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Diabetic retinopathy is an eye disease caused by changes in the retinal blood vessels resulting from long-term diabetes. The retina is the tissue at the back of the eye that detects light and converts it into visual signals. Persistently high blood sugar may damage the structure of the small blood vessels supplying the retina. This may lead to vascular leakage, bleeding, blocked vessels and abnormal blood vessel formation. The disease may progress without causing noticeable symptoms during its early stages. Treatment and follow-up are planned according to the retinal findings, duration of diabetes and effect on vision.
Relationship Between the Retina and Diabetes
The retina is the nerve layer at the back of the eye that detects light. This tissue requires a regular supply of oxygen and nutrients to maintain its function. Small blood vessels within the retina play an important role in this process. Diabetes may gradually affect the structure and permeability of the vessel walls. Damaged vessels may leak fluid, bleed or become blocked. Visual quality may change to varying degrees depending on the area of the retina affected.
Diabetic retinopathy does not occur only in older people. The risk may increase in different age groups as the duration of diabetes increases and blood sugar becomes more difficult to control. High blood pressure, kidney disease and cholesterol imbalances may also affect the retinal vessels. The degree of disease may not be the same in both eyes. The absence of noticeable symptoms does not mean that the retina has not been damaged. People with diabetes should therefore have regular eye examinations.
How Does High Blood Sugar Affect the Eye?
Persistently high blood sugar may cause various biological changes in the retinal blood vessels. Cells supporting the vessel walls may become damaged over time. As a result, the vascular structure may weaken and small bulges may form. These changes, known as microaneurysms, are among the early signs of diabetic retinopathy. When vascular permeability increases, fluid, proteins and lipid components may leak into the retinal tissue. Blockage of some vessels may prevent the retina from receiving sufficient oxygen.
A lack of oxygen in the retina may cause the release of substances that stimulate new blood vessel formation. These new vessels are not as strong as normal vessels. They may bleed easily and leak blood into the vitreous cavity. Fibrous tissue developing alongside the new vessels may contract over time. This may create traction on the retina and contribute to more advanced complications. The rate of progression varies according to diabetes control and other individual risk factors.
What Are the Symptoms of Diabetic Retinopathy?
Symptoms of diabetic retinopathy may not be noticed at all during the early stages. Even when small haemorrhages or leaks develop in the retinal vessels, the person may not notice a change in vision. Symptoms generally appear when the visual centre is affected or bleeding occurs inside the eye. Blurred vision, difficulty focusing and fluctuations in vision are common symptoms. Black floaters or cobweb-like images may be associated with intraocular bleeding. A sudden reduction in vision may develop in advanced cases.
Symptoms that may occur with diabetic retinopathy include:
- Blurred vision.
- Difficulty focusing.
- Dark spots in the visual field.
- Black floaters.
- Cobweb-like images.
- Straight lines appearing distorted.
- Colours appearing faded.
- A shadow in the visual field.
- Sudden reduction in vision.
The disease often progresses without pain or pronounced eye redness. Having an eye examination only when discomfort develops is therefore not sufficient. Newly developed dense floaters or a curtain-like shadow in the visual field should be assessed for intraocular bleeding or retinal traction. Flashes of light may also require investigation for accompanying retinal problems. Not every case of blurred vision is caused by diabetic retinopathy, and other conditions such as cataracts may be responsible. A definitive assessment requires a detailed eye examination.
Stages of Diabetic Retinopathy
The stages of diabetic retinopathy are classified according to the degree of vascular changes in the retina. The disease is mainly divided into non-proliferative and proliferative retinopathy. In the non-proliferative stage, small bulges, haemorrhages and leakage may be present in the retinal vessels. In the proliferative stage, abnormal new blood vessels develop. Macular oedema may occur at different stages of the disease and is assessed separately. Staging is important for determining the timing of treatment and the frequency of follow-up.
The main stages are:
- Mild non-proliferative retinopathy.
- Moderate non-proliferative retinopathy.
- Severe non-proliferative retinopathy.
- Proliferative retinopathy.
- High-risk proliferative retinopathy.
Non-Proliferative Diabetic Retinopathy
Non-proliferative diabetic retinopathy is the stage in which abnormal new blood vessels have not yet developed. Microaneurysms, small haemorrhages and fluid leakage may occur in the retinal vessels. Blockage of certain vessels may impair oxygen delivery to the retina. The findings may be mild, moderate or severe. Vision does not always become noticeably impaired at this stage. However, vision loss may occur even at an early stage if macular oedema develops.
Regular control of blood sugar and other systemic risks is important in mild cases. The frequency of fundus examinations is determined according to the degree of retinal change. The risk of progression to the proliferative stage may increase in more advanced non-proliferative cases. Follow-up intervals should therefore be arranged according to individual risk. Injections or laser treatment are not used in every case of non-proliferative retinopathy. The need for treatment is assessed according to the condition of the visual centre and changes in the retinal vessels.
Proliferative Diabetic Retinopathy
In proliferative diabetic retinopathy, abnormal new blood vessels develop on the retinal surface or around the optic nerve. These vessels may form in response to signals produced by areas of the retina that lack oxygen. Because the walls of the new vessels are weak, the risk of bleeding inside the eye increases. Vision may decrease suddenly when bleeding spreads into the vitreous cavity. Fibrous tissue developing alongside the vessels may contract over time and pull on the retina. This may lead to tractional retinal detachment.
The treatment approach during the proliferative stage is determined according to the extent of the new blood vessels. Laser photocoagulation or intravitreal injections may be used in suitable patients. In some cases, both methods may be planned together. Vitrectomy may be considered if intraocular bleeding does not clear or retinal traction progresses. Treatment aims to reduce the risk of new complications developing. Regular monitoring is important for detecting new bleeding or vascular changes that may occur despite treatment.
What Is Diabetic Macular Oedema?
Diabetic macular oedema occurs when fluid accumulates in the central part of the retina. The macula plays an important role in reading, recognising faces and seeing fine details. When vascular permeability increases, fluid and proteins may pass into the macular tissue. This accumulation may cause the macula to thicken and disrupt its normal structure. Patients may experience blurred central vision, distorted straight lines or difficulty focusing. Macular oedema may develop during both early and advanced stages of retinopathy.
Optical coherence tomography is an important examination for assessing macular oedema. The degree of visual centre involvement and the location of the fluid may be monitored using this method. Not every case of macular oedema requires the same treatment. Intravitreal injections may be considered when the visual centre is affected and vision is reduced. Laser treatment or intraocular corticosteroid treatments may also be appropriate for some patients. The treatment decision is made by evaluating visual acuity and tomography findings together.
How Is Diabetic Retinopathy Diagnosed?
A retinal examination performed after dilating the pupils is the main method used to diagnose diabetic retinopathy. During the examination, the retinal vessels are assessed for haemorrhages, microaneurysms and fluid leakage. The retinal surface and the area around the optic nerve are examined for new blood vessel formation. Optical coherence tomography may be used to assess changes in the macular region. Fundus angiography may be performed when necessary to examine vascular leakage. Ultrasonography may be added to the assessment if the retina cannot be visualised because of intraocular bleeding.
Methods that may be used for diagnosis and follow-up include:
- Retinal examination with dilated pupils.
- Biomicroscopic examination.
- Fundus imaging.
- Optical coherence tomography.
- Fundus fluorescein angiography.
- Ocular ultrasonography.
The duration of diabetes and the treatments used are also considered during the examination. Blood sugar levels, blood pressure and accompanying conditions such as kidney disease may affect the course of the disease. Angiography or ultrasonography is not required for every patient. The imaging method is selected according to the retinal findings. The presence of cataracts or another retinal disease in the same eye may affect the diagnostic process. Follow-up intervals are determined according to the stage of the disease and treatment requirements.
Tomography and Fundus Angiography
Optical coherence tomography provides detailed images of the retinal layers. It is particularly useful for assessing fluid accumulation and tissue thickening in the macular region. Tomography also helps monitor the eye's response following injection or laser treatment. The examination does not use radiation. However, tomography alone does not show the blood supply of all retinal vessels. Additional imaging methods may therefore be required in some patients.
During fundus fluorescein angiography, a special dye is administered intravenously to suitable patients. The passage of the dye through the retinal vessels is monitored using specialised imaging equipment. Vascular leakage, areas lacking oxygen and abnormal blood vessel formation may be assessed using this method. Angiography is not routinely required for every patient with diabetes. Its suitability is determined according to the person's health and clinical findings. Dye-free vascular imaging methods may also support assessment in some patients.
How Is Diabetic Retinopathy Treated?
Treatment of diabetic retinopathy is planned according to the stage of the disease and whether the visual centre has been affected. During the early stages, regular monitoring and control of systemic risk factors may be sufficient. Intravitreal medication injections may be used in some patients with macular oedema. Laser treatment or injections may be considered when abnormal new blood vessels develop. Vitrectomy may be required in advanced cases involving intraocular bleeding or retinal traction. Treatment is selected by considering the patient's ocular findings and general health together.
Treatment methods that may be used for diabetic retinopathy include:
- Regulation of blood sugar control.
- Monitoring blood pressure and cholesterol.
- Intravitreal anti-VEGF injections.
- Intraocular corticosteroid treatments.
- Laser photocoagulation.
- Vitrectomy surgery.
- Regular retinal examinations.
Treatment aims to reduce the progression of existing damage and preserve visual function. Not every patient requires injections or laser treatment at the same frequency. Different treatments may be combined in some cases. The treatment plan may be changed if the disease becomes active again. Eye treatments do not replace the general management of diabetes. Successful follow-up requires ocular findings and systemic health to be considered together.
Intravitreal Injection Treatments
Intravitreal injections are among the treatment options considered particularly for diabetic macular oedema affecting the visual centre. Anti-VEGF medications aim to suppress certain biological signals that increase vascular permeability and abnormal blood vessel formation. This may help reduce fluid accumulation in the macula. Injections may also be part of the treatment plan in some cases of proliferative retinopathy. The procedure is performed under sterile conditions after numbing the ocular surface. The level of discomfort experienced may vary according to individual characteristics.
Injection treatment is often not limited to a single procedure. Treatment frequency is determined according to ocular tomography findings and changes in visual acuity. Some patients may require repeated injections at specific intervals. Mild irritation or ocular surface redness may occur after the procedure. Severe pain, a pronounced reduction in vision or increasing redness requires urgent assessment. Potential risks such as infection and changes in intraocular pressure are considered during follow-up.
When Are Corticosteroid Implants Used?
Intraocular treatments containing corticosteroids may be considered in some cases of diabetic macular oedema. This method may be considered particularly in patients who have not responded adequately to certain injections. Implants placed inside the eye may gradually release medication over a specified period. Not every patient is suitable for a corticosteroid implant. Elevated intraocular pressure or a history of glaucoma may affect the treatment decision. The development or progression of cataracts must also be considered in patients with their natural eye lens.
The expected benefits and potential risks of corticosteroid treatment are evaluated together. Intraocular pressure may require regular monitoring after the procedure. Implant treatment may be repeated in some patients. Anti-VEGF treatment or laser methods may be more appropriate for others. The choice of treatment depends on the characteristics of the macular oedema and the response to previous procedures. The follow-up plan is prepared according to the individual's eye structure and accompanying diseases.
Laser Treatment for Diabetic Retinopathy
Laser photocoagulation is a treatment method used in certain cases of diabetic retinopathy. Particularly in proliferative retinopathy, it may help control retinal areas that stimulate abnormal blood vessel formation. During panretinal laser treatment, controlled laser applications are performed in the peripheral areas of the retina. This approach aims to reduce the biological signals that promote new blood vessel formation. Treatment may be planned over multiple sessions in some patients. The purpose of laser treatment is to reduce the risk of disease progression.
Laser treatment is not the same as refractive laser procedures used to correct vision. Its primary purpose is not to reduce the need for glasses or directly sharpen vision. Focal laser methods may also be considered in some cases of macular oedema. Different laser technologies, such as micropulse, may be used in selected cases. However, not every laser method is suitable for every patient. Treatment is selected according to the condition of the retinal vessels and the macular findings.
Effects that may occur after laser treatment include:
- Temporary sensitivity to light.
- Short-term blurred vision.
- Changes in night vision.
- Restriction of the peripheral visual field.
- Temporary increase in macular oedema.
- Changes in contrast perception.
The occurrence of these effects depends on the extent of the laser treatment and the patient's retinal structure. Some people do not experience any noticeable symptoms after treatment. More extensive laser applications may affect peripheral or night vision. Laser planning must be assessed separately in patients with macular oedema. Regular follow-up after the procedure allows the response to treatment to be monitored. Additional procedures may be required if new blood vessel formation continues.
When Is Vitrectomy Surgery Required?
Vitrectomy is a retinal surgical procedure that may be considered during the advanced stages of diabetic retinopathy. It may be used when bleeding inside the eye does not clear sufficiently on its own. Surgery may also be required when membranes pulling on the retina threaten the visual centre. Surgical planning is performed in detail for patients with tractional retinal detachment. During surgery, blood-filled vitreous tissue and retinal membranes are removed when necessary. Endolaser treatment may also be applied in suitable patients.
During vitrectomy, fine microsurgical instruments are inserted into the eye. Tissues causing traction on the retinal surface are carefully separated. Appropriate procedures are performed if tears or bleeding points are present. Air, gas or silicone oil may be placed inside the eye in some patients. The supporting material used is determined according to the type of retinal damage. Visual acuity after surgery may vary according to the preoperative retinal and macular damage.
Precautions After Surgery
Care after vitrectomy is planned according to the material placed inside the eye and the extent of the procedure. Some patients may be advised to maintain a particular head position. This position does not necessarily require every patient to lie face down. It is important to use eye drops as recommended and attend follow-up appointments. Severe pain, a sudden reduction in vision or rapidly increasing redness requires assessment without delay. Recovery time and the timing of return to daily activities may vary between patients.
Situations that must be avoided while gas remains inside the eye include:
- Air travel.
- Travelling to high-altitude areas.
- Diving that causes pressure changes.
- Driving without an assessment of suitability.
Gas inside the eye may expand with pressure changes and increase intraocular pressure. Air travel must therefore be avoided until the gas has been completely absorbed. Travelling by road to high-altitude areas may also pose a risk. If anaesthesia is required for another reason, the healthcare team must be informed that gas is present inside the eye. Travel restrictions and follow-up may differ for patients with silicone oil. The individual recommendations provided after surgery should be followed in every case.
Monitoring Diabetic Retinopathy During Pregnancy
Pregnancy may affect the course of retinal disease in women with pre-existing diabetes. Hormonal and circulatory changes may contribute to the progression of retinopathy findings in some patients. People with diabetes who are planning a pregnancy should therefore have a fundus examination beforehand. The frequency of examinations during pregnancy is determined according to the existing level of retinopathy. Blood sugar and blood pressure must also be monitored carefully throughout the process. If treatment becomes necessary, options appropriate for both the mother and pregnancy are considered.
Not every type of diabetes occurring during pregnancy carries the same retinal risk. Pre-existing diabetes and previously detected retinopathy findings are particularly important. Some patients with mild changes may require closer monitoring. Treatment planning for people with advanced retinopathy is considered together with the course of the pregnancy. Intravitreal injections or other procedures are not routinely performed in every case. The appropriate approach is determined by evaluating the ocular findings and general health together.
Diabetes and Cataract Surgery
Cataracts may develop at a younger age in people with diabetes. When a cataract develops, the transparency of the eye lens decreases and vision becomes blurred. However, cataract is not always the only cause of reduced vision in a patient with diabetes. Macular oedema or damage to the retinal vessels may also affect visual acuity. The retina must therefore be examined in detail before planning cataract surgery. Active fluid accumulation in the macula may change the timing of surgery.
Retinal treatments may need to be arranged before or after surgery in some patients. Intravitreal injections are not mandatory for every patient with diabetes. The surgical decision is made according to the presence of macular oedema and the stage of diabetic retinopathy. It is important to monitor the retinal findings after cataract surgery. Improvement in vision depends on the health of the retina as well as the lens opacity. Preoperative expectations should therefore be assessed according to the individual examination findings.
Artificial Intelligence-Assisted Retinal Screening
Artificial intelligence-assisted systems may help assess certain changes in retinal images. These applications may be used to examine fundus photographs for haemorrhages, microaneurysms or other vascular changes. They may particularly support the identification of high-risk patients during screening. However, these systems do not replace a detailed eye examination. Images must be assessed together with the patient's symptoms and clinical findings. The use of artificial intelligence applications varies according to the infrastructure and assessment conditions of the healthcare centre.
Potential contributions of these technologies include:
- Rapid examination of retinal images.
- Identification of high-risk findings.
- Detection of patients requiring follow-up.
- Comparison of images.
- Support for screening processes.
Artificial intelligence systems cannot predict with certainty how the disease will progress in every patient. Imaging software alone cannot determine which medication will be more effective or when the next haemorrhage will occur. Visual acuity, macular structure and the person's general health are also important when making treatment decisions. Technology is therefore used as a supportive part of clinical assessment. Appropriate treatment is selected according to individual examination findings. Regular follow-up remains important alongside technological screening.
How Can Disease Progression Be Slowed?
Blood sugar control is an important factor in reducing the risk of diabetic retinopathy progression. Regulating blood pressure and monitoring cholesterol levels are also important for the retinal vessels. If kidney disease or other systemic problems are present, their management should be included in follow-up. A balanced diet and individually appropriate physical activity support general diabetes management. Avoiding tobacco products is important for vascular health. The frequency of eye examinations is determined according to the type of diabetes and retinopathy findings.
The main points requiring attention in daily life include:
- Continuing blood sugar monitoring.
- Controlling blood pressure.
- Monitoring cholesterol levels.
- Following diabetes treatment regularly.
- Following an appropriate nutrition plan.
- Performing individually suitable exercise.
- Avoiding tobacco products.
- Attending retinal examinations.
Receiving intravitreal injections or laser treatment does not remove the importance of diabetes monitoring. Poor blood sugar control may contribute to the development of new vascular problems. However, good metabolic control does not mean that retinopathy will be completely prevented in every patient. The duration of the disease and individual risk factors may affect the ocular findings. Ocular and general health assessments must be managed together throughout treatment. Regular follow-up helps detect changes at an earlier stage.
When Is Urgent Assessment Required?
A sudden reduction in vision, dense black floaters or a curtain-like shadow in the visual field may require urgent assessment. These symptoms may be associated with intraocular bleeding, a retinal tear or retinal detachment. Severe pain and pronounced redness following an intravitreal injection or surgery are also important. The scheduled routine follow-up date should not be awaited in these situations. Because diabetic retinopathy may not cause symptoms during its early stages, monitoring should continue even when no complaints are present. You can contact me using the details on my website to schedule an examination and follow-up appointment.
