To examine the real life impact of the COVID pandemic on the treatment of patients with sight-threatening Diabetic Macular Oedema (DMO). We sought to determine if there was correlation between permanent vision loss and the inability to have treatment delivered as a result of shielding, systemic complications or hospital capacity. We also examined whether there were any correlations or associations between markers of diabetic control and comorbidities with refractory DMO.
This study was conducted at the Ophthalmology Department at the Leicester Royal Infirmary, a hospital of the University Hospitals NHS Trust in the United Kingdom. Almost uniquely in the UK, Leicester has had continuous lockdown or restrictions since March 2020.
Patients were identified from the database of diabetics undergoing intravitreal therapy (IVI) for DMO and laser for complications of Diabetic Eye Disease. The study period was from March 1 2020 to September 1 2020. A retrospective case note analysis was performed and data recorded. The criteria for refractory DMO was as follows: Central Retinal Thickness (CRT) > 400 microns, undergoing a full course of treatment with anti-VEGF and demonstrating insufficient response, as defined as an increase of CRT following treatment or a reduction of CRT of less than 100 microns or 20% from baseline.
DMO was found in 71 eyes from 43 patients in the IVI subgroup and in 23 eyes from 18 patients in the laser subgroup. 36/71 (51%) of eyes in the IVI subgroup demonstrated refractory DMO, while the same was true of 4/23 (17%) eyes in the laser subgroup. Although more Type II diabetics became refractory, (65% vs 35%), Type 1 diabetics were proportionally over-represented in the refractory IVI group. Type I diabetics were also more than 3 times more likely (35% vs 10%) to progress to refractory DMO during lockdown than prior to. 25/43 (58%) of patients in the IVI group missed at least one treatment, while 17/25 (68%) of these missed at least 25% of their scheduled injections. Reasons related to Covid-19 accounted for 17/25 (68%) of missed treatments. 16/25 (64%) of these patients progressed to refractory DMO. In the laser group, only 4/16 (25%) of patients missed at least one treatment. 1/4 (25%) of these progressed to refractory disease. HbA1c >7% was recorded in 19/26 (72%) of IVI Refractory DMO patients. This compares to 34% (14/41) of IVI Refractory DMO patients in a similar audit conducted at our centre (Nov 2019-Jan 2020) immediately prior to Covid-19 lockdowns.
Covid-19 appears to have had a significant negative effect on diabetic control and subsequent diabetic macula oedema. These effects seemed to have impacted Type I diabetics more than Type II diabetics. Early intervention with macular laser and the use of longer acting intravitreal therapeutics such as dexamethasone and fluocinolone acetonide implants may mitigate these effects.
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