After an Extra capsular cataract extraction, spectacles can be prescribed at
First, I need to recall the procedure of extracapsular cataract extraction (ECCE). In ECCE, the cataractous lens is removed through an incision, leaving the posterior capsule intact. Often, an intraocular lens (IOL) is implanted during the same procedure to restore vision. If an IOL is placed, the patient might not need spectacles immediately, but if not, they would require them.
The question is about when to prescribe spectacles. If an IOL is implanted, the patient's refractive error is corrected, so spectacles might not be needed. However, if the IOL isn't placed, the patient would be aphakic and would need strong convex lenses. But the timing of when spectacles can be prescribed depends on the healing process. Immediately after surgery, the eye is swollen and the cornea is edematous, which can affect refraction. Therefore, prescribing spectacles too soon might lead to incorrect prescriptions.
Typically, the corneal edema subsides within 2-3 weeks. So, after that period, once the eye has stabilized, an accurate refraction can be performed. Therefore, the correct answer would be around 2-3 weeks post-surgery, allowing the cornea to heal and the eye to stabilize before prescribing spectacles.
Now, looking at the options (though they are missing), the correct answer would be the one that states 2-3 weeks. The other options might suggest earlier (like a few days) or later (like 6 weeks) times, which would be incorrect. Also, if an IOL was implanted, the need for spectacles might be reduced, but the question is about when to prescribe them, not whether they're needed. So regardless of IOL placement, the timing for accurate refraction is key.
Clinical pearl: After ECCE, wait until corneal edema resolves (2-3 weeks) before prescribing spectacles to ensure accurate refraction. This is a high-yield fact for exams.
**Core Concept**
Post-extracapsular cataract extraction (ECCE), corneal edema and surgical inflammation initially distort refraction. Prescribing spectacles requires waiting until the cornea stabilizes to ensure accurate refractive correction.
**Why the Correct Answer is Right**
After ECCE, corneal edema peaks within 24–48 hours and resolves in 2–3 weeks. Premature refraction risks overcorrection due to unstable corneal shape. Spectacles are prescribed once inflammation subsides, typically 2–3 weeks post-surgery, allowing reliable visual acuity assessment. This aligns with the healing timeline of epithelialization and endothelial recovery.
**Why Each Wrong Option is Incorrect**
**Option A (Immediately post-op):** Corneal edema and inflammation distort refraction; early spectacle use causes myopic shift and poor vision.
**Option B (1 week post-op):** Corneal swelling and healing are still active; refraction remains unstable.
**Option D (1 month post-op):** Delayed beyond necessary; patients may