Cataract

Last updated: April 10, 2022

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Cataract is a condition characterized by clouding of the ocular lens. Acquired cataracts are more common and most frequently occur due to age-related degenerative processes in the lens; they can also occur as a side effect to drugs or be caused by ocular trauma or metabolic disorders. Congenital cataracts may occur due to TORCH infections, disorders of metabolism, or hereditary syndromes. Congenital cataracts can be found on routine newborn red reflex evaluation; detection should be followed by a prompt referral to a pediatric ophthalmologist for further workup and management to prevent deprivation amblyopia. In adults, cataract often manifests discretely and may go unnoticed until visual impairment worsens. Diagnosis is typically established on the basis of a thorough history and direct visualization of the cataract (e.g., via slit-lamp microscopy). Surgery is indicated for patients with significant visual impairment and involves lens extraction and implantation of an artificial lens. Untreated cataracts may lead to complete blindness.

  • Leading cause of visual impairment and blindness in the world
  • Prevalence of acquired cataracts: increases with age
    • > 80 years: ∼70 %
    • 40–80 years: ∼17.5 %
  • Sex: >

References:[1][2][3]

Epidemiological data refers to the US, unless otherwise specified.

Clouding of the lens may be congenital or acquired.

Acquired cataracts (> 99%) [4]

Congenital cataracts (< 1%) [4]

Cataracts are generally classified according to etiology (as above). Age-related cataracts can also be classified according to where they form in the lens (morphology) or how advanced they are.

  • Morphological types
    • Cortical cataract (anterior/posterior): the most common type of cataract; characteristically originates at the outer layer of the lens and grows towards the center, forming a wedge-shaped opacity
    • Nuclear cataract: a type of cataract that affects the center of the lens, appearing as a yellow-brown discoloration of this area
    • Subcapsular cataract (anterior/posterior): a type of cataract that manifests directly under the lens capsule; usually in the posterior lens (rapidly progressive) but can also occur in the anterior lens
  • Stages of progression
    • Immature cataract
      • Early stage of cataract progression
      • Red reflex is still present, allowing for visualization of the retina.
    • Mature cataract
      • Advanced stage in cataract progression
      • Red reflex is absent.
      • There is a white-yellow discoloration of the lens due to complete clouding.
      • Vision can be reduced to mere light perception.
    • Hypermature cataract
      • End stage of cataract progression
      • There is a complete white clouding of the lens due to liquification of the cortex.
      • The nucleus often sinks in the cortex and appears brown.

Acquired cataracts [4]

Clinical features usually develop gradually (especially in the case of age-related cataracts) and depend on the localization and cause(s) of lens clouding.

  • Reduced visual acuity: blurred, clouded, or dim vision, especially at night
  • Impaired vision: painless, often bilateral
  • Glare: in daylight, in low sunlight, and from car headlights; associated with halos around lights
  • Second sight: a temporary improvement in near vision; especially in patients with nuclear cataracts
  • Monocular diplopia: double vision that disappears when the affected eye is covered or shut
  • Change in color perception

Age-related cataracts are the most common cause of vision loss in older adults and can significantly affect quality of life. [6]

Congenital cataracts [4]

Congenital cataracts manifest differently than acquired cataracts.

General principles [7]

Cataract is primarily a clinical diagnosis.

Ocular examination [5][6][7]

Perform a thorough eye examination in all patients with suspected cataracts. This can help identify coexistent eye conditions, which can be present in up to ⅓ of patients and may affect treatment outcomes. [7][13]

Patients with minimal changes in visual acuity may still experience significant disability from glare with bright lights; advanced studies should be performed for these individuals.

Advanced studies [7]

  • Glare testing and visual contrast sensitivity testing
    • Used to assess the degree of visual disability when the eye is exposed to bright light
    • Perform in individuals who report experiencing significant glare [14]
  • B-scan ultrasound: to detect retinal pathology if the fundus is obscured by a dense cataract [11]
  • Optical coherence tomography: used to assess for coexisting macular disease and assist in planning surgery [15]

The differential diagnoses listed here are not exhaustive.

General principles

This section focuses primarily on the management of acquired cataracts.

In most cases, definitive management of cataracts is not possible without surgery. No pharmacologic agents are available to treat cataracts.

Congenital cataracts should be surgically treated as soon as possible to prevent deprivation amblyopia. [18]

Surgery [7]

Indications

  • To improve vision in individuals with significant cataract-related visual disturbances (most common indication)
  • Cataract causing significant difference in refractive power between the two eyes
  • Preventing proper evaluation or treatment of the areas of the eye that are posterior to it (e.g., the fundus)
  • Cataract causing glaucoma (e.g., angle closure glaucoma)

Contraindications

  • Visual disturbances manageable with corrective lenses
  • Vision is not expected to improve after surgery (e.g., concurrent ocular conditions also causing vision impairment)
  • High surgical risk

Preoperative considerations

Most patients do not require modifications to antithrombotic therapy (antiplatelet medications and anticoagulants) before cataract surgery. [7]

Surgical options

Different techniques are available and usually performed using local anesthesia.

Overview of surgical techniques for cataracts [7][19][20]

Description

Characteristics
Phacoemulsification

Extracapsular cataract extraction (ECCE)

Intracapsular cataract extraction (ICCE)
Manual small incision cataract surgery (MSICS) [22]

Postoperative care and considerations [23]

  • Topical antiinflammatory agents, topical antibiotics, NSAIDs, or glucocorticoids may be prescribed postoperatively.
  • Depending on the operation performed and surgeon preference, the following may be recommended:
    • Eye protection during the first week after surgery
    • Activity restrictions for a few days following surgery
  • Patients should follow the advice of the operating surgeon on when to resume driving.
  • Assess prescription for corrective lenses as needed 4–12 weeks postoperatively depending on the type of surgery performed.

We list the most important complications. The selection is not exhaustive.

Several measures can help prevent the development and progression of cataracts:

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  3. Miller KM, Oetting TA, Tweeten JP, et al. Cataract in the Adult Eye Preferred Practice Pattern. Ophthalmology. 2021; 129 (1): p.P1-P126. doi: 10.1016/j.ophtha.2021.10.006 . | Open in Read by QxMD
  4. Eye Health Statistics at a Glance.
  5. Vision Problems in the U.S.: Prevalence of Adult Vision Impairment and Age-Related Eye Disease in America.
  6. Cataracts Defined Tables. https://nei.nih.gov/eyedata/cataract/tables. . Accessed: March 15, 2018.
  7. Liu Y-C, Wilkins M, Kim T, Malyugin B, Mehta JS. Cataracts. Lancet. 2017; 390 (10094): p.600-612. doi: 10.1016/s0140-6736(17)30544-5 . | Open in Read by QxMD
  8. Adams GGW. The Enduring Value of Newborn Red Reflex Testing as a Screening Tool. JAMA Ophthalmol. 2021; 139 (1): p.40. doi: 10.1001/jamaophthalmol.2020.4853 . | Open in Read by QxMD
  9. Self JE, Taylor R, Solebo AL, et al. Cataract management in children: a review of the literature and current practice across five large UK centres. Eye. 2020; 34 (12): p.2197-2218. doi: 10.1038/s41433-020-1115-6 . | Open in Read by QxMD
  10. Díez Ajenjo MA, García Domene MC, Peris Martínez C. Refractive changes in nuclear, cortical and posterior subcapsular cataracts: Effect of the type and grade. J Optom. undefined; 8 (2): p.86-92. doi: 10.1016/j.optom.2014.07.006 . | Open in Read by QxMD
  11. Jammal HM, Khader Y, Shawer R, Al Bdour M. Posterior segment causes of reduced visual acuity after phacoemulsification in eyes with cataract and obscured fundus view. Clin Ophthalmol. 2012; 6 : p.1843-8. doi: 10.2147/OPTH.S38303 . | Open in Read by QxMD
  12. Zehetner C, Bechrakis N. Stellate Cataract. N Engl J Med. 2013; 368 (14): p.e18. doi: 10.1056/nejmicm1204510 . | Open in Read by QxMD
  13. Lundström M, Barry P, Henry Y, Rosen P, Stenevi U. Evidence-based guidelines for cataract surgery: Guidelines based on data in the European Registry of Quality Outcomes for Cataract and Refractive Surgery database. J Cataract Refract Surg. 2012; 38 (6): p.1086-1093. doi: 10.1016/j.jcrs.2012.03.006 . | Open in Read by QxMD
  14. Williamson TH, Strong NP, Sparrow J, Aggarwal RK, Harrad R. Contrast sensitivity and glare in cataract using the Pelli-Robson chart. Br J Ophthalmol. 1992; 76 (12): p.719-22. doi: 10.1136/bjo.76.12.719 . | Open in Read by QxMD
  15. Sudhalkar A, Vasavada V, Bhojwani D, et al. Incorporating Optical Coherence Tomography in the Cataract Preoperative Armamentarium: Additional Need or Additional Burden?. Am J Ophthalmol. 2019; 198 : p.209-214. doi: 10.1016/j.ajo.2018.10.025 . | Open in Read by QxMD
  16. Lim ME, Buckley EG, Prakalapakorn SG. Update on congenital cataract surgery management. Curr Opin Ophthalmol. 2017; 28 (1): p.87-92. doi: 10.1097/icu.0000000000000324 . | Open in Read by QxMD
  17. Stambolian D. Galactose and cataract. Surv Ophthalmol. 1988; 32 (5): p.333-349. doi: 10.1016/0039-6257(88)90095-1 . | Open in Read by QxMD
  18. Lloyd IC, Ashworth J, Biswas S, Abadi RV. Advances in the management of congenital and infantile cataract. Eye. 2007; 21 (10): p.1301-1309. doi: 10.1038/sj.eye.6702845 . | Open in Read by QxMD
  19. Woodcock M. Recent advances in customising cataract surgery. BMJ. 2004; 328 (7431): p.92-96. doi: 10.1136/bmj.328.7431.92 . | Open in Read by QxMD
  20. De Silva SR, Riaz Y, Evans JR. Phacoemulsification with posterior chamber intraocular lens versus extracapsular cataract extraction (ECCE) with posterior chamber intraocular lens for age-related cataract. Cochrane Database Syst Rev. 2014 . doi: 10.1002/14651858.cd008812.pub2 . | Open in Read by QxMD
  21. Davis G. The Evolution of Cataract Surgery. Mo Med. 2016; 113 (1): p.58-62.
  22. Riaz Y, de Silva SR, Evans JR. Manual small incision cataract surgery (MSICS) with posterior chamber intraocular lens versus phacoemulsification with posterior chamber intraocular lens for age-related cataract. Cochrane Database Syst Rev. 2013 . doi: 10.1002/14651858.cd008813.pub2 . | Open in Read by QxMD
  23. Shoss BL, Tsai LM. Postoperative care in cataract surgery. Curr Opin Ophthalmol. 2013; 24 (1): p.66-73. doi: 10.1097/icu.0b013e32835b0716 . | Open in Read by QxMD

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