Lasers in Glaucoma: Meta analysis Dr Parul Ichhpujani Associate Professor Glaucoma and Neuro Ophthalmology Service Department of Ophthalmology, Government Medical College and Hospital, Sector 32, Chandigarh, India No financial disclosures

Meta analysis Outline Lasers for Glaucoma Closed Angle Glaucoma Laser Peripheral Iridotomy (LPI) Iridoplasty Open Angle Glaucoma Selective(SLT)/ Argon Laser Trabeculoplasty(ALT) Cyclophotocoagulation Trans Scleral Cyclophotocoagulation (TSCPC) Endocyclophotocoagulation (ECP) Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement

Laser Peripheral Iridoplasty Is laser iridoplasty a standard treatment in patients with persistent appositional angle-closure after peripheral iridotomy?

2008: No RCT in non acute setting To assess the effectiveness of laser peripheral iridoplasty in the treatment of PACS, PAC or PACG in non-acute situations when compared with any other intervention. 2008: No RCT in non acute setting 2012: 1 RCT; 158 Chinese participants Iridoplasty + Iridotomy Vs. Iridotomy alone Outcomes: Extent of PAS: Significant reduction in PAS post iridoplasty Pre and post (1 year) intraocular pressure (IOP) IOP reduction BCVA, Visual field mean deviation, Corneal endothelial cell count, Number of medications, Need for surgery No difference in 2 groups

Lacunae: Short follow up of only 1 year. Strength: Well designed RCT What do we need to know? Role of laser iridoplasty in patients with residual angle-closure after LPI, with different spectrum of the disease (PACs, PAC, PACG). Comparison of Laser iridoplasty with lens extraction

Laser Peripheral Iridotomy

5RCTs (260 eyes; 195 participants) comparing YAG LPI Vs. no LPI To assess the effects of LPI compared with other Rx, including medication, trabeculoplasty, and trabeculectomy, or no Rx, for pigment dispersion syndrome (PDS) and pigmentary glaucoma(PG). 5RCTs (260 eyes; 195 participants) comparing YAG LPI Vs. no LPI 3 trials: Participants with PG at baseline; 2 trials: Participants with PDS. Follow-up times across trials ranged from 6 months - 10 years No two trials assessed the same outcome at the same follow-up time, precluding meta analysis.

Outcome VF Progression: Evidence for this outcome graded as very low IOP: Little to no difference between groups VA: None of the trials made an observation AC Depth: Little to no difference between groups No trial reported aqueous melanin granule outcomes. Adverse effects: Mild postoperative inflammation No haloes or posterior synechiae

Lacunae: Available data are too sparse and scarcely representative of the whole disease continuum. What do we need? Careful differentiation of baseline characteristics is essential to assess treatment effects at different stages PDS with normal IOP, PDS with established OHTN, PG Subgroup analysis for important co-variates such as age and iris concavity.

Selective Laser Trabeculoplasty

Outcome 8 RCTs 4: SLT Vs Medication 4: SLT Vs ALT IOP reduction, reduction in number of medications, treatment success: SLT was non inferior to both medication and ALT

Adverse effects: SLT is safe Repeatability: 2 studies; Safe to repeat Lacunae: Publication bias was present ;favored SLT when treatment success was compared between SLT and ALT Location bias was present as one relatively large study was excluded as it was not in English or Chinese. Success criteria were not standardized

Selective Laser Trabeculoplasty

SLT Vs. ALT: Which is better? SLT: 253 eyes ALT: 229 eyes IOP Reduction Patients naive to laser: No significant difference of IOP at any time point. Patients with previous laser treatment: Difference in IOP reduction was statistically non-significant at 6 months after the retreatment. (P = 0.18).

Number of Glaucoma medication Post SLT/ ALT No significant difference

Success rate: 4 Studies. No significant difference in success rate was found with RR (95% CI) of 1.03 (0.83, 1.28). Adverse effects: 3 trials reported the proportions of eyes requiring laser retreatment, trabeculectomy or other IOP lowering procedure within 1 year, no differences were found between SLT and ALT. Post laser IOP spike: Reported by 1 study; IOP spike rate was also similar for SLT and ALT.

Lacunae: Limited follow up and sample size Whether SLT has better long-term efficacy than ALT in repeat laser trabeculoplasty treatments remains unclear. Need to focus more on clinical end points than just IOP reduction

Selective Laser Trabeculoplasty

IOP Reduction Patients naive to laser: No significant difference of IOP reduction when comparing SLT with ALT. Patients with previous laser treatment: SLT better than ALT.

Number of medications Post SLT/Post ALT: IOP Reduction Post SLT/Post ALT:

Strengths: Wider range of clinically relevant outcomes Limitations: Relatively small sample size Variable follow up period Potential sources of heterogeneity like patient population and the severity of the disease were present

Transcleral Cyclophotocoagulation 10 Studies were compared with the case review #No significant correlation was found between success rate and Laser power Exposure time Number of laser spots Energy per laser spot #No significant correlation was found between total energy and average decrease in IOP # No significant correlation was found between pretreatment IOP and rate of success Lacunae: Heterogeneity of data Retrospective nature of the case review

Endocyclophotocoagulation 6 Studies 429 eyes 204 ECP 225 Non ECP

Outcome Clinical efficacy and safety did not significantly differ between 2 groups (P > 0.05). Postoperative IOP was dramatically reduced in both groups. Success rate Complication rate Lacunae: Multiple surgical methods were adopted in the non-ECP group refractory glaucoma has a variety of primary diseases and complications. Studies in which ECP was used in combination with other procedures such as Phacoemulsification were not included

Take Home Message Iridotomy: No clear benefit of LPI in eyes with PDS or PG in preventing VF loss. Very low-quality evidence that LPI may be more effective in lowering IOP when compared with no LPI for up to 10 years after treatment. Few adverse effects; the most commonly reported adverse events were mild postoperative inflammation and cataract. Iridoplasty: No strong evidence for iridoplasty’s use in treating angle-closure. SLT: Efficacious in OAG, lowering IOP from 6.9% - 35.9%, and demonstrated comparable treatment success when compared to ALT and medication among patients with maximally tolerated medication and newly diagnosed patients. Overall safety profile was good, with most side effects being transient and amenable to medical therapy. ECP and TSCPC: Safe and efficacious for refractory glaucomas

Thank you for your kind attention!! parul77@rediffmail.com