Published on

1 Comment
No Downloads
Total views
On SlideShare
From Embeds
Number of Embeds
Embeds 0
No embeds

No notes for slide


  1. 1. Abdulaziz Saleh Medical Intern
  2. 2. Lens • Anatomy. • Function: 15D out of 58D
  3. 3. What is cataract? • Origin ? • Opacification . • most common cause of reversible blindness (51% worldwide)
  4. 4. Aetiology Acquired Congenital Age- related (90%) Metabolic disease: DM Traumatic Toxin: steroid, chlorpromazine Secondary to ocular disease: uveitis, acute angle glaucoma. Genetic and metabolic disease: down’s syndrome, galactosemia. Intrauterine infection: rubella. Ocular anomalies: aniridia. Hereditary . ?? Smoking, alcohol, and exposure to UV radiation as factor causing cataract progression, especially nuclear sclerosing cataract
  5. 5. Pathophysiology • Changes in the lens proteins. • Chemical modification of these lens proteins leads to the change in lens colour. affect how the lens refracts light and reduce its clarity, therefore decreasing visual acuity
  6. 6. Nuclear sclerotic cataract • New cortical fibres are produced concentrically and lead to thickening and hardening of the lens. • appears yellow. • can increase the focusing power of the natural lens (myopia, second sight). Patient may read without previously needed reading glasses
  7. 7. Cortical cataracts • Defragment of electrolyte and water balance. • most often seen as whitish spokes peripherally in the lens, separated by fluid.
  8. 8. Posterior sub-capsular cataracts • due to the migration and enlargement of lens epithelial cells (Wedl cells) posteriorly. • DM is a major factor in the formation of this type of cataract.
  9. 9. Diabetic cataract • Osmotic stress due to sorbitol accumulation has been linked with sudden worsening in patients with uncontrolled hyperglycaemia.
  10. 10. Classification By age onset Acquired Congenital Lamellar or zonular cataracts are the most commonly seen form of congenital cataracts. Usually bi-lateral and symmetrical. May be due to transient toxic influences during lens development, or may be inherited in an autosomal-dominant pattern By etiology
  11. 11. Classification By clinical features Nuclear sclerotic: generally age-related opacification, primarily involving the nucleus of the lens Cortical: primarily opacification of the cortex of the lens Posterior sub-capsular: opacification of the posterior sub-capsular cortex, seen frequently in drugrelated (e.g., with topical corticosteroids) or metabolic cataracts Anterior sub-capsular: opacification of the anterior sub-capsular cortex, frequently seen in blunt traumatic injuries Cerulean: small bluish opacity seen in the lens cortex (often also referred to as blue-dot cataracts) Snowflake: grey-white sub-capsular opacities that can be seen in cataracts in uncontrolled diabetes mellitus Sunflower: yellow or brown pigmentation of the lens capsule in a petal-shaped distribution, seen in patients with an intra-ocular copper-containing foreign body or Wilson's disease Christmas tree: polychromatic iridescent crystals, seen in the lens cortex of patients with myotonic dystrophy Oil droplet: on retro-illumination, seen in patients with galactosaemia. An accumulation of galactose and galactitol in lens cells causes an increase in osmotic pressure due to fluid influx.
  12. 12. Classification By stage Immature Partially opaque mature whole lens is opaque and no clear cortex is visible with a slit lamp. The mature cataract appears white, No iris shadow is seen on oblique illumination Hypermature, (Morgagnian ) Rare. the cortex may liquefy and the nucleus becomes free-floating within the capsule. If the liquefied cortex leaks through the intact capsule, wrinkling of the lens capsule may be seen and phacolytic glaucoma may develop
  13. 13. Prevention Primary prevention •UV protection (UV filtration in spectacles and sunglasses) or antioxidants may slow the progression. (??) •no established way to prevent cataract formation. Brimmed hats and UVB-blocking sunglasses are reasonable precautions to recommend.
  14. 14. Secondary prevention many implanted intra-ocular lenses have UV chromophores in them, certain models have fewer than others. This may mean that UV filters could be placed in postoperative glasses to help protect the retina from continued exposure
  15. 15. Diagnosis History: C/O: blurring or cloudy of vision. glary vision especially when driving at night. inadequate glasses prescription. (nuclear sclerosis) Gradual over years ( problem reading words from TV) Relatively sudden (DM) ☟ in color richness (blue) Risk of cataract formation?. Trauma? Ocular disease? Systemic Disease? Medication? . Intraoperative Floppy Iris Syndrome (alpha 1 blocker)
  16. 16. Physical exam Complete ocular examination: •VA, pupillary examination, IOP •A dilated slit-lamp examination using both direct and retroillumination techniques •Refraction Fundus examination Glare stress test
  17. 17. Examination Nuclear sclerosis: Yallow to brown discoloration of center. Cortical: Radial or spoke opacity. Posterior subcapsular
  18. 18. DDx
  19. 19. Treatment • effective and safe. • Surgical Indication:  Functional imairment  To aid management of other ocular exam  surgical therapy for ocular disease (e.g., lens-related glaucoma or uveitis)  Congenital or traumatic cataract. trial of mydriasis (e.g., scopolamine 0.25% q.d.) may be used successfully in some patients if the patient desires nonsurgical treatment. The benefits of this therapy are only temporary.
  20. 20. Rx • preoperative treatments—e.g., topical antibiotics for blepharitis, or atropine for poor dilation. • Type of surgery: • ICCE • ECCE • Phaco
  21. 21. On day of surgery • • • • • • • • Consent. Ensure mydriasis. Topical antibiotic. ? Any ophthalmic problem , or infection. Mark side of operation. Confirm type of IOL and power. Positioning for operation. Scraping and draping.
  22. 22. Biometry/IOL selection • • • • Usually aiming for emmetropia. Check power as discussed with the patient. check the keratometry and axial length Use appropriate formula • ?Refractive surgery before.
  23. 23. Follow up/ post-op • 1 day, 1 week, 1 month: postoperative complication, spectacle change. What to examine? prognosis: excellent if not complicated by other ocular disease. Patient education. When to come back, eye shield. Will need reading glasses.
  24. 24. Complication • Intra-op • Early post-op • Late post-op
  25. 25. Complication • During surgery, the patient starts to cough. What complications can result from this? • Shallow chamber, iris prolapse, choroidal effusion / hemorrhage.