Doctor123.org

Cataract

Doctor123.org

Cataract

para>Some degree of cataract formation is expected in all people >70 years of age. пїЅ

Consistent with lens changes found in the type of cataract; however, diagnosis is made by clinical examination. пїЅ

There are currently no medications to prevent or slow the progression of cataracts. пїЅ

If patient has cataract and symptoms do not seem to support recommended surgery, a second opinion by another ophthalmologist may be indicated. пїЅ

Medline Plus on cataracts at: https://www.nlm.nih.gov/medlineplus/cataract.html пїЅ

11 Asbell пїЅPA, Dualan пїЅI, Mindel пїЅJ, et al. Age-related cataract. Lancet. 2005;365(9459):599-609.22 Abraham пїЅAG, Condon пїЅNG, West Gower пїЅE. The new epidemiology of cataract. Ophthalmol Clin North Am. 2006;19(4):415-425.33 Riaz пїЅY, Mehta пїЅJS, Wormald пїЅR, et al. Surgical interventions for age-related cataract. Cochrane Database Syst Rev. 2006;(4):CD001323.44 Fedorowicz пїЅZ, Lawrence пїЅD, Gutierrez пїЅP. Day care versus in-patient surgery for age-related cataract. Cochrane Database Syst Rev. 2005;(1):CD004242.55 Biber пїЅJM, Sandoval пїЅHP, Trivedi пїЅRH, et al. Comparison of the incidence and visual significance of posterior capsule opacification between multifocal spherical, monofocal spherical, and monofocal aspheric intraocular lenses. J Cataract Refract Surg. 2009;35(7):1234-1238.66 Findl пїЅO, Buehl пїЅW, Bauer пїЅP, et al. Interventions for preventing posterior capsule opacification. Cochrane Database Syst Rev. 2010;(2):CD003738.77 Lundstr пїЅm пїЅM, Barry пїЅP, Henry пїЅY, et al. Visual outcome of cataract surgery; study from the European Registry of Quality Outcomes for Cataract and Refractive Surgery. J Cataract Refract Surg. 2013;39(5):673-679.88 Lundstr пїЅm пїЅM, Goh пїЅPP, Henry пїЅY, et al. The changing pattern of cataract surgery indications: a 5-year study of 2 cataract surgery databases. Ophthalmology. 2015;122(1):31-38.

See "Congenital Cataract"пїЅ; may present as leukocoria.

See "Congenital Cataract"пїЅ (i.e., medications, metabolic dysfunction, intrauterine infection, and malnutrition).

EPIDEMIOLOGY

  • ~48% of the 37 million cases of blindness worldwide result from cataracts (1,2).
  • Leading cause of treatable blindness and vision loss in developing countries (1,2)
  • Predominant age: depends on type of cataract
  • Predominant sex: male > female
  • Cataract type and prevalence are highly variable based on population demographic.
  • An estimated 50% of people 65 to 74 years of age and 70% of people >75 years of age have age-related cataract.

ETIOLOGY AND PATHOPHYSIOLOGY

  • Age-related cataract:Continual addition of layers of lens fibers throughout life creates hard, dehydrated lens nucleus that impairs vision (nuclear cataract).Aging alters biochemical and osmotic balance required for lens clarity; outer lens layers hydrate and become opaque, adversely affecting vision.
  • Congenital:Usually unknown etiologyDrugs (corticosteroids in 1st trimester, sulfonamides)Metabolic (diabetes in mother, galactosemia in fetus)Intrauterine infection during 1st trimester (e.g., rubella, herpes, mumps)Maternal malnutrition
  • Other cataract types:Common feature is a biochemical/osmotic imbalance that disrupts lens clarity.Local changes in lens protein distribution lead to light scattering (lens opacity).
  • Continual addition of layers of lens fibers throughout life creates hard, dehydrated lens nucleus that impairs vision (nuclear cataract).
  • Aging alters biochemical and osmotic balance required for lens clarity; outer lens layers hydrate and become opaque, adversely affecting vision.
  • Usually unknown etiology
  • Drugs (corticosteroids in 1st trimester, sulfonamides)
  • Metabolic (diabetes in mother, galactosemia in fetus)
  • Intrauterine infection during 1st trimester (e.g., rubella, herpes, mumps)
  • Maternal malnutrition
  • Common feature is a biochemical/osmotic imbalance that disrupts lens clarity.
  • Local changes in lens protein distribution lead to light scattering (lens opacity).
  • Congenital (e.g., chromosomal disorders [Down syndrome])
  • Genetics of age-related cataract are not yet established but likely multifactorial contribution.

RISK FACTORS

  • Aging
  • Cigarette smoking
  • Ultraviolet (UV) sunlight exposure
  • Diabetes
  • Prolonged high-dose steroids
  • Positive family history
  • Alcohol

GENERAL PREVENTION

  • Use of UV protective glasses
  • Avoidance of tobacco products
  • Effective control of diabetes
  • Care with high-dose, long-term steroid use (systemic therapy > inhaled treatment)
  • Protective methods using pharmaceutical intervention (e.g., antioxidants, acetylsalicylic acid [ASA], hormone replacement therapy [HRT]) show no proven benefit to date.

COMMONLY ASSOCIATED CONDITIONS

  • Diabetes (especially with poor glucose control)
  • Myotonic dystrophy (90% of patients develop visually innocuous change in 3rd decade; becomes disabling in 5th decade)
  • Atopic dermatitis (AD) (10% of patients with severe AD develop cataracts in 2nd to 4th decades, often bilateral)
  • Neurofibromatosis type 2
  • Associated ocular disease or "secondary cataract"пїЅ (e.g., chronic anterior uveitis, acute [or repetitive] angle-closure glaucoma or high myopia)
  • Drug induced (e.g., steroids, chlorpromazine)
  • Trauma

DIAGNOSIS

HISTORY

  • Age-related cataract:Decreased visual acuity, blurred vision, distortion, or "ghosting"пїЅ of images (1,2)Problems with visual acuity in any lighting conditionFalls or accidents; injuries (e.g., hip fracture)
  • Congenital: often asymptomatic, leukocoria, parents notice child's visual inattention or strabismus
  • Other types of cataract:May also present with decreased visual acuityAppropriate clinical history or signs to help with diagnosis
  • Decreased visual acuity, blurred vision, distortion, or "ghosting"пїЅ of images (1,2)
  • Problems with visual acuity in any lighting condition
  • Falls or accidents; injuries (e.g., hip fracture)
  • May also present with decreased visual acuity
  • Appropriate clinical history or signs to help with diagnosis

PHYSICAL EXAM

  • Visual acuity assessment for all cataracts
  • Age-related cataract: lens opacity on eye examination
  • Congenital:Lens opacity present at birth or within 3 months of birthLeukocoria (white pupil), strabismus, nystagmus, signs of associated syndrome (as with Down or rubella syndrome)Note: must always rule out ocular tumor; early diagnosis and treatment of retinoblastoma may be lifesaving
  • Other types of cataract: may present with decreased visual acuity associated with characteristic physical findings (e.g., metabolic, trauma)
  • Lens opacity present at birth or within 3 months of birth
  • Leukocoria (white pupil), strabismus, nystagmus, signs of associated syndrome (as with Down or rubella syndrome)
  • Note: must always rule out ocular tumor; early diagnosis and treatment of retinoblastoma may be lifesaving

DIFFERENTIAL DIAGNOSIS

  • An opaque-appearing eye may be due to opacities of the cornea (e.g., scarring, edema, calcification), lens opacities, tumor, or retinal detachment. Biomicroscopic examination (slit lamp) or careful ophthalmoscopic exam should provide diagnosis.
  • In the elderly, visual impairment is often due to multiple factors such as cataract and macular degeneration, both contributing to visual loss.
  • Age-related cataract is significant if symptoms and ophthalmic exam support cataract as a major cause of vision impairment.
  • Congenital lens opacity in the absence of other ocular pathology may cause severe amblyopia.
  • Note: Cataract does not produce a relative afferent pupillary reaction defect. Abnormal pupillary reactions mandate further evaluation for other pathology.

DIAGNOSTIC TESTS & INTERPRETATION

  • Visual quality assessment: Glare testing, contrast sensitivity is sometimes indicated.
  • Retinal/macular function assessment: potential acuity meter testing
  • Workup of underlying process

TREATMENT

  • Outpatient (usually)
  • ~1.64 million cataract extractions in the United States yearly (3,4)

GENERAL MEASURES

MEDICATION

ISSUES FOR REFERRAL

SURGERY/OTHER PROCEDURES

  • Age-related cataract:Surgical removal is indicated if visual impairment-producing symptoms are distressing to the patient, interfering with lifestyle or occupation, or posing a risk for fall or injury (3,4)[A].Because significant cataract may develop gradually, the patient may not be aware of how it has changed his or her lifestyle. Physician may note a significant cataract, and patient reports "no problems."пїЅ Thus, evaluation requires effective physician-patient exchange of information.Surgical technique: Cataract extraction via small incisions, followed by implantation of a prosthetic intraocular lens; lenses have power calculated based on size of the eye and curvature of cornea usually to correct for distance vision; surgery performed on one (worse) eye, with contralateral surgery only after recovery and if deemed necessary; generally takes <1 hour depending on surgical techniqueAnesthesia: usually regional injection or topical with sedation and monitoring of vital signsPreoperative evaluation: by the primary care physician:Patients on anticoagulants may need to be temporarily discontinued 1 to 2 weeks before surgery if possible (but not always necessary; thus, need to discuss with ophthalmologist).Patients who have ever taken an О±-blocker such as tamsulosin (Flomax) should alert their ophthalmologist (increased risk of intraoperative floppy iris syndrome [IFIS] even in patients who no longer use these drugs).Postoperative care: usually protective eye shield as directed, topical antibiotic, NSAIDs, and steroid ophthalmic medications; avoid lifting or bending over for a few weeks.
  • Congenital cataract:Treatment is surgical removal of cataract. Newborns may require surgery within days to reduce risk of severe amblyopia. Use of lens implants is controversial because the eyes are growing.Postoperative care: long-term patching program for good eye to combat amblyopia; refractive correction of operative eye, with multiple repeat examinations; challenging for physician and parents
  • Surgical removal is indicated if visual impairment-producing symptoms are distressing to the patient, interfering with lifestyle or occupation, or posing a risk for fall or injury (3,4)[A].
  • Because significant cataract may develop gradually, the patient may not be aware of how it has changed his or her lifestyle. Physician may note a significant cataract, and patient reports "no problems."пїЅ Thus, evaluation requires effective physician-patient exchange of information.
  • Surgical technique: Cataract extraction via small incisions, followed by implantation of a prosthetic intraocular lens; lenses have power calculated based on size of the eye and curvature of cornea usually to correct for distance vision; surgery performed on one (worse) eye, with contralateral surgery only after recovery and if deemed necessary; generally takes <1 hour depending on surgical technique
  • Anesthesia: usually regional injection or topical with sedation and monitoring of vital signs
  • Preoperative evaluation: by the primary care physician:Patients on anticoagulants may need to be temporarily discontinued 1 to 2 weeks before surgery if possible (but not always necessary; thus, need to discuss with ophthalmologist).Patients who have ever taken an О±-blocker such as tamsulosin (Flomax) should alert their ophthalmologist (increased risk of intraoperative floppy iris syndrome [IFIS] even in patients who no longer use these drugs).
  • Postoperative care: usually protective eye shield as directed, topical antibiotic, NSAIDs, and steroid ophthalmic medications; avoid lifting or bending over for a few weeks.
  • Patients on anticoagulants may need to be temporarily discontinued 1 to 2 weeks before surgery if possible (but not always necessary; thus, need to discuss with ophthalmologist).
  • Patients who have ever taken an О±-blocker such as tamsulosin (Flomax) should alert their ophthalmologist (increased risk of intraoperative floppy iris syndrome [IFIS] even in patients who no longer use these drugs).
  • Treatment is surgical removal of cataract. Newborns may require surgery within days to reduce risk of severe amblyopia. Use of lens implants is controversial because the eyes are growing.
  • Postoperative care: long-term patching program for good eye to combat amblyopia; refractive correction of operative eye, with multiple repeat examinations; challenging for physician and parents

ONGOING CARE

FOLLOW-UP RECOMMENDATIONS

  • As cataract progresses, an ophthalmologist may change spectacle correction to maintain vision. When this is no longer successful and interferes with patient's activities of daily living, surgery is indicated.
  • Following surgery, spectacle correction may be required to maximize near and/or far visual acuity. Refraction is usually prescribed several weeks after surgery.

PATIENT EDUCATION

PROGNOSIS

  • Ocular prognosis is good after cataract removal if no prior or coexisting ocular disease: 94.3% of otherwise healthy eyes achieve best corrected visual acuity of 20/40 or better. Success rates are lower with comorbidities such as diabetes and glaucoma (5).
  • In congenital cataracts, prognosis often is poorer because of the high risk of amblyopia.

COMPLICATIONS

  • Vary widely from delay in visual recovery or protracted visual discomfort to blindness and loss of eye
  • Nearly all reported complications occur rarely (<2% of eyes) except for posterior capsule opacification (14.7-42.7% of eyes, usually treated with Nd-YAG laser capsulotomy in office with a rate of 4-25.3%) (6,7)[B].
  • Poor preoperative visual acuity is related to surgical complications (8).

REFERENCES

SEE ALSO

  • Algorithm: Cataracts
  • Floppy Iris Syndrome

CODES

ICD10

  • H26.9 Unspecified cataract
  • H25.9 Unspecified age-related cataract
  • Q12.0 Congenital cataract
  • H26.40 Unspecified secondary cataract
  • H26.32 Drug-induced cataract, left eye
  • H26.491 Other secondary cataract, right eye
  • H26.31 Drug-induced cataract, right eye
  • H26.33 Drug-induced cataract, bilateral
  • H26.493 Other secondary cataract, bilateral
  • H26.499 Other secondary cataract, unspecified eye
  • H26.492 Other secondary cataract, left eye
  • H26.103 Unspecified traumatic cataract, bilateral
  • H26.102 Unspecified traumatic cataract, left eye
  • H26.30 Drug-induced cataract, unspecified eye
  • H26.109 Unspecified traumatic cataract, unspecified eye
  • H26.101 Unspecified traumatic cataract, right eye

ICD9

  • 366.9 Unspecified cataract
  • 366.10 Senile cataract, unspecified
  • 743.30 Congenital cataract, unspecified
  • 366.50 After-cataract, unspecified
  • 366.20 Traumatic cataract, unspecified
  • 366.45 Toxic cataract
  • 366.53 After-cataract, obscuring vision
  • 366.52 Other after-cataract, not obscuring vision

SNOMED

  • 193570009 Cataract (disorder)
  • 39450006 Senile cataract
  • 79410001 congenital cataract (disorder)
  • 47337003 after-cataract (disorder)
  • 34361001 traumatic cataract (disorder)
  • 38583007 Toxic cataract

CLINICAL PEARLS

  • Cataracts are the leading cause of blindness worldwide; 90% are age-related.
  • Primary indication for cataract surgery is visual impairment leading to significant lifestyle changes for the patient.
  • For congenital cataracts, must always rule out ocular tumor because early diagnosis and treatment of retinoblastoma may be lifesaving.
  • Before prescribing an О±-blocker for an older adult with hypertension or a prostate or urinary retention problem, consider whether the patient has cataracts (due to increased risk of IFIS).