Multivariate Analysis of Factors Associated With Contact Lens Induced Peripheral Ulcers (CLPU) in Extended Soft Contact Lens Wearers

Abstract

Abstract: : Purpose:Contact Lens induced Peripheral Ulcer (CLPU) is a significant corneal infiltrative response associated with contact lens wear. Its occurrence leads patients to temporarily if not permanently discontinue lens wear and threatens the success of contact lens wear. This study sought to determine factors associated with the occurrence of CLPU. Methods: Data was obtained from 1354 eyes of 677 subjects who participated in Extended Wear (EW) trials involving eyes wearing 6-night weekly replacement low-Dk soft lens or 30-night monthly replacement high-Dk soft lenses, in three one-year clinical trials conducted between Jan-1993 and May-2000, at LV Prasad Eye Institute, India. Seventy-three (73) eyes developed a CLPU were compared to 984 eyes that had no adverse event during the follow-up period. Clinical and microbial data from all scheduled EW visits, as well as data of CLPU cases from scheduled EW visits prior to the event were analyzed. Multivariate logistic regression was used to develop the statistical model. Results:Age and sex were not significantly associated with CLPU. The significant factors associated with CLPU included: Ionic lenses (p<0.001), lens contamination with gram-positive bacteria (p<0.001), tighter fitting high Dk lenses (p=0.004), higher levels of mucin balls (p=0.014), subjective symptoms of tearing (p=0.001) and lower levels of conjunctival redness (p=0.004). Conclusions: The statistical model of CLPU suggests a multi factorial effect with the broad entities being lens factor, lens contamination, mechanical interaction of the lens and subjective differences.

Keywords: contact lens • clinical (human) or epidemiologic studies: ris