Bacterial Contaminants of Bandage Contact Lenses Used After Laser Subepithelial or Photorefractive Keratectomy

Microbial contamination of therapeutic contact lenses after photorefractive keratectomy: a prospective analysis

PURPOSE

The objective of this study was to examine bacterial contamination in therapeutic contact lenses (TCLs) utilized following photorefractive keratectomy (PRK) and to identify factors correlated to positive culture outcomes.

METHODS

This prospective study comprised 120 eyes from 60 patients who underwent bilateral PRK surgery at Farabi Eye Hospital in 2022. TCLs, applied postoperatively, were collected between the fifth and seventh days, placed in sterile containers with culture media, and analyzed for microbial growth. The documentation included patient demographic information, refractive status, preoperative conditions, culture results, and antibiotic susceptibility data.

RESULTS

The results indicated microbial growth was detected in seven lenses, which accounts for 5.8% of the total number of lenses (120 TCLs). Coagulase-negative staphylococci (CoNS) (4 lenses, 2 methicillin-resistant staphylococci (MRS)), Escherichia coli (E. coli) (1 lens), diphtheroid (1 lens), and micrococcus species (1 lens) were the isolated organisms. The patients did not experience any instances of microbial keratitis during the study period. Patients with positive cultures demonstrated a significantly higher mean age (35.00 ± 7.09 years, P-value = 0.036). No significant gender disparities were identified (P-value = 0.263).

CONCLUSION

The incidence of microbial contamination in postoperative TCLs following PRK was minimal, with no occurrence of microbial keratitis. Older ages correlated with positive culture outcomes, highlighting the necessity for customized postoperative care approaches.

Ocular Surface Microbial Flora and Photorefractive Keratectomy

Purpose. To assess the influence of photorefractive keratectomy (PRK) on ocular surface microbial flora. Methods. A prospective study was conducted on patients who underwent PRK. The samples were taken from the inferior conjunctival fornix using a sterile swab, immediately before surgery, and then within three months following the PRK. The samples were tested using three culture mediums including blood agar, chocolate agar, and eosin methylene blue agar. Results. Thirty-five eyes of 35 patients including 19 females (54.3%) with a mean age of 24 ± 3.2 years were enrolled. The culture-positive rate was 15/35 eyes (42.9%) preoperative and 17/35 (48.6%) postoperative samples ( $P=0.47$ ). The most common microorganisms isolated from preoperative samples were coagulase-negative Staphylococcus (CoNS) spp. in 14 (40%) samples, followed by Streptococcus spp. in 2 (5.7%), and Staphylococcus aureus in one (2.9%). Postoperative microorganisms isolated from conjunctival samples were CoNS spp. in 15 (42.9%), Streptococcus spp. in 3 (8.6%), and Staphylococcus aureus in one (2.9%), and Corynebacterium spp. in one (2.9%). Conclusion. This study indicated that there is not any remarkable difference in microorganisms isolated from conjunctival samples three months after PRK.

CLEAR - Medical use of contact lenses

The medical use of contact lenses is a solution for many complex ocular conditions, including high refractive error, irregular astigmatism, primary and secondary corneal ectasia, disfiguring disease, and ocular surface disease. The development of highly oxygen permeable soft and rigid materials has extended the suitability of contact lenses for such applications. There is consistent evidence that bandage soft contact lenses, particularly silicone hydrogel lenses, improve epithelial healing and reduce pain in persistent epithelial defects, after trauma or surgery, and in corneal dystrophies. Drug delivery applications of contact lens hold promise for improving topical therapy. Modern scleral lens practice has achieved great success for both visual rehabilitation and therapeutic applications, including those requiring retention of a tear reservoir or protection from an adverse environment. This report offers a practical and relevant summary of the current evidence for the medical use of contact lenses for all eye care professionals including optometrists, ophthalmologists, opticians, and orthoptists. Topics covered include indications for use in both acute and chronic conditions, lens selection, patient selection, wear and care regimens, and recommended aftercare schedules. Prevention, presentation, and management of complications of medical use are reviewed.

Micrococcus keratitis following microkeratome-assisted laser in situ keratomileusis

We hereby report a case of infectious keratitis after laser in situ keratomileusis (LASIK) caused by Micrococcus luteus, a commensal, managed successfully in a nonimmunocompromised individual. A 25-year-old healthy male underwent uneventful bilateral simultaneous LASIK for myopia using disposable blades. Postoperatively, topical antibiotic and steroids were advised; he discontinued antibiotic on his own after using for a day. On the 5^th postoperative day, he had pain, redness, decreased vision, and white spot in the left eye (LE) for 1-day duration. Uncorrected visual acuity (UCVA) of LE reduced to 20/80 from postoperative 20/20. Slit-lamp biomicroscopy revealed tiny infiltrate in the interface with reticular haze in the flap and stroma. Gram-positive cocci in pairs and tetrads were found on corneal smears that were collected after lifting the flap from infiltrate, stromal bed, and undersurface of the flap. M. luteus was isolated on culture. The infiltrate resolved with scarring with intensive topical antibiotics. UCVA was 20/25. To the best of our knowledge, this is a first case report of post-LASIK infectious keratitis caused by M. luteus.

Microbiological Evaluation of Bandage Soft Contact Lenses Used in Management of Persistent Corneal Epithelial Defects

PURPOSE

To investigate the rate and agents of contamination in bandage soft contact lenses fitted for management of persistent corneal epithelial defects.

METHODS

This prospective comparative case series enrolled 57 consecutive eyes fitted with bandage contact lenses for treatment of persistent corneal epithelial defects. The lenses were collected at the time of epithelial closure or when it was necessary to exchange contact lenses and were immediately placed in sterile tubes containing an enriched thioglycolate liquid medium. When contamination of the contact lens was detected, the microorganism was cultured in different media and identified based on various tests. All isolates were tested for susceptibility to various antibiotics. Univariate analyses were used to evaluate the influence of different variables (duration of contact lens use, use of topical corticosteroids, presence of blepharitis, contact lens deposits, and presence of sutures) on bandage contact lens contamination.

RESULTS

Seventeen of the contact lenses (29.8%) were contaminated. The most commonly isolated pathogen was Staphylococcus epidermidis (n = 10), followed by Enterobacter cloacae (n = 3), Staphylococcus aureus (n = 1), Streptococcus viridans (n = 1), and Alcaligenes spp. (n = 1). One contact lens yielded a mixed infection with E. cloacae and Candida spp. Infectious keratitis was not observed in any eyes. Correlations between contact lens contamination and patient- and lens-related variables were not statistically significant.

CONCLUSIONS

Most bandage contact lenses (70.2%) used for treatment of persistent corneal epithelial defects did not show bacterial growth. Staphylococcus epidermidis was the most common microorganism isolated from the contaminated contact lenses.

Evaluation of the safety and efficacy of therapeutic bandage contact lenses on post-cataract surgery patients

AIM

To evaluate the safety of therapeutic bandage contact lens for post-cataract surgery patients and to illustrate its efficacy on post-operative comfort and tear-film stability.

METHODS

A total of 40 participants were recruited and randomly divided into two groups. Group one was instructed to wear bandage contact lenses for a week and use antibiotic eye drops for a month since the first day after surgery. Group two received sub-conjunctival injection of tobramycin and was asked to wear eye pads on the first day after surgery and then were instructed to use antibiotic eye drops as the first group did. Ocular surface disease index (OSDI) questionnaire, slit-lamp microscope examination of tear break-up time (TBUT), corneal fluorescein score (CFS), tear meniscus height (TMH) together with anterior segment optical coherence tomography (AS-OCT) and corneal topography were evaluated preoperatively and postoperatively.

RESULTS

The subjective feeling (P=0.004), TBUT (P<0.001) and TMH (P=0.02) post-surgery had improved in patients who used bandage contact lenses compared with those who did not at 1wk post-surgery. Until three month postoperatively, the comfort degree (P=0.004) and TMH (P=0.01) of group two were still worse than group one. Moreover, TBUT (P<0.001) and CFS (P=0.004) of the group with eye pads got worse than the results before, whereas the group with bandage contact lenses recovered to normal. None of these patients had infections or other complications.

CONCLUSION

Wearing therapeutic bandage contact lens after cataract surgery, compared with traditional eye-pads, is a safe method to improve tear-film stability and reduce post-operative discomfort without hindering corneal incision recovery.

Nasal and conjunctival screening prior to refractive surgery: an observational and cross-sectional study

OBJECTIVES

To investigate bacterial flora of clinically healthy conjunctiva and nasal cavity among patients prior to refractive surgery, as well as the characteristics of patients with methicillin-resistant Staphylococcus aureus (MRSA) colonisation.

DESIGN

Observational and cross-sectional study.

SETTING

A single-centre study in Japan.

PARTICIPANTS

120 consecutive patients pre-refractive surgery.

PRIMARY AND SECONDARY OUTCOME MEASURES METHODS

Samples were obtained from the right conjunctival sac and the nasal cavity of 120 consecutive patients prior to refractive surgery and were then measured for the levels of the minimum inhibitory concentration (MIC) of antibiotics. Patients were interviewed regarding their occupation, family living situation and any personal history of atopic dermatitis, asthma, smoking or contact lens wear.

RESULTS

Propionibacterium acnes (P. acnes) (32.5%) and Staphylococcus epidermidis (4.2%) were detected from the conjunctival sac. S. epidermidis was the most commonly isolated (68.3%) in the nasal cavity. Of the 30 patients (25.0%) with colonisation by S. aureus, 2 patients, both of whom were healthcare workers with atopic dermatitis, were found to be positive for MRSA in the nasal cavity. A history of contact lens wear, asthma or smoking, as well as patient gender and age, was not associated with MRSA colonisation.

CONCLUSIONS

There were only 2 patients who were colonised with MRSA, both of whom were healthcare workers with atopic dermatitis. P. acnes was predominantly found in the conjunctival sac. Further study is needed to investigate the involvement between nasal and conjunctival flora, and risk factors for infectious complications.

Post-photorefractive keratectomy contact lens microbiological findings of individuals who work in a hospital environment

OBJECTIVE

To describe the microbiological findings from bandage contact lenses in patients who work in a hospital environment submitted to photorefractive keratectomy (PRK).

METHODS

This prospective comparative case series enrolled 43 eyes of 22 volunteers (28.05 ± 3.50 years). Fourteen individuals (n = 27) were health care professionals who work in health care facilities or community physician's offices. Eight individuals (n = 16) were patients who do not work in hospital environment. Photorefractive keratectomy was performed using standard technique, and a silicone hydrogel bandage contact lens was placed on the cornea and evaluated for adequate fit. Seven days after surgery, the bandage lenses were removed and imprinted in the following culture media: blood agar, chocolate agar, anaerobic-selective agar, and Sabouraud agar. When microbial growth was detected, the microorganism was identified, colony-forming units were quantified, and morphology and Gram-staining properties were analyzed. All isolates were tested for susceptibility to various antibiotics. Significance was assessed by Fisher exact test.

RESULTS

Microbial growth was detected in 16.27% of all contact lenses samples. No fungi or anaerobes were found. Microbial growth was only observed in bandage lenses removed from patients who work in hospital environments. Most microorganisms found were sensitive to all antibiotics tested.

CONCLUSION

These results suggest that working in hospital environments increase contamination of the contact lenses after PRK.

Microbiologic Examination of Bandage Contact Lenses Used after Corneal Collagen Cross-linking Treatment

PURPOSE

To investigate the agents of bacterial contamination of contact lenses after corneal collagen cross-linking (CCL), and to present the possible changes of ocular flora after riboflavin/ultraviolet A.

METHODS

Seventy-two contact lenses of patients who underwent CCL and 41 contact lenses of patients who underwent photorefractive keratectomy (PRK) as control group were enrolled to the study. After 48 h of incubation, broth culture media was transferred to plates. Samples were accepted as positive if one or more colony-forming units were shown.

RESULTS

There were positive cultures in 12 (16.7%) contact lenses in the CCL group and 5 (12.2%) had positive cultures in PRK group. Coagulase-negative staphlycocci (CNS) were the most frequent microorganism. Alpha hemolytic streptococci and Diphteroid spp. were the other isolated microorganisms.

CONCLUSIONS

Bacterial colonization can occur during and early after the CCL procedure in epithelial healing. To prevent corneal infections after the treatment, prophylactic antibiotics should be prescribed.

Iris rubeosis and hyphema caused by chemical injury due to household detergent

We report an unusual case of iris rubeosis and hyphema caused by chemical injury due to household detergent. A 74-year-old man with a 15-year history of diabetes mellitus was refilling a container with household detergent at home. He splashed the detergent in his eyes. Slit-lamp examination revealed extensive epithelial damage to the left eye, leading to a persistent corneal epithelial defect. We used a bandage soft contact lens with levofloxacin eye drops as concomitant therapy in order to promote healing. However, a strain of fluoroquinolone-resistant Corynebacterium colonized the eye, so that the corneal ulcer eventually became severe. Use of the bandage soft contact lens was discontinued. His antimicrobial agent was changed to cefmenoxime, a drug to which fluoroquinolone-resistant Corynebacterium is sensitive, and topical instillation of autologous serum subsequently promoted improvement of the ulcer. On day 38 after injury, iris rubeosis led to hyphema and ghost cell glaucoma. With improvement of his corneal epithelial defect, the iris rubeosis and hyphema regressed and his visual acuity improved to 20/25 on the left eye. To the best of our knowledge, this is the first report of a case resulting in severe complications due to chemical injury by a neutral detergent. Ophthalmologists should be aware that corneal epithelial damage may become prolonged in elderly patients with diabetes, and unexpectedly severe when wearing bandage soft contact lens, with infection of Corynebacterium resistant to fluoroquinolones, even if the chemical agent is a neutral detergent.