‘Unstable’ clear corneal wound may allow entry of pathogens
A retrospective case series identified four cases of acute postoperative endophthalmitis following temporal clear corneal phacoemulsification performed with intravitreal administration of triamcinolone and moxifloxacin.
Of approximately 2,000 cataract surgeries performed over a 15-month period, the four patients, who all underwent uneventful surgeries with topical anesthesia and implantation of a one-piece acrylic posterior chamber IOL in the capsular bag, demonstrated onset of symptoms between 3 and 14 days postoperatively.
“Because a clear corneal wound might remain unstable for up to 1 week postoperatively, bacteria could enter the eye late because of the valve-like nature of a clear corneal wound,” the study authors wrote.
The study suggests that 200 µg of intravitreal moxifloxacin administered in a “dropless” approach in these cases might not be suitable for preventing postoperative endophthalmitis, Kamal Kishore, MD, a study co-author, told Healio.com/OSN. Each 0.2 mL of the injection yields a total dose of 3 mg of triamcinolone and 200 µg of moxifloxacin. The four patients received only the intravitreal injection and no other antibiotics or steroids either preoperatively or postoperatively.
“First, coagulase-negative staphylococci, the most common causative organisms for [postoperative endophthalmitis], are increasingly resistant to moxifloxacin, with resistance rates approaching 60% in recent studies. Second, the 200 µg dose of moxifloxacin in the ‘dropless’ approach is considerably less than the 500 µg intravitreal dose used previously for the treatment of endophthalmitis, and third, moxifloxacin, being a highly lipophilic compound, has a very short half-life of 1.7 hours in the vitreous cavity,” Kishore said.
After 14 hours, the dropless approach may not provide adequate prophylaxis against susceptible organisms through the period when the eye is at risk, Kishore said.
All four eyes responded to treatment, resolving to corrected distance visual acuity of 20/40 in three eyes and 20/400 in one eye, which was attributed to pre-existing atrophic age-related macular degeneration. – by Robert Linnehan
Disclosures: The authors report no relevant financial disclosures.