Title: Dexamethasone intravitreal implant for treating diabetic macular oedema in people without a pseudophakic lens (part review of TA349) [ID3951]
Funder: Department of Health and Social Care

Abstract: Diabetic macular oedema (DMO) is a common complication associated with diabetic retinopathy, and is the most common cause of visual impairment in diabetes mellitus. It occurs as a result of changes in retinal blood vessels in people with diabetes. Disruption of the blood–retinal barrier allows fluid to leak from blood vessels in the central part of the retina (the macula), leading to fluid accumulation and thickening of the macula. This can lead to severe visual impairment in the affected eye._x000D_ _x000D_ DMO can be classed as focal, diffuse or ischaemic (although no universal definition has been agreed). The majority of vision loss occurs when DMO involves the centre of the macula. This is known as clinically significant macular oedema (CSMO), and is regarded as the threshold for treatment._x000D_ _x000D_ More than 3.5 million people have been diagnosed with diabetes in England and Wales (2019) [1] , and the condition is more common in people of African–Caribbean and South Asian family origin than in those of European family origin. Approximately 7% of people with diabetes may have DMO in England, of whom 39% have CSMO[2] . The prevalence of DMO is related to the duration and severity of diabetes, and to numerous risk factors including age, pregnancy, smoking, hypertension, nephropathy, obesity and high cholesterol._x000D_ _x000D_ Good management of diabetes and other risk factors may delay the onset and progression of DMO. This includes diet and lifestyle modification, blood pressure control and pharmacological treatments. For DMO specifically, NICE technology appraisals TA274 and TA346 recommend anti vascular endothelial growth factor (anti-VEGF) treatments ranibizumab and aflibercept as options for treating visual impairment caused by DMO if the eye has a central retinal thickness (CRT) of 400 micrometres or more at the start of treatment. For eyes with a CRT of less than 400 micrometres, laser photocoagulation may be a treatment option. In addition, bevacizumab, another anti-VEGF treatment, is used outside its marketing authorisation in some NHS centres. In NICE technology appraisal TA613 (a partial review of TA301), fluocinolone was not recommended for treating chronic diabetic macular oedema that is insufficiently responsive to available therapies in an eye with a natural lens (phakic eye). In cases where there is no suitable treatment available, a watch-and-wait strategy may be adopted until the point where treatment with antiVEGFs becomes suitable, or surgical intervention is required. _x000D_ _x000D_ NICE technology appraisal TA349 recommends dexamethasone intravitreal implants as an option for treating DMO that is insufficiently responsive to available therapies if the implant is to be used in an eye with an intraocular (pseudophakic, or artificial) lens. There is new evidence supporting the clinical and cost effectiveness of dexamethasone intravitreal implants for people with phakic (natural) lenses. Therefore, the decision was taken to part-review TA349 in an appraisal for people with phakic lenses._x000D_ _x000D_ References_x000D_ 1 Diabetes UK (2020) Diabetes prevalence 2019. Accessed September 2021._x000D_ 2 Minassian DC, Owens DR, Reidy A. Prevalence of diabetic macular oedema and related health and social care resource use in England. British Journal of Ophthalmology 2012;96:345-349.

Lay abstract: To appraise the clinical and cost effectiveness of dexamethasone intravitreal implant within its marketing authorisation for treating diabetic macular oedema in people without a pseudophakic lens.

Research activity codes: 6.1 PHARMACEUTICALS
Health categories: EYE;METABOLIC AND ENDOCRINE