Cyclodestructive procedures for non-refractory glaucoma

Abstract

Background Glaucoma is a leading cause of blindness worldwide. It results in a progressive loss of peripheral vision and, in late stages, loss of central vision leading to blindness. Early treatment of glaucoma aims to prevent or delay vision loss. Elevated intraocular pressure (IOP) is the main causal modifiable risk factor for glaucoma. Aqueous outflow obstruction is the main cause of IOP elevation, which can be mitigated either by increasing outflow or reducing aqueous humor production. Cyclodestructive procedures use various methods to target and destroy the ciliary body epithelium, the site of aqueous humor production, thereby lowering IOP. The most common approach is laser cyclophotocoagulation. Objectives To assess the effectiveness and safety of cyclodestructive procedures for the management of non-refractory glaucoma (i.e. glaucoma in an eye that has not undergone incisional glaucoma surgery). We also aimed to compare the effect of different routes of administration, laser delivery instruments, and parameters of cyclophotocoagulation with respect to IOP control, visual acuity, pain control, and adverse events. Search methods We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 8); Ovid MEDLINE; Embase.com; LILACS; the metaRegister of Controlled Trials (mRCT) and ClinicalTrials.gov . The date of the search was 7 August 2017. We also searched the reference lists of reports from included studies. Selection criteria We included randomized controlled trials of participants who had undergone cyclodestruction as a primary treatment for glaucoma. We included only head-to-head trials that had compared cyclophotocoagulation to other procedural interventions, or compared cyclophotocoagulation using different types of lasers, delivery methods, parameters, or a combination of these factors. Data collection and analysis Two review authors independently screened search results, assessed risks of bias, extracted data, and graded the certainty of the evidence in accordance with Cochrane standards. Main results We included one trial (92 eyes of 92 participants) that evaluated the efficacy of diode transscleral cyclophotocoagulation (TSCPC) as primary surgical therapy. We identified no other eligible ongoing or completed trial. The included trial compared low-energy versus high-energy TSCPC in eyes with primary open-angle glaucoma. The trial was conducted in Ghana and had a mean follow-up period of 13.2 months post-treatment. In this trial, low-energy TSCPC was defined as 45.0 J delivered, high-energy as 65.5 J delivered; it is worth noting that other trials have defined high- and low-energy TSCPC differently. We assessed this trial to have had low risk of selection bias and reporting bias, unclear risk of performance bias, and high risk of detection bias and attrition bias. Trial authors excluded 13 participants with missing follow-up data; the analyses therefore included 40 (85%) of 47 participants in the low-energy ...

An update on continuous‐wave cyclophotocoagulation (CW‐CPC) and micropulse transscleral laser treatment (MP‐TLT) for adult and paediatric refractory glaucoma

“…Although CPC has been studied in the early stages of glaucoma (Egbert et al 2001; Kramp et al 2002; Singh et al 2017b; Abdull et al 2018), its complications remain common enough to limit its use to the treatment of glaucoma refractory to conventional surgical treatments (Michelessi et al 2018; Hasan et al 2019; Paul et al 2019) (Table 3). Moreover, the inflammatory (mostly CD4 T‐cell lymphocytic infiltrates) and fibrotic histological conjunctival lesions induced by the procedure are likely to impair future filtration blebs (Tan et al 2019).…”

Cyclodestructive Procedures in Glaucoma: A Review of Current and Emerging Options

“…A detailed account of the available research for each particular technique in the following sections of this review suggests a paradigm shift in recent years: these procedures are increasingly used earlier in the course of the disease, for a wider range of indications and in eyes with good visual function or potential. Nonetheless, there is currently insufficient high-quality controlled evidence to evaluate the relative safety and effectiveness of cyclodestructive techniques for the management of non-refractory glaucoma [ 23 ].…”

Physiological function of myocilin and its role in the pathogenesis of glaucoma in the trabecular meshwork (Review)

“…Elevated IOP is a known primary risk factor for glaucoma (22,23); however, not all cases of glaucoma exhibit high IOP (63,64). Elevated IOP is caused by increased resistance to aqueous humor outflow through the TM (65,66) and accounts for visual field loss; however, its pathogenesis remains unknown (67). Homeostasis of aqueous humor drainage through the TM is essential for the maintenance of normal IOP (68).…”