Cataract

pediatric cataract adult cataract

1. CONCEPT , MAGNITUDE & MANAGEMENT OF COMMUNICAL & NON COMMUNICAL COMMON OCULAR CONDITIONs /DISORDERs SUCH AS TRACHOMA, CATARACT, DIABETIC RETINOPATHY , VARIOUS CORNEAL INFECTIONs & CONJUNCTIVAL INFECTIONs Dr. Vinit Kumar

2. Cataract Dr. Vinit

3. Classification A . Etiological classification I. Congenital and developmental cataract II. Acquired cataract 1. Senile cataract 2. Traumatic cataract 3. Complicated cataract 4. Metabolic cataract 5. Electric cataract 6. Radiational cataract

4. 7. Toxic cataract e.g., i Corticosteroid-induced cataract ii. Miotics -induced cataract iii. Copper (in chalcosis ) and iron (in siderosis ) induced cataract. 8. Cataract associated with skin diseases ( Dermatogenic cataract). 9. Cataract associated with osseous diseases. 10. Cataract with miscellaneous syndromes e.g., i . Dystrophica myotonica ii. Down's syndrome. iii. Lowe's syndrome iv. Treacher - Collin's syndrome

5. B. Morphological classification 1. Capsular cataract. It involves the capsule and may be: i . Anterior capsular cataract ii. Posterior capsular cataract 2. Subcapsular cataract. It involves the superficial part of the cortex (just below the capsule) and includes: i . Anterior subcapsular cataract ii. Posterior subcapsular cataract 3. Cortical cataract. It involves the major part of the cortex. 4. Supranuclear cataract. It involves only the deeper parts of cortex (just outside the nucleus). 5. Nuclear cataract. It involves the nucleus of the crystalline lens.

6. 6. Polar cataract. It involves the capsule and superficial part of the cortex in the polar region only and may be: i . Anterior polar cataract ii. Posterior polar cataract

7. Etiology A. Factors affecting age of onset, type and maturation of senile cataract. 1. Heredity. incidence , age of onset and maturation of senile cataract 2. Ultraviolet irradiations- exposure to UV irradiation from sunlight 3. Dietary factors- proteins, amino acids, vitamins 4. Dehydrational crisis . 5. Smoking

8. B. Causes of presenile cataract. The term presenile before 50 years of age 1. Heredity 2 . Diabetes mellitus . Nuclear cataract progress rapidly. 3. Myotonic dystrophy 4. Atopic dermatitis

9. C. Mechanism of loss of transparency - different in nuclear and cortical senile cataracts. 1 . Cortical senile cataract.

10. Nuclear senile cataract. the total protein content and distribution of cations remain normal.

11. Stages of maturation [A] Maturation of the cortical type of senile cataract 1. Stage of lamellar separation. demarcation of cortical fibres owing to their separation by fluid. demonstrated by slit-lamp reversible .

12. 2. Stage of incipient cataract. In this stage early detectable opacities with clear areas between them are seen . (a) Cuneiform senile cortical cataract (b) Cupuliform senile cortical cataract 3. Immature senile cataract (ISC ). Greyish white iris shadow is visible.

13. 4. Mature senile cataract ( MSC) 5. Hypermature senile cataract (HMSC). (a) Morgagnian hypermature cataract (b) Sclerotic type hypermature cataract

14. [B] Maturation of nuclear senile cataract diffusely cloudy ( greyish ) or tinted (yellow to black) due to deposition of pigments . amber, brown ( cataracta brunescens ) or black ( cataracta nigra ) reddish ( cataracta rubra ) in colour

15. Clinical features Symptoms. 1 . Glare- intolerance of bright light ; such as direct sunlight or the headlights of an oncoming motor vehicle. 2. Uniocular polyopia (i.e., doubling or trebling of objects ) 3. Coloured haloes 4. Black spots in front of eyes 5. Image blur, distortion of images and misty vision 6. Loss of vision second sight- improved near vision Nuclear sclerosis

16. Signs . 1. Visual acuity testing . 2. Oblique illumination examination. 3. Test for iris shadow. 4.Distant direct ophthalmoscopic examination 5.Slit-lamp examination

17. Grading of nucleus hardness on slit-lamp biomicroscopy . Grade of Description of Colour of hardness of nucleus Grade I Soft White or greenish yellow Grade II Soft-medium Yellowish Grade III Medium-hard Amber Grade IV Hard Brownish Grade V Ultrahard Blackish (rock-hard )

18. Immature senile cataract versus nuclear sclerosis 1. Painless progressive loss of vision 2. Greyish colour of lens 3. Iris shadow is present 4. Black spots against red fundal glow observed on distant direct ophthalmoscopy 5. Slit-lamp examination reveals area of cataractous cortex 6. Visual acuity does not improves on pin-hole testing testing 1. Painless progressive loss of vision 2. Greyish colour of lens 3. Iris shadow is absent 4. No black spots / glow are observed on seen against red glow in DDO 5. Slit-lamp examination reveals clear lens 6.Visual acuity usually improve on pin-hole

19. Complications 1. Phacoanaphylactic uveitis . A hypermature cataract may leak lens proteins into anterior chamber. These proteins may act as antigens and induce antigenantibody reaction leading to uveitis . 2. Lens-induced glaucoma. It may occur by different mechanisms e.g., due to intumescent lens ( phacomorphic glaucoma) and leakage of proteins into the anterior chamber from a hypermature cataract ( phacolytic glaucoma). 3. Subluxation or dislocation of lens