Profile of microbial keratitis after corneal collagen cross-linking

Corneal Collagen Cross-linking for Keratoconus in Pediatric and Developmentally Delayed Patients

PURPOSE

Corneal cross-linking (CXL) is the standard of care in patients with keratoconus but presents unique challenges in children and developmentally delayed patients. We present our clinical decision-making algorithm, CXL surgical technique, and outcomes in these groups.

METHODS

A retrospective chart review was undertaken at a tertiary referral center of all patients who underwent CXL for keratoconus at University of Pittsburgh Medical Center (UPMC) Children's Hospital of Pittsburgh between October 1, 2017, and April 1, 2021. Demographic information along with preoperative, intraoperative, and postoperative ophthalmic examination findings were collected. The main outcome measures were indications of CXL, postoperative complications, and visual acuity (VA).

RESULTS

Forty-eight eyes of 34 patients [21 patients (30 eyes) with developmental delay (DD) and 13 patients (18 eyes) with no DD (NDD)] underwent epithelium-off, standard CXL. General anesthesia was used for CXL in all patients except for 3 with NDD. A temporary central tarsorrhaphy was performed in all patients with DD and 7 patients with NDD. The remaining got a bandage contact lens. There were no immediate postoperative complications. A trend toward improvement in VA was noted postoperatively. The mean logMAR VA (with habitual correction) was 0.67 preoperatively and 0.57 postoperatively (P = 0.3) in DD and 0.52 and 0.36, respectively (P = 0.13), in NDD.

CONCLUSIONS

This retrospective review presents a technique for assessment and treatment of keratoconus in children and those with DD. Our technique ensures timely diagnosis and provides a safe method for CXL in these groups. Temporary central tarsorrhaphy is a well-tolerated option to reduce postoperative pain.

[Current aspects of vernal and atopic keratoconjunctivitis]

BACKGROUND

Vernal keratoconjunctivitis (VKC) and atopic keratoconjunctivitis (AKC) are complex and rare diseases. Thus, their diagnosis and treatment are often a challenge.

OBJECTIVE

Discussion on the epidemiology, new pathogenetic concepts, interesting clinical findings, diagnostic possibilities and new treatment options and their side effects in severe ocular allergies. Analysis of the presentation of VKC in the internet.

MATERIAL AND METHODS

Evaluation of recent review articles, original publications, and case reports on the topics of VKC and AKC over the past 5 years.

RESULTS

Ocular allergies have significantly increased over the last decades. Recent concepts discussed in the pathogenesis of VKC and AKC are the role of the local and gut microbiome as well as the influence of neuroinflammation. Keratoconus is significantly more common in patients with VKC and AKC compared to the normal population. It is associated with faster progression and a more severe course of disease. A conjunctival provocation test is only rarely necessary in the diagnosis of allergic conjunctivitis. Treatment of atopic dermatitis with dupilumab, an interleukin 4 receptor alpha (IL-4Ra) antagonist, can cause ocular side effects. Unfortunately, information available on the internet for patients and parents on the topic of VKC is sometimes dangerously incorrect.

CONCLUSION

From the abovementioned new pathogenetic concepts, preventive and personalized treatment options could be developed in the future. Keratoconus in AKC/VKC must be recognized and treated early. Official guidelines are now available for a standardized conjunctival provocation test in the diagnosis of allergic conjunctivitis. The unwanted ocular side effects of dupilumab are often difficult to discriminate from the actual underlying AKC and respond well to anti-inflammatory treatment. Patients with VKC must be informed about the incorrect information on the internet regarding their disease.

Observation and assessment of the immediate use of a silicon hydrogel contact lens after transepithelial corneal cross linking: a prospective study

BACKGROUND

Transepithelial corneal crosslinking (CXL) is a novel surgical approach for the treatment of keratoconus, which is a bilateral asymmetrical ophthalmological disease accompanied by progressive corneal ectasia. Silicon hydrogel (SiH) contact lenses have been extensively used in clinical ophthalmologic medicine, as a postoperative ophthalmological intervention. However, the ideal lens application duration after transepithelial CXL remains uncertain. Here, we aimed to investigate the effects and comfort of immediate corneal contact lens use after transepithelial CXL for keratoconus.

METHODS

In this prospective study, 60 patients with keratoconus who underwent transepithelial CXL treatment were enrolled from September 2021 to January 2023 with a male:female ratio of 39:21, and an average age of 25.42 ± 5.47 years. The patients were divided randomly into two groups: group A contained 30 patients wearing silicone hydrogel contact lenses for 7 days postoperatively, and group B contained 30 patients wearing the same contact lenses for 3 days. Ten subjective ophthalmologic symptoms were surveyed by the patients, including pain, photophobia, foreign body sensation, tearing, burning, blurred vision, dry eyes, difficulty opening the eyes, astringency, and stinging. Ophthalmologic signs, including corneal edema and conjunctival congestion, were recorded by a single clinician on postoperative days 1, 3, and 7.

RESULTS

Each surgical procedure was readily performed without complications, and both groups postoperative day 7 (P = 0.04), where group B scored (0.01 ± 0.41) lesser than group A (0.12 ± 0.29), whilst corneal edema in both groups recorded significantly different on postoperative days 5 and 7 (group A demonstrated the result of 0.17 ± 0.14 and 0.08 ± 0.11 for the respective days, whereas group B indicated 0.10 ± 0.13 and 0.03 ± 0.07 at the corresponding times).

CONCLUSIONS

Immediate use of silicone hydrogel corneal lenses after transepithelial CXL effectively alleviates postoperative ocular distress, particularly with a three-day use period as the ideal duration.

Rates of infectious keratitis and other ocular surface adverse events in corneal cross-linking for keratoconus and corneal ectasias performed in an office-based setting: a retrospective cohort study

BACKGROUND

This study aimed to compare the complication rates of epithelium-off corneal cross-linking (epi-off CXL) performed in an office-based setting with those of epi-off CXL performed in an operating room.

METHODS

A retrospective cohort study, comprising 501 consecutive epi-off CXL procedures, performed in a non-sterile procedure room without laminar flow ventilation at the ELZA Institute in Zurich, Switzerland, between November 2015 and October 2021, was conducted.

RESULTS

No cases of postoperative infectious keratitis were observed, while sterile infiltrates occurred in 10 out of 501 (2.00%) patients, all of whom responded well to topical steroid therapy. Delayed epithelialization (> 7 days) occurred in 14 out of 501 (2.79%) patients. No other adverse events were noted.

CONCLUSIONS

Office-based epi-off CXL does not appear to be associated with an increased risk of complications when compared to operating room settings.

A Case Series of Infectious Keratitis After Corneal Cross-linking

PURPOSE

To present the 7-year experience of a tertiary eye hospital while exploring possible risk factors and incidence of infectious keratitis in patients undergoing standard corneal cross-linking (CXL).

METHODS

This retrospective cohort study included patients with progressive keratoconus undergoing standard CXL in the Farabi Eye Hospital and all other patients who had undergone CXL in other facilities and were diagnosed as having infectious keratitis in the 7-year period of the study.

RESULTS

Among the total of 4,863 eyes that underwent CXL, 6 eyes developed infectious keratitis, yielding an incidence rate of 0.12%. Additionally, 13 eyes from 10 patients with a CXL history in other facilities who developed infectious keratitis were included. The mean age was 23.75 years, and 75% of patients were men and 25% were women. Gram-positive bacteria and Staphylococcus aureus were the most prevalent pathogens. Meibomian gland dysfunction, dry eye disease, or blepharitis were present in 12 patients. Medical treatment did not arrest the disease progress in 5 patients, which eventually required cases to undergo keratoplasty.

CONCLUSIONS

This study supports the need for proper patient selection by using a comprehensive medical history. It also highlights the imperative role of rigorous patient education and follow-up, particularly in the first postoperative week. Finally, the study emphasizes aggressive early therapy for patients with suspicious findings. [J Refract Surg. 2023;39(8):564-572.].

Safety and Efficacy of Corneal Cross-Linking in Patients Affected by Keratoconus: Long-Term Results

The present study evaluated the effectiveness and safety of corneal collagen cross-linking (CXL). A total of 886 eyes with progressive keratoconus were enrolled in a retrospective cohort study in a tertiary care university hospital. CXL was performed using a standard epithelium-off Dresden protocol. Visual outcomes, maximum keratometry (Kmax), demarcation line measurements, and complications were recorded. Visual outcomes and keratometric data were analyzed in a subgroup comprising 610 eyes. Uncorrected distance visual acuity (UDVA) improved from 0.49 ± 0.38 LogMAR to 0.47 ± 0.39 LogMAR (p = 0.03, n = 610) three years after the procedure, while corrected distance visual acuity (CDVA) improved from 0.15 ± 0.14 LogMAR to 0.14 ± 0.15 LogMAR (p = 0.007, n = 610). A significant reduction of Kmax from 56.28 ± 6.10 to 54.98 ± 6.19 (p < 0.001, n = 610) was observed three years after CXL. In five eyes (0.82%, 5/610) keratoconus progression continued after CXL. Three eyes were retreated successfully with documented refractive and topographic stability after five years. In the 35 eyes that completed 10 years of follow-up, mean visual acuity and topographic parameters remained stable. In conclusion, CXL is a safe and effective treatment for avoiding keratoconus progression. Long-term data are encouraging, supporting a high safety profile for this procedure.

Current clinical practice in corneal crosslinking for treatment of progressive keratoconus in four Nordic countries

PURPOSE

To evaluate clinical practice in the diagnosis and treatment of progressive keratoconus with corneal crosslinking (CXL) in four Nordic countries.

METHODS

A questionnaire was sent to all centres at which keratoconus patients are evaluated and CXL is performed in Sweden, Denmark, Norway and Iceland. Nineteen of 20 centres participated.

RESULTS

CXL is performed approximately 1300 times per year in these four Nordic countries with a population of around 21.7 million (2019). In most cases, progression is evaluated using the Pentacam HR, and the maximum keratometry reading (K_max ) is considered the most important parameter. The most frequently used treatment protocol in Scandinavia is the 9 mW/cm² epi-off protocol, using hydroxylpropyl methylcellulose riboflavin (HPMC-riboflavin). The participants deemed the following areas to be in most need of improvement: adaptation of the CXL protocol to individual patients (5/19), the development of effective epi-on treatment protocols (4/19), optimal performance of CXL in thin corneas (4/19), improvement of the definition of progression (2/19), and diagnosis of the need for re-treatment (2/19).

CONCLUSIONS

We concluded that the diagnosis of progressive keratoconus and the diagnostic equipment used are similar. Treatment strategies are also similar but are suitably different to provide an interesting basis for the comparison of treatment outcomes. The high degree of participation in this survey indicates the possibility of future scientific collaboration on CXL focusing on the areas deemed to need improvement. It would also be of interest to evaluate the possibility of creating a Nordic CXL Registry. The high number of CXL treatments performed ensures sufficient statistical power to solve many questions. Such a registry could be an important contribution to evidence-based care and would allow for longitudinal evaluation.

Acute corneal melt and perforation – A possible complication after riboflavin/UV-A crosslinking (CXL) in keratoconus

Purpose

To report two cases of acute corneal melting and perforation requiring emergency penetrating keratoplasty after corneal crosslinking (CXL) in advanced keratoconus.

Observations

Case 1 was a 34 and case 2 was a 16-year old male, both with progressive keratoconus, who underwent CXL (Dresden protocol). After riboflavin imbibition, patients had a minimal pachymetry of 337 μm and 347 μm, and therefore required stromal swelling by hypoosmolar riboflavin resulting in pachymetries of 470 μm and 422 μm, prior to the 30 minute UV-irradiation with 3mW/cm². In case 1, on the 7th postoperative day a 4mm linear perforation occurred. Extensive post-hoc examinations revealed no infectious cause. In case 2, a corneal melting developed within 24 hours, from which Staphylococcus aureus was cultured.

Conclusions and importance

Acute corneal melting and perforation may occur after CXL. Dysfunctional collagen metabolism, atopia, thin preoperative pachymetry and the use of hypoosmolar substances may have initiated this complication in our cases.

Evaluation of a Post-Operative Therapy Protocol after Epithelium-Off Corneal Cross-Linking in Patients Affected by Keratoconus

A large retrospective study evaluated the safety of a post-operative therapy protocol after epithelium-off corneal collagen cross-linking (CXL). In total, 1703 eyes of the 1190 patients with progressive keratoconus were enrolled in a retrospective cohort study in a tertiary care university hospital. CXL was performed using a standardized technique (Dresden protocol: 0.1% riboflavin solution containing dextran 20% for 30 min during the soaking phase followed by 30-min ultraviolet A irradiation (3 mW/cm²)). Postoperatively, a bandage contact lens was applied, and therapy included a topical fluoroquinolone antibiotic until the epithelium healed, followed by topical fluorometholone treatment for three weeks. Post-operative complications were recorded and analyzed. No cases of infectious keratitis occurred, whereas peripheral sterile infiltrates were observed in 1.17% of cases. Trace haze was typically present but did not have an impact on visual acuity. In fifteen cases (0.88%), visually significant anterior stromal opacity developed. Mild signs of dry eye were observed in 22 eyes (1.29%). The present study demonstrates that a post-operative treatment protocol including fluoroquinolone antibiotics and a BCL in the first phase until complete epithelial healing, followed by a three-week period of topical steroid treatment is safe and not associated with the development of microbial keratitis.

The Safety Profile of FDA-Approved Epithelium-Off Corneal Cross-Linking in a US Community-Based Healthcare System

Purpose

To determine the occurrence of early post-operative complications following FDA-approved epithelium-off corneal cross-linking in the United States.

Materials and Methods

This multicenter, retrospective cohort study identified patients who underwent epithelium-off (epi-off) corneal cross-linking (CXL) for keratoconus and post-refractive keratectasia within the Kaiser Permanente Northern California healthcare system between 2016 and 2018. Post-operative complications including delayed epithelial healing, infection, and loss of visual acuity were recorded.

Results

The study included 878 eyes of 654 patients. The mean age was 27±9.4 years (range 7–71). Five hundred ninety-nine patients (91.6%) had keratoconus while 55 had post-refractive corneal ectasia (8.4%). Forty-seven eyes had prolonged follow-up because of the occurrence of complications in the early post-operative period. The respective rates of delayed epithelial healing, and keratitis were 3.9% (95% CI 2.7–5.3%), and 1.5% (95% CI 0.8–2.5%). Four approaches for management of delayed epithelial healing were compared; epithelium healing duration was the longest in the repeat bandage contact lens (BCL) group (23.8 days) and the shortest in the antibiotic ointment group (14.3 days), with statistically significant differences (p < 0.05) in the healing time between these 2 groups.

Conclusion

The concern for early clinical complications after epi-off CXL often leads to delayed CXL intervention and further keratoconus progression with increased economic burdens. A large retrospective review of 878 eyes found that FDA-approved epi-off CXL protocol appears to be safe with low occurrence rates of early post-operative complications. The recommended management for delayed epithelial healing is using antibiotic ophthalmic ointment.

Polymicrobial keratitis after accelerated corneal collagen cross-linking in keratoconus: Case reports and literature review

PURPOSE

To report two cases of polymicrobial keratitis following corneal collagen cross-linking for keratoconus and to review the literature.

METHODS

Retrospective case note and literature review.

RESULTS

The first case involved a 27-year-old male who presented with amebic corneal ulcers 3 days after the collagen cross-linking procedure. Some gram-negative (gram-ve) cocci were found upon staining, and cysts were observed by confocal microscopy at 7 days after surgery. Acanthamoeba infection mixed with gram-ve organisms was diagnosed. In the second case, a 14-year male developed Staphylococcus aureus corneal infection with anterior chamber empyema 3 days after the collagen cross-linking procedure for keratoconus. Occasional gram-positive (gram + ve) cocci and gram-ve bacilli were observed under a microscope. The mixed keratitis in the two patients resolved after systemic and topical antibiotic therapy, but the infection ultimately resulted in corneal scarring. Follow-up keratoplasty was needed to improve vision acuity in both patients.

CONCLUSION

Although ultraviolet irradiation and the reactive oxygen released by riboflavin during collagen cross-linking have bactericidal effects, a lack of a corneal epithelial barrier, bandage contact lens usage, perioperative hygiene, and an abnormal immune state are risk factors for infectious keratitis after collagen cross-linking. Perioperative management of collagen cross-linking is important to prevent infection.

Vernal keratoconjunctivitis and keratoconus

PURPOSE OF REVIEW

Vernal keratoconjunctivitis (VKC) is a severe allergic inflammatory disease affecting the conjunctiva in children and young adults. Keratoconus (KC) is a progressive corneal disease characterized by thinning of the corneal stroma, increased and asymmetric corneal curvature, with a potential for significant visual deterioration and is one of the most common corneal complications of VKC. We aimed to review the association of these two diseases, with focus on the mechanisms, prevalence, natural history and treatment strategies of KC associated with VKC.

RECENT FINDINGS

KC is a common complication of VKC. KC prevalence can be as high as 26.8% among VKC patients, whereas abnormal corneal topography may appear in up to 71% of them. It is more severe and progresses faster in the setting of VKC (P < 0.05), with remarkable visual deterioration and with an increased need for keratoplasty. Crosslinking treatment and corneal transplantation appear to be as effective for KC patients with VKC as compared to the patients without VKC. However, postoperative complications are higher in patients with VKC and demand close monitoring, tight control of local inflammation and prompt awareness with consequent restrain of eye rubbing.

SUMMARY

Patients with VKC should be closely monitored for KC. Prompt recognition of VKC and KC allows tight control of KC pathogenesis mechanisms, timely management of KC progression and preservation of vision and quality of life of young patients.

Infectious keratitis after corneal crosslinking for keratoconus caused by levofloxacin-resistant microorganisms

Introduction

We present seven cases of infectious keratitis after corneal crosslinking (CXL) to attenuate keratoconus progression.

Methods

Of 524 consecutive patients who underwent CXL, 7 cases (4 males and 3 females; 21.5 ± 7.1 years) developed postoperative infectious keratitis were retrospectively reviewed. CXL was performed using the Dresden protocol or an accelerated protocol involving epithelial removal.

Results

All cases appeared normal on the day after surgery, but subsequently developed eye pain, blurred vision, corneal infiltration, inflammation of the anterior chamber, and ciliary injection on day 2 or 3. Methicillin-resistant Staphylococcus aureus was cultured from two eyes, methicillin-sensitive Staphylococcus aureus from two eyes, and Streptococcus pneumoniae from one eye. All detected bacteria were resistant to levofloxacin (LVFX). Five of the seven cases, especially four of the five severe cases with hypopyon, had a history of atopic dermatitis. All cases were observed after 2015.

Conclusions

Infectious keratitis after CXL caused by microbes resistant to LVFX is increasing. In addition to careful postoperative observation of the cornea, preoperative evaluation of bacteria within the conjunctival sac evident on nasal swab cultures may be useful to identify potentially problematic microbes and inform the selection of appropriate antibiotics.

Infectious keratitis after corneal crosslinking: systematic review

Corneal crosslinking is a U.S. Food and Drug Administration--approved therapy to stiffen the cornea and prevent progression of corneal ectasia in patients with keratoconus. The standard procedure involves removal of the corneal epithelium (epithelial-off) prior to treatment. Variations to the standard procedure include accelerated crosslinking and transepithelial procedures. This study reviewed what is known regarding the risk for infection after epithelial-off crosslinking, the spectrum of pathogens, and clinical outcomes. 26 publications were identified. All eyes were fit with a bandage contact lens postoperatively. Available data indicate that the overall frequency of infectious keratitis after epithelium-off crosslinking is low. Bacterial infections are the most common, with a mean time of presentation of 4.8 days postoperatively. The use of steroids and bandage contact lenses in the immediate postoperative period and/or a history of atopic or herpetic disease were associated with infection. These patients require intense postoperative care with prophylactic antiviral therapy when appropriate.

A case of infectious crystalline keratopathy after corneal cross-linking

Purpose

To present a case of infectious crystalline keratopathy after corneal cross-linking in a child with delayed wound healing, and its successful management with antibiotic and anti-fungal eye drops.

Observations

A 14-year-old male presented for a second opinion with a non-staining crystalline keratopathy after corneal crosslinking for progressive keratoconus. He reportedly rubbed his eyes vigorously in the post-operative course and had a slowly healing epithelial defect. He was treated with several antibiotic drops and was put on high dose topical difluprednate drops post-procedure for persistent corneal haze. His infection continued to progress until steroids were stopped and he was treated with topical voriconazole. While cultures were negative, the patient's visual acuity and corneal lesions improved significantly after starting voriconazole therapy and stopping steroid drops, pointing to a diagnosis of infectious crystalline keratopathy.

Conclusions and Importance

This is one of the first case reports to describe a primary infectious crystalline keratopathy after a corneal cross-linking procedure, and the first to describe this phenomenon in a child with delayed corneal re-epithelialization. Though corneal cross-linking is a relatively safe procedure, atypical infections like crystalline keratopathy can occur in these patients in the setting of topical steroid use. Atypical organisms such as fungi should always be on the differential, especially for patients with recalcitrant infection in the setting of immunosuppression.

Bilateral Keratoconus Progression: Immediate Versus Delayed Sequential Bilateral Corneal Cross-linking

PURPOSE

To compare immediate sequential bilateral corneal cross-linking (CXL), wherein both eyes are treated on the same day, to delayed sequential bilateral CXL, where each eye is treated on different days for bilateral progressive keratoconus.

METHODS

This was a retrospective case note review of all patients who underwent sequential CXL or delayed CXL for keratoconus at Royal Liverpool University Hospital, United Kingdom. Parameters assessed were the change in maximum keratometry and minimum central corneal thickness on corneal tomography scan, corrected distance visual acuity, and cost estimates of treatment.

RESULTS

A total of 38 patients (31 men and 7 women) with keratoconus with a mean age of 25.3 ± 7.0 years were included. Twenty patients received sequential CXL and 18 received delayed CXL treatment. In both the sequential CXL and delayed CXL groups, the treated eye(s) showed no evidence of progression after the corneal CXL treatment at last follow-up visit after 358 ± 158 days for sequential CXL and 451 ± 205 days for delayed CXL. There were no complications from the treatment in either group. In the delayed CXL group, the mean time interval between the two CXL procedures was 146 ± 129 days. Five of 18 patients (27%) showed progression of keratoconus in their second eye during the waiting time. Economical evaluation showed that four visits were saved for each sequential CXL treatment compared to delayed CXL.

CONCLUSIONS

Delayed CXL carries a risk of progression in the second eye and is associated with a higher economic burden. [J Refract Surg. 2020;36(8):552-556.].

Bilateral methicillin-resistant Staphylococcus aureus keratitis after corneal crosslinking for keratoconus in a child

We report the case of an 11-year-old boy known to have atopic dermatitis who was referred for management of allergic conjunctivitis, meibomian gland dysfunction, and anterior blepharitis. After achieving quiescence of these ophthalmic manifestations, he was lost to follow-up and subsequently presented with bilateral keratoconus. He developed bilateral keratitis with methicillin-resistant Staphylococcus aureus (MRSA) 1 week after corneal cross-linking. Children with underlying atopic dermatitis are more likely to harbor MRSA on their eyelid margins and conjunctival sacs and are therefore at higher risk of postoperative infection. Prevention and treatment measures, such as preoperative screening and the use of appropriate perioperative antibiotics against MRSA should always be considered in this population.

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.

Microbial Keratitis After Corneal Collagen Cross-Linking for Corneal Ectasia

PURPOSE

The aim of this study was to report the clinical profile and microbiological of patients with microbial keratitis post accelerated corneal collagen cross-linking (CXL).

METHODS

A retrospective case series of all patients diagnosed with microbial keratitis post-CXL who attended the Sydney Eye Hospital, Australia from January 1, 2012 to December 31, 2019 were included. Patients were identified from hospital coding and pathology data. Data were extracted from patients' medical records.

RESULTS

Eleven eyes from 10 patients with a mean age of 29 ± 11 years (range 16-48) were included. The median time of infection after CXL surgery was 4 days [interquartile range (IQR) 3-83]. Median initial and final Visual acuity at presentation were 1.3 logMAR (IQR 1-2.0) and 0.8 logMAR (IQR 0.6-1.2), respectively. The culture positivity rate was 92%, identifying 13 isolates, predominately made up of coagulase-negative Staphylococcus (n = 6, 50%) and Staphylococcus aureus (n = 3, 25%). The median epithelial healing time was 30 days (IQR 15-53).

CONCLUSIONS

Post-CXL microbial keratitis was predominately associated with gram-positive bacteria and in some cases delayed epithelialization. Microbial keratitis post-CXL may lead to moderate to poor patient outcomes.

Corneal Cross-Linking for Keratoconus: Current Knowledge and Practice and Future Trends

Corneal collagen cross-linking (CXL) with riboflavin is an accepted universal standard of care for our keratoconus patients with progressive disease. It has been a game changer in how we manage keratoconus. Early diagnosis and treatment is essential in paediatric patients as younger patients progress more rapidly and have poorer transplant outcomes. There is an ongoing debate around standard, accelerated, and transepithelial protocols of CXL, the role of CXL, and the combination of laser refractive surgery. Future developments will improve CXL safety and efficacy and the scope of utilization, but we must be careful not to leap too far ahead with clinical applications before publication of basic science research and good clinical results with standardized protocols.

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.

Clinical outcomes of KeraVio using violet light: emitting glasses and riboflavin drops for corneal ectasia: a pilot study

BACKGROUND/AIMS

We developed a novel technology consisting of violet light (VL)-emitting glasses and defined the combination of VL irradiation and riboflavin treatment as KeraVio. Our goal was to evaluate the clinical results of KeraVio in patients with progressive corneal ectasia.

METHODS

Eyes were exposed to VL (375 nm, irradiance 310 μW/cm²)-emitting glasses for 3 hours daily for 6 months, and a riboflavin solution was administered onto the corneal epithelium six times during each 3-hour VL irradiation. The primary end point was a change in the maximum keratometry (Kmax) value over 6 months compared with that over the 1 year before baseline.

RESULTS

The efficacy of KeraVio was evaluated in 20 eyes with severe progression, and its safety was evaluated in all 40 eyes. The mean changes in Kmax over the 1 year before baseline and during the 6-month observation period were 6.03±3.41 dioptres (D) and -0.81±3.34 D, respectively (p=0.002). At 6 months, the Kmax value decreased by more than 2 D in 4 eyes (20%), remained within 2 D in 13 eyes (65%), and increased by 2 D or more in 3 eyes (15%). The corneal stromal demarcation line was identified in 16 eyes (80%), and its depth was 206.3±54.9 μm at 1 month. No significant decrease in endothelial cell density, lenticular opacity or transient corneal haze was noted.

CONCLUSION

Based on our 6-month results, daily treatment of progressive corneal ectasia with KeraVio can halt disease progression without any safety concerns.

CLINICAL TRIAL REGISTRATION NUMBER

jRCTs032180217.

Profile of infectious and sterile keratitis after accelerated corneal collagen cross-linking for keratoconus

PURPOSE:

The aim of this study was to assess the potential risk factors and causes of infectious and sterile keratitis after accelerated collagen cross-linking.

METHODS:

Case records of 968 eyes that underwent accelerated corneal collagen cross-linking (ACXL) over the period of 4 years were reviewed retrospectively. ACXL was done using (Avedro KXL^® system, Waltham, MA, USA) 9 mW/cm² for 10 min protocol providing total energy of 5.4 J/cm².

RESULTS:

Of 968 eyes, a total of three eyes developed infectious keratitis and seven eyes developed sterile infiltrates. Three of this infectious keratitis had two cases which were resistant to fourth-generation fluoroquinolones. Seven cases of sterile infiltrates had excellent resolution after treatment with topical steroids. Sterile infiltrates were common in corneas with thinnest pachymetry of <400 µm, except in one case of intra stromal corneal ring segments (INTACS) + ACXL.

CONCLUSION:

Judicious use of steroids in the initial postoperative period is recommended so as to prevent any form of microbial keratitis. Very steep corneas and too thin corneas should be looked with high index of suspicion in view of chances of developing sterile infiltrates.

Alternaria keratitis after corneal crosslinking

Purpose

To report a case of fungal keratitis after corneal collagen crosslinking (CXL) surgery.

Observations

We report a case of fungal keratitis after CXL for post-refractive surgery ectasia. The patient presented 12 days after surgery with a corneal ulcer that was culture positive for Alternaria species of fungus. She subsequently developed a bacterial superinfection. The keratitis resolved with medical therapy, although the patient required a penetrating keratoplasty (PKP) due to central corneal scarring.

Conclusions and Importance

To our knowledge, this is the first case of fungal keratitis as a complication after CXL in the United States and the first case of Alternaria infection after CXL using the Dresden protocol. Infectious keratitis is a rare but serious complication of CXL, and we suggest continued innovation of operative techniques that may reduce the risk of infectious keratitis.

Bandage contact lens and topical steroids are risk factors for the development of microbial keratitis after epithelium-off CXL

Objective

To investigate the role of bandage contact lenses (BCL) and topical steroids as risk factors for the development of microbial keratitis after epithelium-off corneal collagen cross-linking (CXL).

Methods and Analysis

Patients undergoing CXL between February 2011 and July 2017 were included. Patients were divided into two groups: those who were treated postoperatively with a BCL, topical antimicrobial and steroids (group 1) and those who received only a topical antimicrobial until healing of the epithelial defect before introduction of topical steroids (group 2).

Results

1273 eyes of 964 patients were included. Group 1 comprised 316 eyes and group 2 comprised 957 eyes. There were no significant differences in the presence of persisting corneal haze or scarring between the two groups (p=0.57). Microbial keratitis occurred in nine eyes (0.71% of eyes) of eight (0.83%) patients (one case was bilateral) out of 1273 eyes. Staphylococcus aureus was cultured from corneal scrapes in seven out of nine (77.8%) cases and from contiguous sites in the two cases. All cases occurred in group 1 (incidence=2.85%) and none in group 2 (p<0.0001). A greater proportion of patients who developed microbial keratitis were atopic (75%, p=0.4).

Conclusion

The use of BCL and topical steroids prior to healing of the epithelium is a significant risk factor for microbial keratitis. S. aureus is the most common micro-organism and is likely to originate from an endogenous site. Not using a BCL and delaying the introduction of topical steroids until epithelial healing significantly reduce the risk of developing microbial keratitis without increasing the risk of persistent corneal haze.

Comparison of standard and accelerated corneal cross-linking for the treatment of keratoconus: a meta-analysis

PURPOSE

To compare results between standard and accelerated corneal collagen cross-linking (CXL) for the treatment of progressive keratoconus.

METHODS

We performed literature searches in PubMed, Cochrane Library, Web of Science, ISRCTN registry, ClinicalTrials.gov, and EMBASE for studies comparing conventional Dresden (C-CXL) and accelerated CXL (A-CXL). Outcomes were clinical results and changes in corneal properties. Weighted mean differences were used to evaluate the effects.

RESULTS

Here, 22 studies with 1158 eyes (C-CXL: 577 eyes; A-CXL: 581 eyes) were included. At the last follow-up, C-CXL was superior regarding minimum keratometry (p < 0.00001) and demarcation line depth (p < 0.00001), whereas A-CXL should be favoured when considering minimum corneal thickness (p = 0.0005). No differences in uncorrected and corrected distance visual acuity (p = 0.09 and 0.98), spherical equivalent (p = 0.11), spherical and cylindrical error (p = 0.29 and 0.32), maximal and average keratometry (p = 0.05 and 0.65), central corneal thickness (p = 0.15), corneal biomechanical properties (p ≥ 0.21 respectively), time of reepithelialization (p = 0.76), subbasal nerve density (p = 0.69), endothelial cell density (p = 0.30) and morphology (p ≥ 0.40 respectively) were found among both groups.

CONCLUSION

Consideration of less corneal thinning favours A-CXL, whereas the deeper demarcation line and greater changes in minimum keratometric values in C-CXL may indicate a higher treatment efficacy. Altogether, C-CXL, as well as A-CXL, provides successful results in the strengthening of corneal tissue.

Corneal crosslinking without epithelial removal

PURPOSE

To evaluate the effect of riboflavin-ultraviolet (UV)-A corneal crosslinking (CXL) without epithelial removal on ectatic corneal disease.

SETTING

Woolfson Eye Institute, Atlanta, Georgia, USA.

DESIGN

Prospective observational study.

METHODS

Patients were treated with a new riboflavin formulation without epithelial removal, then exposed to UV light (365 nm) at 4 mW/cm² with on-off cycling for 30 minutes. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, maximum corneal curvature (maximum keratometry [Kmax]), total higher-order aberrations (HOAs), and coma were measured at 3, 6, 12, and 24 months postoperatively. Progression was defined as an increase of more than 1 diopter (D) in Kmax and loss of more than 1 line of CDVA.

RESULTS

Five hundred twelve eyes of 308 patients with keratoconus or forme fruste keratoconus and 80 eyes of 55 patients with ectasia after laser in situ keratomileusis (LASIK) were treated with the new riboflavin formulation without epithelial removal; 229 patients received bilateral treatments, 95 of which were simultaneous. The mean UDVA and CDVA improved by 1 to 1.5 Snellen lines at 1 and 2 years postoperatively (P < .0001). Mean Kmax decreased by 0.48 D at 2 years postoperatively (P = .0002). Mean total HOAs and coma decreased by 36% (P < .0001) and 37% (P = .0002), respectively, at 2 years postoperatively. Kmax decreased more than 1 D in three times as many eyes as it increased more than 1 D (P < .0001). No eyes progressed, and there was no loss of effect between 1 and 2 years postoperatively. No vision-threatening events were observed. Pain typically resolved within 24 hours, and visual acuity returned to preoperative levels in 1 to 2 days.

CONCLUSION

Epithelium-on CXL using this new protocol halted the progression of keratoconus and ectasia after LASIK. It was safer and provided more rapid visual recovery than CXL with epithelial removal, allowing routine bilateral, simultaneous treatment.

A Review of Corneal Collagen Cross-linking - Current Trends in Practice Applications

Objective:

To review the literature on current applications of corneal Collagen Cross-Linking (CXL).

Methods:

A review of publications on corneal cross-linking was conducted. This included systemic reviews, randomized controlled clinical trials, cohort studies, case-controlled studies and case series. A summary of the publications is tabulated.

Results:

The original indication of riboflavin – Ultraviolet-A (UVA) induced corneal collagen cross-linking is to arrest the progression of keratoconus. Studies show that it is effective in arresting the progression of keratoconus and post-LASIK ectasia with the standard Dresden protocol (epithelium-off). There are also improvements in visual, keratometric and topographic measurements over time. Severe complications of cross-linking are rare. The epithelium-on techniques have less efficacy than the Dresden protocol. Accelerated protocols have variable results, with some studies reporting comparable outcomes to the Dresden protocol while other studies reporting less efficacious outcomes. Cross-linking combined with refractive procedures provide better visual outcome but long term studies are warranted. Cross-linking for the treatment of infective keratitis is a promising new treatment modality. Initial studies show that it is more effective for superficial rather than deep infections and for bacterial rather than fungal infections.

Conclusions:

Corneal cross-linking is a procedure with an expanding list of indications from the treatment of corneal ectasias to infective keratitis. While the standard Dresden protocol is established as the gold standard treatment for progressive keratoconus, the more recent protocols may require further refinements, investigative and long-term studies.

Corneal Cross-Linking for Pediatric Keratcoconus Review

PURPOSE

To comprehensively review the available published literature for cross-linking in the pediatric population.

METHODS

Review of the literature published in English in PubMed.

RESULTS

Two hundred ten publications were considered. One hundred fifteen were considered relevant to this review.

CONCLUSIONS

Studies of cross-linking in pediatric patients are sparse, with relatively short follow-up times, and mostly on small groups of patients. Treatment with cross-linking halts progression of keratoconus in the pediatric population, and early treatment seems to be cost-effective compared with later penetrating keratoplasty. Long-term effects and regression rates remain unclear, and further studies are needed in this population.

Updates on corneal collagen cross-linking: Indications, techniques and clinical outcomes

Purpose

To review the historical background and basic principles of collagen cross-linking, to bring together the data regarding the outcomes and complications of collagen cross-linking and finally to explore the efficacy and safety of new variations of this technique.

Methods

A literature review was performed using PubMed and Scopus. The following keywords were used for literature search: cross linking, crosslinking, cross-linking, keratoconus, keratectasia.

Results

In contrast to traditional treatment modalities for keratoconus (KCN), this new technique addresses the progression of the disease. Several clinical studies have been conducted to assess the efficacy of corneal collagen cross-linking (CXL) in the last decade. The results were promising as collagen cross-linking showed significant improvement in visual acuity and keratometric values. Moreover, initial results show that it is a safe procedure with few reported complications.

Conclusion

CXL is an emerging treatment method in ophthalmology that offers the possibility to effectively treat progressive KCN.

Cost-Effectiveness Analysis of Corneal Collagen Crosslinking for Progressive Keratoconus

PURPOSE

To evaluate the cost effectiveness of corneal collagen crosslinking (CXL) for progressive keratoconus from the healthcare payer's perspective.

DESIGN

A probabilistic Markov-type model using data from published clinical trials and cohort studies.

PARTICIPANTS

Two identical cohorts, each comprising 1000 virtual patients with progressive bilateral keratoconus, were modeled; one cohort underwent CXL and the other cohort received no intervention.

METHODS

Both cohorts were modeled and evaluated annually over a lifetime. Quality-adjusted life years (QALYs), total cost, disease progression, and the probability of corneal transplantation, graft failure, or both were calculated based on data from published trials and cohort studies. These outcomes were compared between the 2 cohorts. In our base scenario, the stabilizing effect of CXL was assumed to be 10 years; however, longer durations also were analyzed. One-way sensitivity analyses were performed to test the robustness of the outcomes.

MAIN OUTCOME MEASURE

Incremental cost-effectiveness ratio (ICER), defined as euros per QALY.

RESULTS

Assuming a 10-year effect of CXL, the ICER was €54 384/QALY ($59 822/QALY). When we adjusted the effect of CXL to a lifelong stabilizing effect, the ICER decreased to €10 149/QALY ($11 163/QALY). Other sensitivity and scenario analyses that had a relevant impact on ICER included the discount rate, visual acuity before CXL, and healthcare costs.

CONCLUSIONS

Corneal collagen crosslinking for progressive keratoconus is cost effective at a willingness-to-pay threshold of 3 times the current gross domestic product (GDP) per capita. Moreover, a longer stabilizing effect of CXL increases cost effectiveness. If CXL had a stabilizing effect on keratoconus of 15 years or longer, then the ICER would be less than the 1 × GDP per capita threshold and thus very cost effective.

Phototoxic Effect of Topical Fluoroquinolones Administered Before Corneal Crosslinking in a Murine Model

PURPOSE

Corneal crosslinking by UV light (UV-CXL) has become a popular treatment for keratoconus and corneal ectasia. Fluoroquinolones (FQs), commonly administered topically before UV-CXL, are known to be phototoxic to the skin and lens. The purpose of this study was to investigate phototoxic effects of topical FQ treatment on murine corneas before UV-CXL, in which the corneal epithelium was kept intact.

METHODS

Murine corneas were treated with various antibiotics with or without riboflavin before UV-CXL. At 24 h, the animals were sacrificed, and the corneas were analyzed for histologic evidence of inflammation and apoptosis and for expression of apoptosis markers BAX and caspases 3 and 9 and for expression of matrix metalloproteinase 9 (MMP-9). Spectrofluorometric analysis was performed.

RESULTS

Corneas treated with topical FQ with or without riboflavin before UV-CXL showed mild corneal stromal inflammation, apoptosis by both terminal deoxynucleotidyl transferase dUTP nick end labeling staining and increased expression of BAX gene and caspases 3 and 9 by densitometric analysis. Untreated corneas, corneas treated with azithromycin before UV-CXL, and corneas undergoing UV-CXL without any antibiotic or riboflavin pretreatment showed normal histology, no staining for apoptosis, and no increased production of apoptosis markers by polymerase chain reaction.

CONCLUSIONS

The phototoxic effects of FQs on the cornea may lead surgeons to consider another antibiotic class for prophylaxis against infectious keratitis in UV-CXL. These effects, along with the known cytotoxic effects of FQs independent of UV radiation, may contribute to some of the complications of corneal UV-CXL. Dosage studies may be warranted.

Corneal collagen crosslinking for corneal ectasias: a review

PURPOSE

To review the published literature on corneal collagen crosslinking (CXL).

METHODS

Importance has been placed on seminal publications, systemic reviews, meta-analyses, and randomized controlled clinical trials. Where such evidence was not available, cohort studies, case-controlled studies, and case series with follow-up greater than 12 months were examined.

RESULTS

Corneal collagen crosslinking with riboflavin and ultraviolet A (UVA) 370 nm radiation appears to be capable of arresting the progression of ectatic corneal disorders, with most studies reporting significant improvements in visual, keratometric, and topographic measurements. Its mode of action at the molecular level is undetermined. Follow-up is limited to 5-10 years but suggests sustained stability and enhancement in corneal shape with time. Nearly all published long-term data and comparative studies are with epithelium-off techniques. Epithelium-on investigations suggest some efficacy but less than with epithelium-off treatments and long-term data are unavailable. Accelerated techniques with higher UVA fluencies and shorter treatments times, delivering the same UVA energy dosage, are the subject of recent investigation, with some laboratory and clinical studies suggesting reduced efficacy compared to the standard 3 mW/cm2 for 30 minutes irradiation procedure. Combined methodologies of CXL with techniques such as photorefractive keratectomy and intrastromal rings show promise but long-term follow-up is indicated. Sight-threatening complications of CXL are rare.

CONCLUSIONS

Studies of epithelium-off CXL with irradiation at 3 mW/cm2 for 30 minutes support its efficacy. Refinement in techniques may allow for safer and more rapid procedures with less patient discomfort but require further investigation.

Ex vivo rabbit and human corneas as models for bacterial and fungal keratitis

PURPOSE

In the study of microbial keratitis, in vivo animal models often require a large number of animals, and in vitro monolayer cell culture does not maintain the three-dimensional structure of the tissues or cell-to-cell communication of in vivo models. Here, we propose reproducible ex vivo models of single- and dual-infection keratitis as an alternative to in vivo and in vitro models.

METHODS

Excised rabbit and human corneoscleral rims maintained in organ culture were infected using 10⁸ cells of Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans or Fusarium solani. The infection was introduced by wounding with a scalpel and exposing corneas to the microbial suspension or by intrastromal injection. Post-inoculation, corneas were maintained for 24 and 48 h at 37 °C. After incubation, corneas were either homogenised to determine colony-forming units (CFU)/cornea or processed for histological examination using routine staining methods. Single- and mixed-species infections were compared.

RESULTS

We observed a significant increase in CFU after 48 h compared to 24 h with S. aureus and P. aeruginosa. However, no such increase was observed in corneas infected with C. albicans or F. solani. The injection method yielded an approximately two- to 100-fold increase (p < 0.05) in the majority of organisms from infected corneas. Histology of the scalpel-wounded and injection models indicated extensive infiltration of P. aeruginosa throughout the entire cornea, with less infiltration observed for S. aureus, C. albicans and F. solani. The models also supported dual infections.

CONCLUSIONS

Both scalpel wounding and injection methods are suitable for inducing infection of ex vivo rabbit and human cornea models. These simple and reproducible models will be useful as an alternative to in vitro and in vivo models for investigating the detection and treatment of microbial keratitis, particularly when this might be due to two infective organisms.

Keratoconus and Other Corneal Diseases: Pharmacologic Cross-Linking and Future Therapy

The ability to cross-link collagen fibers and use this technique to strengthen the cornea has become of great interest to ophthalmologists in the last decade. For progressive diseases such as keratoconus, collagen cross-linking confers the possibility of halting progression and stabilizing the cornea, a benefit that is not observed with any other current treatment. Collagen cross-linking uses riboflavin combined with ultraviolet A light to induce the formation of bonds between collagen fibrils that strengthen the cornea. This chapter will discuss the theory, technique, indications, and complications of corneal cross-linking. Much of what will be discussed is in areas of active research that will likely be further clarified as more experience is gained with this procedure.

Dectin-1 agonist curdlan modulates innate immunity to Aspergillus fumigatus in human corneal epithelial cells

AIM

To explore the immunomodulatory effects of curdlan on innate immune responses against Aspergillus fumigatus (A. fumigatus) in cultured human corneal epithelial cells (HCECs), and whether C-type lectin receptor Dectin-1 mediates the immunomodulatory effects of curdlan.

METHODS

The HCECs were stimulated by curdlan in different concentrations (50, 100, 200, 400 µg/mL) for various time. Then HCECs pretreated with or without laminarin (Dectin-1 blocker, 0.3 mg/mL) and curdlan were stimulated by A. fumigatus hyphae. The mRNA and protein production of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were determined by real-time quantitative polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The protein level of Dectin-1 was measured by Western blot.

RESULTS

Curdlan stimulated mRNA expression of TNF-α and IL-6 in a dose and time dependent manner in HCECs. Curdlan pretreatment before A. fumigatus hyphae stimulation significantly enhanced the expression of TNF-α and IL-6 at mRNA and protein levels compared with A. fumigatus hyphae stimulation group (P<0.05). Both curdlan and A. fumigatus hyphae up-regulated Dectin-1 protein expression in HCECs, and Dectin-1 expression was elevated to 1.5- to 2-fold by curdlan pretreatment followed hyphae stimulation. The Dectin-1 blocker laminarin suppressed the mRNA expression and protein production of TNF-α and IL-6 induced by curdlan and hyphae (P<0.05).

CONCLUSION

These findings demonstrated that curdlan pretreatment enhanced the inflammatory response induced by A. fumigatus hyphae in HCECs. Dectin-1 is essential for the immunomodulatory effects of curdlan. Curdlan may have high clinical application values in fungal keratitis treatment.

Methicillin-Resistant Staphylococcus aureus Ocular Infection after Corneal Cross-Linking for Keratoconus: Potential Association with Atopic Dermatitis

Purpose. To report the risk of methicillin-resistant Staphylococcus aureus (MRSA) ocular infection after UVA-riboflavin corneal collagen cross-linking in a patient with atopic dermatitis. Methods. A 22-year-old man, with bilateral evolutive keratoconus and atopic dermatitis, underwent UVA-riboflavin corneal cross-linking and presented with rapidly progressive corneal abscesses and cyclitis in the treated eye five days after surgery. The patient was admitted to the hospital and treated with broad-spectrum antimicrobic therapy. Results. The patient had positive cultures for MRSA, exhibiting a strong resistance to antibiotics. Antibiotic therapy was modified and targeted accordingly. The intravitreal reaction is extinguished, but severe damage of ocular structures was unavoidable. Conclusion. Riboflavin/UVA corneal cross-linking is considered a safe procedure and is extremely effective in halting keratoconus' progression. However, this procedure is not devoid of infectious complications, due to known risk factors and/or poor patients' hygiene compliance in the postoperative period. Atopic dermatitis is a common disease among patients with keratoconus and Staphylococcus aureus colonization is commonly found in patients with atopic dermatitis. Therefore, comorbidity with atopic dermatitis should be thoroughly assessed through clinical history before surgery. A clinical evaluation within three days after surgery and the imposition of strict personal hygiene rules are strongly recommended.