TABLE 58 Types of Cataracts

Localization and Appearance

Comments

Congenital (formed in utero or during infancy)

1. Polar Anterior or posterior (axial area) of the lens capsule; appears as fine white dots

2. Zonular (Lamellar)

Gray round opacities surrounded by a dark, clear zone; can occur in pre- or postnatal development

Presenile (formed during early childhood/young adulthood)

1. Coronary Wreath of opacities in periphery of cortex

Senile (appearance generally following ages 30 to 40)

1. Nuclear Sclerosis (NS) Lens nucleus normally hardens with age;

index of refraction of nucleus increases, inducing myopia; the world appears "yellower" as the lens acts as a filter for blue wavelengths

2. Cortical (Cort)

3. Posterior Subcapsular (PSC)

Cortex absorbs water and swells, creating radial opacities (waterclefts); can progress to form cortical spokes

Opacity on the posterior capsular face; appears along optical axis or just inferiorly

Toxic or Complicated

1. Steriods

3. Infrared (glass blower's)

4. Copper (chalasis)

5. Iron (siderosis)

7. Chronic inflammation

Typically PSC types Anterior subcapsular opacities Anterior lens capsule exfoliation Sunflower cataract in subcapsular cortex Brownish subcapsular opacity PSC type PSC type

Usually hereditary; commonly remains stationary throughout life; visual acuity is only affected if opacity is large

Hereditary; usually occurs bilaterally; has tendency to increase in size during 3rd to 5th decade

Appears in puberty; inherited; need widely dilated pupil to view, vision rarely affected

Myopic changes in Rx ("second sight"); slow, gradual reduction in vision

Can occur in combination with other senile lens changes

Appears as dark irregularity in retroillumination; glare, especially at night, is common complaint; this type can be most visually impairing due to its axial placement and density

*Adapted with permission from Nemeth SC, Shea CA. Medical Sciences for the Ophthalmic Assistant. rev. ed. Thorofare, NJ; SLACK Incorporated; 1991.

TABLE 5-9

Grading Cortical Cataracts

Feature

Grade

Gray lines, dots, and flakes aligned along the cortical fibers in periphery; visible in oblique direct illumination.

1+ (early or incipient)

Opaque spokes, anterior chamber may be shallower than normal for patient

2+ (immature or intumescent)

Cortex opaque up to capsule, anterior chamber may again be normal depth

3+ (mature)

Lens is smaller, wrinkly capsule, nucleus may float in liquefied cortex

4+ (hypermature)

Figure 5-32. Nuclear sclerotic cataract. (Photo by Val Sanders.)

so peripheral that they are only seen when dilated. Eventually cortex may liquefy and nucleus "floats".

Doc: note, grade 1+ to 4+ (Table 5-9), describe location by the clock, note if spoke extends into the optic zone, draw

• intraocular lens (IOL) - plastic implant inserted during or after cataract surgery. If the lens is in front of the iris, it is an AC lens. If the lens is AC but clipped into the iris (with pegs or clips), it is an iris plane. An IOL behind the iris and pupil is a PC lens. The lens should be centered, but rarely they slip or drift (this is best seen after dilation).

Doc: note according to location (AC, iris plane, PC), type (if known), centration (note, draw)

• nuclear sclerosis (Figure 5-32) - generalized yellowing of the lens. If the color is more brownish, it is termed "brunescent." If totally white and opaque, it is "mature."

Doc: note, grade 1+ to 4+ (Table 5-10), note color abnormalities

Doc: note, describe (color, size, location), draw

• posterior subcapsular cataract (Figure 5-33) - whitish opacity on the far back part of the lens. Can be hard to see (especially if you are trying to see through nuclear sclerosis). May be best viewed in retroillumination.

TABLE 5-10 Grading Nuclear Sclerotic Cataracts

Lens Color

Grade

Gray-blue (normal)

0

Yellow overtone

1+

Light amber

2+

Reddish brown

3+

Brown or black, opaque,

4+

no fundus reflection

TABLE 5-11

Grading Posterior Subcapsular Cataracts

Feature

Grade

Optical irregularity on posterior capsule; visible

1+

only on retroillumination

Small, white fleck

2+ (early)

Enlarged plaque; round or irregular borders

3+ (moderate)

Opaque plaque

4+ (advanced)

• precipitates (Figure 5-34) - brown dots, or may be a fine brown weblike deposit on IOL. Doc: note, grade 1+ to 4+

• Pseudoexfoliation (Figure 5-35) - gray dandrufflike flecks on lens (may also appear on pupillary margin).

Doc: note, grade 1+ to 4+, give location

• subluxation - the lens has slipped out of place partially or entirely. Doc: note, describe, draw

Figure 5-34. Precipitates on an IOL implant. (Photo by Val Sanders.)

Figure 5-35. Pseudoexfoliation. (Photo by Val Sanders.)

Figure 5-34. Precipitates on an IOL implant. (Photo by Val Sanders.)

• vacuoles - look like little bubbles in the lens.

Doc: note, draw

+1 0

Responses

  • Cirillo
    How to notice a posterior subcapsular cataract in a slit lamp?
    2 months ago

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