Interventions for strabismic amblyopia

Efficacy of interventions for amblyopia: a systematic review and network meta-analysis

BACKGROUND

Many treatments are currently available for amblyopic patients; although, the comparative efficacy of these therapies is unclear. We conducted a systematic review and network meta-analysis (NMA) to establish the relative efficacy of these treatments for amblyopia.

METHODS

Electronic databases (MEDLINE, EMBASE, Cochrane Library) were systematically searched from inception to Sep. 2019. Only Randomized clinical trials comparing any two or three of the following treatments were included: refractive correction (spectacles alone), patching of 2 h per day (patch 2H), patch 6H, patch 12H, patch 2H + near activities (N), patch 2H + distant activities (D), atropine (Atr) daily, Atr weekly, Atr weekly + plano lens over the sound eye (Plano), optical penalization and binocular therapy. The reviewers independently extracted the data according to the PRISMA guidelines; assessed study quality by Cochrane risk-of-bias tool for randomized trials. The primary outcome measure was the change in best-corrected visual acuity (BCVA) expressed as log MAR lines. Direct comparisons and a Bayesian meta-analysis were performed to synthesize data.

RESULTS

Twenty-three studies with 3279 patients were included. In the network meta-analysis, optical penalization was the least effective of all the treatments for the change of visual acuity, spectacles (mean difference [MD], 2.9 Log MAR lines; 95% credibility interval [CrI], 1.8-4.0), patch 2H (MD, 3.3; 95% CrI, 2.3-4.3), patch 6H (MD, 3.6; 95% CrI, 2.6-4.6), patch 12H (MD, 3.4; 95% CrI, 2.3-4.5), patch 2H + N (MD, 3.7; 95% CrI, 2.5-5.0), patch 2H + D (MD, 3.5; 95% CrI, 2.1-5.0), Atr daily (MD, 3.2; 95% CrI, 2.2-4.3), Atr weekly (MD, 3.2; 95% CrI, 2.2-4.3), Atr weekly + Plano (MD, 3.7; 95% CrI, 2.7-4.7), binocular therapy (MD, 3.1; 95% CrI, 2.0-4.2). The patch 6H and patch 2H + N were better than spectacles ([MD, 0.73; 95% Crl, 0.10-1.40]; [MD, 0.84; 95% CrI, 0.19-1.50]).

CONCLUSIONS

The NMA indicated that the efficacy of the most of the examined treatment modalities for amblyopia were comparable, with no significant difference. Further high quality randomized controlled trials are required to determine their efficacy and acceptability.

SYSTEMATIC REVIEW REGISTRATION

CRD42019119843.

Cost and quality of life of overlooked eye care needs of children

Background

The objective of this research was to conduct a systematic review and cost analysis to summarize, from the Ministry of Health perspective, the costs families might incur because of their child’s prescription for refractive errors and amblyopia correction.

Methods

Databases including MEDLINE, Embase, BIOSIS, CINAHL, HEED, ISI Web of Science, and the Cochrane Library as well as the gray literature were searched. Systematic review was conducted using EPPI-Reviewer 4. Percentage difference in cost of glasses and patches per patient per various diagnoses were computed. The cost of glasses and patches was projected over a 5-year time horizon. Cost-utility analysis was performed.

Results

In total, 302 records were retrieved from multiple databases and an additional 48 records were identified through gray literature search. From these, a total of 14 studies (10,388 subjects) were eligible for quantitative analysis. The cost of glasses increased significantly for congenital cataract patients to US$1,820, esotropia patients to US$840, myopes to US$411, amblyopes (mixed) to US$916, anisometropes to US$521, and patients with strabismus to US$728 over a 5-year period making them unaffordable for low-income families. Incremental cost of glasses of congenital cataract patients with delayed treatment was computed to be US$1,690 per health utility gained. Incremental cost of glasses for high refractive error was US$93 per health utility gained in non-compliant children. For amblyopia patients, incremental cost of glasses per quality-adjusted life years gained was US$3,638.

Conclusion

Cost of corrective lenses is associated with significant financial burden and thus other means of mitigating costs should be considered. Eyesight problems in children are perceived as low-priority health needs. Thus, educational interventions on substantial visual deficits of not wearing glasses should be offered to families and governmental health agencies.

Interventions for strabismic amblyopia

BACKGROUND

Amblyopia is reduced visual acuity in one or both eyes in the absence of any demonstrable abnormality of the visual pathway. It is not immediately resolved by the correction of refractive error. Strabismus develops in approximately 5% to 8% of the general population. The aim of treatment for amblyopia is to obtain the best possible level of vision in the amblyopic eye. Different treatment options were examined within the review.

OBJECTIVES

By reviewing the available evidence we wanted to establish the most effective treatment for strabismic amblyopia. In particular this review aimed to examine the impact of conventional occlusion therapy for strabismic amblyopia and to analyse the role of partial occlusion and optical penalisation for strabismic amblyopia.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2013, Issue 12), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to January 2014), EMBASE (January 1980 to January 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to January 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 30 January 2014.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) for the treatment of strabismic amblyopia including participants of any age.

DATA COLLECTION AND ANALYSIS

Two authors working independently extracted and entered data into Review Manager 5 and then independently checked the data for errors.

MAIN RESULTS

We included three RCTs in this review. The studies reported mean logMAR visual acuity achieved. Mean difference in visual acuity was calculated. When comparing conventional part-time occlusion (with any necessary glasses), PEDIG 2006 reported that this treatment was more beneficial than glasses alone for strabismic amblyopia; the mean difference between groups was -0.18 LogMAR (statistically significant 95% confidence interval (CI) -0.32 to -0.04). Supplementing occlusion therapy with near activities may produce a better visual outcome compared to non-near activities after four weeks of treatment (PEDIG 2005). The results of the pilot study showed mean difference between groups was -0.17 LogMAR (95% CI -0.53 to 0.19). Results from a larger RCT (PEDIG 2008) are now available, showing that supplementing occlusion therapy with near activities may produce a better visual outcome after eight weeks of treatment; the mean difference between groups was -0.02 LogMAR (95% CI -0.10 to 0.06). One further article ia awaiting assessment as in its current format there is insufficient information to include (Alotaibi 2012).

AUTHORS' CONCLUSIONS

Occlusion, whilst wearing necessary refractive correction, appears to be more effective than refractive correction alone in the treatment of strabismic amblyopia. The benefit of combining near activities with occlusion is unproven. No RCTs were found that assessed the role of either partial occlusion or optical penalisation to refractive correction for strabismic amblyopia.

Conventional occlusion versus pharmacologic penalization for amblyopia

BACKGROUND

Amblyopia is defined as defective visual acuity in one or both eyes without demonstrable abnormality of the visual pathway, and is not immediately resolved by wearing glasses.

OBJECTIVES

To assess the effectiveness and safety of conventional occlusion versus atropine penalization for amblyopia.

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE, LILACS, the WHO International Clinical Trials Registry Platform, preference lists, science citation index and ongoing trials up to June 2009.

SELECTION CRITERIA

We included randomized/quasi-randomized controlled trials comparing conventional occlusion to atropine penalization for amblyopia.

DATA COLLECTION AND ANALYSIS

Two authors independently screened abstracts and full text articles, abstracted data, and assessed the risk of bias.

MAIN RESULTS

Three trials with a total of 525 amblyopic eyes were included. One trial was assessed as having a low risk of bias among these three trials, and one was assessed as having a high risk of bias.Evidence from three trials suggests atropine penalization is as effective as conventional occlusion. One trial found similar improvement in vision at six and 24 months. At six months, visual acuity in the amblyopic eye improved from baseline 3.16 lines in the occlusion and 2.84 lines in the atropine group (mean difference 0.034 logMAR; 95% confidence interval (CI) 0.005 to 0.064 logMAR). At 24 months, additional improvement was seen in both groups; but there continued to be no meaningful difference (mean difference 0.01 logMAR; 95% CI -0.02 to 0.04 logMAR). The second trial reported atropine to be more effective than occlusion. At six months, visual acuity improved 1.8 lines in the patching group and 3.4 lines in the atropine penalization group, and was in favor of atropine (mean difference -0.16 logMAR; 95% CI -0.23 to -0.09 logMAR). Different occlusion modalities were used in these two trials. The third trial had inherent methodological flaws and limited inference could be drawn.No difference in ocular alignment, stereo acuity and sound eye visual acuity between occlusion and atropine penalization was found. Although both treatments were well tolerated, compliance was better in atropine. Atropine penalization costs less than conventional occlusion. The results indicate that atropine penalization is as effective as conventional occlusion.

AUTHORS' CONCLUSIONS

Both conventional occlusion and atropine penalization produce visual acuity improvement in the amblyopic eye. Atropine penalization appears to be as effective as conventional occlusion, although the magnitude of improvement differed among the three trials. Atropine penalization can be used as first line treatment for amblyopia.