Oman Journal of Ophthalmology

: 2022  |  Volume : 15  |  Issue : 1  |  Page : 3--5

How to treat diabetic retinopathy and diabetic macular edema most efficiently

Anselm Kampik 
 Direktor Augenzentrum im Brienner Hof, München; Emeritus Augenklinik der Universität München Member; Academia Ophthalmologica Internationalis, Briennerstrasse 12, D-80333 München, Germany

Correspondence Address:
Prof. Anselm Kampik
FEBO, FARVO, Augenzentrum im Brienner Hof, Briennerstrasse 12, D-80333 Munchen

How to cite this article:
Kampik A. How to treat diabetic retinopathy and diabetic macular edema most efficiently.Oman J Ophthalmol 2022;15:3-5

How to cite this URL:
Kampik A. How to treat diabetic retinopathy and diabetic macular edema most efficiently. Oman J Ophthalmol [serial online] 2022 [cited 2022 May 23 ];15:3-5
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Full Text

Diabetes mellitus is and will be a major health-care problem and is the leading cause of permanent blindness in working-age adults. Whereas in Europe at present 61 Mio. persons are affected and 69 Mio. are projected until 2045, in the Middle East and North Africa region, persons with diabetes mellitus at present are 73 Mio. and are projected to 136 Mio. by the year 2045. This is an extraordinary increase as compared to the European region. In Oman, the current prevalence of 13.6% (=445.600 persons) will increase to 15.4% (=897.000 persons) in 2045.[1] A high percentage of patients suffering from diabetes mellitus are and will be undiagnosed. The sheer number of patients with diabetes poses a challenge to all physicians caring for these patients. To cope with this challenge, a multidisciplinary care and an efficient approach for diagnosis and treatment are mandatory. Over the last decades, it became clear that with better medical control of diabetes, the severity of diabetic eye disease can become less prominent: intensive blood glucose self-management via diet and with medication‒if required‒can prevent the onset of diabetic retinopathy (DR) by 76% and its progression by 54% at least for insulin-treated patients. Nevertheless, a certain number of patients with diabetes mellitus will develop DR, either as nonproliferative DR (NPDR), as proliferative DR (PDR), or as diabetic macular edema (DME). NPDR or PDR may be combined with DME. DME may also be the only finding. Early studies reported that 60% of patients with DR will progress to proliferative DR (PDR) within 10 years.[2]

In general, the prevalence of any DR is 35%, of NPDR 20%, of PDR up to 7%, and of DME up to 11%. In general, one has to deal with a higher prevalence of DR and DME in type 1 diabetes as compared to type 2 diabetes mellitus. Each entity has sound and successful evidence-based treatment options enabling to avoid severe vision loss or blindness and to preserve good visual acuity. Based on data from several countries all costs from diabetic eye disease including medical expenditures and productivity loss need considerable amounts in health-care expenditures.[3]

Considering these facts about DR and DME, we as ophthalmologists are asked to deliver our diagnosis and treatment for this disease in the most efficient way. Not only the burden of the disease for each patient but also the economic burden for the health-care system asks for an algorithm taking into account all the current possible options as evidenced by many studies. Depending on the number of ophthalmologists, the number of patients, and the economic possibilities in a given region, an adjustment of evidence-based study findings has to be considered.

These adjustments include diagnosis and treatment and ask for an algorithm on these two interdependent actions: how to screen diabetic eye disease in diabetic patients and how to treat most efficiently NPDR, PDR, and DME.

How to screen patients with diabetes most efficiently:

At present in Oman, more than 450,000 people need a screening to find out the 35% of persons with diabetes and DR and further decision to find those 5%–10% with DME and roughly those 25% with NPDR or PDR in need for treatment, to avoid severe vision loss or even blindness.

One option to screen all these patients with diabetes is individual eye examinations with the examination of the retina and also optical coherence tomography (OCT), and OCT angiographic screening done by an ophthalmologist to detect diabetic eye disease needing treatment. This option is potentially the best but costly and potentially not reaching all diabetic patients. The number of hours to be spent for screening are exceeding the potential working hours of ophthalmologists/year in the region.

Therefore, another option to consider is teleretinal screening for DR. This can be performed with devices ranging from a smartphone-based retinal picture, handheld fundus camera to sophisticated wide field nonmydriatic fundus camera and further evaluation by a reading center or by artificial intelligence (AI). The future certainly will be teleretinal screening and efforts should be undertaken to implement such screening methodology. Ideally, screening all patients with diabetes in future will be a reachable application of AI in ophthalmology.

Such an application of AI will reduce the burden from ophthalmologists of screening patients without any DR and will focus the efforts of the ophthalmologist to treat those patients in need.[4],[5],[6] Together with such an advanced and accessible screening, it remains essential that persons with diabetes are educated about the importance of regular retinal screening. The community of eye physicians has to consider this option and potentially has to take action.

How to treat patients with DR or DME most efficiently:

Treatment options for NPDR, PDR, or DEM include intravitreal medical treatment with anti‒vascular endothelial growth factor (VEGF) substances, laser coagulation treatment, and vitrectomy. The decision for a treatment option is based on the disease severity and on an individual basis.

For NPDR and PDR, multiple studies have demonstrated the effectiveness of pan-retinal laser coagulation to prevent further progression of the disease. Newer studies found a similar effectiveness by treatment with anti-VEGF intravitreally.

 Nonproliferative Diabetic Retinopathy and Proliferative Diabetic Retinopathy

For severe NPDR (= more than 20 microaneurysms in each quadrant + intraretinal hemorrhages in all four quadrants or venous beading in two quadrants or intraretinal microvascular abnormalities in one quadrant), mild scatter photocoagulation (about 1000 spots) has to be considered.

As soon as signs of PDR (= neovascularization at the disc or elsewhere, or pre-retinal hemorrhages) are observed a full-scatter retinal photocoagulation (PRP) is still the most efficient treatment option. This is in accordance with the findings of several studies which found no inferiority of intravitreal treatment of PDR with anti-VEGF substances.[7],[8] Visual acuity after 3 years was not inferior in either arm of the study. However, visual field defects, the occurrence of macular edema, and the necessity for vitrectomy were less with anti-VEGF as compared to PRP. In comparison to a treatment with PRP (eventually in a few sessions), anti-VEGF treatment in these studies needed about 19 intravitreal injections. Thus, the efficiency of PRP versus anti-VEGF treatment for PDR has advantages which should be considered in a given environment of health care.

 Diabetic Macular Edema

Regarding DME center involving macular edema has to be differentiated from macular edema outside the center of the macula. As long as the center of the macula is not involved, observation is recommended. If a clinically significant macular edema is developing, but the center of the macula is not involved, focal laser coagulation is recommended.[9]

If the center of the macula is involved intravitreal anti-VEGF therapy is the therapy of choice. Treatment has to be considered when visual acuity is dropping below 0.8.[10] For centers involving macular edema, several intravitreal injections of anti-VEGF substances are necessary. To follow these patients ideally, OCT and OCT-A examinations are useful and can determine together with the visual development how effective this therapy is. At these examinations, it can also be determined whether treatment needs to be changed to intravitreal steroids. Tractional components and retinal ischemia have to be ruled out to adjust the treatment for an optimum functional outcome.

In case of combined PDR and DME, intravitreal injections of anti-VEGF substances should be performed before treating additionally with pan-retinal laser photocoagulation to stabilize the retinopathy,[11] if still necessary.

In summary, treatment options for DR and DME in future ask for an optimized screening using fundus photographs with AI to find efficiently those patients in need for treatment. In treating those patients in need not only the very effective anti-VEGF treatment but also laser treatment has to be used to reach the most efficient treatment for the best possible functional outcome with a minimum in the burden of disease.


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3International Diabetes Federation. IDF Diabetes Atlas. 8th ed. Brussels, Belgium: International Diabetes Federation; 2017. Available from: [Last accessed on 2022 Jan 03].
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9Amoaku WM, Ghanchi F, Bailey C, Banerjee S, Banerjee S, Downey L, et al. Diabetic retinopathy and diabetic macular oedema pathways and management: UK Consensus Working Group. Eye (Lond) 2020;34 Suppl 1:1-51.
10Baker CW, Glassmann AR, Beaulieu WT, Antoszyk AN, Browning DJ, Chalam KV, et al. Effect of initial management with aflibercept vs. laser photocoagulation vs. observation on vision loss among patients with diabetic macular edema involving the center of the macula and good visual acuity: A randomized clinical trial. JAMA 2019;321:1880-94.
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