Which sequence best describes how cataracts can result in uveitis?

Which sequence best describes how cataracts can result in uveitis?

• A. Encapsulated lens fibers prior to birth → disruption of lens fibers → leakage into aqueous humor → immune reaction causing uveitis
• B. Lens proteins never leak; uveitis is unrelated to cataracts
• C. Leakage of lens proteins only after extraction leads to uveitis
• D. Uveitis causes cataract formation due to lens protein leakage

Answer: (A)

When lens proteins escape into the front chamber, they can trigger an immune reaction in the eye, leading to uveitis. Lens proteins are normally hidden from the immune system; if the capsule or lens fibers are disrupted—something that can happen with congenital cataracts or injury—these proteins leak into the aqueous humor. The immune system then sees them as foreign and mounts an inflammatory response in the uvea, causing uveitis. This sequence describes phacoantigenic (phacogenic) uveitis, where immune-mediated inflammation follows leakage of lens proteins. The other ideas miss this link: uveitis can be related to cataracts and can occur without extraction; leakage can happen with congenital or traumatic rupture, not only after surgery; and uveitis does not typically cause cataracts in the order implied by the reversed sequence.

When lens proteins escape into the front chamber, they can trigger an immune reaction in the eye, leading to uveitis. Lens proteins are normally hidden from the immune system; if the capsule or lens fibers are disrupted—something that can happen with congenital cataracts or injury—these proteins leak into the aqueous humor. The immune system then sees them as foreign and mounts an inflammatory response in the uvea, causing uveitis. This sequence describes phacoantigenic (phacogenic) uveitis, where immune-mediated inflammation follows leakage of lens proteins.

The other ideas miss this link: uveitis can be related to cataracts and can occur without extraction; leakage can happen with congenital or traumatic rupture, not only after surgery; and uveitis does not typically cause cataracts in the order implied by the reversed sequence.