Bacterial Keratitis After Photorefractive Keratectomy

Enterobacter Cloacae keratitis after corneal cross-linking for keratoconus: A case report

PURPOSE

To report a case of Enterobacter cloacae (E. cloacae) keratitis in a patient who underwent corneal crosslinking (CXL) for progressive keratoconus.

OBSERVATIONS

A 19-year-old female underwent CXL for keratoconus in her left eye. The patient neglected her post-procedure medications and missed the follow-up visit. Subsequently, she presented on day-10 post CXL with redness and pain in the treated eye. Clinical examination revealed a ring-shape infiltrate measuring 7.8 mm in diameter. Culture indicated the presence of E. cloacae. Treatment with gentamicin failed after the emergence of resistance. The patient was successfully treated with amikacin and moxifloxacin over several weeks.

CONCLUSIONS

Judicious antibiotic selection is crucial to limit the emergence of resistance in multidrug-resistant (MDR) pathogens. All patients need to be educated about their role in the management plan.

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.

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.

Bilateral methicillin-resistant Staphylococcus aureus keratitis after photorefractive keratectomy

A 52-year-old woman with a history of liver transplantation developed bilateral corneal infiltrates 1 week after uneventful photorefractive keratectomy (PRK). Cultures grew methicillin-resistant Staphylococcus aureus (MRSA), resistant to fluoroquinolone antibiotics. The infections responded to topical vancomycin and resolved bilaterally over 3 weeks. Three months postoperatively, the uncorrected visual acuity (UCVA) was 20/20 in the right eye and 20/25 in the left eye; the best spectacle-corrected visual acuity (BSCVA) was 20/20 in both eyes. During the course of treatment, the patient reported chronic intermittent prophylactic use of oral ciprofloxacin. While fluoroquinolones typically provide excellent postoperative coverage, Staphylococcus organisms have a growing antibiotic resistance to fluoroquinolones, and MRSA may become a more prevalent organism in corneal infections. Chronic subtherapeutic fluoroquinolone use can increase the mutational resistance of Staphylococcus to fluoroquinolone and methicillin. The patient's frequent hospital visits placed her at high risk for MRSA colonization. This case represents the fifth reported case of MRSA keratitis after PRK.

Bilateral Bacterial Keratitis in Three Patients Following Photorefractive Keratectomy

PURPOSE

To report clinical manifestations and the bacteriologic profiles of three patients with bilateral bacterial keratitis following photorefractive keratectomy (PRK).

METHODS

Photorefractive keratectomy was performed for mild to moderate myopia or compound myopic astigmatism. Bandage contact lenses were fitted at the conclusion of each surgery. Bilateral infectious keratitis was diagnosed within 3 days after surgery. Smear and culture were obtained in all three cases. Patients were treated with topical fortified antibiotics (cefazolin and gentamicin).

RESULTS

All patients presented with severe bilateral ocular pain, photophobia, purulent discharge, and dense corneal infiltration. Causative organisms were Staphylococcus aureus (n = 2) and Streptococcus pneumoniae (n = 1). Ulcers were controlled with aggressive medical therapy in five eyes; however, tectonic penetrating keratoplasty was required in one eye.

CONCLUSIONS

Uncontrolled blepharitis and bandage contact lens use appears to play a role in the development of bacterial keratitis after PRK. Avoidance of simultaneous bilateral surgery in patients with risk factors for bacterial keratitis, preoperative control of blepharitis, and good contact lens hygiene is suggested.

Fourth-generation fluoroquinolone-resistant bacterial keratitis after refractive surgery

We report the first 2 cases of bacterial keratitis resistant to fourth-generation fluoroquinolones after laser in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK). The first patient had Pseudomonas aeruginosa keratitis after PRK despite treatment with moxifloxacin. The second patient was on gatifloxacin post-LASIK when she had methicillin-resistant Staphylococcus aureus (MRSA) keratitis diagnosed. In both cases, culture susceptibilities showed isolates resistant to moxifloxacin and gatifloxacin, and treatment with topical aminoglycosides and surgical intervention was necessary to effect a cure. These cases show the potential limitations in the coverage of these antibiotics.

Bilateral methicillin-resistant staphylococcus aureus keratitis in a medical resident following an uneventful bilateral photorefractive keratectomy

PURPOSE

To present a case of bilateral methicillin-resistant Staphylococcus aureus (MRSA) keratitis after photorefractive keratectomy (PRK).

METHODS

Retrospective chart review. RESULTS A 26-year-old female internal medicine resident underwent an uneventful bilateral PRK. After the procedure, the patient was fit with a bandage contact lens and was prescribed tobramycin 0.3%, fluorometholone 0.1%, and diclofenac sodium 0.1% four times per day. Postoperatively, corneal ulcers were noted in each eye, and the patient was referred for a consultation. Gram stain showed gram-positive cocci. The patient immediately started using vancomycin, 35 mg/mL every half hour, and ofloxacin 0.3% every hour around the clock. Forty-eight hours later, corneal and lid cultures were positive for MRSA. Three months after the infection, there was approximately 40% corneal thinning in the right eye and 10% thinning in the area of the corneal ulceration of the left eye. The patient is awaiting corneal transplantation of the right eye.

CONCLUSIONS

To our knowledge, this represents the first reported case of bilateral MRSA keratitis after PRK. Methicillin-resistant S. aureus is a potentially serious infectious agent after PRK and may be associated with exposure to a hospital setting. For patients who have had extensive exposure to a hospital environment and are undergoing ocular surgery, we recommend prophylaxis against MRSA. To treat a possible MRSA keratitis, we suggest starting a fourth-generation topical fluoroquinolone every 30 minutes, alternating it with vancomycin 50 mg/mL every 30 minutes, and discontinuing steroid use. A high degree of suspicion coupled with rapid and appropriate treatment may result in improved visual recovery.

Fungal Keratitis After Photorefractive Keratectomy: Delayed Diagnosis and Treatment in a Co-managed Setting

PURPOSE

To report a case of fungal keratitis following photorefractive keratectomy (PRK) in a co-managed setting.

METHODS

A 35-year-old man with a preoperative refraction of -13.00 +3.75 x 18 degrees OD, and -12.50 +2.50 x 70 degrees OS underwent bilateral simultaneous PRK. On postoperative day 16, the patient presented with complaints of decreased vision and foreign body sensation. Examination by the co-managing optometrist revealed a visual acuity of 20/200, and a central corneal ulcer. Cultures were not taken and the patient was started on topical ofloxacin and prednisolone acetate 1% every hour. The patient was instructed to follow-up with another optometrist closer to the patient's home. Tobradex (tobramycin 0.3% combined with dexamethasone 0.1%) was added to the treatment regimen on postoperative day 23, but the ulcer continued to worsen. The patient was then referred to an ophthalmologist where corneal cultures were performed, but came back negative.

RESULTS

Despite treatment with fortified antibiotics, the ulcer perforated, requiring penetrating keratoplasty. Bacterial and fungal cultures were negative. Pathology examination of the specimen revealed fungal hyphae.

CONCLUSIONS

Although co-management of refractive patients may be a common practice, it is not without risks. In this case, delayed diagnosis and inappropriate treatment resulted in a poor final outcome.

Infectious keratitis after photorefractive keratectomy

PURPOSE

To elucidate risk factors, microbial culture results, and visual outcomes for infectious keratitis after photorefractive keratectomy (PRK).

DESIGN

Multicenter, retrospective chart review, case report, and literature review.

METHODS

The records of 12 patients with infectious keratitis after PRK were reviewed.

MAIN OUTCOME MEASURES

Causative organism, response to medical treatment, and visual outcome.

RESULTS

Infectious keratitis developed in 13 eyes of 12 patients after PRK. Organisms cultured were Staphylococcus aureus (n = 5), including a bilateral case of methicillin-resistant Staphylococcus aureus; Staphylococcus epidermidis (n = 4); Streptococcus pneumoniae (n = 3); and Streptococcus viridans (n = 1). Four patients manipulated their contact lenses, and 2 patients were exposed to nosocomial organisms while working in a hospital environment. Prophylactic antibiotics used were tobramycin (nine cases), polymyxin B-trimethoprim (three cases), and ciprofloxacin (one case). Final best spectacle-corrected visual acuity ranged from 20/20 to 20/100.

CONCLUSIONS

Infectious corneal ulceration is a serious potential complication of PRK. Gram-positive organisms are the most common pathogens. Antibiotic prophylaxis should be broad spectrum and should include gram-positive coverage.

Acanthamoeba keratitis after photorefractive keratectomy

A 37-year-old women developed severe suppurative keratitis immediately after having photorefractive keratectomy in her left eye. The keratitis was unresponsive to intensive topical antibiotic agents and topical and systemic steroids. Although the differential diagnosis included nonmicrobial and fungal keratitis, the clinical course and confocal microscopy suggested, and subsequent histopathologic examination confirmed, a diagnosis of Acanthamoeba keratitis. The amebic contamination probably resulted from exposure of the deepithelialized cornea to contaminated freshwater in a northern Wisconsin marsh. This case emphasizes the importance of encouraging patients with epithelial defects and bandage soft contact lenses to avoid exposure to contaminated freshwater until reepithelialization is complete.

Relation between corneal haze and transforming growth factor-beta1 after photorefractive keratectomy and laser in situ keratomileusis

PURPOSE

To investigate the relation between corneal haze formation and transforming growth factor-beta (TGF-beta) after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK).

SETTING

Department of Ophthalmology, University of Tokyo Graduate School of Medicine, Tokyo, Japan.

METHODS

White rabbits were divided into 4 groups, with each group receiving 1 of the following surgeries: manual epithelial abrasion, PRK, lamellar keratotomy, or LASIK. The degree of corneal haze was quantitatively analyzed by measuring the light scattering intensity of corneas before and 4 and 12 weeks after surgery. The expression of type IV collagen and TGF-beta1 in the corneas at baseline and at 4 weeks was examined immunohistochemically.

RESULTS

The light scattering intensity was significantly greater 4 and 10 weeks after PRK. In contrast, epithelial abrasion, lamellar keratotomy, and LASIK did not influence the light scattering intensity of the corneas. Type IV collagen was detected in the basal lamina of the corneal epithelium and in Descement's membrane in the normal cornea. After epithelial abrasion, there was no change in the distribution of type IV collagen. Four weeks after PRK, the expression of type IV collagen was detected in the subepithelial layer of the laser-ablated area. Four weeks after lamellar keratotomy, type IV collagen was linearly and fragmentarily detected in the corneal stroma. Four weeks after LASIK, type IV collagen was linearly and continuously detected in the corneal stroma and was detected slightly in the subepithelial region of the laser-ablated area. In the normal corneas, the expression of TGF-beta1 was not detected in the keratocytes. Four weeks after PRK, the expression of TGF-beta1 increased in the keratocytes that proliferated in the subepithelial fibrous layer. In contrast, epithelial abrasion, lamellar keratotomy, and LASIK did not change the expression pattern of TGF-beta1 in the keratocytes.

CONCLUSION

The multiplier effect of epithelial abrasion and excimer laser ablation in PRK may increase the expression of TGF-beta1 in keratocytes and induce corneal haze.

Infectious keratitis after laser refractive surgery

PURPOSE

To report two cases of infectious keratitis, one fungal after photorefractive keratectomy (PRK) and the other bacterial after laser in situ keratomileusis (LASIK).

DESIGN

Two interventional case reports.

PARTICIPANTS

Case 1 is a male who was seen 3 weeks after PRK with a corneal ulceration. Case 2 involves a female who was seen 7 weeks after LASIK with interface granularity.

RESULTS

Cultures in case 1 were identified as Scopulariopsis species, and despite intensive treatment, a therapeutic penetrating keratoplasty (PK) was eventually performed. Case 2 had cultures identified as Mycobacterium chelonae and also ultimately required a therapeutic PK.

CONCLUSIONS

Two unusual infectious keratitides are reported after different laser refractive surgery techniques.

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.

Acute haemorrhagic keratoconjunctivitis following laser in situ keratomileusis

We report two cases of acute haemorrhagic keratoconjunctivitis which occurred following laser in situ keratomileusis (LASIK) during an ongoing epidemic. Both cases underwent preoperative investigation and surgery on the same day. The possible sources of contamination include the paramedical staff, the contact instruments used for performing preoperative investigation, surgeon, nurse, surgical instruments and eye drops. However, the flap was intact with no haze or regression and at 1 year follow up, the visual acuity was maintained at 6/6 in both the patients. We recommend greater caution while performing contact investigations and strict surgical asepsis during LASIK surgery, routinely as well as during epidemics of conjunctivitis.

Postoperative Inflammation, Microbial Complications, and Wound Healing Following Laser in situ Keratomileusis

Although the biology of corneal wound healing is only partly understood, healing after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) differs in many respects, and the mechanisms appear to be differently controlled. There is less of an inflammatory and healing response after LASIK, but a longer period of sensory denervation. The cellular, molecular, and neural regulatory phenomena associated with postoperative inflammation and wound healing are likely to be involved in the adverse effects after LASIK, such as flap melt, epithelial ingrowth, and regression. Interface opacities in the early postoperative period include diffuse lamellar keratitis (DLK), microbial keratitis, epithelial cells, and interface opacities. Diffuse lamellar keratitis (sands of the Sahara syndrome) describes an apparently noninfectious diffuse interface inflammation after lamellar corneal surgery probably caused by an allergic or a toxic inflammatory reaction. Noninfectious keratitis must be distinguished from microbial keratitis to avoid aggressive management and treatment with antimicrobial drugs. Microbial keratitis is a serious complication after LASIK, but a good visual outcome can be achieved following prompt and appropriate treatment.

Topical Tetracaine With Bandage Soft Contact Lens Pain Control After Photorefractive Keratectomy

PURPOSE

A major disadvantage of photorefractive keratectomy (PRK) is pain and discomfort in the first three postoperative days. We tried to assess the efficacy and safety to the cornea of a limited amount of topical tetracaine given to patients for use when needed to manage severe pain.

METHODS

Sixty-nine eyes of 49 patients who underwent PRK between June 21, 1996 and June 15, 1998 by a single surgeon were prospectively included. Approximately 10 drops of commercial, non-preserved 0.5% tetracaine were given to patients to use when needed to control severe pain. A bandage soft contact lens was applied. Patients were examined at 1 and 3 days after surgery, at which time corneal re-epithelization was assessed and the number of tetracaine drops used was noted. No systemic analgesic or topical non-steroidal anti-inflammatory was prescribed.

RESULTS

All eyes healed within 3 days. The mean number of drops of tetracaine used was 2.3 drops over 3 days, although in 33 eyes (48%) the patient did not use any tetracaine. There was no correlation between the attempted correction in diopters and the number of drops used. No significant difference was found in the number of drops used in the second eye of patients who had both eyes treated.

CONCLUSIONS

Limited use of topical anesthetics is an effective and safe analgesic option after PRK. Use of tetracaine in this protocol did not prolong the time to re-epithelialization. Giving only a limited amount of tetracaine to patients prevents abuse and toxicity to the cornea while managing severe pain.

Nocardia Keratitis After Traumatic Detachment of a Laser in situ Keratomileusis Flap

PURPOSE

Nocardia are gram-positive bacteria existing ubiquitously in the environment; they can cause keratitis. Nocardia asteroides keratitis occurred in the interface between the stromal bed and flap after traumatic detachment of the flap 4 months after an initially uncomplicated laser in situ keratomileusis (LASIK) procedure.

METHODS

Nocardia asteroides keratitis was confirmed by culture. Therapy included topical and oral trimethoprim-sulfamethoxazole.

RESULTS

Thirteen months after the trauma, the patient's spectacle-corrected visual acuity was 20/20 with a manifest refraction of -2.25 -1.00 x 30 degrees.

CONCLUSIONS

The immediate steps of management consisting of surgically lifting the corneal flap, rapid microbial identification, and proper treatment with specific antibiotics resulted in the successful treatment of Nocardia asteroides keratitis in a traumatized eye after LASIK.

Delayed keratitis after laser in situ keratomileusis

We report 2 cases of delayed keratitis that occurred after uneventful laser in situ keratomileusis (LASIK). The first patient presented with a peripheral corneal infiltrate 3 months after a LASIK enhancement procedure. The infiltrate progressed despite treatment with topical combination tobramycin-dexamethasone. The flap was then lifted and the interface was irrigated with fortified antibiotics. The keratitis promptly resolved, and the patient recovered a best corrected visual acuity (BCVA) of 20/20. The second patient presented with decreased vision, inflammation, and a sublamellar infiltrate 1 month after primary LASIK. The flap was promptly lifted and irrigated with antibiotics. Cultures were positive for Staphylococcus epidermidis. One week later, the infiltrate had resolved and BCVA had returned to 20/20. Delayed bacterial keratitis has been described as a rare occurrence after incisional refractive surgery. To the best of our knowledge, it has not yet been reported after LASIK. It is important to consider infectious keratitis in the differential diagnosis of a patient who presents with corneal inflammation, even months after having LASIK.

Pneumococcal keratitis after laser in situ keratomileusis

A 20-year-old man developed keratitis in his right eye 2 days after laser in situ keratomileusis (LASIK). The patient had rubbed the eye with unclean fingers the night before the onset of symptoms. Examination showed an inferior corneal ulcer with dense infiltration at the junction of the lamellar flap and the surrounding cornea associated with a hypopyon. Streptococcus pneumoniae was isolated on culture. The ulcer resolved with combination therapy of cephazolin 5% and tobramycin 1.3% eyedrops. Patients having LASIK should be instructed that inadequate patient hygiene may predispose to bacterial keratitis.

Infectious keratitis after photorefractive keratectomy in a comanaged setting

A 48-year-old man had simultaneous bilateral photorefractive keratectomy (PRK). The surgeon who performed the PRK did not see the patient in follow-up, and there was confusion regarding the comanaging doctor. Therefore, the patient was not examined immediately postoperatively. Several days later, he was hospitalized for an unrelated, painful orthopedic problem and heavily sedated. Seven days after the PRK, an ophthalmologist was consulted for ocular irritation and discharge. Examination showed bilateral, purulent conjunctivitis and severe infectious keratitis in the left eye. The patient was treated with periocular and topical antibiotics. Corneal cultures yielded Staphylococcus aureus. The keratitis resolved slowly, leaving the patient with hand motion visual acuity. A corneal transplant and cataract extraction was performed 15 months later, resulting in a best corrected visual acuity of 20/400 because of glaucomatous optic nerve damage. Severe infectious keratitis may occur after PRK. Poor communication between the surgeon, comanaging doctor, and patient may result in treatment delay.

Culture-negative ulcerative keratitis after laser in situ keratomileusis

A 40-year old man, highly myopic in both eyes, had laser in situ keratomileusis (LASIK) in the left eye in November 1996. Corneal melting and ulceration and fine striae-like interface infiltrates were noticed 1 day postoperatively. There was no response to intensive topical antibiotics in the form of hourly ofloxacin 3% (Tarivid), and satellite lesions developed on day 4. Corneal scrapings for gram stain and culture were done twice. No bacterial or fungal organisms were identified. Intensive topical fortified vancomycin (50 mg/mL) was added, and the lesions resolved gradually over the ensuing 2 weeks. Eighteen months after LASIK, refraction was -1.50 - 0.75 x 105 in the left eye, and uncorrected visual acuity was 20/70, correctable to 20/25 with spectacles.

Keratitis with loss of useful vision after photorefractive keratectomy

A 30-year-old man was referred as an acute case for keratitis. Two days earlier he had had photorefractive keratectomy for myopia at another clinic; a bandage contact lens was placed over the eye, but prophylactic antibiotics were not prescribed. The keratitis was treated with gentamicin sulfate (Garamycin) and chloramphenicol eyedrops. Scrapings from the cornea showed nonhemolytic streptococci. Two and a half months later, visual acuity was finger counting because of gross distortion of the corneal contour. The combination of a bandage contact lens and the lack of prophylactic antibiotics may have been the source of bacterial keratitis.

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

BACKGROUND

Disposable soft contact lenses are known to be colonized by bacteria and play a key role in bacterial keratitis pathogenesis. Such lenses, commonly used after laser refractive surgery procedures in which postoperative corneal infiltrations are sometimes observed, are potentially a substrate for bacterial inoculation. This study evaluates the extent of such a contamination.

METHODS

Sixty disposable lenses collected from 60 eyes of patients who underwent photorefractive keratectomy (PRK), photoastigmatic refractive keratectomy (PARK), or laser in situ keratomileusis (LASIK) for the treatment of myopia or hyperopia were collected under sterile conditions over 4 months and cultured in various media. Results were statistically analyzed and the correlation with clinical and epidemiological data was examined.

RESULTS

Eleven (18.3%) of the examined lenses were contaminated with Staphylococcus epidermidis. No other bacteria or fungi were found. Contamination was significantly more common among female patients (P = .036). Correlation with the other clinical or operative parameters examined was statistically insignificant.

CONCLUSIONS

Contamination was independent of the surgical procedure and females who were frequent users of eyelid cosmetics displayed higher contamination frequencies, suggesting that bacteria possibly originate from eyelid flora. The isolation of Staphylococcus epidermidis requires close postoperative surveillance, since it is a known cause of keratitis. Prophylactic postoperative treatment with tobramycin, gentamycin, or sulphonamides could be indicated.

Corneal Interface Abscess after Excimer Laser in situ Keratomileusis

Laser in situ keratomileusis (LASIK) carries the risk of infection. We report a case culture-negative interface abscess following LASIK that was successfully treated with antibiotics and povidone iodine.

Efficacy and safety of the ProTek (Vifilcon A) therapeutic soft contact lens after photorefractive keratectomy

PURPOSE

To test the ProTek (Vifilcon A) therapeutic soft contact lens in the alleviation of post-photorefractive keratectomy pain, its effect on epithelial healing, and its safety.

METHODS

Forty-seven consecutive eligible patients undergoing unilateral excimer laser photorefractive keratectomy for myopia were randomly assigned to receive standard postoperative care with or without the use of a ProTek soft contact lens. Patients prospectively graded a self-administered 5-point scale for pain and a 4-point scale for abnormal sensations at 4, 8, 12, 16, and 20 hours after surgery. They also recorded the type and dose of all medications taken during that time period. All patients were examined on the first and third days after surgery. The lenses were worn continuously for 3 days.

RESULTS

The soft contact lens group (n = 24) disclosed a statistically significant (P < .05) reduction in pain intensity and abnormal sensations that was greatest at 8, 12, 16, and 20 hours postoperatively. Compared with control patients (n = 23), the soft contact lens group showed significant decreased dependence on most pain medications after the 12th hour (P < .05) and faster epithelial healing (P = .03). However, one case of bacterial keratitis, two cases of subepithelial infiltrates, and seven cases of contact lens intolerance were present in the soft contact lens group.

CONCLUSIONS

The ProTek therapeutic soft contact lenses were effective in decreasing pain and other related abnormal sensations after excimer photorefractive keratectomy. They decreased dependence on pain medications and hastened epithelial healing but were not well tolerated in some patients.

Nocardial Keratitis after Laser in situ Keratomileusis

PURPOSE AND METHODS

Corneal interface central nodules appeared in a patient who underwent uncomplicated laser in situ keratomileusis (LASIK) retreatment for residual myopia.

RESULTS/CONCLUSIONS

Nocardia asteroides keratitis was confirmed by microbiologic studies, which guided treatment. Six months after the appearance of the keratitis, the patient's uncorrected visual acuity was 20/45, and spectacle-corrected visual acuity was 20/40. The postoperative refraction was +0.75 -0.75 X 95 degrees, and slit-lamp examination revealed a clear cornea with a mild rounded scar in the central area. Night halos and starbursts were the main complaints in this patient. The immediate management of lifting the corneal flap for stromal bed scraping, fast microbial identification, and proper treatment was the key for the results in this patient.