Clinical Efficacy and Safety Outcomes of Micropulse Transscleral Diode Cyclophotocoagulation in Patients With Advanced Glaucoma

Incidence of Sympathetic Ophthalmia after Intraocular Surgery: A Systematic Review and Meta-analysis

TOPIC

Sympathetic ophthalmia (SO) is a rare bilateral granulomatous panuveitis that can present after trauma or intraocular surgery (IOS). The incidence of SO after IOS varies among studies. The purpose of this review was to determine the incidence proportion of SO after IOS.

CLINICAL RELEVANCE

The incidence proportion of SO after IOS can provide physicians and patients with information on the risk of SO during the consent process before surgery.

METHODS

In this systematic review and meta-analysis, MEDLINE, EMBASE, and Cochrane databases were searched from inception to January 1, 2023 for population-based studies of SO after IOS. Two reviewers independently screened the results. Random-effects meta-analyses calculated incidence proportion. Subgroup analysis assessed SO incidence based on IOS type and technological advancements. Study quality and bias were assessed using the Newcastle-Ottawa scale and the Grades of Recommendation, Assessment, Development, and Evaluation framework.

RESULTS

The final meta-analyses included 19 studies, with 118 cases of SO occurring after 505 178 inciting events. The estimated overall incidence proportion of SO after IOS was 0.061% (95% confidence interval [CI], 0.033%-0.111%; I2 = 83%), and the estimated incidence rate was 9.24 cases per 100 000 person-years (95% CI, 4.03-21.19; I2 = 88%). The average study duration across these studies was 10.8 years. Within the reviewed literature, SO after glaucoma and vitreoretinal IOS was studied most, with 9 and 6 studies, respectively. Observed differences in incidence between glaucoma (0.098%; 95% CI, 0.042%-0.232%; I2 = 40%) and vitreoretinal (0.043%; 95% CI, 0.022%-0.085%; I2 = 88%) IOS were not statistically significant (P = 0.14). Also, no significant difference was found in the incidence proportion before and after 1975, when modern intraocular surgical techniques emerged (0.060% vs. 0.058%; P = 0.98). The outcome measures showed low-certainty Grades of Recommendation, Assessment, Development, and Evaluation evidence.

DISCUSSION

Sympathetic ophthalmia after IOS is rare and might not have changed over the past 5 decades. The estimated incidence proportion of SO may be useful during the consent process before surgery. Also, no significant difference may exist in the incidence of SO between glaucoma and vitreoretinal IOS, based on low-certainty evidence.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Settings and effectiveness of the revised probe compared to the original probe for micropulse transscleral cyclophotocoagulation

PURPOSE

The goal of this study was to compare the settings and effectiveness of the original P3 and revised P3 probes for micropulse transscleral cyclophotocoagulation.

METHODS

This retrospective cross sectional study includes a total of 56 patients with glaucoma who received micropulse transscleral cyclophotocoagulation. 32 patients received treatment with the original P3 probe and 24 received treatment with the revised P3 probe. Success was defined as a 20% reduction in intraocular pressure. Laser settings, pre-op and post-op intraocular pressures, and pre-op and post-op medications were assessed.

RESULTS

A 20% IOP reduction was achieved in 50% of patients in the original probe vs. 58.3% in the revised probe at one month (P = 0.536) and 71.9% vs. 50% at three months (P = 0.094), respectively. The revised P3 probe used higher values of power (2500 mW vs. 2023 mW, P < 0.0001), total duration (217 s vs. 179 s, P < 0.0001), and energy (170 J vs. 113 J, P < 0.001). There was a significant decrease in IOP lowering meds with the original probe at one month (-0.9 +/- 1.5 vs. -0.0 +/- 0.7, P = 0.010), but this was not seen at three months.

CONCLUSIONS

There is no significant difference in IOP lowering effect between probes despite the revised probe using higher total energy. The original probe may be associated with fewer medications at 1 month, but not at 3 months. Further studies with longer follow up are needed to optimize the treatment parameters in order to maximize effectiveness while limiting side effects.

Micropulse Transscleral Cyclophotocoagulation Results in Secondary Glaucoma

The aim of this study was to analyze the long-term outcome of first session of micropulse transscleral cyclophotocoagulation (MP-CPC) for refractory glaucoma developed after vitreoretinal surgery combined with silicone oil implantation. The inclusion criteria of this consecutive case series were: patients with secondary glaucoma in the refractory stage who underwent MP-CPC between 2018 and 2021, vitreoretinal surgery combined with silicon oil implantation, and at least a 24-month follow-up period after MP-CPC. Success was defined as the baseline eye pressure reduced at least 20%, and it should be ranged between 10 to 20 mmHg without further MP-CPC at the end of the follow-up. For this retrospective study, 11 eyes of 11 patients were selected. The reduction in IOP was found to be significant (p = 0.004) at the end of the follow-up time, and the success rate was 72% according to our results. The change in the number of antiglaucoma agents in the administered eyedrops was not significant compared to the baseline values. At the end of the follow-up period the change in BCVA values was not significant (p = 0.655). Our results confirm significant IOP lowering effect of this subthreshold method preserving visual performance safely even in eyes with previous vitrectomy surgery with a silicone oil implantation.

MicroPulse Transscleral Laser Therapy Dosimetry Utilizing the Revised P3 Delivery Device: A Randomized Controlled Trial

PURPOSE

To compare the long-term effectiveness and safety outcomes of 2 treatment dosages of the MicroPulse Transscleral Laser Therapy (MPTLT) procedure on intraocular pressure (IOP) control in patients with primary open-angle glaucoma.

DESIGN

Single-blinded randomized controlled trial.

SUBJECTS

A total of 19 patients with POAG without prior history of incisional glaucoma surgery.

METHODS

Subjects randomized into 2 treatment groups, 100-second (total energy 78.25 joules [J], fluence 109.2 J/cm²) or 120-second (total energy 93.9 J, fluence 131.0 J/cm²) total treatment duration, underwent the MPTLT procedure with the revised P3 delivery probe delivering 2.5 W energy, 31.3% duty cycle, applied in 3 sweeps per hemisphere, avoiding 3 and 9 o'clock. All subjects were followed at 1, 3, 6, 9, and 12 months to compare reduction in IOP and medication.

MAIN OUTCOME MEASURES

Absolute and percentage IOP reduction at 6 months.

RESULTS

The treatment groups were similar in age, sex, and stage of glaucoma at baseline (all P > 0.05). The 120-second group had significantly better baseline best-corrected visual acuity (BCVA) and a higher percentage of patients with prior MPTLT therapy (ranging from 4-19 months before study). Significantly greater IOP reduction was noted in the 120-second group compared with the 100-second group at 3 months, with mean IOP reduction of 7.3 ± 4.2 mmHg (vs. 0.9 ± 2.5 mmHg, P = 0.006) and percentage IOP reduction of 32.2% ± 18.3% (vs. 4.1% ± 13.7%, P = 0.007). The 120-second group continued to outperform at 6-month follow-up: mean IOP reduction of 9.0 ± 4.8 mmHg (vs. 0.8 ± 2.5 mmHg, P = 0.016) and percentage IOP reduction of 37.8% ± 19.8% (vs. 3.6% ± 13.3%, P = 0.021). At 12 months, 37.5% and 18.2% of the 100- and 120-second groups, respectively, required an additional IOP-lowering procedure (P = 0.35); however, Kaplan-Meier analysis of time to intervention was not significantly different (P = 0.38). There were no vision-threatening complications or changes in BCVA during the study period.

CONCLUSIONS

This study demonstrates a dose-response relationship with improved IOP control and excellent safety profile in patients treated with higher treatment total energy and fluence using the revised MPTLT probe.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Assessment of Pain in Glaucoma Patients Undergoing Micropulse Transscleral Laser Therapy

Background: This study aimed to assess the pain experienced during micropulse transscleral laser therapy (MPTLT) and overnight thereafter and explore the factors associated with the pain. Methods: This prospective study included 100 eyes of 81 glaucoma patients undergoing MPTLT under retrobulbar anesthesia. All patients were asked to rate both types of pain using a numerical rating scale (NRS). The risk factors were explored using multivariable mixed-effects ordinal logistic regression. Results: The mean (SD) NRS pain score during the procedure was 3.57 (3.41) (range 0–10), which included no, mild, moderate, and severe pain in 30 (30%), 33 (33%), 17 (17%), and 20 (20%) eyes, respectively. The mean (SD) NRS score of overnight pain was 2.99 (2.28) (range 0–9), which included no, mild, moderate, and severe pain in 17 (17%), 59 (59%), 17 (17%), and 7 (7%) eyes, respectively. Twenty-seven (27%) eyes reported worse pain overnight than during the procedure. Increased age, initial intraocular pressure, and pain during the procedure were significantly associated with increased overnight pain (p < 0.05). Conclusions: Up to a fourth of eyes had worse pain after discharge. Older age, initial intraocular pressure, and pain during the procedure were risk factors for higher levels of overnight pain.

Clinical Outcomes of Micropulse Transscleral Cyclophotocoagulation: 2 Years of Experience in Portuguese Eyes

Aim

This study evaluates the safety and efficacy of micropulse transscleral cyclophotocoagulation (MPTSCPC) in glaucoma patients, with standard parameters, over a 24-month period.

Methods

Retrospective analysis of 61 eyes undergoing MPTSCPC from January 2018 to December 2020 was carried out. Patients received 160 seconds of laser, with settings of 2000 mW/cm2 and a duty cycle of 31.3%.

Results

A total of 61 eyes were included, arranged in an age distribution of 73.9 ± 10.8 years. The most frequent diagnosis was primary open-angle glaucoma (POAG), with a mean best-corrected visual acuity (BCVA) of 5/10 in the Snellen Visual chart. Around 37.7% of the eyes had undergone at least one glaucoma filtration surgery prior to MPTSCPC. The mean pretreatment intraocular pressure (IOP) was 24.9 ± 8.6 mm Hg. Except for the contrast at 24 months, at every other follow-up visit, there was a significant reduction (p ≤ 0.001) in IOP and in the number of topical drugs required to control IOP, from four (baseline) to three, with oral acetazolamide suspension in most cases. The total success rate (absolute and clinical successes combined) was 81.9% after 1 year of the treatment. There was no drop in visual acuity or cases of serious complications. There is a positive and significant correlation between prior glaucoma surgery and the need for reinterventions (p = 0.028).

Conclusions

Micropulse transscleral cyclophotocoagulation (MPTSCPC) is an effective and safe procedure for reducing IOP within a broad spectrum of glaucoma patients. Additional studies are needed to confirm the current indications, widen their scope, and determine the optimal treatment settings on an individual basis.

How to cite this article

Basto RC, Almeida J, Roque JN, et al. Clinical Outcomes of Micropulse Transscleral Cyclophotocoagulation: 2 Years of Experience in Portuguese Eyes. J Curr Glaucoma Pract 2023;17(1):30-36.

MicroPulse Transscleral Laser Therapy Demonstrates Similar Efficacy with a Superior and More Favorable Safety Profile Compared to Continuous-Wave Transscleral Cyclophotocoagulation

Purpose. The aim of this study was to compare effectiveness and safety of MicroPulse transscleral laser therapy (MP-TLT) using the original MicroPulse P3® device and continuous-wave transscleral cyclophotocoagulation (CW-TSCPC) using the G-Probe® device in glaucoma. Methods. Spherical equivalent, intraocular pressure (IOP), best-corrected visual acuity (BCVA), and number of topical or oral ophthalmic pressure-reducing medications were registered at every time point, up to the last follow-up at 12 months. A complete slit-lamp examination was conducted to record the following complications: corneal edema, persistent ocular hypotony (IOP ≤5 mmHg) on two consecutive follow-up visits, choroidal detachment, phthisis bulbi, sympathetic ophthalmia, cystoid macular edema, or other abnormal ocular findings. Success was defined as IOP between 6 and 21 mmHg and >20% reduction in IOP with or without antiglaucoma medications. Results. 47 eyes underwent MP-TLT and 150 CW-TSCPC. At 12 months, success was achieved in 88.6% in the CW-TSCPC group and 87.5% in the MP-TLT group ( $p$  = 0.883). In the CW-TSCPC group, eyes achieved a 42.4% IOP reduction (from 28.3 ± 12.3 mmHg to 15.3 ± 6.0 mmHg) and a 31.1% reduction (from 22.0 ± 7.2 mmHg to 15.7 ± 4.8 mmHg) in the MP-TLT group. Visual acuity remained primarily unaltered in both groups. Conclusion. MP-TLT was as effective in lowering IOP as CW-TSCPC and achieved comparable success. Additionally, MP-TLT demonstrated consistent and effective outcomes at every time point. The improved safety profile of MP-TLT allows the therapeutic spectrum to be broadened, granting ophthalmologists’ treatment of glaucoma in earlier stages of glaucoma than those typically treated with CW-TSCPC, i.e., early to moderate and to patients with good central-vision.