Diabetic Macular Edema: Focal vs. Diffuse Treatment Approaches

Learn about OCT classification of macular edema and how Dr. Mahmoud Hassan determines the optimal injection therapy based on retinal thickness measurements in microns.

Diabetic Macular Edema (DME): Understanding the Differences Between Focal and Diffuse Types and the Latest Treatment Options

Diabetic Macular Edema (DME) is one of the most serious complications that can affect the retina in people with diabetes. It is a condition characterized by fluid accumulation within or beneath the macula, the central part of the retina responsible for detailed vision and visual acuity. This accumulation leads to swelling and distortion of the macula, resulting in blurry vision, difficulty reading, and changes in color perception. Since diabetes affects the tiny blood vessels throughout the body, the retina is no exception. High blood sugar levels damage these vessels, causing fluid and fat leakage, which is known as diabetic macular edema.

Diagnostic Classification: Focal vs. Diffuse

Clinically, diabetic macular edema is classified based on the pattern of fluid leakage and accumulation in the macula, which can be accurately determined using advanced imaging techniques such as Optical Coherence Tomography (OCT). This classification aims to precisely guide the treatment plan, as each type may require a different therapeutic strategy in terms of effectiveness.

1. Focal Diabetic Macular Edema (Focal DME)

This type is characterized by fluid leakage from specific, well-defined points in the damaged retinal blood vessels, often microaneurysms or weak areas in vessel walls. When imaged with OCT, the accumulated fluid appears as cystoid spaces in the retinal layers, often confined around the main leakage site. This type may be more responsive to targeted treatment, such as focal thermal laser in some cases, or localized drug injections.

2. Diffuse Diabetic Macular Edema (Diffuse DME)

In contrast, diffuse edema is characterized by widespread fluid leakage from multiple, scattered areas of the retina, without a clear, specific leakage point. This type is often associated with more extensive damage to retinal blood vessels and may be accompanied by widespread hard exudates in the retina. Diffuse edema appears on OCT images as widespread fluid accumulation throughout the retinal layers, leading to a general increase in macular thickness. This type often requires systemic treatment or repeated intravitreal injections.

The Importance of Optical Coherence Tomography (OCT) in Guiding Treatment

Optical Coherence Tomography (OCT) is a cornerstone in the diagnosis and evaluation of diabetic macular edema. It not only determines whether the edema is focal or diffuse but also provides precise measurements of retinal thickness in microns, identifies the depth of fluid accumulation, and evaluates the condition of various retinal layers, including the presence of inner layer detachment or hard exudates. This detailed information is crucial for Dr. Mahmoud Hassan, a consultant retinal and vitreous surgeon, to determine the optimal treatment strategy for each patient. For instance, the choice of the appropriate drug for intravitreal injection, such as Eylea or Vabysmo, may differ based on the edema pattern, retinal thickness, and the presence of other signs such as retinal traction or macular holes.

Available Treatment Options for Diabetic Macular Edema

Treatment selection depends on several factors, including the type of edema (focal or diffuse), severity of the condition, extent of vision impairment, presence of other complications, and the patient's general health. The main treatment options include:

1. Intravitreal Injections

Intraocular injections, especially with anti-vascular endothelial growth factor (Anti-VEGF) drugs like Eylea and Vabysmo, are considered the most common and effective treatment for diabetic macular edema, particularly in diffuse cases or those unresponsive to other treatments. These drugs reduce fluid leakage from damaged blood vessels, which helps decrease swelling and improve vision. The patient may require a series of injections, and the number of injections needed varies from person to person. The estimated cost of intravitreal injection (IVI) in Egypt for 2026 starts at approximately 7,000 EGP. The estimated cost of Eylea / Lucentis injections in Egypt for 2026 is approximately 9,000 EGP, and the estimated cost of Vabysmo injections in Egypt for 2026 is approximately 11,000 EGP.

2. Laser Treatment

In cases of specific focal edema, thermal laser photocoagulation may be used to seal leaking blood vessels. However, laser use has declined in recent years in favor of injections, especially with the development of anti-VEGF drugs. Argon laser may be used in other cases related to diabetic retinopathy, such as treating abnormal blood vessels in the peripheral retina. The estimated cost of argon laser (per eye) in Egypt for 2026 is approximately 5,000 EGP.

3. Corticosteroid Implants

In some stubborn cases or those unresponsive to other treatments, long-acting intraocular corticosteroid implants, such as the Ozurdex implant, may be used. These implants reduce inflammation and swelling in the retina but may carry some side effects such as increased intraocular pressure or cataract formation. The estimated cost of an Ozurdex implant injection in Egypt for 2026 is approximately 27,000 EGP.

4. Surgery (Vitrectomy)

In advanced cases accompanied by retinal traction, severe vitreous hemorrhage, or the presence of fibrous membranes, vitrectomy may be necessary. This surgery aims to remove the damaged vitreous, relieve any traction on the macula, clear the retina of blood or membranes, and restore the retina to its normal position. The estimated cost of a simple vitrectomy in Egypt for 2026 starts at approximately 35,000 EGP, while the estimated cost of a complex / tractional / retinal detachment vitrectomy in Egypt for 2026 averages approximately 50,000 EGP.

Prevention and Regular Follow-up

Prevention remains the first line of defense against diabetic macular edema. This requires strict control of blood sugar levels, blood pressure, and cholesterol. Regular eye examinations, especially for diabetic patients, are crucial for early detection of any retinal changes, including diabetic retinopathy that may progress to macular edema. Regular fundus examination is an integral part of healthcare for diabetic patients and is performed at Al Mashreq Eye Center by a team of specialists.

Understanding the difference between focal and diffuse diabetic macular edema, and relying on advanced diagnostic techniques like OCT, enables ophthalmologists, such as Dr. Mahmoud Hassan, to develop personalized treatment plans aimed at preserving the patient's vision and preventing its loss. Do not hesitate to consult your specialist if you experience symptoms indicating retinal problems.

You can follow more valuable medical information and tips on our YouTube channel: .

For appointments and inquiries: 01002310813

Articles you might like to read

• Best Intraocular Lens Types After Cataract Surgery and the Advantages of Each
• Retinal Laser Treatment: Benefits, Types, and Post-Session Care

https://drmahmoud-hassaan.com/en/articles/diabetic-macular-edema-focal-diffuse-treatment