because of this, adequate IOP-lowering is the most important treatment strategy, mostly through topical eyedrops. Well-functioning meibomian glands are paramount for maintaining a stable tear film, and their dysfunction is the most common cause of dry eye disease. There is a growing concern that both topical glaucoma medications themselves and their added preservatives damage the meibomian glands, and consequently, the ocular surface. Preserved topical glaucoma medications appear to cause dysfunction and atrophy of the meibomian glands. Upon comparison, preserved formulations caused more symptoms of dry eye, tear film instability, inflammatory changes and meibomian gland dropout than the preservative-free counterpart. However, although seemingly less detrimental, unpreserved alternatives may diminish glandular efficacy, and, depending on the active ingredient, lead to glandular death. This negatively impacts quality of life, adherence to treatment regimens and prognosis. In this review, we explore the available evidence regarding the effects of IOP-lowering eye drops on the meibomian glands.

Travoprost Intracameral Implant for Open-Angle Glaucoma or Ocular Hypertension: 12-Month Results of a Randomized, Double-Masked Trial

INTRODUCTION

This prospective, multicenter, randomized, double-masked pivotal phase 3 trial evaluated the efficacy and safety of the travoprost intracameral SE-implant (slow-eluting implant, the intended commercial product) and FE-implant (fast-eluting implant, included primarily for masking purposes) compared to twice-daily (BID) timolol ophthalmic solution, 0.5% in patients with open-angle glaucoma (OAG) or ocular hypertension (OHT).

METHODS

The trial enrolled adult patients with OAG or OHT with an unmedicated mean diurnal intraocular pressure (IOP) of ≥ 21 and unmedicated IOP ≤ 36 mmHg at each diurnal timepoint (8 A.M., 10 A.M., and 4 P.M.) at baseline. The eligible eye of each patient was administered an SE-implant, an FE-implant or had a sham administration procedure. Patients who received an implant were provided placebo eye drops to be administered BID and patients who had the sham procedure were provided timolol eye drops to be administered BID. The primary efficacy endpoint, for which the study was powered, was mean change from baseline IOP at 8 A.M. and 10 A.M. at day 10, week 6, and month 3. Non-inferiority was achieved if the upper 95% confidence interval (CI) on the difference in IOP change from baseline (implant minus timolol) was < 1.5 mmHg at all six timepoints and < 1 mmHg at three or more timepoints. The key secondary endpoint was mean change from baseline IOP at 8 A.M. and 10 A.M. at month 12. Non-inferiority at month 12 was achieved if the upper 95% CI was < 1.5 mmHg at both timepoints. Safety outcomes included treatment-emergent adverse events (TEAEs) and ophthalmic assessments.

RESULTS

A total of 590 patients were enrolled at 45 sites and randomized to one of three treatment groups: 197 SE-implant (the intended commercial product), 200 FE-implant, and 193 timolol. The SE-implant was non-inferior to timolol eye drops in IOP lowering over the first 3 months, and was also non-inferior to timolol at months 6, 9, and 12. The FE-implant was non-inferior to timolol over the first 3 months, and also at months 6 and 9. Of those patients who were on glaucoma medication at screening, a significantly greater proportion of patients in the SE- and FE-implant groups (83.5% and 78.7%, respectively) compared to the timolol group (23.9%) were on fewer topical glaucoma medications at month 12 compared to screening (P < 0.0001, chi-square test). TEAEs, mostly mild, were reported in the study eyes of 39.5% of patients in the SE-implant group, 34.0% of patients in the FE-implant group and 20.1% of patients in the timolol group.

CONCLUSIONS

The SE-travoprost intracameral implant demonstrated non-inferiority to timolol over 12 months whereas the FE-implant demonstrated non-inferiority over 9 months. Both implant models were safe and effective in IOP lowering in patients with OAG or OHT.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT03519386.

Risk Factors for Failure in Glaucoma Patients Undergoing Microshunt Implantation

PURPOSE

To evaluate risk factors for failure of Microshunt in glaucoma patients.

DESIGN

Multicenter retrospective cohort study.

METHODS

The study included 220 eyes from 220 consecutive glaucoma patients undergoing Microshunt implantation at six glaucoma units. Four intraocular pressure (IOP) success criteria were defined: (A) IOP ≤21 mm Hg with ≥20% IOP reduction; (B) IOP ≤18 mm Hg with ≥20% IOP reduction; (C) IOP ≤15 mm Hg with ≥25% IOP reduction; and (D) IOP ≤12 mm Hg with ≥30% IOP reduction from baseline. Kaplan-Meier analysis was used to estimate success rates according to the criteria above, and multivariable Cox models were used to identified risk factors for failure according to criterion A.

RESULTS

Success rates varied based on different criteria, ranging from 43.3% to 62.5% (overall success for criteria D and A, respectively) and from 35.3% to 44.4% (complete success for criteria D and A, respectively) at 1-year follow-up. Higher intraoperative MMC concentration was associated with reduced risk of failure to maintain complete (0.4 vs 0.2 mg/mL: hazard ratio [HR] = 0.441, P < .001) and overall (0.4 vs 0.2 mg/mL: HR = 0.360, P = .004) success. For complete success, other risk factors for failure were pseudoexfoliation glaucoma/pigmentary glaucoma (HR = 1.641, P = .004), primary angle closure glaucoma (HR = 1.611, P < .001), and previous non-glaucomatous ocular surgeries (HR = 2.301, P = .002). For overall success, other risk factors for failure were lower preoperative IOP (for 1-mm Hg increase, HR = 0.934, P = .005), higher number of preoperative antiglaucoma agents (HR = 1.626, P < .001), and Microshunt combined with cataract surgery (HR = 1.526, P = .033).

CONCLUSIONS

This study identified risk factors for Microshunt failure, highlighting the importance of high intraoperative MMC dose and careful patient selection to optimize surgical success.

Identifying Baseline Predictors of Selective Laser Trabeculoplasty Effectiveness: An Alternative Mathematical Approach

BACKGROUND

Selective laser trabeculoplasty (SLT) emerges as a first-line treatment for newly diagnosed open-angle glaucoma and ocular hypertension. However, the interindividual response to SLT considerably varied. Large-scale clinical investigations concerning predictive factors for SLT effectiveness are limited. This study aimed to identify baseline predictors of the percentage intraocular pressure (IOP)-lowering effectiveness of SLT using an alternative mathematical approach.

METHODS

Mathematical equations of IOP under the steady state of aqueous humour flow were formulated. The conclusive equation integrates physiological variables, including trabecular outflow facility, uveoscleral outflow fraction, plasma protein concentration, albumin/globulin ratio, mean arterial pressure, episcleral venous pressure, and plasma osmolarity. The equation was employed to estimate the percentage of IOP reduction following SLT and subsequently subjected to global sensitivity analysis to determine significant predictors of the IOP-lowering effect of SLT using the Monte Carlo simulation of 8,192 samples.

RESULTS

In the current model, a 50% improvement in the trabecular outflow facility impacted by SLT is associated with a mean percentage IOP reduction of 16.6%. Lower baseline trabecular outflow facilities were the strongest predictors, showing a correlation with greater effectiveness of SLT in terms of percentage of IOP reduction. The second most influential factor includes baseline uveoscleral outflow fraction, followed by baseline episcleral venous pressure. Specifically, lower baseline uveoscleral outflow fraction and episcleral venous pressure were found to be correlated with increased effectiveness of SLT. Baseline levels of plasma protein concentration, albumin/globulin ratio, mean arterial pressure, and plasma osmolarity have minimal impact on SLT success or failure.

CONCLUSION

This study identifies baseline trabecular outflow facilities as the strongest predictor of SLT effectiveness. The results suggested that pre-SLT medical treatment that augments uveoscleral outflow and/or trabecular outflow facilities could compromise the effectiveness of subsequent SLT in terms of percentage IOP reduction compared to those who never received pre-SLT medication.

Evaluation of ocular surface following PreserFlo Microshunt implantation: Functional outcomes and quality of life

BACKGROUND

This study aimed to evaluate the impact of PreserFlo Microshunt on the ocular surface, focusing on both objective and subjective parameters.

METHODS

Prospective-observational study on 48 eyes undergoing PreserFlo Microshunt implantation, standalone or combined with phacoemulsification. At baseline, 1-month, 6-months and 12-months post-operative follow-ups, we performed Ocular Surface Disease Index (OSDI) questionnaire, Schirmer's test (ST), Tear-film break-up time (TBUT), fluoresceine staining (FS), tear osmolarity and minimum corneal epithelial thickness (Epi-ThkMIN. ) measurements.

RESULTS

OSDI score improved from 37.43 ± 17.49 at baseline, to 24.13 ± 12.55 at 1-month (p = 0.003) and to 12.89 ± 8.54 and 13.09 ± 10.22 at 6-months and 12-months (p < 0.0001). TBUT and ST, in a similar way, non-significantly increased at 1-month, but then improved at 6-months and 12-months (p < 0.05 for both). Tear osmolarity significantly decreased from 308.2 ± 7.3 mOsm/L at baseline, to 303.3 ± 8.2 mOsm/L, 295.6.2 ± 7.0 mOsm/L and 297.6 ± 6.8 mOsm/L at 1-month, 6-months and 12-months (p < 0.05 for all). Epi-ThkMIN was stable when comparing baseline (44.9 ± 5.7 μm) and 1-month (p = 0.28), and successively increased in 6-months (47.8 ± 5.5 μm, p = 0.02) and 12-months (48.0 ± 3.6 μm, p = 0.01). In subgroup analysis, OSDI score and tear osmolarity were significantly higher at 1-month in combined group compared to standalone group (p = 0.03 and p = 0.02, respectively), but reaching comparable values in successive follow-ups. Further, Oxford scale grades for FS were significantly improved when comparing baseline-6-months and baseline-12-months.

CONCLUSION

PreserFlo implantation improved ocular surface subjective symptoms, increased TBUT and ST, and reduced FS, highlighting the potential benefits of this surgical intervention. Moreover, we reported significant improvements of tear osmolarity and corneal epithelium.

Alternatives to Topical Glaucoma Medication for Glaucoma Management

Topical glaucoma medications have favorable safety and efficacy, but their use is limited by factors such as side effects, nonadherence, costs, ocular surface disease, intraocular pressure fluctuations, diminished quality of life, and the inherent difficulty of penetrating the corneal surface. Although traditionally these limitations have been accepted as an inevitable part of glaucoma treatment, a rapidly-evolving arena of minimally invasive surgical and laser interventions has initiated the beginnings of a reevaluation of the glaucoma treatment paradigm. This reevaluation encompasses an overall shift away from the reactive, topical-medication-first default and a shift toward earlier intervention with laser or surgical therapies such as selective laser trabeculoplasty, sustained-release drug delivery, and micro-invasive glaucoma surgery. Aside from favorable safety, these interventions may have clinically important attributes such as consistent IOP control, cost-effectiveness, independence from patient adherence, prevention of disease progression, and improved quality of life.