History

Careful history taking is essential in determining the progression and functional impairment in vision resulting from the cataract and in identifying other possible causes for the lens opacity. A patient with cataract often presents with a history of gradual progressive deterioration and disturbance in vision. Such visual aberrations are varied depending on the type of cataract present in the patient.

* Decreased visual acuity
o Decreased visual acuity is the most common complaint of patients with senile cataract. The cataract is considered clinically relevant if visual acuity is affected significantly. Furthermore, different types of cataracts produce different effects on visual acuity.
o For example, a mild degree of posterior subcapsular cataract can produce a severe reduction in visual acuity with near acuity affected more than distance vision, presumably as a result of accommodative miosis. However, nuclear sclerotic cataracts often are associated with decreased distance acuity and good near vision.
o A cortical cataract generally is not clinically relevant until late in its progression when cortical spokes compromise the visual axis. However, instances exist when a solitary cortical spoke occasionally results in significant involvement of the visual axis.
* Glare
o Increased glare is another common complaint of patients with senile cataracts. This complaint may include an entire spectrum from a decrease in contrast sensitivity in brightly lit environments or disabling glare during the day to glare with oncoming headlights at night.
o Such visual disturbances are prominent particularly with posterior subcapsular cataracts and, to a lesser degree, with cortical cataracts. It is associated less frequently with nuclear sclerosis. Many patients may tolerate moderate levels of glare without much difficulty, and, as such, glare by itself does not require surgical management.
* Myopic shift
o The progression of cataracts may frequently increase the diopteric power of the lens resulting in a mild-to-moderate degree of myopia or myopic shift. Consequently, presbyopic patients report an increase in their near vision and less need for reading glasses as they experience the so-called second sight. However, such occurrence is temporary, and, as the optical quality of the lens deteriorates, the second sight is eventually lost.
o Typically, myopic shift and second sight are not seen in cortical and posterior subcapsular cataracts. Furthermore, asymmetric development of the lens-induced myopia may result in significant symptomatic anisometropia that may require surgical management.
* Monocular diplopia
o At times, the nuclear changes are concentrated in the inner layers of the lens, resulting in a refractile area in the center of the lens, which often is seen best within the red reflex by retinoscopy or direct ophthalmoscopy.
o Such a phenomenon may lead to monocular diplopia that is not corrected with spectacles, prisms, or contact lenses.

Physical

After a thorough history is taken, careful physical examination must be performed. The entire body habitus is checked for abnormalities that may point out systemic illnesses that affect the eye and cataract development.

* A complete ocular examination must be performed beginning with visual acuity for both near and far distances. When the patient complains of glare, visual acuity should be tested in a brightly lit room. Contrast sensitivity also must be checked, especially if the history points to a possible problem.
* Examination of the ocular adnexa and intraocular structures may provide clues to the patient's disease and eventual visual prognosis.
o A very important test is the swinging flashlight test which detects for a Marcus Gunn pupil or a relative afferent pupillary defect (RAPD) indicative of optic nerve lesions or diffuse macular involvement. A patient with RAPD and a cataract is expected to have a very guarded visual prognosis after cataract extraction.
o A patient with long-standing ptosis since childhood may have occlusion amblyopia, which may account more for the decreased visual acuity rather than the cataract. Similarly, checking for problems in ocular motility at all directions of gaze is important to rule out any other causes for the patient's visual symptoms.
* Slit lamp examination should not only concentrate on evaluating the lens opacity but the other ocular structures as well (eg, conjunctiva, cornea, iris, anterior chamber).
o Corneal thickness and the presence of corneal opacities, such as corneal guttata, must be checked carefully.
o Appearance of the lens must be noted meticulously before and after pupillary dilation.
o The visual significance of oil droplet nuclear cataracts and small posterior subcapsular cataracts is evaluated best with a normal-sized pupil to determine if the visual axis is obscured. However, exfoliation syndrome is appreciated with the pupil dilated, revealing exfoliative material on the anterior lens capsule.
o After dilation, nuclear size and brunescence as indicators of cataract density can be determined prior to phacoemulsification surgery. The lens position and integrity of the zonular fibers also should be checked because lens subluxation may indicate previous eye trauma, metabolic disorders, or hypermature cataracts.
* The importance of direct and indirect ophthalmoscopy in evaluating the integrity of the posterior pole must be underscored. Optic nerve and retinal problems may account for the visual disturbance experienced by the patient. Furthermore, the prognosis after lens extraction is affected significantly by detection of pathologies in the posterior pole preoperatively (eg, macular edema, age-related macular degeneration).