How should I perform a physical examination for cataracts in an adult patient?

Physical Examination for Cataracts in Adults

Clinically significant cataracts can be visualized on physical examination as change of color or opacities in the eye lens, best assessed using slit-lamp examination after pupillary dilation. 1

Essential Components of the Examination

Visual Function Assessment

• Visual acuity testing at distance and near is the foundation of cataract evaluation, noting whether acuity improves with refraction or pinhole testing 2
• Glare testing is critical because it reveals functional disability greater than Snellen acuity alone suggests—patients with cataracts often have significant reduction in visual acuity under glare conditions 2
• Contrast sensitivity testing should be performed, as reduced contrast sensitivity affecting daily activities is a significant finding that may not be captured by standard acuity testing 2
• Visual acuity alone may underestimate the functional impact of cataracts; glare and contrast sensitivity provide essential additional information 2

Pupillary and External Examination

• Pupillary examination should be performed to assess for afferent pupillary defects that might indicate other pathology 1
• External examination evaluates for signs of trauma, inflammation, or other ocular surface disease 1
• Intraocular pressure measurement is necessary to rule out concurrent glaucoma 1

Slit-Lamp Biomicroscopy (The Definitive Examination)

• Slit-lamp examination after pupillary dilation is the gold standard for diagnosing cataracts and allows classification of opacities according to their anatomical distribution 3
• Look for specific patterns of lens opacity:
  • Nuclear cataracts (central lens clouding, often yellowish-brown discoloration)
  • Posterior subcapsular cataracts (opacities at the back surface of the lens)
  • Cortical cataracts (spoke-like opacities in the lens periphery) 3
• The anatomical distribution helps direct any etiologic work-up and can distinguish age-related from secondary causes 3

Fundus Examination

• Dilated fundus examination with direct ophthalmoscope assesses the optic nerve and retina 4
• This is essential to rule out other causes of vision loss before attributing symptoms solely to cataracts 2

Supplemental Testing to Consider

• Optical coherence tomography of the macula to rule out concurrent retinal pathology that could limit visual recovery after surgery 2
• Corneal topography/tomography to assess for corneal irregularities that may affect surgical planning 2
• Refraction to determine if visual symptoms can be improved with updated spectacle correction, particularly for early cataracts 2

Critical Clinical Pitfalls

• Do not rely on visual acuity alone—a patient may have 20/30 vision but severe glare disability that significantly impairs driving and reading 2, 5
• Always rule out other causes of vision loss such as macular degeneration, diabetic retinopathy, or glaucoma before concluding symptoms are solely from cataracts 2
• Assess for secondary causes before labeling a cataract as age-related: look for history of corticosteroid use, ocular trauma, diabetes, uveitis, or radiation exposure 3, 6
• Document medication history, particularly alpha-1 antagonists like tamsulosin, which increase risk of intraoperative floppy iris syndrome 2, 6

Functional Impact Assessment

Beyond the physical findings, document:

• Specific activities of daily living affected (driving at night, reading small print, recognizing faces) 5
• Whether symptoms improve with updated spectacle correction—if not, this supports surgical intervention 5
• Presence of monocular diplopia, photophobia, or myopic shift, which are common symptoms depending on cataract type 3