Diabetic retinopathy: Symptoms, diagnosis and treatment in Turkey

What is diabetic retinopathy and why does it progress silently?

Diabetic retinopathy (DR) is a complication of diabetes that damages the tiny blood vessels of the retina. The real danger? It often develops without any symptoms in its early stages, making it a silent thief of vision.

According to the WHO, DR remains one of the leading causes of vision loss among working-age adults worldwide (20–74 years). Yet many patients discover it only after their vision has already been compromised.

Early on, there is no pain and no noticeable change in vision. By the time symptoms like blurring, floaters, or dark spots appear, the disease is often already advanced. This is precisely why people with diabetes are strongly advised to undergo annual eye examinations, even when their vision feels completely normal. Rare, but it happens: some patients develop advanced disease within months.

From a medical perspective, the pathophysiology is straightforward. High blood sugar persistently damages the walls of retinal capillaries, causing them to leak fluid or bleed into surrounding tissue. Over time, the retina becomes starved of oxygen (retinal ischemia),triggering the release of vascular endothelial growth factor (VEGF),a potent signaling molecule that the body produces in response to tissue hypoxia.

VEGF drives abnormal, fragile blood vessel growth. These vessels leak easily. They scar the retina. In severe cases, and this can happen within months in poorly controlled diabetes, they lead to retinal detachment and permanent vision loss.

Understanding the stages of diabetic retinopathy

Not all cases of DR require the same intervention. The internationally recognised classification divides the disease into five distinct stages, each with different treatment urgency and approach:

One critical point: diabetic macular oedema (DME) can occur at any stage, even in mild NPDR, this is not uncommon. Fluid leaks into the macula, the central retina responsible for sharp vision, making it the most common cause of vision loss in diabetes. The good news? Prompt anti-VEGF treatment can often reverse fluid accumulation and restore central vision, allowing patients to read, drive, and maintain independence. The longer treatment is delayed, the more scar tissue forms, reducing reversibility.

Diagnosing diabetic retinopathy: Key tests your ophthalmologist will use

Accurate diagnosis and proper staging are essential. Why? Because treatment strategies differ dramatically between mild NPDR and proliferative disease. Partner clinics throughout Istanbul use the same advanced diagnostic tools found in Europe's leading retinal centres to ensure precise assessment and appropriate management:

1. Optical Coherence Tomography (OCT): The gold standard for detecting diabetic macular edema. OCT produces high-resolution, cross-sectional images of the retina, measuring thickness and fluid accumulation with micron-level precision. Non-invasive. Takes under five minutes. Many patients find this their first objective evidence of disease.
2. Fluorescein Angiography (FA): A fluorescent dye injected into the arm highlights retinal blood vessels in real time. FA identifies leakage zones, areas of poor perfusion, and abnormal new vessels (neovascularization) that OCT cannot detect. Essential for managing advanced disease. This is what clinicians cannot skip.
3. Colour Fundus Photography: Standardized retinal photographs document and stage disease according to the ETDRS scale. These baseline images allow tracking of progression over months and years. They also serve as crucial documentation for insurance and follow-up ophthalmologists.
4. Fundoscopy: Direct and indirect examination of the retina, optic disc, and vitreous remains part of every consultation. Subtle changes that imaging misses, early vitreous haze, subtle neovascularization at the disc margin, often surface during careful clinical examination.

Critical clinical note: OCT alone is insufficient for evaluating proliferative DR. Fluorescein angiography is mandatory to map ischemic zones and guide laser treatment. Clinics relying solely on OCT for advanced diabetic eye disease may not deliver comprehensive care, potentially missing contraindications to treatment or misidentifying disease severity.

What are the treatment options of diabetic retinopathy in Turkey?

One striking observation: international patients undergoing consultation in Istanbul immediately notice the emphasis on precision before any treatment proposal. One-size-fits-all protocols do not exist in modern retinal practice.

Treatment hinges on multiple factors. The disease stage. Presence or absence of macular edema. The degree of retinal ischemia. The patient's metabolic control. Age. Life expectancy. Ocular anatomy. No single variable determines the path forward.

Metabolic control: The foundation no treatment can replace

Before any eye intervention is considered, specialists coordinate closely with endocrinologists to stabilise blood sugar (HbA1c),blood pressure, and lipid levels. This is non-negotiable.

Simple truth: no injection or laser compensates for poorly controlled diabetes.

The DCCT landmark study demonstrated that reducing HbA1c from 9% to 7% lowers retinopathy progression risk by up to 76%. One of the most powerful findings in diabetic eye care. This remains true decades later.

Anti-VEGF injections: The current standard of care

Anti-VEGF injections (ranibizumab, bevacizumab, aflibercept) are now first-line treatment for diabetic macular edema and proliferative retinopathy. They block VEGF, the molecule driving both fluid leakage and abnormal vessel proliferation.

Major clinical trials (RESTORE, VIVID/VISTA, PROTOCOL T) demonstrate average gains of 8–12 letters on the ETDRS scale at 12 months. Practically speaking? Many regain the ability to read or drive.

In practice, procedures follow strict sterile protocols in operating theatres. Most patients receive 3 to 7 injections during the first year, with monthly or bi-monthly follow-up depending on retinal response. A subset improves dramatically after just 2 injections; others require closer to 8–10 over time.

Laser photocoagulation

Laser remains essential in proliferative DR management, though anti-VEGF has shifted its role considerably over the past decade.

The Diabetic Retinopathy Study (1976) showed panretinal photocoagulation (PRP) reduced severe vision loss risk by approximately 50% in high-risk patients. That finding stands today.

Two complementary approaches:

• Focal/grid laser: targets leaking areas in the macula (non-central edema)
• Panretinal photocoagulation (PRP): treats the ischemic peripheral retina to prevent abnormal new vessel growth

Modern laser systems (Pascal, Navilas) used throughout Istanbul enable faster, more precise, and substantially more comfortable treatments compared to older solid-state technology. Recovery is measured in days, not weeks.

Intravitreal corticosteroids

When anti-VEGF treatment fails or tolerability is poor, long-acting corticosteroid implants (dexamethasone, triamcinolone) provide a proven alternative. Effects typically persist 4 to 6 months and are repeatable. Particularly effective in chronic or refractory macular edema that has resisted multiple anti-VEGF rounds.

Vitrectomy: When surgery becomes necessary

Vitrectomy enters the picture in advanced cases:

• Persistent vitreous hemorrhage obscuring vision for ≥3 months
• Tractional retinal detachment threatening or involving the macula
• Dense fibrotic membranes impairing vision despite medical therapy

This is major intraocular surgery, performed under local or general anaesthesia, requiring 1 to 3 weeks recovery. Specialised retinal teams in Istanbul employ minimally invasive techniques (23G, 25G, 27G instruments),dramatically reducing surgical trauma and accelerating visual recovery compared to older 20G approaches.

Anatomical success rates in experienced hands exceed 90% at 3 months for vitreous hemorrhage cases. But not all cases succeed equally, dense proliferation, extensive fibrosis, and multiple prior surgeries lower success rates moderately.

Risks and how Turkey's specialists manage them?

Honest disclosure about risk reflects medical integrity, not reason for avoidance. Untreated diabetic retinopathy carries vastly greater blindness risk than any therapeutic intervention used to control it.

What happens when you choose Turquie Santé for diabetic eye treatment?

For most patients, the logistical journey proves far simpler than anticipated.

1. Step 1: Remote preliminary assessment. Send your OCT scans, fundus photographs, most recent HbA1c results, and diabetic history before travelling. A partner retinal specialist reviews your case and provides preliminary assessment, confirming whether Istanbul treatment is appropriate and recommending the specific modality.
2. Step 2: In-person confirmation appointment. Upon arrival, a comprehensive clinical examination occurs, repeat OCT imaging, fluorescein angiography when indicated, measurement of visual acuity and eye pressures. The treatment plan is confirmed or refined based on current retinal status.
3. Step 3: Treatment delivery. Anti-VEGF injections and laser procedures typically occur same-day or the following morning. Vitrectomy is scheduled within 24–48 hours after pre-operative assessment and imaging.
4. Step 4: Return and coordinated follow-up. Most patients depart within two to three days post-injection, or after seven to ten days following vitrectomy. Your Turkish specialist provides detailed follow-up protocols for your local ophthalmologist and remains accessible via video consultation between visits, critical for continuity of care.