Cause of blindness in trachoma ?
**Core Concept**
Trachoma is a chronic granulomatous bacterial infection of the eye caused by Chlamydia trachomatis. The disease leads to inflammation of the conjunctiva and cornea, resulting in potential blindness if left untreated.
**Why the Correct Answer is Right**
The cause of blindness in trachoma is due to the formation of scarring and subsequent opacification of the cornea, known as trachomatous trichiasis. This occurs when the repeated inflammation and scarring of the conjunctiva cause the eyelashes to turn inward, rubbing against the cornea and leading to its opacification. The opacification of the cornea impairs vision, ultimately causing blindness. The scarring and opacification are a result of the body's immune response to the chronic infection.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not directly relate to the cause of blindness in trachoma. While conjunctivitis is a symptom of trachoma, it is not the direct cause of blindness.
**Option B:** This option is incorrect because it is a symptom of trachoma, not the cause of blindness. The presence of lymphoid follicles is an indicator of the body's immune response to the infection, but it is not the direct cause of blindness.
**Option C:** This option is incorrect because it is a characteristic of the infectious agent, Chlamydia trachomatis, but not the direct cause of blindness.
**Clinical Pearl / High-Yield Fact**
Trachoma is a major cause of preventable blindness worldwide, particularly in areas with poor sanitation and hygiene. The World Health Organization (WHO) has launched a global initiative to eliminate trachoma by 2025 through the SAFE strategy, which includes surgery, antibiotic treatment, facial cleanliness, and environmental improvement.
**Correct Answer:** D.