Comparison of pain scores among patients undergoing conventional and novel pan retinal photocoagulation for diabetic retinopathy: a systematic review

Author: Azarcon CP, Artiaga JCM.

Geographical coverage: India, Turkey, the UK, France, Germany, China, South Korea, Czech Republic and Egypt

Sector: Biomedical

Sub-sector: Treatment

Equity focus: Not reported

Study population: Patients with diabetic retinopathy

Review type: Other review

Quantitative synthesis method: Not applicable

Qualitative synthesis method: Narrative synthesis

Background: Diabetic retinopathy (DR), a microvascular complication of diabetes mellitus (DM), is characterised by an earlier stage non-proliferative diabetic retinopathy (NPDR) and an advanced stage proliferative diabetic retinopathy (PDR). Pan retinal photocoagulation (PRP) is commonly used in the management of PDR. Pain is one of the adverse events of PRP that affects compliance with therapy and results in deterioration of vision. In addition, pain can cause further complications if it stimulates sudden movement of the eye during the procedure.

Objectives: To summarise key findings from focusing on pain as an adverse outcome of pan retinal photocoagulation (PRP) among patients with diabetic retinopathy.

Main findings: A total of 176 articles were identified from the electronic database and manual reference searches, of which 17 were included in this review. Thirteen of 17 included studies were randomised controlled trials (RCTs), whereas the remaining four were controlled clinical trials (CCTs). Overall, four RCTs had high risk of bias, one had low risk of bias, and the remaining had medium risk of bias; while for CCTs, three had low risk of bias, and one had high risk of bias. Thirteen studies compared conventional single-spot laser (SSL) versus conventional multi-spot laser (MSL), three compared novel navigated laser (NNL) versus conventional MSL, and three compared NNL versus conventional SSL. Most of the studies used 532-nm wavelength for both laser groups, however, some compared 577-nm with 532-nm. In addition, laser methodology varied across the studies. A total of 783 patients and 1,961 eyes were included in this review. The review showed that pain score was the lowest for NNL, followed by conventional MSL, and then by conventional SSL.

Methodology: Searches were conducted in Medline, CENTRAL, EMBASE, ClinicalTrials.gov, LILACS, and Herdin.ph databases to identify RCTs and CCTs that compared pain scores of patients undergoing PRP by conventional single-spot laser (SSL), conventional MSL (PASCAL®) and NNL (NAVILAS®). No language limits were applied. Reference lists of identified studies were manually reviewed to identify any additional studies.

The title and abstract and full-text screening were conducted by two reviewers independently. The risk of bias of the RCTs and CCTs was assessed using the Cochrane the risk of bias tool 2 and the ROBINS-I tool, respectively. Results of the RCTs and CCTs were included in the qualitative analysis. Heterogeneity was assessed using I² statistics. Sensitivity analysis was conducted to see the impact of studies with high or serious risk of bias on the overall results.

Applicability/external validity: The authors did not discuss the applicability or external validity of the results.

Geographic focus: Worldwide

The geographic region of the included studies in this review is mostly Asia and Europe. The authors did not discuss the applicability of findings to low and middle income settings.

Summary of quality assessment:

Authors used appropriate search strategies on databases and appropriate approaches to screen and extract data and analyse the findings of included studies. However, the authors did not analyse the findings according to the risk of bias of included articles. Therefore, a medium confidence was placed on the conclusions about the effects of this review.