Acquired Cataracts: Causes, Symptoms, and Management.pptx

Overview:
Acquired cataracts are a common eye condition characterized by the clouding of the lens, often leading to vision impairment. They typically develop due to age, but can also result from medical conditions, medications, trauma, or radiation exposure.

Early detection and management are crucial for maintaining vision health. Regular eye exams are essential, especially for at-risk individuals.

1. ACQUIRED CATARACT Acquired Cataract refers to the c ataract that results from the aging process, an injury, or as a manifestation of a systemic disorder . 

2. Etiology Risk Factors Age : Usually after the age of 50yrs. - When it occurs before 45yrs the term pre – senile cataract is used. Causes of Pre – Senile cataract – Heredity Diabetes Mellitus Atopic Dermatitis Myotonic Dystrophy

3. Christmas Tree Cataract A Christmas tree cataract is a rare age-related change resulting from accelerated breakdown of membrane-associated denatured proteins induced by elevated calcium levels.  There is a relationship to Christmas tree cataracts and myotonic dystrophy, but not all patients with Christmas tree cataracts have this condition.

4. 2. Gender : Senile cataract affects both males as well as females. Heredity Ultraviolet Irradiations Dehydrational Crisis : Due to Diarrhoea, Cholera etc. Dietary Factors : Diet deficient in certain proteins, amino acids, vitamins, (Riboflavin, Vitamin A, C & E), and essential elements have also been blamed for early onset and maturation of senile cataract. Smoking

5. B. Mechanism of loss of lens transparency Cortical Senile Cataract : It’s main biochemical features are decreased levels in the crystalline lens of total proteins, amino acids and potassium associated with increased concentration of sodium and marked hydration of the lens, followed by coagulation of lens proteins.

6. Nuclear Senile Cataract : In this, the usual degenerative changes are intensification of the age related nuclear sclerosis associated with dehydration and compaction of the nucleus resulting in a hard. It is accompanied by a significant increase in water soluble proteins. However, the total protein content and distribution of cations remains normal. These may or may not be associated deposition of pigment urochrome or melanin derived from amino acids in the lens.

7. Prevalence & Incidence Many studies in 2010 reveal that cataracts are most common in the White American race, where prevalence ranges from 17 to 18% per 100 people. Blacks were the 2 nd highest affected by cataracts, with a 13% prevalence, followed by Hispanics with a prevalence rate of almost 12%.

8. Stages of Maturation Maturation of the cortical type of senile cataract

9. Stage of lamellar separation Earliest sign Formation of vacuoles and water clefts in the anterior and posterior cortex. Stage of Incipient Cataract Early detectable opacities with clear areas between them. Two distinct types of senile cortical cataract can be recognised at this stage. Cortical Senile Cataract Posterior Senile Subcapsular Cataract (PSC)

10. Immature senile cataract (ISC) Opacification becomes more diffuse and irregular. The lens appears greyish white but clear cortex is still present and so iris shadow is visible. In some patients at this stage, lens may become swollen due to continued hydration. This condition is called ‘intumescent cataract’.

11. 4 . Mature senile cataract (MSC) Opacification becomes complete. Lens becomes pearly white in colour. Such a cataract is also labelled as ‘ripe cataract’.

12. 5. Hypermature senile cataract (HMSC) When the mature cataract is left in situ, the stage of hypermaturity set in. The Hypermature cataract may occur in any two forms Morganian Hypermature Cataract b) Sclerotic type Hypermature Cataract

13. B. Maturation of Nuclear Senile Cataract Progressive nuclear sclerotic process renders the lens inelastic and hard, decrease it’s ability to accommodate and obstructs light rays. The nucleus may become diffusely cloudy (greyish) or tinted (yellow to black). Commonly observed pigmented nuclear cataracts are either- Whitish Yellowish Amber Brownish (Cataracta Brunescens) Reddish (Cataracta Rubra) Blackish (Cataracta Nigra)

14. Clinical Features: ( Symptoms ) Glare : The amount of glare or dazzle will vary with the location and size of the opacity, being most common with PSC and Cortical Cataract. Uniocular Diplopia or Polyopia : Seen more commonly with incipient stage of cortical category. Coloured Halos around lights : More common in Nuclear Cataract. Poor colour discrimination : It occurs due to progressive yellowing or browning of the lens. Black spots in front of eyes Image blur & misty vision

15. Deterioration of vision : It is painless and gradual progressive in nature. Some specific features are – Patients with central opacities, have early loss of vision. These patients see better when pupil is dilated due to dim light in the evening. (day blindness). In patients with peripheral opacities , visual loss is delayed and the vision improves in bright light. In patients with nuclear sclerosis, distant vision deteriorates due to progressive index myopia. Such patients may be able to read without presbyopia glasses. This improvement in near vision is referred to as “second sight”. As opacification progresses, vision steadily diminishes until only perception of light and accurate projection of light rays remains in the stage of mature cataract. Gradual progressive loss of vision, may occur during the stage of intumescent cataract.

16. Clinical Features ( Signs ) Examination Nuclear Cataract ISC MSC HMSC (M) HMSC (S) 1. Visual Acuity 6/9 to PL+, PR+ 6/9 to FC+, PR+ HM+ to PL+, PR+ PL+, PR+ PL+, PR+ 2. Colour of lens Grey, amber, brown, black or red Greyish white Pearly white with sinking brownish nucleus Milky white Dirty white with hyper white spots. 3. Iris shadow Not seen Seen Not seen Not seen Not seen 4. DDO with dilated pupil Central dark area Multiple dark areas No red glow but white pupil due to CC. No red glow milky white pupil. No red glow dirty white pupil. 5. Slit lamp examination Nuclear opacity clear cortex Areas of normal with cataractous cortex. Complete cortex is cataractous Milky white cortex with sunken brownish nucleus. Shrunken cataractous lens with thickened anterior capsule. 6. Refraction/ Retinoscopy Myopia(index) Hypermetropia (index) in cortical cataract Not possible Not possible Not possible

17. MSC Leucocoria White reflex in pupillary area. Size of pupil usually normal. Fourth Purkinje image is absent. Slit lamp examination shows cataractous lens. Ultrasonography normal. White reflex in pupillary area. Pupil usually semi dilated. Fourth Purkinje image is present. Slit lamp examination shows transparent lens with white reflex behind the lens. Ultrasonography reveals opacity in the vitreous cavity. Differential Diagnosis

18. ISC Nuclear Sclerosis Painless progressive loss of vision. Greyish colour of lens on oblique illumination examination. Iris shadow is present. Black spots against red glow are observed on DDO. Slit lamp examination reveals area of cataractous cortex. Visual Acuity does not improve on pinhole testing. Painless progressive loss of vision . Greyish colour of lens. Iris shadow is absent. No black spots are seen against red glow when observed in DDO. Slit lamp examination reveals clear lens with nuclear sclerosis. Visual Acuity usually improves on pinhole testing.

19. Complications Phacoanaphylactic uveitis 2. Lens induced glaucoma a. Phacomorphic glaucoma : Caused by intumescent lens. Type of secondary angle closure glaucoma. b. Phacolytic glaucoma : It is associated with Morganian type Hypermature cataract. It is a type of secondary open angle glaucoma. c. Phacotopic glaucoma 3. Subluxation or dislocation of lens

20. NON – SURGICAL MANAGEMENT Treatment of the cause In acquired cataracts, thorough search should me made to find out the cause of cataract. Some common examples include: Adequate control of Diabetes Mellitus Removal of cataractogenic drugs Removal of irradiation may delay or prevent cataract formation. Early and adequate treatment of ocular diseases like uveitis may prevent occurrence of complicated cataract.

21. Measures to delay progression Topical preparations containing iodide salts of calcium & potassium are prescribed in early stages of cataract. However, till date no conclusive results about their role are available. Vitamin E & Aspirin in delaying the process of cataractogenesis. Measures to improve vision in the process of early cataract Prescription of glasses for refractive status. Arrangement of illumination Dark goggles Mydriatics

22. SURGICAL MANAGEMENT INDICATIONS Visual Improvement : It varies from person to person depending upon the individual visual needs. Medical Indication : Cataract surgery should be advised in the presence of – Lens induced glaucoma Phacoanaphylactic uveitis Dislocated or subluxated lens Retinal diseases like Diabetic Retinopathy & Retinal Detachment C. Cosmetic Indication : It can be done in order to obtain the black pupil.

23. Preoperative evaluation and workup Ocular examination Visual Status Assessment Visual Acuity should be noted unaided, best corrected and with pinhole. Perception of light Projection of light Potential visual acuity tests can be done in dense opaque media Pupils Light reactions and RAPD 3. Intraocular Pressure (IOP)

24. Anterior Segment Evaluation Cornea should be examined to note any scarring, endothelial status. In patients with suspicion of endothelial dystrophy, Specular Microscopy should be done. Keratic Precipitates (KPs) Cataractous lens for morphology and maturity of cataract for grade of nuclear sclerosis. Other signs to be looked are posterior synechiae, pseudoexfoliation, iridodonesis, pigments over the anterior lens capsule and anterior chamber depth. Examination of lids, conjunctiva and lacrimal apparatus Search for local source of infection should be made by ruling out conjunctival infections, meibomitis, blepharitis and lacrimal sac function. Dilated fundus examination To rule out the other causes of decreased vision. Indirect Ophthalmoscopy may be useful in hazy media.

25. Retinal/Macular Function tests Two light discrimination test Maddox Rod test Color Perception Entoptic visualisation B - Scan Ultrasonography Important to detect any associated vitreous haemorrhage, RD, Intraocular tumour and posterior staphyloma. Electrophysiological evaluation ERG & VEP, though not required routinely, may be useful to detect retinal and optic nerve affections in suspected cases. Keratometry, Corneal topography and Biometry To calculate the power of IOL to be implanted.

26. BIOMETRY (Calculation of IOL Power) The basic formula for determining the IOL power is SRK Formula S (Sanders) R (Retzlaff) K (Kraff) P = A – 2.5L – 0.9K in which, P - Power of IOL A - Constant which is specific for each lens type L - Axial length of the eyeball (in mm) Determined by A Scan K - Average Corneal Curvature determined by Keratometry

27. General medical examination Pre-anaesthetic (PAC) is essential to exclude the presence of systemic diseases especially: Diabetes Mellitus Hypertension Cardiac Problems Obstructive lung disorders Any potential source of infection in the body such as septic gums, urinary tract infection, etc. History of current medications Investigations ECG Random Blood Sugar (RBS) Other Investigations as per specific indications.

28. Preoperative medications and preparations Consent Scrub bath, care of hair and marking of the eye Preoperative antibiotics & disinfectants Topical antibiotics Povidone-Iodine (10%) solution Povidone-Iodine (5%) solution IOP lowering Mydriasis

29. Anaesthesia The vast majority of cataract surgery is performed under Local Anaesthesia (LA). Although General Anaesthesia can also be used in certain circumstances such as children's and young adults, very anxious patients, some patients with learning difficulties, epilepsy, dementia and those with a head tremor.

30. CATARACT SURGERY Extracapsular Cataract Extraction (ECCE) Indications: Presently, extracapsular cataract extraction techniques are the surgery of choice for almost all types of adulthood as well as childhood cataracts unless contraindicated. Contraindications: The only absolute contraindication for ECCE is markedly subluxated or dislocated lens.

31. Phacoemulsification Phacoemulsification is a modern-day cataract surgery that employs ultrasound energy to emulsify the nucleus, vacuum to catch the nuclear material, and irrigation and aspiration for cortex and viscoelastic removal. A typical phaco machine consists of a handpiece, foot pedal, irrigation, and aspiration system.

32. Steps of Phacoemulsification Side port entry Clear corneal incision Continuous curvilinear capsulorrhexis (CCC) Hydro dissection Nucleus Removal Divide and conquer technique Stop and chop technique Direct phaco chop technique Remaining cortical lens matter is aspirated IOL implantation Removal of viscoelastic substance Wound closure

33. Microincision Cataract Surgery (MICS) MICS refers to the phacoemulsification techniques which can be performed through a microincision <2mm. These technique offers almost no surgically induced astigmatism.

34. Femtosecond Laser - Assisted Cataract Surgery FLACS is the best available procedure presently. It is basically MICS or microphaco in which femtosecond laser is used to perform certain steps. Surgical steps with femtosecond laser Clear Corneal Incision Arcuate Corneal Incision Capsulorrhexis Lens Fragmentation

35. Post – femtosecond laser surgical steps Corneal incision are opened up with fine iris repositor Anterior Chamber is filled with viscoelastic material Capsulorrhexis flap is removed with the forceps Lens fragments are phacoaspirated Foldable IOL is implanted in the capsular bag and the procedure is completed.

36. TYPES OF IOL As part of cataract surgery, your natural lens will be removed and replaced with an artificial intraocular lens. Over the years, a large no. of different types and styles of IOL lenses have been developed.

37. Based on the method of fixation in the eye Anterior Chamber IOL : These lenses lie entirely in front of iris and are supported in the angle of anterior chamber. Iris supported IOL : These lenses are fixed on the iris with the help of sutures, loops or claws. Posterior Chamber IOL: PCIOLs rest entirely behind the iris. They may be supported and fixed as below - In the capsular bag fixation of PCIOL In the ciliary sulcus fixation of PCIOL Scleral fixation of PCIOL Retro – iris fixation

38. Rigid IOL : These are made entirely from polymethylmethacrylate (PMMA). Depending on the material of manufacturing Foldable IOL : It is to be implanted through a small incision. Studies generally have shown postoperative inflammatory reactions to be low grade and clinically insignificant with modern foldable IOLs, although the intensity and duration of responses may vary with the IOL material. (American Academy of Ophthalmology)

39. Based on the focusing ability Monofocal IOL 2. Multifocal IOL 3. Trifocal IOL 4. Extended Depth of focus IOL

40. Special Function IOL Aniridia IOL: It is devised to cosmetically cover the defect of aniridia or partial iris loss in cases like trauma. Implantable Miniature Telescope: Unique Prosthetic designed specially to improve vision in patients with late stage ARMD and Maculopathies. Piggyback IOL: It is a very thin IOL which are implanted over the convential posterior chamber IOL.