Microbiological Examination of Bandage Soft Contact Lenses Used in Laser Refractive Surgery

Results of Fibrin Glue Applied Over the Corneal Surface Immediately After Pterygium Surgery: A Novel Pain Relief Technique

PURPOSE

The aim of this study was to compare the use of fibrin glue on the corneal epitheliectomy site at the end of pterygium surgery versus conventional eye patch regarding pain levels, need for oral analgesic medications, number of days feeling pain, and awakening due to pain after surgery.

METHODS

Forty-eight eyes of 24 patients with bilateral primary pterygium were included in this prospective, randomized, double-masked controlled trial. Each eye of the same patient was randomized to the intervention or control group. The intervention group received 2 drops of fibrin glue in the epitheliectomy site at the end of surgery and an eye patch, whereas the control group was only received an eye patch. Patients returned on the first and seventh days after surgery. Pain intensity (measured using the visual pain analog scale), need for oral analgesics, the number of days the pain lasted, and quality of sleep were assessed during follow-up visits and compared between groups. Comparison analysis accounted for sex, age, pterygium grading, and comorbidities.

RESULTS

Visual analog pain scale after surgery was significantly lower in eyes receiving fibrin glue (-1.58; 95% confidence interval: -2.84 to -0.32; P = 0.014). In addition, the intervention group presented a 73% lower chance of using oral analgesics (OR: 0.27; 95% confidence interval: 0.07-0.95; P = 0.041). No difference in the awakenings at night was noted ( P = 0.240) nor the mean days of ocular pain in the first week after surgery ( P = 0.474).

CONCLUSIONS

Fibrin glue at the end of pterygium surgery effectively reduces pain and the need for oral analgesics compared with conventional eye patching. This study is the first to describe the results of this strategy.

Post photorefractive keratectomy (PRK) infectious keratitis; six-year experience of a tertiary eye hospital

BACKGROUND/OBJECTIVES

As an essential development in the new century, surface ablation procedures have attracted increasing attention. There exists a concern regarding the risk of infectious keratitis. Hence, we aimed to investigate the rate and predisposing factors of infectious keratitis after photorefractive keratectomy (PRK).

SUBJECTS/METHODS

This retrospective study was designed in two phases. First, the rate of post-PRK keratitis of Farabi Eye Hospital was investigated. In other words, the targeted population was the patients who developed keratitis after performing procedure at Farabi Eye Hospital. In the second phase, all the patients with the diagnosis of post-PRK keratitis were studied regardless of the centre where surgery was performed. Patients with the diagnosis of infectious keratitis between 2014 and 2020 were enrolled and following information was analyzed: demographics, presentation time after surgery, perioperative medications, culture results, risk factors, medical treatment, complications, and final visual acuity.

RESULTS

The total number of PRK procedures in our centre was 24,986 (13,253 patients), in which 6 eyes of 5 patients developed keratitis. Beside these 5 patients, 24 referred patients (24 eyes) from the other centres were enrolled. Finally, a total number of 29 patients (30 eyes) were included. Our analysis revealed that manipulation of contact lens, dry eye, and blepharitis were the essential predisposing factors for keratitis development.

CONCLUSION

The overall post-PRK keratitis occurrence rate of our study was 0.02%. Our observation highlighted the importance of preoperative examination and treatment of the lids and dry eye disease.

Postrefractive infectious keratitis: prevention, diagnosis, management, and prognosis

PURPOSE OF REVIEW

Improve outcomes from an elective procedure by preventing a rare but sight-threatening complication.

RECENT FINDINGS

Advancement in anti-infective prophylaxis, and therefore shift in the causative organism permits better diagnostic and empiric management.

SUMMARY

Infectious keratitis presents in different patterns depending on the refractive procedure. Atypical causative organisms may respond poorly to empiric therapy and impair vision. Therefore, microbial identification is of utmost importance and therapy is adjusted accordingly.

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.

MLST-Based Analysis and Antimicrobial Resistance of Staphylococcus epidermidis from Cases of Sheep Mastitis in Greece

Staphylococcus epidermidis is an important causal agent of ovine mastitis. A literature search indicated a lack of systematic studies of causal agents of the infection by using multi-locus sequence typing (MLST). The objectives were to analyse MLST-based data and evaluate the antimicrobial resistance of S. epidermidis isolates from ovine mastitis in Greece. The database included 1593 isolates from 46 countries: 1215 of human, 195 of environmental and 134 of animal origin, distributed into 949 sequence types (STs) and cumulatively with 450 alleles therein. Among mastitis isolates, bovine isolates were distributed into 36 different STs and ovine ones into 15 STs. The 33 isolates from ovine mastitis in Greece were in 15 different STs, 6 of these (ST677, ST678, ST700, ST 709, ST710, ST711) assigned for the first time; in addition, 5 alleles (65 for arcC, 59 for aroE, 56 and 57 for gtr and 48 for tpiA) were identified for the first time. The spanning tree of these isolates included 15 nodes and 14 edges (i.e., branches). Among these isolates, 19 showed resistance to antimicrobial agents (tetracycline, penicillin, fucidic adic, erythromycin, clindamycin, cefoxitin). Resistance-related genes (tetK, tetT, msrA, tetM, tetS, ermC, mecA) were detected. There was no association between STs and resistance to antimicrobial agents. Isolates with antimicrobial resistance were recovered more often from flocks where hand-milking was practised.

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.

Microbiological study of therapeutic soft contact lenses used in the treatment of recurrent corneal erosion syndrome

OBJECTIVE

To determine the bacteriological spectrum of the removed therapeutic soft contact lenses (TSCLs) and to establish efficacy of prophylactic antibiotics on TSCLs used for 2 weeks for treatment of patients with recurrent corneal erosion syndrome (RCES).

METHODS

This study included idiopathic RCES treated using highly oxygen-permeable silicone hydrogel contact lenses (CLs), and treated 4 times per day with topical tobramycin 3% for 2 weeks. After TSCLs were applied for 2 weeks, the lenses were removed with sterile forceps under which a speculum was inserted, and placed on blood agar with the inner face down. The TSCLs were analyzed for bacterial colonization, and antibiotic susceptibility tests were performed for the isolates, using disk diffusion.

RESULTS

Of the 40 lenses analyzed, 9 (22.5%) yielded positive cultures. Staphylococcus epidermidis was the most commonly isolated microorganism; there were five methicillin-sensitive coagulase-negative staphylococci and two methicillin-resistant coagulase-negative staphylococci. Furthermore, we found two lenses that were colonized by Enterobacter gergoviae and Citrobacter freundii. All cultured bacteria showed intermediate or complete sensitivity to ciprofloxacin, tigecycline, and tobramycin. Despite bacterial colonization in 9 CLs, no clinical signs of infectious keratitis were found in any of the patients with prophylactic topical tobramycin 3%.

CONCLUSIONS

In case of using TSCLs for 2 weeks, tobramycin or ciprofloxacin may be useful as prophylactic topical antibiotics for preventing secondary corneal infections. Considering currently growing incidence of ciprofloxacin-resistant ocular isolates, tobramycin seems to be a reasonable prophylactic topical antibiotic susceptible broad spectrum of bacteria in clinics.

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.

Monitor corneal epithelial healing under bandage contact lens using ultrahigh-resolution optical coherence tomography after pterygium surgery

OBJECTIVE

To monitor corneal epithelial healing under bandage contact lens (BCL) using ultrahigh-resolution optical coherence tomography (UHR-OCT) after pterygium surgery.

METHODS

Thirty-nine eyes of 39 patients undergoing pterygium excision and conjunctival autografting were randomly allocated into 2 groups: 20 eyes were covered with silicone hydrogel BCLs at the end of surgery and 19 eyes served as a control. Ultrahigh-resolution optical coherence tomography scans of the cornea were performed sequentially at 1, 2, and 3 days, and then every other day until the end of re-epithelialization after surgery. Complete epithelial healing was verified with fluorescein staining examination after removal of BCLs. Postsurgery pain was evaluated using the visual analog scale.

RESULTS

All BCLs were successfully fit without any contact lens-related complications. Ultrahigh-resolution optical coherence images clearly revealed the architectural features of postoperative cornea with BCL in situ and showed epithelial healing process. Ultrahigh-resolution optical coherence tomography imaging agreed with the fluorescein staining examinations in detecting corneal epithelial defect. Based on the assessment by UHR-OCT, the average time course of re-epithelialization in the BCL group was 3.9±1.2 days, whereas in the control group, it was 5.7±1.8 days (P=0.001). Visual analog scale scoring showed lower pain levels in the BCL group comparing with the control group at each point of time (all P<0.05).

CONCLUSIONS

Ultrahigh-resolution optical coherence tomography is an excellent tool in monitoring corneal epithelial healing under BCLs and determining the appropriate time for lens removal. Silicone hydrogel BCL is recommended as an adjuvant therapy after pterygium surgery for its efficacy in improving re-epithelialization and postoperative comfort.

Microbiologic study of soft contact lenses after laser subepithelial keratectomy for myopia

PURPOSE

To evaluate the extent and agents of bacterial contamination of bandage disposable soft contact lenses after laser subepithelial keratectomy (LASEK) and to correlate the findings with clinical data.

METHODS

Disposable soft contact lenses were collected from 52 eyes of 26 consecutive patients treated with LASEK for myopia. The patients were treated with a fixed combination of tobramycin and diclofenac until epithelial closure. The lenses were removed on the fourth or fifth postoperative day with sterile forceps and immediately placed in sterile tubes containing culture media brain-heart infusion broth. The lenses were evaluated for microbial colonization.

RESULTS

Of the 52 contact lenses analyzed, six (11.5%) had positive cultures. However, no clinical finding of infection was noted. Isolated microorganisms were coagulase-negative staphylococci (two lenses), Stenotrophomonas maltophilia (two lenses), Acinetobacter species (one lens), and Aeromonas hydrophila (one lens). Except for one case, the microorganisms were sensitive to the administered antibiotic.

CONCLUSIONS

The risk of infectious keratitis after LASEK seems to be low. Except for staphylococci, the isolated microorganisms have not been previously reported to colonize the ocular surface or cause keratitis after refractive surgery. These findings may suggest a changing trend of potentially infectious agents after surface ablation.

Corneal interface contamination during laser in situ keratomileusis

PURPOSE

To measure the rate of corneal interface contamination during laser in situ keratomileusis (LASIK), determine probable sources of the contamination, and evaluate how the cornea reacts to the contamination.

SETTING

Department of Ophthalmology, Baqyatallah Hospital, Baqyatallah University, Tehran, Iran.

METHODS

In this case series, 200 eyes were evaluated for the corneal interface contamination at the end of LASIK. Cultures were taken from the upper and lower eyelid margins and the inferior fornices before surgery and from the corneal interface and the instrument at the end of surgery. Media were cultured at 37 degrees C for 14 days under aerobic and anaerobic conditions. Bacteria from positive cultures were isolated and identified by biochemical procedures to determine the species of the organisms.

RESULTS

The rate of contamination was 24.5%. The most common retrieved organism was Staphylococcus epidermidis (43 cases, 87.7%). None of the contaminated or noncontaminated cases developed corneal ulcers; however, 2 eyes developed diffuse lamellar keratitis.

CONCLUSION

The corneal stroma has the ability to clear introduced microorganisms during LASIK.

Contact lens fitting post-laser-in situ keratomileusis (LASIK)

Despite recent advances in refractive surgical procedures a small proportion of patients still achieve sub-optimal results for a variety of reasons. In such cases, contact lenses may provide the only option for visual rehabilitation and restoration of binocular vision post-refractive surgery. The indications for contact lenses post-LASIK may be one, or a combination of the following: *Initial bandage lens for corneal protection. *Residual ametropia--over and under correction. *Irregular astigmatism. * Anisometropia. * Decentred ablation zones. In low powered corrections conventional soft lenses can be fitted in the normal way, giving good levels of acuity. Where there is astigmatism (>0.75 DC) then toric soft contact lenses may appropriate. Rigid lenses may prove to be the only viable option in a number of cases where visual correction is required post-refractive surgery, or in the presence of high levels of astigmatism. Fitting can be more complex however, since a conventional rigid lens cannot follow the shape of both the flattened central cornea and the relatively steeper periphery in higher corrections, as the amount of laser ablation increases. Reverse geometry lenses are indicated where there is a significant difference between the flat central ablated zone and the relatively steeper peripheral cornea. On rare occasions scleral lenses may also be indicated.

Corneal Infiltrates After Excimer Laser Photorefractive Keratectomy and LASIK

PURPOSE

To determine the frequency and clinical characteristics of corneal infiltrates after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) and to evaluate the efficacy of treatment.

METHODS

We retrospectively reviewed the records of 8508 eyes treated with PRK or LASIK in a university-based clinic for the correction of refractive errors for 60 days postoperatively.

RESULTS

Corneal infiltrates were observed in 35 (0.8%) of 4492 PRK-operated eyes and in 4 (0.1%) of 4016 LASIK-operated eyes. The mean time of diagnosis was 5.46 days. Among the 39 eyes with infiltrates, 10 (9 PRK, 1 LASIK) had culture-verified infectious keratitis. Coagulase-negative Staphylococcus was the most frequently isolated bacterium (50%), followed by S aureus (20%), Corynebacterium xerosis (10%), Streptococcus viridans (10%), and an unidentified gram-positive coccus (10%). Final visual acuity of > or = 20/30, without correction, was achieved in 79.5% of the 39 eyes.

CONCLUSIONS

Corneal infiltrates occurred in 0.8% of PRK eyes and 0.1% of LASIK eyes. Bacterial smears were positive for several eyes. In all cases, prompt treatment was responsible for good visual outcome.

Microbial Keratitis After Laser in situ Keratomileusis

PURPOSE AND METHOD

To review the literature on microbial keratitis reported after laser in situ keratomileusis (LASIK).

RESULTS

Forty-one eyes have been reported to have microbial keratitis after LASIK. The causative organisms vary from gram positive bacteria to atypical mycobacteria, fungal, and viral pathogens. The infection is usually acquired intraoperatively, but may also be caused by postoperative contamination. A majority of the patients present within 72 hours of the surgery with an acute onset of symptoms. Management of microbial keratitis after LASIK includes aggressive topical fortified antibiotic therapy, irrigation of stromal bed with antibiotic solution after lifting the flap, and sending the scraping of the infiltrate for microbiological evaluation. The keratitis heals with scarring and a best spectacle-corrected visual acuity of 20/40 or better can be obtained in the majority of the patients.

CONCLUSION

Microbial keratitis is a sight-threatening complication of LASIK.

Role of the bandage soft contact lens in the postoperative laser in situ keratomileusis patient

PURPOSE

To determine whether a bandage soft contact lens (BSCL) is routinely needed in the postoperative laser in situ keratomileusis (LASIK) patient and whether topical tetracaine 0.5% or diclofenac sodium 0.1% (Voltaren) is more effective in relieving patient discomfort than a BSCL.

SETTING

LCA-Vision Center, Toronto, Ontario, Canada.

METHODS

In this prospective randomized comparative study, all patients had bilateral simultaneous LASIK procedures. Post-LASIK patient comfort was evaluated through 3 arms of the study: BSCL versus no BSCL, 40 consecutive patients with 1 eye randomized to receive a BSCL and no BSCL in the fellow eye; BSCL versus tetracaine 0.5%, 26 consecutive patients with 1 eye randomized to receive a BSCL and tetracaine 0.5% in the fellow eye; tetracaine 0.5% versus Voltaren, 54 consecutive patients with 1 eye randomized to receive tetracaine 0.5% and Voltaren in the fellow eye.

RESULTS

The patient preferences after LASIK were as follows: BSCL versus no BSCL-12 (30%) versus 23 (58%) (P =.062); BSCL versus tetracaine 0.5%-4 (15%) versus 22 (85%) (P <.001). On average, the eyes with no BSCL had a 2-line improvement in uncorrected visual acuity over the BSCL eyes. Tetracaine 0.5% versus Voltaren-13 (24%) versus 21 (39%) (P =.170).

CONCLUSIONS

The routine use of a BSCL in the postoperative LASIK patient is not necessary. Voltaren and tetracaine 0.5% were safe and more effective in relieving postoperative patient discomfort and resulted in improved visual acuity immediately postoperatively.

LASIK complications: etiology, management, and prevention

Laser in situ keratomileusis (LASIK) is a rapidly evolving ophthalmic surgical procedure. Several anatomic and refractive complications have been identified. Anatomic complications include corneal flap abnormalities, epithelial ingrowth, and corneal ectasia. Refractive complications include unexpected refractive outcomes, irregular astigmatism, decentration, visual aberrations, and loss of vision. Infectious keratitis, dry eyes, and diffuse lamellar keratitis may also occur following LASIK. By examining the etiology, management, and prevention of these complications, the refractive surgeon may be able to improve visual outcomes and prevent vision-threatening problems. Reporting outcomes and mishaps of LASIK surgery will help refine our approach to the management of emerging complications.

Perioperative Microbiologic Profile of the Conjunctiva in Photorefractive Keratectomy

PURPOSE

Therapeutic soft contact lenses are used commonly as an adjunctive treatment after photorefractive keratectomy (PRK) to decrease postoperative pain caused by the movement of lids over the corneal epithelial defect and to facilitate epithelial healing. We assessed the microbiological profile of the conjunctiva of patients undergoing PRK for myopia, before and after the concurrent use of a therapeutic soft contact lens, and compared the effect on ocular bacterial colonization of prophylactic administration of topical tobramycin 0.3% versus ofloxacin 0.3%.

METHODS

Forty-three consecutive eyes from 37 patients underwent PRK for myopia or myopic astigmatism. Eyes were assigned randomly to prophylactic antibacterial treatment with either topical ofloxacin 0.3% or tobramycin 0.3%, applied prior to surgery and three times daily after surgery until therapeutic soft contact lens removal. Material from the conjunctival sac was obtained for bacteriologic cultures prior to surgery. Clinical evaluation of all eyes was conducted prospectively. Three days after PRK, the therapeutic soft contact lenses were removed and cultured. Cultures from the conjunctival sac were then repeated.

RESULTS

No statistically significant differences were observed in culture positivity between the two groups of eyes, in spite of some positive preoperative and postoperative cultures. Only one out of 43 eyes (assigned to the ofloxacin group) developed a peripheral corneal infiltrate. The corneal infiltrate healed completely without sequelae using antibiotic and corticosteroid therapy.

CONCLUSIONS

The use of therapeutic soft contact lenses after PRK with either topical tobramycin 0.3% or ofloxacin 0.3% were well tolerated. However, perioperative positive conjunctival cultures were relatively frequent and prophylactic antibiotics should be used in the setting of an epithelial defect and therapeutic soft contact lens following PRK.