Senile Cataract Overview

Senile Cataract

• Most prevalent cataract type, primarily affects individuals over 50 years.
• Bilateral, with slow progression; one eye often affected before the other.
• Can be hereditary, with equal incidence in males and females.

Types of Senile Cataract

• Cortical (75%): Most common type, starts at the periphery.
• Nuclear (20%): Central opacity, affects day and near vision.
• Corticonuclear (5%): Combination of both cortical and nuclear features.

Etiology

• Exact cause unknown, but potential risk factors include UV rays, smoking, alcohol, and deficiencies in Vitamin C and glutathione.

General Symptoms

• Gradual, painless vision loss; may experience fixed dark spots (musca), uniocular diplopia, and colored haloes around light.
• Vision impairment can vary based on the type:
  • Cortical affects night vision.
  • Nuclear affects day and far vision, can lead to index myopia.

Stages of Cortical Cataract

• Immature: Lens shows partial opacity.
• Mature: Lens is fully opaque.
• Hypermature: Lens shrinks due to water loss.

Complicated (Secondary) Cataract

• Developed due to local or systemic diseases.
• Local causes lead to unilateral cataracts while systemic causes typically result in bilateral cataracts.

Local Causes of Complicated Cataract

• Includes high myopia, glaucoma, keratitis, retinitis pigmentosa, and intraocular tumors, among others.
• Extended use of topical drugs such as steroids can also cause cataracts.

Systemic Causes of Complicated Cataract

• Conditions such as diabetes mellitus, hypoparathyroidism, Galactosemia, and myotonic dystrophy are implicated.
• Certain medications (e.g., steroids, Amiodarone) can also contribute.

Treatment

• Cataract extraction combined with intraocular lens (IOL) implantation.

Subcapsular Cataracts

• Types include anterior and posterior, with posterior being more common.
• Symptoms include glare issues and difficulty with near vision; patients may see well in dim light.

Complications of Cataract Extraction

• Pre-operative: Risks include retrobulbar hematoma, globe perforation, and optic nerve damage.
• Intra-operative: Potential issues such as hyphema, iris prolapse, and vitreous loss causing excessive astigmatism or glaucoma.
• Post-operative complications can lead to corneal decompensation, after cataract, and infections.

Subluxation of Lens

• Causes include congenital conditions (e.g., Marfan syndrome, homocystinuria) and acquired factors such as trauma and hypermature cataract.
• Symptoms: Vision defects with possible uniocular diplopia; signs include irregular anterior chamber depth and phacodenesis.

Dislocation of Lens

• Complete displacement classified into anterior (in anterior chamber) and posterior (in vitreous cavity).
• Treatment may involve lens removal, especially if complications arise.

Intra-Ocular Lens (IOL)

• Two main types: Anterior chamber IOL and posterior chamber IOL.
• Indications include monocular cataracts with good vision in the other eye and facial deformities contraindicating glasses.
• Absolute contraindications include recurrent ocular inflammation and retinal detachment.

IOL Complications

• Uveitis, secondary glaucoma, and IOL displacement are notable risks.

Lens Power Calculation

• Use SRK formula: P = A - 2.5L - 0.9K, where 'A' is the axial length, 'L' is a constant, and 'K' is the curvature of the cornea.

Explore the characteristics, incidence, and types of senile cataracts that commonly affect individuals over 50 years old. This quiz covers the progressive nature of lens opacity and the factors influencing its occurrence. Test your knowledge on the most prevalent form of cataracts and their implications.