Age-Related Cataract

ARC: Intro & Risks - Lens Clouding Culprits

• Age-Related Cataract (ARC): Gradual, progressive opacification (clouding) of the eye's crystalline lens.
• Leading cause of treatable blindness and ↓ vision in adults >60 years.

  ⭐ Age-related cataract is the leading cause of blindness worldwide and the most common cause of treatable blindness in India.

• Major Risk Factors:
  • Age: Primary, non-modifiable factor.
  • UV Radiation: Chronic exposure (especially UVB).
  • Smoking: Oxidative stress.
  • Diabetes Mellitus: Osmotic stress, earlier onset.
  • Corticosteroids: Long-term systemic/topical use.
  • Ocular Trauma.
  • Genetics/Family History.
  • Poor Nutrition: Low antioxidant intake.
  • Excessive Alcohol.

ARC: Pathophys & Types - Opacity Unveiled

Pathophysiology:

• Protein denaturation & aggregation (crystallins → insoluble albuminoids).
• Oxidative stress: ↑ Reactive Oxygen Species (ROS), ↓ glutathione.
• Electrolyte imbalance: ↑ Na⁺, Ca²⁺; ↓ K⁺.
• Non-enzymatic glycosylation.

Morphological Types:

• Nuclear Sclerosis (NS):
  • Central, yellowish/brown opacity.
  • Myopic shift ("second sight").
  • Slow progression.
• Cortical Cataract (CC):
  • Peripheral, radial spoke-like/cuneiform opacities.
  • Glare.
  • Stages: Incipient → Intumescent → Mature → Hypermature (Morgagnian).
• Posterior Subcapsular Cataract (PSC):
  • Granular/plaque-like opacity on posterior capsule.
  • Near vision ↓, glare ↑.
  • Rapid progression.

  ⭐ Posterior Subcapsular Cataracts (PSC) cause disproportionate glare and difficulty with near vision, often progressing faster than other types.

• Christmas Tree Cataract: Polychromatic needle-like crystals.

ARC: Clinical & Diagnosis - Unmasking the Haze

• Symptoms:
  • Painless, progressive ↓ vision (most common)
  • Glare & halos (e.g., night driving difficulties)
  • Difficulty reading fine print; needs ↑ illumination
  • Altered color perception (blues appear faded/yellowish)
  • Frequent changes in spectacle prescription
  • Monocular diplopia (less common)
• Signs (Ocular Examination):
  • ↓ Visual acuity (Snellen chart)
  • Lens opacities visible on slit-lamp biomicroscopy & direct ophthalmoscopy
  • Leukocoria (white pupillary reflex) in advanced/mature cataracts
  • Diminished or altered red reflex (e.g., "oil droplet" sign in nuclear sclerosis)
• Diagnostic Workup:
  • Comprehensive history taking
  • Visual acuity assessment (distant & near)
  • Slit-lamp examination (essential for type & grading)
  • Ophthalmoscopy (direct & indirect) to view fundus
  • Retinoscopy (may reveal "scissoring reflex")

⭐ The phenomenon of 'second sight' (myopic shift improving near vision temporarily due to increased refractive index of the lens nucleus) is characteristic of nuclear sclerosis.

ARC: Management & Complications - Restoring Sight Safely

• Management:
  • Non-Surgical: Spectacles, improved lighting. Mydriatics (rarely).
  • Surgical (Definitive):
    • Indications: ↓VA (daily activities), phacolytic/morphic glaucoma, anisometropia.
    • Pre-op: Biometry (IOL power calculation), B-scan (if opaque media).
    • Techniques:
      • Phacoemulsification + Foldable IOL: Preferred.
      • Manual SICS + PMMA/Foldable IOL: For mature cataracts, high volume.
      • ECCE: Largely historical.
• Surgical Steps Overview:

• Complications:
  • Intraoperative: Posterior Capsular Rupture (PCR), dropped nucleus/IOL.
  • Early Postoperative:
    • Corneal edema, uveitis (TASS vs Endophthalmitis ⚠️).
    • ↑IOP, wound leak.
  • Late Postoperative:

    ⭐ Posterior Capsular Opacification (PCO), also known as 'after-cataract', is the most common long-term complication following cataract surgery, treatable with YAG laser capsulotomy.

    • Cystoid Macular Edema (CME - Irvine-Gass syndrome).
    • IOL subluxation/dislocation, bullous keratopathy.

High‑Yield Points - ⚡ Biggest Takeaways

• Age-related cataract: most common cause of reversible blindness worldwide.
• Presents with painless, progressive blurring of vision.
• Nuclear sclerosis (commonest) causes myopic shift ("second sight").
• Cortical cataracts cause glare and haloes, especially with night driving.
• Posterior subcapsular (PSC) affects near vision most, progresses rapidly.
• Major risk factors: age, diabetes, UV exposure, smoking, steroids.
• Treatment: phacoemulsification with IOL implantation.