Topical non-steroidal anti-inflammatory agents for diabetic cystoid macular oedema

Review question
We reviewed the evidence about the effect of non-steroidal anti-inflammatory drugs for diabetic cystoid macular oedema.

Background
Diabetic retinopathy is a frequent cause of blindness in adults aged between 20 and 74 years. The major cause of vision impairment in those with diabetic retinopathy is the accumulation of fluid in the central part of the retina (macula) known as cystoid macular oedema (CMO). CMO is the chronic and diffuse variety of diabetic macular oedema (DMO).The use of topical anti-inflammatory agents has been suggested as a potential treatment for diabetic CMO.

We aimed to review randomised controlled trials (RCTs) and quasi-RCTs (these are clinical research studies, which give good quality evidence on the effects of interventions) that investigated the effects of various topically applied non-steroidal anti-inflammatory drugs (NSAIDs) in treating diabetic CMO, and evaluate whether significant benefits have occurred with topical NSAIDs.

We reviewed the evidence on the effect of locally applied NSAID eye preparations on restoring vision in people with diabetic CMO. Although various topical NSAIDs have been used to treat diabetic CMO, namely bromfenac 0.09%, nepafenac 0.1% and ketorolac 0.5%, we did not find any RCTs or quasi-RCTs that were eligible for this review. We also found that most of the studies identified through the electronic searches had been conducted to analyse the effect of topical NSAIDs for pseudophakic CMO.

Greater research is required to understand the effects of topical NSAIDs on diabetic CMO. We would recommend a RCT to assess the effects of topical NSAIDs in patients with diabetic CMO. The trial would need to have a follow-up of at least one year, and include a large sample size and a robust design in order to assess any potential long-term beneficial or adverse effects of locally applied NSAIDs.

Search date
The evidence is current to January 2015.

Authors' conclusions: 

The review did not identify any RCTs investigating the effects of topical NSAIDs in the treatment of diabetic CMO. Most of the studies identified through the electronic searches had been conducted to analyse the effect of topical NSAIDs for pseudophakic CMO.In the absence of high quality evidence, clinicians need to use their clinical judgement and other low level evidence, such as observational non-randomised trials, to decide whether to use topical NSAIDs in cases of diabetic CMO.

More research is needed to better understand the cause of this condition and its pathophysiology. This systematic review has identified the need for well designed, adequately powered RCTs to assess possible beneficial and adverse effects of topical NSAIDs in people with diabetic CMO. Future trials should aim to include a large sample size with an adequate follow-up period of up to one year.

Read the full abstract...
Background: 

Diabetic cystoid macular oedema (CMO) is a condition which involves fluid accumulation in the inner portion of the retina. It often follows changes in retinal blood vessels which enhance the fluid to come out of vessels. Although it may be asymptomatic, symptoms are primarily painless loss of central vision, often with the complaint of seeing black spots in front of the eye.

It is reported that CMO may resolve spontaneously, or fluctuate for months, before causing loss of vision. If left untreated or undiagnosed, progression of CMO may lead to permanent visual loss.

It has been noted that patients with diabetic retinopathy have elevated inflammatory markers, and therefore it is likely that inflammation aids in the progression of vascular disease in these patients. Several topical non-steroidal anti-inflammatory drugs (NSAIDs) such as ketorolac 0.5%, bromfenac 0.09%, and nepafenac 0.1%, have therefore also been used topically to treat chronic diabetic CMO. Hence this review was conducted to find out the effects of topical NSAIDs in diabetic CMO.

Objectives: 

To assess the effects of topical non-steroidal anti-inflammatory drugs (NSAIDs) for diabetic cystoid macular oedema (CMO).

Search strategy: 

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 12), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to January 2015), EMBASE (January 1980 to January 2015), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to January 2015), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the 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 12 January 2015.

Selection criteria: 

Randomised controlled trials (RCTs) and quasi-RCTs investigating the effects of topically applied NSAIDs in the treatment of people with diabetic CMO aged 18 years of age or over.

Data collection and analysis: 

Two review authors independently assessed trial eligibility and screened all available titles and abstracts for inclusion. There were no discrepancies and we did not have to contact trial investigators for missing data.

Main results: 

We did not identify any RCTs matching the inclusion criteria for this review.

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