Noninvasive glaucoma procedures: current options and future innovations

Micropulse laser trabeculoplasty on Chinese patients with glaucoma or ocular hypertension: average 35 months follow-up results

Background

Glaucoma is a group of eye diseases that can damage the optic nerve and cause vision loss. A novel technology micropulse laser trabeculoplasty (MLT) can use duty-circle subvisible laser pulses to treat glaucoma. The aim of this study is to evaluate the efficacy of 360° MLT to alleviate intraocular pressure (IOP) in patients with glaucoma.

Methods

This was a single-center prospective study on patients treated with 360° MLT using a Diode True-Yellow 577-nm Laser with MicroPulse technology. All the patients were recruited from the Department of Ophthalmology. Follow-up visits were carried out at 1 day, 1 week, 1 month, 3 months, 6 months, 18 months, and 36 months after the procedure. Best-corrected visual acuity (BCVA), Intraocular pressure (IOP), and vertical cup-to-disc ratio (C/D ratio) were measured during the follow-up. Repeated-measures analysis of variance (ANOVA) and Kaplan–Meier analysis were performed to evaluate the outcomes.

Results

A total of 39 eyes from 25 patients were included in this study (10 men/15 women). The average age of patients was 41.47 ± 14.39 years old, and the baseline IOP was 21.13 ± 7.75 mmHg. MLT significantly reduced the IOP at 1 day (range 15.61–19.01, P = 0.0218), 3 months (range 16.47–19.22, P = 0.0390), and 6 months (range 15.38–18.56, P = 0.0332) compared with the baseline. However, by the end of the study, only 21.88% of patients demonstrated a ≥ 20% IOP reduction, while seven eyes needed further laser or surgical treatment. The IOP of glaucoma patients was significantly lower than the ocular hypertension patients at 1 month (P = 0.0124), 3 months (P = 0.0004), 18 months (P = 0.0061) and 36 months (P = 0.0119).

Conclusions

Micropulse laser trabeculoplasty reduce IOP in patients with glaucoma or ocular hypertension for a short period, but its lowering efficiency is limited up to 6 months of the follow-up period.

Incremental Health Care Expenditures Associated With Glaucoma in the United States: A Propensity Score-matched Analysis

PRCIS

Adjusting for sociodemographics and comorbidities, patients with glaucoma incur an annual incremental economic burden of $1863.17, translating to $9.2 billion nationally. When analyzed by the health care service sector, prescription medication expenditures were higher for glaucoma patients.

PURPOSE

The purpose of this study was to estimate the incremental health care burden, defined as attributable costs solely due to a diagnosis, of patients with diagnosed glaucoma, controlling for comorbidities, and sociodemographics.

DESIGN

A retrospective cross-sectional analysis of Medical Expenditure Panel Survey (MEPS) participants (age above 18 y) between 2016 and 2018.

METHODS

A cross-validated 2-part generalized linear regression model estimated the incremental glaucoma expenditures in aggregate and by sociodemographic subgroups and health care service sector [inpatient, outpatient (including surgical procedures), emergency room, home health, and medications] after 1:3 propensity matching.

RESULTS

After 1:3 propensity matching for sociodemographics and the Charlson Comorbidity Index, this study analyzed 1521 glaucoma patients (mean expenditures: $13,585.68±1367.03) and 4563 patients without glaucoma (mean expenditures: $12,048.92±782.49). A higher proportion of glaucoma patients are female, elderly, publicly insured (Medicare/Medicaid), college educated, identify ethnically as non-Hispanic, reside in the Northeast, and have more comorbidities (P<0.001). There were no differences in health care burden based on sex, income, insurance status, education, and year of care received for patients with glaucoma. Controlling for comorbidities and socioeconomic factors, propensity-matched glaucoma patients incur an annual incremental health care burden of $1863.17 (95% confidence interval, 393.44-3117.23, P=0.013), translating into an additional $9.2 billion in population-level US health care expenditures. By health care service sector, the expenditure ratio for health care expenditures was higher for prescription medications (expenditure ratio=1.20, 95% confidence interval, 1.02-1.42, P=0.031).

CONCLUSIONS

Glaucoma patients have a substantial incremental economic health care burden after accounting for demographics and comorbidities, largely secondary to prescription medications. There is a need to continue identifying and studying treatment options for patients with glaucoma to maintain vision while minimizing health care expenditures.

Ultrasonic circular cyclocoagulation prospective safety and effectiveness study

PURPOSE

To evaluate the efficacy and safety of ultrasound cycloplasty procedures (UCP) in patients with uncontrolled glaucoma.

METHODS

Prospective longitudinal study with UCP was performed by EyeOP1© probe with 8 s duration on 6 or 8 sectors, according to baseline intraocular pressure (IOP). Complete ophthalmic examination was performed pre- and post-operatively at 1st day, 1st week, 1st, 3rd, 6th, 9th and 12th months. UCP was repeated beyond 3rd month if IOP was > 21 mmHg, under maximum therapy, without major complications. Primary outcomes were complete (IOP reduction ≥ 20% or reduction in number of antiglaucomatous drugs and IOP ≥ 5 mmHg without occurrence of major complications) and qualified (IOP reduction ≥ 20% or reduction in number of antiglaucomatous drugs and IOP ≥ 5 mmHg) surgical success rates at 12 months. Secondary outcomes were mean IOP reduction, mean number of drugs reduction, rates of failure, number of repeated procedures, mean time to failure and occurrence of complications.

RESULTS

Fourteen eyes of 13 patients (11 male) with advanced glaucoma (Hoddap classification) were included. Six were surgically naïve. Mean age was 68.29 ± 10.66 years. Four eyes were treated in 8 sectors (28.5%). Patients were followed for 12 months after first UCP procedure. Overall surgical success was achieved in 92.9% at 6 months and in 100% of cases at 12 months. Mean IOP significantly reduced from 28.50 ± 7.61 mmHg to 13.79 ± 6.97 at 1 month, 17.36 ± 8.58 at 3 months, 17.79 ± 6.29 at 6 months, 16.3 ± 4.6 at 9 months and to 15.23 ± 5.09 at 12 months (p < 0.01). Mean number of drugs reduced from 3.71 ± 0.61 to 2.43 ± 1.51 at 3 months, 2.86 ± 1.1 at 6 months, 2.64 ± 0.93 at 9 months and to 2.92 ± 0.86 at 12 months (p < 0.05). Major reversible complications included choroidal detachment in 2 (14.29%) and corneal edema in 1 eye (7.14%), without permanent visual acuity reduction. Minor reversible complications included anterior chamber reaction (92.25%), conjunctival hyperemia (71.43%) and superficial keratitis (57.4%). Four eyes (28.57%) had indication for repeating UCP, with mean period to failure of 8.1 ± 3.95 months.

CONCLUSION

UCP procedures are effective in reducing IOP in severe glaucoma. Its application and repetition seem to be a medium-long term acceptable alternative to cyclodestructive surgery. However, long-term efficacy and safety require yet further investigation.

Why chitosan could be apt candidate for glaucoma drug delivery - An overview

Most of the people in the world are affected by glaucoma, which leads to irreversible blindness. Several patient friendly treatments are available, nevertheless medications lack an easy and efficient way of sustained delivery. To make the delivery with enhanced bioavailability, biodegradable and non-biodegradable polymers-based drug carriers are explored. However, ocular drug delivery issues have not been resolved yet due to less adhesiveness, poor penetration ability, pH, and temperature dependent burst releases. Chitosan is found to be effective for ocular drug delivery due to excellent physio-chemical properties in terms of overcoming the existing issues. In this review, we aim to highlight why it has been chosen and the holy grail for ocular drug delivery. Besides, we have comprehensively reviewed recent patents on chitosan as a platform for ocular drug delivery and future perspectives on factors, lacunae and challenges that need to be addressed for better ocular delivery methods for glaucoma management.

Comparison of ultrasound cycloplasty and transscleral cyclophotocoagulation for refractory glaucoma in Chinese population

Background

To compare the efficacy and safety of focused ultrasound cycloplasty (UCP) and transscleral cyclophotocoagulation (TSCP) in the treatment of refractory glaucoma in a Chinese population.

Methods

We retrospectively compared twenty-eight eligible patients with refractory glaucoma, who were divided into the UCP group and TSCP group. Patients in these two groups underwent a corresponding procedure from June 2018 to February 2019. The intraocular pressure (IOP), visual acuity, the number of anti-glaucoma agents used and complications were reviewed and compared between groups. Proper statistical methods were selected according to comparison models under IBM SPSS 25 software.

Results

After the 12-months follow-up, postoperative IOP and number of anti-glaucoma agents used in the two groups were both reduced than the baseline level, and the differences were statistically significant (P < 0.05). There were no significant differences in IOP, number of anti-glaucoma agents and the best-corrected visual acuity between the two groups at each follow-up time point (P>0.05). In terms of complications, the pain at 1 day after surgery in the UCP group was significantly milder than that in the TSCP group (P < 0.05). And there were no significant differences in other complications between the two groups (P > 0.05).

Conclusions

Both UCP and TSCP are safe and effective methods for the treatment of refractory glaucoma. Nevertheless, pain is less severe after UCP.

Selective laser trabeculoplasty in exfoliative glaucoma eyes with prior argon laser trabeculoplasty

PURPOSE

To explore the efficacy of selective laser trabeculoplasty (SLT) within eyes with exfoliative glaucoma and history of prior argon laser trabeculoplasty (ALT).

METHODS

A single-centre trial consisting of 47 patients (47 eyes) with uncontrolled exfoliative glaucoma. The main outcome measure was intraocular pressure (IOP) reduction 3 and 9 months after SLT. Treatment success was defined as reduction from the preoperative IOP by 20% and 2 mmHg (<12 mmHg), 3 mmHg (12-16 mmHg) or 4 mmHg (>16 mmHg) depending on the baseline IOP.

RESULTS

Patient age was 79.3 ± 7.6 years (mean ± SD) and gender distribution 15 males and 32 females. The mean pre-SLT IOP was 15.6 ± 5.1 (range 9-28) mmHg, and mean number of glaucoma drugs 2.0 ± 1.2. The mean interval between prior ALT and SLT was 44.0 ± 36.9 (range 11-137) months. After SLT, the mean IOP change was -2.7 ± 4.2 mmHg (-14.8 ± 23.5%) at 3 months, and -2.8 ± 3.5 mmHg (-16.3 ± 19.4%) at 9 months. Pre-SLT IOP correlated with the IOP reduction at 3 months (r = 0.530, p < 0.001) and at 9 months (r = 0.432, p = 0.007). The overall success rate was 50% at 3 months, and 42% at 9 months. At both 3 and at 9 months, the cut-off level for treatment success was achieved when preoperative IOP was 18 mmHg and above. IOP lowering effect of SLT did not correlate with the number of glaucoma drugs, age, gender or use of prostaglandin inhibitors. Neither postoperative iritis nor other adverse effects were documented during the follow-up.

CONCLUSIONS

Selective laser trabeculoplasty is a safe and noteworthy treatment option to reduce IOP in exfoliative glaucoma eyes, especially with pre-SLT IOP over 18 mmHg.

New approaches to selective laser trabeculoplasty

Selective laser trabeculoplasty (SLT) is the “golden standard” of laser glaucoma surgery. Its efficacy can be compared to pharmacological therapy, while in some cases its advantages may even lead to a more stable hypotensive effect. SLT may be used as a primary treatment for primary open-angle glaucoma patients and patients with ocular hypertension, while also considered safe and effective in cases when a repeat procedure is required. SLT may potentially decrease the demand for antiglaucoma drugs, improve patient’s response to treatment, make the treatment more comfortable and overall increase the patient’s quality of life. New modifications of standard laser treatment procedures have been emerging lately. This article summarizes scientific data on the efficacy and safety of the new generation of laser trabeculoplasty. It specifies the charateristics of micropulse laser trabeculoplasty (MLT), pattern-scanning trabeculoplasty (PLT) and titaniumsapphire laser trabeculoplasty (TSLT) and recounts the latest research dedicated to them.

Application of high intensity focused ultrasound for treatment of open-angle glaucoma in Indian patients

Purpose:

The aim of this study is to assess the efficacy of ultrasound cycloplasty (UCP) in Indian patients with open angle glaucoma (OAG).

Methods:

A prospective interventional study was designed to treat 73 eyes of 73 patients with OAG with the EyeOP1 device equipped with six miniaturized cylindrical piezoelectric transducers. Two treatment protocols of ultrasound delivery depending on exposure time (8 s and 10 s of shot per transducer) were used. Complete ophthalmic examination, ocular biometry and anterior segment optical coherence tomography were performed preoperatively and patients were followed up at day 1, day 7 and months 1, 2, 3, 6, and 12. The primary outcome measure was “successful” intraocular pressure (IOP) control defined as IOP reduction ≥20% from baseline and IOP value >5 mm Hg at the last follow-up visit. Secondary outcomes were the occurrence of complications and mean IOP during the follow-up period.

Results:

In all patients, the mean IOP reduced from 23.5 ± 3.0 mmHg before treatment to 15.7 ± 5.4 mmHg at 12 months (P < 0.05). Successful IOP control after a single procedure was 78.3% (79% and 78% in the 8 s and 10 s groups, respectively) at 12 months. Overall, the mean IOP reduction achieved in responding patients was 41% (standard deviation = 12%). Notwithstanding minor side effects such as transient pain, anterior chamber reaction, and refractive error changes, no major intraoperative or postoperative complications (severe hypotony or phthisis) were observed during the follow-up.

Conclusion:

Our short-term results reveal that UCP is a simple, safe, and noninvasive procedure which enables to significantly reduce the IOP in patients with OAG. The study results in Indian eyes corroborate findings in earlier studies on Caucasian eyes.

High-Intensity Focused Ultrasound Circular Cyclocoagulation in Glaucoma: A Step Forward for Cyclodestruction?

The ciliary body ablation is still considered as a last resort treatment to reduce the intraocular pressure (IOP) in uncontrolled glaucoma. Several ablation techniques have been proposed over the years, all presenting a high rate of complications, nonselectivity for the target organ, and unpredictable dose-effect relationship. These drawbacks limited the application of cyclodestructive procedures almost exclusively to refractory glaucoma. High-intensity focused ultrasound (HIFU), proposed in the early 1980s and later abandoned because of the complexity and side effects of the procedure, was recently reconsidered in a new approach to destroy the ciliary body. Ultrasound circular cyclocoagulation (UC³), by using miniaturized transducers embedded in a dedicated circular-shaped device, permits to selectively treat the ciliary body in a one-step, computer-assisted, and non-operator-dependent procedure. UC³ shows a high level of safety along with a predictable and sustained IOP reduction in patients with refractory glaucoma. Because of this, the indication of UC³ was recently extended also to naïve-to-surgery patients, thus reconsidering the role and timing of ciliary body ablation in the surgical management of glaucoma. This article provides a review of the most used cycloablative techniques with particular attention to UC³, summarizing the current knowledge about this procedure and future possible developments.