Bilateral corneal infiltrates after excimer laser photorefractive keratectomy

Wessely corneal ring phenomenon: An unsolved pathophysiological dilemma

The cornea is a densely innervated, avascular tissue showing exceptional inflammatory and immune responses. The cornea is a site of lymphangiogenic and angiogenic privilege devoid of blood and lymphatic vessels that limits the entry of inflammatory cells from the adjacent and highly immunoreactive conjunctiva. Immunological and anatomical differences between the central and peripheral cornea are also necessary to sustain passive immune privilege. The lower density of antigen-presenting cells in the central cornea and the 5:1 peripheral-to-central corneal ratio of C1 are 2 main features conferring passive immune privilege. C1 activates the complement system by antigen-antibody complexes more effectively in the peripheral cornea and, thus, protects the central corneas' transparency from immune-driven and inflammatory reactions. Wessely rings, also known as corneal immune rings, are non-infectious ring-shaped stromal infiltrates usually formed in the peripheral cornea. They result from a hypersensitivity reaction to foreign antigens, including those of microorganism origin. Thus, they are thought to be composed of inflammatory cells and antigen-antibody complexes. Corneal immune rings have been associated with various infectious and non-infectious causes, including foreign bodies, contact lens wear, refractive procedures, and drugs. We describe the anatomical and immunologic basis underlying Wessely ring formation, its causes, clinical presentation, and management.

Staphylococcus-associated marginal keratitis secondary to pterygium surgery: a case report

Background

Staphylococcus-associated marginal keratitis is an immune-mediated corneal disorder mainly secondary to chronic blepharoconjunctivitis. We report a rare case of Staphylococcus-associated marginal keratitis following pterygium excision. To the best of our knowledge, none of the previous literature has described such an acute complication after pterygium surgery.

Case presentation

We report a case of a 50-year-old woman who suffered from pterygium in the left eye and underwent pterygium surgery. After surgery, slit-lamp examination showed an incomplete ring-shaped creamy white infiltrate. Corneal pathogenic microbial detection was negative. Staphylococcus aureus was found on the upper eyelid margin of the affected eye. Therefore, she was clinically diagnosed with Staphylococcus-associated marginal keratitis. The infiltrate was gradually absorbed after steroids, topical antibiotics, and lubricant eye drops were administered. After 2 years of follow-up, neither corneal infiltrate nor pterygium recurrence was observed.

Conclusion

Staphylococcus-associated marginal keratitis is an immune reaction mainly secondary to chronic blepharoconjunctivitis, which usually activates an antigen-antibody reaction with complementary activation and neutrophil infiltration in patients sensitized to staphylococcal antigens. Early detection and treatment is of great importance. Topical steroids are effective and should be initiated early once pathogenic microbial infections are excluded. Although chronic staphylococcal blepharoconjunctivitis is a common disease, ophthalmologists should pay more attention to it to avoid potential complications.

Visual outcomes of sterile corneal infiltrates after photorefractive keratectomy

Purpose:

Sterile infiltrates following laser refractive surgery is an uncommon complication. This study was undertaken to analyze the visual outcomes of sterile infiltrates following photorefractive keratectomy (PRK).

Methods:

This retrospective study included 14 eyes that developed sterile infiltrates following PRK out of a total of 6280 eyes that underwent PRK between 2014 and 2017. Medical records of these patients, including patient demographics, characteristics of the infiltrate, presenting visual acuity, and treatment outcomes were recorded and analyzed.

Results:

The incidence of sterile corneal infiltrates post-PRK in our study was 0.22% (14/6280). The mean age of the patients was 27.42 ± 4.87 years. The uncorrected visual acuity (UCVA) at presentation was 0.49 ± 0.13 log MAR units. The mean size of the infiltrate was 3.22 ± 2.85 mm². All cases were successfully managed medically with topical steroids. The mean UCVA and best-corrected visual acuity (BCVA) at the last follow-up visit were 0.08 ± 0.08 and 0.05 ± 0.07 log MAR units, respectively. The mean time taken for resolution of the infiltrate was 8.91 ± 4.57 days.

Conclusion:

Sterile infiltrates following PRK can be effectively treated with aggressive topical steroids. The outcome is generally favorable and does not require surgical intervention if treatment is instituted early.

Hypersensitivity reactions after femtosecond laser small incision lenticule extraction: a case report of corneal infiltrates

BACKGROUND

Femtosecond laser corneal refractive surgery is generally considered safe and effective; however, this procedure is rarely associated with severe allergic reactions. We reported a rare case of hypersensitivity reactions which caused bilateral peripheral corneal infiltrates after femtosecond laser small incision lenticule (SMILE) surgery in a man with a history of fruits allergy.

CASE PRESENTATION

Here we report the case of a young man who developed white, ring-shaped bilateral peripheral infiltrates that appeared 1 day after an uneventful SMILE surgery. The overlying corneal epithelium was intact; the infiltrate was negative for bacterial culture, but high titers of immunoglobulin E was demonstrated in the blood. Symptomatically, a clinical diagnosis of sterile corneal infiltrates was made, and the patient was treated with topical and systemic steroids. The infiltrates were immunogenic in origin, which may be caused by the contact lenses used for suction duration in surgery. It resolved without corneal scarring in the subsequent months following steroid treatment. The patient's visual acuity improved.

CONCLUSIONS

When patients with a history of allergy who aim to perform corneal refractive surgery, surgeons must consider possible hypersensitivity reactions after treatment. More studies are needed to clarify the relationship between contact glass used in femtosecond laser corneal refractive surgery and IgE mediated hypersensitivity reactions.

Infectious keratitis in 18,651 laser surface ablation procedures

PURPOSE

To evaluate the incidence, culture results, risk factors, treatment strategies, and visual outcomes of infectious keratitis after surface ablation.

SETTING

Multicenter study in Spain.

DESIGN

Case series.

METHODS

The medical records of patients who had surface ablation between January 2003 and December 2009 were reviewed to identify cases of infectious keratitis. The incidence, risk factors, clinical course, days to diagnosis, medical and surgical treatment, and visual outcome were recorded. Main outcome measures were incidence of infectious keratitis after surface ablation, culture results, response to treatment, and visual outcomes.

RESULTS

The study reviewed the records of 9794 patients (18,651 eyes). Infectious keratitis after surface ablation was diagnosed in 39 eyes of 38 patients. The onset of infection was early (within 7 days after surgery) in 28 cases (71.79%). Cultures were positive in 13 of 27 cases in which samples were taken. The most frequently isolated microorganism was Staphylococcus species (9 cases). The final corrected distance visual acuity (CDVA) was 20/20 or better in 23 cases (58.97%), 20/40 or better in 36 cases (92.30%), and worse than 20/40 in 3 cases (7.69%).

CONCLUSIONS

The incidence of infectious keratitis after surface ablation was 0.20%. Infectious keratitis is a potentially vision-threatening complication. Prompt and aggressive management with an intensive regimen of fortified antibiotic agents is strongly recommended. Proper management can preserve useful vision in most cases.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

Peripheral sterile corneal infiltrate in two brothers after photorefractive keratectomy

This is a report of two brothers who underwent bilateral photorefractive keratectomy and developed bilateral peripheral corneal infiltrate on the third day following surgery. The patients were treated with antibiotics and low concentration steroid until negative culture was reported 48 h later, when intensive topical steroid was started. The infiltrate resolved by day 10 with residual subepithelial haze that was apparent 8 months after surgery. Sterile infiltrate has been reported as complication of photorefractive keratectomy and can be managed successfully with excellent outcome. The fact that it happened in two brothers may raise the possibility of genetic predisposition.

Infectious Keratitis after Photorefractive Keratectomy in the United States Army and Navy

PURPOSE

To review the incidence, culture results, clinical course, management, and visual outcomes of infectious keratitis after photorefractive keratectomy (PRK) at 6 Army and Navy refractive surgery centers.

DESIGN

Retrospective study.

PARTICIPANTS

Twelve thousand six hundred sixty-eight Navy and Army sailors and service members.

METHODS

Army and Navy refractive surgery data banks were searched for cases of infectious keratitis. A retrospective chart review and query of the surgeons involved in the care of those patients thus identified provided data regarding preoperative preparation, perioperative medications, treatment, culture results, clinical course, and final visual acuity.

RESULTS

Between January 1995 and May 2004, we performed a total of 25337 PRK procedures at the 6 institutions. Culture proven or clinically suspected infectious keratitis developed in 5 eyes of 5 patients. All patients received topical antibiotics perioperatively. All cases presented 2 to 7 days postoperatively. Cultures from 4 cases grew Staphylococcus, including 2 methicillin-resistant S. aureus (MRSA). One case of presumed infectious keratitis was culture negative. There were no reported cases of mycobacterial or fungal keratitis. In addition, we identified 26 eyes with corneal infiltrates in the first postoperative week that were felt to be sterile, and which resolved upon removal of the bandage contact lens and increasing antibiotic coverage.

CONCLUSIONS

Infectious keratitis is a rare but potentially vision-threatening complication after PRK. It is often caused by gram-positive organisms, including MRSA. Early diagnosis, appropriate laboratory testing, and aggressive antimicrobial therapy can result in good outcomes.

Peripheral sterile corneal infiltrates after refractive surgery

PURPOSE

To report 5 eyes of peripheral sterile corneal infiltrates after refractive surgery.

SETTING

Department of Ophthalmology, Soroka University Medical Center, Beer-Sheva, Israel, and Enaim Ophthalmological Center, Jerusalem, Israel.

METHODS

Three patients had bilateral refractive procedures for correcting myopia. The procedures included laser epithelial keratectomy in 2 eyes, laser in situ keratomileusis (LASIK) in 2 eyes using a keratome, and LASIK in 1 eye using femtosecond laser.

RESULTS

All the patients complained of ocular pain between 1 and 3 days after the procedure. A ring stromal infiltrate peripheral to the flap edge with intact epithelium and an intervening clear zone between the peripheral corneal infiltrates and the limbus was observed in 5 eyes without anterior chamber reaction. All cases improved after several days of topical steroid and antibiotic treatment and systemic steroid. Final visual acuity was 20/25 or better in all cases.

CONCLUSIONS

The exact mechanism of this complication is still unknown, which can be confused with infectious keratitis. It is important to maintain a high degree of suspicion for infectious keratitis because the management is very different. The potential outcome can be much worse if the keratitis is due to an infectious etiology which can appear after all types of refractive laser procedures.

Bilateral peripheral corneal infiltrates after simultaneous myopic laser in situ keratomileusis

We describe a patient with multiple superior corneal infiltrates in both eyes, separated from the limbus by an intervening clear zone, that appeared 1 day after uneventful laser in situ keratomileusis. The overlying epithelium was intact, and the flap and interface were uninvolved. Based on these features, a clinical diagnosis of sterile corneal infiltrates was made and the eyes were treated with topical antibiotics and steroids. The infiltrates resolved during the ensuing weeks without corneal scarring. Good visual acuity was maintained. Recognition of this benign complication is important because aggressive corneal scrapings are not required. The infiltrates appear to be immunogenic in origin, although the exact etiopathogenesis is not clear.