Apraclonidine 1% is instilled immediately before and after argon laser trabeculoplasty. Its main purpose in this setting, and the reason it is rarely used for long-term glaucoma control, are respectively:

• A Prevention of post-laser IOP spikes; tachyphylaxis within weeks ✓
• B Prevention of post-laser inflammation; permanent iris depigmentation
• C Prophylaxis against endophthalmitis; corneal decompensation
• D Reduction of laser energy requirement; irreversible miosis

Explanation

Apraclonidine, an alpha-2 adrenergic agonist, reduces aqueous secretion and prevents the transient IOP rise seen in a minority of eyes after anterior segment laser procedures such as ALT and Nd:YAG iridotomy or capsulotomy. Its effectiveness wanes over weeks because of tachyphylaxis, and local allergic reactions are frequent, so brimonidine, which shows less tachyphylaxis, is preferred for chronic therapy. Apraclonidine has no anti-inflammatory or antimicrobial role.

Reference: Katzung's Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.