Sunday, October 02, 2005

Chapter 6- Approaching Different Kinds of Cataract

Ectopia lentis

  • Displacement of the lens

    • Subluxed - partially displaced within pupillary aperture
    • Luxated or completely displaced from the pupil congenital, developmental, or acquired

  • Epidemiology

    • Trauma is the most common cause.
    • Greater than 50% of patients with Marfan's syndrome exhibit ectopia lentis

  • Pertinent clinical features

    • Sub or total luxation of the lens
    • Phacodonesis
    • Marked lenticular astigmatism
    • Iridodonesis
    • Impaired accommodation

  • Non-traumatic differential diagnosis
  • Primarily ocular

    • Pseudoexfoliation
    • Simple ectopia lentis
    • Ectopia lentis et pupillae
    • Aniridia
    • Congenital glaucoma

  • Systemic

    • Marfan's syndrome
    • Homocystinuria
    • Weil-Marchesani syndrome
    • Hyperlysemia
    • Ehlers Danlos
    • Sulfite oxidase deficiency

  • Surgical therapy options

    • ICCE
    • Phaco/ECCE

      1. Attend to any vitreous in anterior chamber – staining with Kenalog helps to visualize the clear vitreous [view video]
      2. Use iris hook to stabilize anterior lens capsule
      3. Capsular tension ring (CTR) with or without Cionni modification
      4. IOL in bag – mild cases aided by CTR/Cionni ring
      5. Iris fixated posterior or anterior IOL
      6. Angle supported IOL
      7. Sulcus sutured posterior chamber IOL
      8. Contact lens or spectacles


Intumescent Cortical Cataract

  • Etiology

    • Opacification of the cortical lens fibers
    • Swelling of the lens material creates intumescent cataract

  • Clinical features

    • Initially vacuoles and water left in the lens cortex
    • Wedge shaped opacities or cortical spokes
    • Progresses to form white intumescent cortical cataract
    • Risk of phacolytic glaucoma
  • Risk factors
    • Smoking
    • Ultraviolet light exposure
    • Diabetes mellitus
    • Poor nutrition
    • Trauma

  • Phaco/ECCE

    • Capsular staining techniques
    • Capsulorhexis techniques

      • Initial small tear
      • Removal of liquid cortical material to relieve capsular tension
      • Liberal use of viscoelastic material

  • Complications of surgery

    • Increased risk of capsular radial tear
    • Increased risk of vitreous loss
    • Increased risk of loss of lens material into vitreous



Hypermature Cataract

  • Etiology

    • Opacification of the cortical lens fibers
    • Swelling of the lens material creates intumescent cataract
    • Degenerated cortical material leaks through capsule leaving wrinkled capsule
    • Pertinent clinical features
    • Wrinkled anterior capsule
    • Increased anterior chamber flare
    • Calcium deposits in lens
    • White cortical material
    • Risk of phacolytic glaucoma

  • Phaco/ECCE

    • Capsular staining techniques
    • Capsulorhexis techniques

      • Initial small tear
      • Removal of liquid cortical material
      • Use of viscoelastic material in anterior chamber and bag

  • Complications of surgery

    • Increased risk of capsular radial tear
    • Increased risk of vitreous loss
    • Increased risk of zonular dialysis
    • Increased risk of loss of lens into the vitreous


Morgagnian Cataract

  • Etiology

    • Opacification of the cortical lens fibers
    • Can be swelling of the lens material as in intumescent cataract
    • Can be wrinkled capsule as in hypermature cataract
    • Hallmark sign - liquefied cortex allows nucleus to move freely in bag

  • Pertinent clinical features

    • Wrinkled anterior capsule
    • Increased anterior chamber flare
    • Dense brown nucleus freely moving in capsular bag
    • Calcium deposits within the lens

  • Phaco/ECCE

    • Capsular staining techniques
    • Capsulorhexis techniques

      • Initial small tear
      • Removal of liquid cortical material to decompress the pressure in the lens bag.
      • Use of viscoelastics material in anterior chamber and bag to stablize the anterior capsule during the CCC.

Stabilize nucleus with viscoelastic

  • Complications of surgery

    • Increased risk of capsular radial tear
    • Increased risk of vitreous loss
    • Increased risk of zonular dialysis
    • Increased risk of loss of lens into the vitreous



Anterior Polar Cataracts

  • Etiology

    • Opacity of the anterior subcapsular cortex and capsular
    • Bilateral
    • Non progressive usually
    • Frequently autosomal dominant

  • Clinical features

    • Usually asymptomatic with good vision
    • Central opacity involving the anterior capsular
    • Associated with microphthalmos, persistent papillary membrane, anterior lentic
    • Differential diagnosis includes penetrating capsule trauma
  • Phaco/ECCE - with capsulorhexis start away from polar cataract make bigger and go around polar cataract if possible

Posterior Polar Cataracts

  • Etiology

    • Opacity of the posterior capsular cortex and capsule
    • Familial autosomal dominant bilateral; sporadic unilateral
    • Slowly progressive

  • Pertinent clinical features

    • Good vision but at nodal point more symptomatic than anterior polar
    • Central opacity involving the posterior capsule
    • Glare
    • Differential diagnosis includes

      • Posterior subcapsular cataract
      • Penetrating capsule trauma
      • Mittendorf dot

  • Phaco/ECCE

    • No hydrodissection
    • Sculpt out a bowl to relieve capsular tension
    • Gentle hydrodelineation
    • Leave central opacity or take at the end of surgery

  • Complications

    • Increased risk of posterior capsular tear
    • Increased risk of vitreous loss
    • Increased risk of loss of lens material into vitreous


Perforating and penetrating injury of the lens


  • Etiology of this disease

    • Penetrating injury results in cortical opacification at site
    • Rarely can seal resulting in a focal opacity
    • Usually progresses to complete opacification

  • Pertinent clinical features

    • Focal cortical cataract
    • White cataract with capsular irregularity/scar
    • Full thickness corneal scar

  • Laboratory testing

    • B-scan ultrasound - check if posterior capsular intact? Is there an intraocular foreign body?
    • CT scan to rule out intraocular foreign body

  • Phaco/ECCE

    • Capsular staining to identify traumatic tear
    • No hydrodissection if posterior penetration suspected
    • Usually can aspirate in younger patients without need for nucleofractis

  • Complications

    • Increased risk of anterior radial capsular tear
    • Increased risk of vitreous loss
    • Increased risk of lens material in vitreous
    • Increased risk of retinal detachment

Diabetes mellitus and cataract formation

  • Etiology

    • Increased aqueous glucose concentration drives glucose into lens
    • Glucose converted into sorbitol that is not metabolized by lens
    • Sorbitol creates an osmolar gradient forcing hydration of the lens
    • This sorbitol induced lenticular hydration

      • Decreases accommodation
      • Changes the refractive power of the lens
      • Generates cataract

  • Pertinent clinical features

    • Snowflake or true diabetic cataract

      • Bilateral
      • Posterior and anterior subcapsular, cortical vacuoles and clefts

    • Typical nuclear, cortical, or posterior subcapsular cataracts

  • Phaco/ECCE

    • Indicated when view of posterior pole is poor
    • Standard technique

  • Complications

    • Exacerbation of diabetic macular edema

      • Focal or grid laser therapy prior to surgery if indicated/possible
      • Sutured wound to allow early laser therapy if indicated

Increased risk of cystoid macular edema

      • Pretreatment with steroid and non-steroidal drops
      • Prophylactic treatment for 1-3 months with steroid and/or non-steroidal drops (prednisolone and ketorolac drops)




Cataract Associated with Uveitis

  • Etiology

    • Posterior subcapsular cataract

      • Initially an iridescent sheen appears in the posterior cortex
      • Followed by granular and plaque like opacities

    • May progress to or involve anterior subcapsular cortical fibres
    • May present as cortical cataract without posterior subcapsular component
    • Associated with uveitis and corticosteroids to treat uveitis
    • May progress rapidly to a mature cataract

  • Pertinent clinical features

    • Central opacity of the posterior cortical fibers
    • Cortical cataract
    • Posterior synechiae
    • Papillary membrane
    • Anterior chamber cell or flare

  • Prior to phaco/ECCE

    • Several months without inflammation
    • 1 week prior to surgery suppresses immune system
      • Topical agents in those patients who typically quiet with topical agents alone
      • Oral prednisone in those that typically require oral steroid with a flare
      • Consider intraoperative IV steroids

  • Phaco/ECCE

    • Synechiolysis with viscoelastic agents/hooks
    • May require iris hooks to stabilize floppy iris and control papillary aperture
    • Capsular dye to allow continuous tear
    • IOL material acrylic=heparin coated PMMA better than silicon
    • Consider aphakia in children with juvenile rheumatoid arthritis (JRA)

  • Complications of cataract surgery

    • Increased risk of post operative inflammation
    • Increased risk of post operative pressure spike
    • Increased risk of cystoid macular edema
    • Consider using steroid and non-steroidal drops for months following surgery


Exfoliation Syndrome (Pseudoexfoliation)

  • Etiology

    • Systemic disease in which a fibrillar material is deposited in the eye

      • Similar material to the basement membrane proteoglycan
      • The material is found throughout the body

    • Within the eye the fibrillar material comes from the lens capsule, iris, and ciliary body
    • The zonules are weak in this condition
    • Often asymmetric or even unilateral
    • Glaucoma develops when the fibrillar material blocks the trabecular meshwork

  • Epidemiology

    • Patients tend to be over 60 years of age
    • Geographic clustering suggests a hereditary pattern

      • In Scandinavia for example pseudoexfoliation causes 75% of glaucoma

    • Glaucoma develops in 22-82% of patients with exfoliative material
    • Increased incidence of age related cataract

  • Pertinent clinical features

    • Ground glass appearing deposition of fibrillar material on anterior lens capsule

      • Iris may sweep material into rings on the lens capsule
      • Best viewed with dilation

    • Transillumination defect and fibrillar material at the papillary margin
    • Open angle with brown clumps of fibrillar material on trabecular meshwork
    • Flakes of fibrillar material on corneal endothelium
    • Evidence of zonular weakness

      • Phaco or iridodonesis
      • Lens subluxation or even luxation
  • Phaco/ECCE

    • Use of iris hooks for capsular support during phacoemulsification
    • Use of capsular tension ring with or without Cionni modification [view video]
    • Placement of AC IOL, sutured Cionni ring with capsular IOL, sutured PC IOL
    • Sutured iris IOL
    • Consider surgery sooner while zonules are relatively strong
    • Minimize zonule stress during surgery

  • Complications of phaco/ECCE

    • Increased risk of capsular radial tear
    • Increased risk of zonular dialysis
    • Increased risk of loss of lens material into vitreous
    • Increased risk of late dislocation of IOL capsular bag complex into vitreous
    • Post operative intra-ocular pressure spike

      • Completely remove OVD
      • Intra-operative miotic
      • Postoperative aqueous suppressant


Conclusion

This eBook is written for the young surgeon learning cataract surgery. I hope you have found this educational material useful during your training. This eBook is currently being expanded to discuss the topics presented here in detail. Good luck!


Tom Oetting, MS, MD

Associate Professor of Clinical Ophthalmology, University of Iowa

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1 Comments:

Blogger NYC PGY3 said...

Thank you for the fantastic tutorials! Feeling much better about doing my first phaco case...

7:18 PM  

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