Diabetic Retinopathy Summary
1) Disease Description (Causes and Symptoms)
- Causes and pathophysiology
- Chronic hyperglycemia caused by diabetes damages the retinal microvasculature, resulting in increased vascular wall permeability, vascular occlusion, and ischemia. When factors such as VEGF increase in ischemic areas, neovascularization (abnormal blood vessels) can develop and progress to hemorrhage and tractional retinal detachment. When fluid accumulates in the macula, diabetic macular edema (DME) develops and central vision decreases.
- Main classifications
- Nonproliferative diabetic retinopathy (NPDR): Mainly microvascular lesions (microhemorrhages, dot-blot hemorrhages, edema, etc.).
- Proliferative diabetic retinopathy (PDR): Development of neovascularization, with a risk of vitreous hemorrhage and tractional retinal detachment.
- Diabetic macular edema (DME): Causes decreased vision due to macular exudation or edema (can occur at any stage).
- Main symptoms
- It is common to have no symptoms in the early stages. When symptoms occur, they may include decreased vision, floaters (floating spots), metamorphopsia (objects appearing distorted), photopsia, visual field defects, and decreased night vision. Acute vitreous hemorrhage or retinal detachment can cause sudden vision loss or a curtain-like visual field defect.
2) Treatment Methods and Precautions
- Principles
- Control of systemic risk factors: Manage blood glucose (individualize the A1c target), blood pressure (the recommended target is determined according to the patient's situation), and lipids (especially LDL), and stop smoking. Systemic management delays the onset and progression of the disease.
- Local and ophthalmic treatments
- Observation: Regular follow-up for mild nonproliferative lesions or when there is no macular involvement.
- Laser treatment
- Focal/grid laser: Used for macular edema located slightly away from the center (in modern practice, it plays a combined or adjunctive role with drug treatment).
- Panretinal photocoagulation (PRP): Reduces the risk of blindness in proliferative retinopathy by coagulating neovascularization.
- Local anti-VEGF injections (intravitreal injections)
- Mainly used as standard treatment for macular edema and proliferative lesions (e.g., aflibercept and ranibizumab; bevacizumab is also often used off-label in clinical practice). Regular injections are required, and the decision is made by considering effectiveness, treatment interval, and cost.
- Steroid preparations (intraocular implants or injections)
- Effective for DME, but indications and patient selection are important because of the risk of increased intraocular pressure and cataract progression (e.g., dexamethasone implants and fluocinolone).
- Surgical treatment (vitrectomy)
- Surgical removal is necessary in cases of nonresolving vitreous hemorrhage, tractional retinal detachment, or extensive fibrovascular proliferative membranes.
- Main treatment side effects
- Intravitreal injections: Infection (endophthalmitis), hemorrhage, and temporary elevation of intraocular pressure.
- Steroids: Increased intraocular pressure and cataract progression.
- Laser: Visual field defects, decreased night vision, and macular damage (if excessive), among others.
- Surgery: Hemorrhage, retinal tear/detachment, infection, etc.
- Prognosis
- Early detection and appropriate treatment can greatly reduce the risk of blindness. Whether the macula is involved is important in determining the prognosis for central vision. The prognosis varies greatly depending on the stage of progression.
3) Checklist Before an Outpatient Visit (Including Items to Bring and Example Questions)
- Items to bring (recommended)
- A list of current medications (including oral medications, insulin, and anticoagulants) or medication bags
- Recent blood glucose records (self-monitoring) and glycated hemoglobin (A1c) test results (include the dates if possible)
- Recent blood pressure readings (values measured at home)
- Previous ophthalmic examination results (fundus photographs, OCT, fluorescein angiography, etc.) and examination CDs/photos (if available)
- A record of symptom changes (when vision changes began, floaters/flashes/curtain-like visual disturbances, etc.)
- Pregnancy status (for women) and history of ophthalmic procedures (injections, laser treatment, surgery, etc.)
- Information to note for the outpatient visit
- Date of the last eye examination, recommended follow-up interval, necessary examinations (OCT, fluorescein angiography, etc.), and treatment plan (possibility of injections, laser treatment, or surgery)
- Symptoms to check before the outpatient visit (emergency signs)
- Sudden vision loss, a large number of new floaters/flashes, or a curtain-like visual field defect → Immediate emergency ophthalmic evaluation is required
4) Examples of General Questions to Ask the Doctor
- What is the current stage of my retinopathy (nonproliferative/proliferative, and whether the macula is involved)?
- What treatment options do you recommend, and what are the expected effects and side effects of each?
- Is it acceptable to observe the condition without starting treatment, and what should the follow-up interval be?
- If I receive injection treatment (anti-VEGF or steroids), what would be the expected interval and duration?
- How should management of systemic diseases (blood glucose, blood pressure, and lipids) be adjusted?
5) Examples of Disease-Specific Questions (1–2)
- In my case, based on the examination findings, do I have macular edema? If the macula is involved, what is the likelihood of recovering central vision?
- If anti-VEGF injection treatment is recommended, when can I expect vision improvement, and what are the criteria for stopping injections (no response or recurrence)?
Note: Early detection and systemic risk-factor management are essential for diabetic retinopathy. Even in the absence of symptoms, regular fundus examinations and monitoring with OCT/fluorescein angiography when necessary are essential. If emergency symptoms occur, seek specialist medical attention immediately.