Senile Cataract (Age-Related Cataract) Clinical Presentation

Updated: Mar 02, 2021
  • Author: Vicente Victor Dizon Ocampo, Jr, MD; Chief Editor: Andrew A Dahl, MD, FACS  more...
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Presentation

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 senile 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

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.

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.

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

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 debilitating glare with oncoming headlights at night.

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

The progression of cataracts may frequently increase the dioptric 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.

Typically, myopic shift and second sight are not seen in cortical and posterior subcapsular cataracts. Furthermore, asymmetric development of lens-induced myopia may result in significant symptomatic anisometropia that may itself require surgical management.

Monocular diplopia

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.

Such a phenomenon, which some call “lens within a lens phenomenon,” may lead to monocular diplopia that is not correctable with spectacles, prisms, or contact lenses.

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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. Whether or not the patient complains of glare, visual acuity should be tested in a brightly lit room or with one of the many commercially available glare-testing devices, such as the brightness acuity tester (BAT). Contrast sensitivity may also be checked, especially if the history points to a possible problem.

Examination of the ocular adnexa and intraocular structures may also provide clues to the patient's disease and eventual visual prognosis.

A very important test is the swinging flashlight test, which is used to detect a Marcus Gunn pupil or relative afferent pupillary defect (RAPD), indicative of optic nerve lesions or severe diffuse retinal involvement. A patient with a RAPD and a cataract is expected to have a very guarded visual prognosis, even after uncomplicated cataract extraction.

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, a careful history regarding visual acuity in each eye during childhood, checking for problems in ocular motility in all directions of gaze, as well as anisometropia, is important to rule out any other amblyogenic 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). Corneal thickness and the presence of corneal opacities, such as corneal guttate, must be checked carefully. Appearance of the lens must be noted meticulously before and after pupillary dilation.

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 best appreciated with the pupil dilated, revealing exfoliative material on the anterior lens capsule, as well as the pupillary margin, trabecular meshwork, and other intraocular structures.

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, antecedent ocular surgery, 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 preoperative detection of pathologies in the posterior pole (eg, macular edema, retinal dystrophy, optic atrophy, severe glaucomatous cupping, age-related macular degeneration) and in the retinal periphery (eg, retinal breaks or extensive vitreoretinal traction).

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Causes

Numerous studies have been conducted to identify risk factors for development of senile cataracts. Various culprits have been implicated, including environmental conditions, systemic diseases, UV exposure, diet, and age. [14, 15]

West and Valmadrid stated that age-related cataract is a multifactorial disease with different risk factors associated with each of the different cataract types. [16] In addition, they stated that cortical and posterior subcapsular cataracts were related closely to environmental stresses, such as UV exposure, diabetes, and drug ingestion. However, nuclear cataracts seem to have a correlation with smoking. Alcohol use has been associated with all cataract types.

A similar analysis was completed by Miglior et al. [17] They found that cortical cataracts were associated with the presence of diabetes for more than 5 years and increased serum potassium and sodium levels. A history of surgery under general anesthesia and the use of sedative drugs were associated with reduced risks of senile cortical cataracts. Posterior subcapsular cataracts were associated with steroid use and diabetes, while nuclear cataracts had significant correlations with calcitonin and milk intake. Mixed cataracts were linked with a history of surgery under general anesthesia.

In a population-based, longitudinal study of 3471 Latinos with 4 years of follow-up, Richter et al found that independent risk factors for incident nuclear-only lens opacities included older age, current smoking, and the presence of diabetes. Risk factors for cortical-only lens opacities included older age and having diabetes at baseline. Female gender was a risk factor for posterior subcapsular-only lens opacities. Presence of diabetes at baseline and older age were risk factors for mixed lens opacities. [18]

Systemic diseases and senile cataract

Senile cataracts have been associated with numerous systemic illnesses, to include the following: cholelithiasis, allergy, pneumonia, coronary disease and cardiac insufficiency, hypotension, hypertension, mental retardation, and diabetes.

Systemic hypertension was found to significantly increase the risk for posterior subcapsular cataracts. In a related study by Jahn et al, hypertriglyceridemia, hyperglycemia, and obesity were found to favor the formation of posterior subcapsular cataracts at an early age. [19]

A possible pathway for the role of hypertension and glaucoma in senile cataract formation was proposed with induced changes in the protein conformational structures in the lens capsules, subsequently causing alterations in membrane transport and permeability of ions, and, finally, increasing intraocular pressure resulting in the exacerbation of cataract formation.

UV light and senile cataract

The association of UV light and development of senile cataract has generated much interest. One hypothesis implies that senile cataracts, particularly cortical opacities, may be the result of thermal damage to the lens.

An animal model by Al-Ghadyan and Cotlier documented an increase in the temperature of the posterior chamber and lens of rabbits after exposure to sunlight due to an ambient temperature effect through the cornea and to increased body temperature. [20]

In related studies, people living in areas with greater UV exposure were more likely to develop senile cataracts and to develop them earlier than people residing in places with less UV exposure.

Other risk factors

Significant associations with senile cataract were noted with increasing age, female sex, social class, and myopia. Consistent evidence from the study of West and Valmadrid suggested that the prevalence of all cataract types was lower among those with higher education. [16] Workers exposed to infrared radiation also were found to have a higher incidence of senile cataract development.

Although myopia has been implicated as a risk factor, it was shown that persons with myopia who had worn eyeglasses for at least 20 years underwent cataract extraction at a significantly older age than emmetropes, implying a protective effect of the eyeglasses to solar UV radiation.

The role of nutritional deficiencies in senile cataract has not been proven or established. However, a high intake of the 18-carbon polyunsaturated fatty acids linoleic acid and linolenic acid reportedly may result in an increased risk of developing age-related nuclear opacity.

In the Blue Mountains Eye Study, pseudoexfoliation increased the risk of cataract and subsequent cataract surgery. [21]

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