👓 Patient Education — Eye Conditions ஀யறியின் கல்வி — கண் நோய்கள்

Eye Conditions — Patient Guides

கண் நோய்கள் — ஀யறியின் வ୶ிகாடு

Understand your eye condition in depth — causes, symptoms, investigations, treatment, and follow-up. Available in English and Tamil.

Jump to: அடிக்: Refractive Errors Diabetic Eye Disease Conjunctivitis
01
Patient Guide

Refractive Errors

Myopia · Hyperopia · Astigmatism · Presbyopia
What are Refractive Errors? தெறிவு குறைபாடு என்றால் என்ன?

For clear vision, the eye must bend (refract) incoming light so that it focuses precisely on the retina. A refractive error occurs when the shape of the eye prevents light from focusing correctly, resulting in blurred vision.

Four Types of Refractive Error

  • Myopia (short-sightedness): The eyeball is too long, or the cornea too curved — distant objects are blurry, near objects are clear. Very common and often begins in childhood.
  • Hyperopia (long-sightedness / far-sightedness): The eyeball is too short — near objects are blurry; distant objects may also be blurry if severe. Young children often have mild hyperopia which resolves naturally.
  • Astigmatism: The cornea or lens is oval (like a rugby ball) instead of round. Light focuses at two different points, causing blur and distortion at all distances.
  • Presbyopia: The natural age-related loss of near-focusing ability that affects virtually everyone after age 40. The lens becomes less flexible and cannot accommodate for near vision. Reading glasses or bifocals are the usual solution.
How are Refractive Errors Diagnosed? எப்படி கண்டறிவார்கள்?
  • Visual acuity test: Reading the eye chart at distance and near with and without correction
  • Retinoscopy / auto-refraction: Objective measurement of the refractive error using light reflex
  • Subjective refraction: Patient feedback — "which is clearer, 1 or 2?" — to fine-tune the prescription
  • Keratometry: Measures corneal curvature — important for astigmatism assessment and contact lens fitting
  • Corneal topography: Detailed mapping of the corneal surface — screens for keratoconus (progressive corneal thinning)
  • Dilated fundus exam: After dilating drops, the retina and optic nerve are examined to rule out pathology behind any visual symptoms
Correction Options — Spectacles, Contact Lenses, Surgery சரிசெய்யும் வழிகள் — கண்ணாடி, கான்டாக்ட் லென்ஸ், அறுவை
OptionAdvantagesLimitations
SpectaclesSafest, no risk to eye, easy to update, corrects all typesVisual field restriction, fogging, inconvenience for sports
Contact LensesBetter cosmesis, full visual field, good for sportsInfection risk if hygiene poor, dry eyes, not for all cornea types
LASIK / Laser SurgerySpectacle/lens independence, quick recoveryRequires suitable cornea thickness & stable power, cost, not reversible
ICL (Implantable lens)Suits thin corneas, reversible, excellent qualitySurgical risk, cost, requires specialist assessment

The best option depends on your age, power, corneal thickness, and lifestyle. Dr. Laavanyaa will assess your eyes and discuss the most appropriate solution for you.

Children's Eye Health & Myopia Control குழந்தைகள் கண் ஆரோக்கியம் மற்றும் Myopia கட்டுப்பாடு

Children's refractive errors are very common, often undetected. A child who cannot see the board in school may not volunteer this information — they assume everyone sees the same way.

Warning signs in children

  • Sitting too close to the TV or screen
  • Squinting to see the board or distant objects
  • Frequent headaches, especially after school
  • One eye turning in or out (possible amblyopia — lazy eye)
  • Poor academic performance despite effort

Myopia progression in children

Myopia often worsens rapidly between ages 8 and 18. Strategies to slow progression include:

  • Outdoor time: At least 90 minutes of outdoor activity daily has been shown to slow myopia progression
  • Atropine eye drops: Low-concentration atropine drops (0.01%) at night — proven to slow myopia progression
  • Orthokeratology (Ortho-K): Special contact lenses worn overnight to reshape the cornea temporarily
  • Myopia-control spectacle lenses: Specific lens designs (e.g. DIMS, MiSight) that reduce eye growth

First eye check: All children should have a complete eye examination before starting school (age 4–5) and annually thereafter. Early detection of amblyopia (lazy eye) before age 7–8 is critical for successful treatment.

Refractive Errors — Focus Points Normal Focus on retina Myopia Focus in front of retina Hyperopia Focus behind retina Astigmatism Two focal points ⇒ Concave lens ⇒ Convex lens ⇒ Cylindrical lens

Types of refractive error

Power Ranges (Approximate)
Mild Myopia ≤-3.00D
Moderate Myopia -3 to -6D
High Myopia ≥-6.00D
Mild Hyperopia +1 to +3D
Presbyopia add +1 to +3D
02
Patient Guide

Diabetic Eye Disease

Diabetic Retinopathy · Diabetic Macular Oedema · Cataract · Glaucoma
Stages of Diabetic Retinopathy Stage 0 No DR Annual screen 🟢 Mild NPDR Stage 1 Micro- aneurysms 🟡 Moderate NPDR Stage 2 Haemorrhages exudates 🟨 Proliferative PDR Stage 3 New vessels PRP Laser! 🔴 DMO Stage 4 Macular fluid+Injections 🟥 Progression can be silent — regular screening is essential

Stages of diabetic retinopathy

Screening Schedule
Type 1 DM: 5 yrs after diagnosis, then annual
Type 2 DM: At diagnosis, then annual
If DR present: Every 3–6 months
Pregnancy & DM: Each trimester
If PDR / DMO: Monthly
How Diabetes Damages the Eyes — Silently நீரிழிவு கண்ணை அமைதியாக எப்படி பாதிக்கும்?

High blood sugar over years causes progressive damage to the small blood vessels supplying the retina. This process is called diabetic retinopathy (DR) — the leading cause of preventable blindness in working-age adults worldwide.

The critical danger: diabetic retinopathy causes no symptoms in its early stages. By the time the patient notices blurred or distorted vision, significant irreversible damage has often already occurred. This is why regular screening is so important even when vision feels normal.

How the damage occurs

  1. High glucose damages the walls of retinal capillaries (tiny blood vessels)
  2. Vessel walls weaken — they bulge (microaneurysms) and leak fluid and lipids
  3. Leaking causes oedema (swelling) in the retina
  4. Oxygen deprivation signals the eye to grow new, fragile blood vessels (neovascularisation)
  5. These new vessels bleed easily, causing vitreous haemorrhage and traction retinal detachment

Warning: Diabetic retinopathy can progress silently to an advanced stage while vision feels completely normal. All diabetics must have annual dilated eye examinations regardless of how good their vision is.

Stages of Diabetic Retinopathy நீரிழிவு விழித்திரை நோயின் நிலைகள்
🟢
No DR
No visible retinal changes. Annual screening. Focus on glucose control.
🟡
Mild NPDR
Microaneurysms only. Annual review. Strict HbA1c <7%.
🟨
Moderate NPDR
Haemorrhages & exudates. Review every 3–6 months. Tighter control.
🔴
Severe NPDR
Extensive lesions, cotton wool spots, venous beading. Risk of progression high. Consider PRP.
🟥
PDR
New vessels! PRP laser urgently needed. High risk of vitreous bleed & detachment.
🔵
DMO
Macular fluid at any DR stage. Anti-VEGF injections or laser. OCT monitoring.
Essential Investigations for Diabetic Eye Disease நீரிழிவு கண் நோய்க்கு அவசிய பரிசோதனைகள்
InvestigationWhat it showsWhen needed
Dilated Fundus ExamDirect view of retina, vessels, optic discEvery visit
OCT (Macula)Cross-section of macular layers — detects fluid (DMO)Every visit if DMO known or suspected
Fundus PhotographyDocument baseline and monitor progressionAnnually, or when DR present
FFA (Fluorescein Angiography)Leaking vessels, ischaemia, neovascularisationBefore laser/injection or to map disease
Visual Field (Perimetry)Peripheral vision defects, concomitant glaucomaIf optic nerve involvement suspected
TonometryIOP — neovascular glaucoma risk in PDREvery visit

Blood tests required: HbA1c, fasting glucose, lipid profile, kidney function (eGFR/creatinine), and BP monitoring are all important — systemic control directly influences the rate of DR progression.

Precautions, Lifestyle & Daily Protection முன்னெச்சரிக்கைகள், வாழ்க்கை முறை மற்றும் அன்றாட பாதுகாப்பு

✓ Do

  • Keep HbA1c < 7% — this is the single most powerful way to prevent DR
  • Control blood pressure below 130/80 mmHg
  • Control cholesterol — statins reduce hard exudate formation
  • Have annual dilated eye exam even if vision is normal
  • Have eye exam immediately if vision changes
  • Exercise regularly — improves glucose control
  • Eat a diet low in refined sugar and saturated fats
  • Report new floaters, flashes, or vision loss immediately

✗ Avoid

  • Smoking — accelerates vascular damage significantly
  • Skipping medications (antidiabetics, antihypertensives)
  • Self-adjusting insulin or oral agents without medical advice
  • Ignoring symptoms ("my vision is fine, I don't need a check")
  • Delaying treatment — DR worsens faster than most realise
  • High-salt diet (raises BP)
  • Alcohol in excess
Follow-up Schedule for Diabetic Eye Disease நீரிழிவு கண் நோய் பின்தொடர் அட்டவணை
No DR
Annual dilated retinal examination. Focus on optimising blood glucose, BP, and lipids.
Mild NPDR
Annual eye review. HbA1c target <7%. Reinforce lifestyle changes.
Moderate NPDR
Every 3–6 months. OCT if macular involvement suspected. Consider referring to retina specialist.
Severe NPDR
Every 3 months. High risk of PDR — PRP may be discussed.
PDR
Monthly. Urgent PRP laser. Anti-VEGF if vitreous bleed. Close monitoring for tractional detachment.
DMO (any stage)
Monthly OCT. Anti-VEGF injection series. Focal laser as adjunct if needed.
Pregnancy + DM
Eye exam each trimester. Pregnancy can accelerate DR significantly.

Emergency: See an ophthalmologist the same day if you notice: sudden loss of vision, a shower of black spots or floaters, a dark curtain or shadow across part of your vision, or a significant sudden change in vision.

03
Patient Guide

Conjunctivitis — Red Eye

Bacterial · Viral · Allergic · When to seek urgent care
Types of Conjunctivitis — and How to Tell Them Apart கண் சிவப்பின் வகைகள் மற்றும் வேறுபாடு

Conjunctivitis is inflammation of the conjunctiva — the thin transparent tissue covering the white of the eye and the inner surface of the eyelids. Red eye is the cardinal sign, but the cause matters enormously for correct treatment.

🦠 Bacterial
Common Bacteria: Staphylococcus, Streptococcus

Key features: Thick yellow-green sticky discharge, crusting in the morning making lids stick together. Usually starts in one eye, may spread to both. Moderate redness. Generally no significant pain.

😷 Viral
Adenovirus (most common), HSV, EKC

Key features: Watery discharge, significant redness, foreign body sensation. Often associated with cold, sore throat, or lymph node swelling. Highly contagious. Both eyes usually involved. Antibiotic drops have no benefit for viral conjunctivitis.

🌹 Allergic
Dust, pollen, pets, contact lens solutions

Key features: Intense itching (the hallmark), watery discharge, both eyes, seasonal or perennial pattern. No fever, no lymph node enlargement. Not contagious. Associated with other allergies (rhinitis, asthma).

Treatment — What Works for Each Type சிகிச்சை — ஒவ்வொரு வகைக்கும் என்ன சரியானது?
TypeFirst-Line TreatmentDurationNotes
BacterialAntibiotic eye drops (Tobramycin / Moxifloxacin)5–7 daysStarts to improve within 24–48 hrs. Complete the course.
ViralLubricant drops, cold compresses, hygiene1–3 weeksNo effective antiviral for adenovirus. Antibiotic drops prevent secondary infection only.
AllergicAntihistamine drops (Olopatadine), mast cell stabilisers, avoid triggersAs neededLubricant drops help dilute allergens. Avoid rubbing — worsens mast cell release.
HSV (Herpes)Antiviral drops (Acyclovir), oral antiviral if indicated7–10 daysMust be diagnosed and treated by specialist — can cause corneal scarring if missed.

Do not self-prescribe steroid drops for red eye. Steroid eye drops can dramatically worsen herpes simplex conjunctivitis, cause fungal infections, raise intraocular pressure, and accelerate cataract. Only use steroid drops when prescribed by your ophthalmologist.

Hygiene, Prevention & Stopping Spread சுகாதாரம், தடுப்பு மற்றும் பரவல் தடுக்க

✓ Do

  • Wash hands thoroughly before and after touching the eye
  • Use a clean tissue or cotton to wipe discharge (single use, then discard)
  • Use separate towels and pillowcases from family members
  • Cold compresses for viral conjunctivitis — 3 times a day for comfort
  • Complete the full antibiotic course even if the eye looks better
  • Avoid contact lenses until the infection fully clears
  • Discard any contact lens solution or eye drops used during the infection

✗ Avoid

  • Rubbing the eye — spreads the infection and can worsen corneal involvement
  • Sharing eye drops, towels, pillows, or makeup
  • Swimming pools while infected (highly contagious in pool water)
  • School or office attendance with active viral conjunctivitis in the first 5–7 days
  • Using expired or previously opened eye drops
  • Steroid drops without a prescription
When to Seek Urgent Ophthalmology Review எப்போது உடனே கண் மருத்துவர் வாசல் தேட வேண்டும்?

Most conjunctivitis resolves on its own or with simple drops. However, certain features demand urgent specialist review as they may indicate more serious conditions.

See a doctor urgently (same day or next day) if you have red eye with any of the following:

  • Significant pain — simple conjunctivitis is uncomfortable but not significantly painful; pain suggests corneal involvement (ulcer, keratitis) or acute glaucoma
  • Blurred or reduced vision — vision should not be affected by simple conjunctivitis
  • Photophobia (severe sensitivity to light) — suggests uveitis or keratitis
  • Coloured halos around lights — sign of raised IOP (acute angle-closure glaucoma)
  • Profuse pus-like discharge in a newborn — neonatal conjunctivitis is an emergency (Gonococcal)
  • Contact lens wearer with red eye — risk of Acanthamoeba or bacterial corneal ulcer
  • Not improving after 5–7 days of appropriate treatment
  • Corneal opacity or white spot visible on the eye

Need a Consultation?

Book an appointment with Dr. Laavanyaa at SRM Prime Hospital or P&G Multispeciality Hospital, Chennai.