ESCRS - FP10.06 - Topical Meropenem As An Alternative To Moxifloxacin For Pseudomonas Aeruginosa Keratitis: A Comparative Experimental Study

Topical Meropenem As An Alternative To Moxifloxacin For Pseudomonas Aeruginosa Keratitis: A Comparative Experimental Study

Published 2026 - 44th Congress of the ESCRS

Reference: FP10.06 | Type: Free paper | DOI: 10.82333/rvrv-5p12

Authors: Dr Rukiye Kilic Ucgul* 1 , A/Prof. Muhammet Guzel Kurtoglu 2 , A/Prof. Abdulgani Kaymaz 3 , A/Prof. Mustafa Behcet 2

1Ophthalmology,Ulucanlar Eye Training and Research Hospital,Ankara,Türkiye, 2Microbiology,Bolu Abant Izzet Baysal University,Bolu,Türkiye, 3Ophthalmology,Bolu Abant Izzet Baysal University,Bolu,Türkiye

Purpose

To investigate whether topical meropenem can provide comparable early clinical and microbiological efficacy to moxifloxacin in the treatment of Pseudomonas aeruginosa keratitis. In light of the rising global concern of fluoroquinolone resistance, this study aims to evaluate meropenem as a potential alternative therapeutic option using a standardized experimental rabbit model, assessing both infection severity and bacterial load reduction to determine its viability in resistant or treatment-refractory cases.

Setting

This controlled experimental study was conducted at Bolu Abant Izzet Baysal University. The study was performed in a laboratory setting using a standardized rabbit model of Pseudomonas aeruginosa keratitis under institutional ethical approval and in accordance with ARVO guidelines.

 
 

Methods

Experimental keratitis was induced in 18 New Zealand white rabbits by intrastromal injection of Pseudomonas aeruginosa (ATCC 27853). After 48 hours, animals were randomized into three groups (n=6 each): topical saline (control), 5 mg/mL meropenem, or 5 mg/mL moxifloxacin. Treatments were administered over 48 hours using a standardized intensive dosing regimen. Clinical severity was graded using an eight-parameter composite scoring system. Following euthanasia, corneal tissues were harvested for quantitative microbiological analysis (log₁₀ CFU/g) and MIC determination.

 

Results

Compared to baseline, total clinical scores significantly increased in the control group (p<0.001), while no significant changes were observed in the meropenem (p=0.280) or moxifloxacin (p=0.509) groups. Post-treatment scores were significantly lower in both antibiotic groups compared to control (p < 0.001). Clinical parameters such as iritis, epithelial erosion, corneal infiltrate, and corneal edema were significantly improved in treated groups (p < 0.05). Quantitative bacterial analysis revealed the highest bacterial load in the control group (5.30 ± 0.23 log₁₀ CFU/g), followed by meropenem (3.00 ± 1.39) and moxifloxacin (2.67 ± 0.63) groups. Both treatment groups showed significantly lower CFU values compared to control (p=0.001).

Conclusions

Topical meropenem demonstrated clinical and microbiological efficacy comparable to moxifloxacin in the early treatment of Pseudomonas aeruginosa keratitis in this experimental model. Both agents significantly limited disease progression and reduced bacterial load compared to control, with no observed safety concerns. Given the increasing prevalence of fluoroquinolone resistance, meropenem may represent a promising alternative therapeutic option, particularly in resistant or treatment-refractory cases.