Treatment of Progressive or Recurrent Epithelial Ingrowth With Ethanol Following Laser in situ Keratomileusis

Selection of an Appropriate In Vitro Susceptibility Test for Assessing Anti-Pythium insidiosum Activity of Potassium Iodide, Triamcinolone Acetonide, Dimethyl Sulfoxide, and Ethanol

The orphan but highly virulent pathogen Pythium insidiosum causes pythiosis in humans and animals. Surgery is a primary treatment aiming to cure but trading off losing affected organs. Antimicrobial drugs show limited efficacy in treating pythiosis. Alternative drugs effective against the pathogen are needed. In-house drug susceptibility tests (i.e., broth dilution, disc diffusion, and radial growth assays) have been established, some of which adapted the standard protocols (i.e., CLSI M38-A2 and CLSI M51) designed for fungi. Hyphal plug, hyphal suspension, and zoospore are inocula commonly used in the drug susceptibility assessment for P. insidiosum. A side-by-side comparison demonstrated that each method had advantages and limitations. Minimum inhibitory and cidal concentrations of a drug varied depending on the selected method. Material availability, user experience, and organism and drug quantities determined which susceptibility assay should be used. We employed the hyphal plug and a combination of broth dilution and radial growth methods to screen and validate the anti-P. insidiosum activities of several previously reported chemicals, including potassium iodide, triamcinolone acetonide, dimethyl sulfoxide, and ethanol, in which data on their anti-P. insidiosum efficacy are limited. We tested each chemical against 29 genetically diverse isolates of P. insidiosum. These chemicals possessed direct antimicrobial effects on the growth of the pathogen in a dose- and time-dependent manner, suggesting their potential application in pythiosis treatment. Future attempts should focus on standardizing these drug susceptibility methods, such as determining susceptibility/resistant breakpoints, so healthcare workers can confidently interpret a result and select an effective drug against P. insidiosum.

Disruption of ingrown epithelium via Nd:YAG laser or DIEYAG. A retrospective case series of Post-LASIK patients

Purpose

To describe in detail the technique used and results of disruption of ingrown epithelium via Nd:YAG laser (DIEYAG) after LASIK treatment and enhancement.

Observations

Epithelial ingrowth following laser in situ keratomileusis (LASIK) enhancement has the potential to cause significant refractive error and discomfort when allowed to progress. This retrospective case series following seven eyes after LASIK enhancement and one eye with flap trauma, assessed the effectiveness and safety of the disruption of ingrown epithelium via Nd:YAG laser. In all cases, we found that the progression of ingrown epithelium was eliminated. Using best spectacle corrected visual acuity and topography as our main outcome measures, we found that refractive error and visual disturbance caused by ingrowth stabilized or improved, with no subsequent complications identified.

Conclusion and Importance

The disruption of ingrown epithelium via Nd:YAG laser offers a safe and effective alternative to other treatments for epithelial ingrowth after LASIK treatment and enhancement.

Management of Complex Epithelial Ingrowth After Laser In Situ Keratomileusis Using Fibrin Tissue Glue

OBJECTIVES

To evaluate the efficacy and safety of adjunctive fibrin tissue glue in the treatment of complex epithelial ingrowth after laser in situ keratomileusis (LASIK).

METHODS

A retrospective review was performed of 12 eyes in 12 patients treated for clinically significant epithelial ingrowth after LASIK with mechanical debridement of the ingrowth and placement of fibrin tissue glue. Primary outcome measurements including recurrence of ingrowth, visual acuity, and manifest refraction were evaluated at each postoperative examination. Changes in higher-order aberrometry were also evaluated.

RESULTS

After epithelial ingrowth removal with adjunctive fibrin tissue glue, 11 eyes (91.7%) had no recurrence of ingrowth at the final follow-up examination. Uncorrected distance visual acuity changed from 20/20 or better in 3 eyes (25%) and 20/40 or better in 6 eyes (50%) preoperatively to 20/20 or better in 5 eyes (41.7%) and 20/40 or better in 10 eyes (83.3%) postoperatively. Nine eyes (75%) gained one or more lines of best-corrected distance visual acuity (CDVA). No eyes lost any lines of CDVA. There was no significant change in mean spherical equivalent (P=0.22) or mean cylinder (P=0.26) before and after surgery. Higher-order aberrations also remained stable with no significant change in root-mean-square error, coma, trefoil, and spherical aberration. There were no complications associated with the treatment.

CONCLUSIONS

Adjunctive fibrin tissue glue seems to be a safe and effective treatment for epithelial ingrowth after LASIK. This therapy may be particularly useful in managing challenging cases of complex or recalcitrant ingrowth.

Post-Laser In Situ Keratomileusis Epithelial Ingrowth: Treatment, Recurrence, and Long-Term Results

PURPOSE

To study outcomes after surgical removal of epithelial ingrowth (EI) in post-laser in situ keratomileusis patients, specifically comparing visual results and recurrence rates between 2 different EI management techniques.

METHODS

In this retrospective chart review of 67 eyes of 54 patients who underwent surgical treatment for EI after laser in situ keratomileusis between July 1999 and July 2014 at the Bascom Palmer Eye Institute, Miami, FL, surgical techniques, recurrence rates, visual acuity (VA), and refractive error were assessed.

RESULTS

Of the 67 eyes, 56 eyes (83.6%) had flap lift + scraping alone, and 11 eyes (16.4%) had flap lift + scraping + suturing. After mean follow-up of 2.5 years, 11 of 56 eyes (19.6%) treated with flap lift + scraping alone had EI recurrence, whereas no eyes treated with flap lift + scraping + suturing had EI recurrence. VA results and refractive errors were better in eyes treated with lift + scraping alone compared with lift + scraping + suturing at 1 month. In the 67 eyes with 1-year follow-up, VA and refractive errors improved from preoperative values and were comparable between groups.

CONCLUSIONS

Scraping alone provides significantly better initial visual outcomes but higher EI recurrence rates compared with scrape-suturing. Long-term visual outcomes are comparable between 2 techniques.

Incidence, Indications, and Outcomes of Eyes Needing Early Flap Lifting After LASIK

PURPOSE

To analyze the incidence, indications, and outcomes associated with early flap relifting after uncomplicated laser in situ keratomileusis (LASIK).

METHODS

All LASIK cases from a single surgical center between 2007 and 2015 were reviewed. Early postoperative flap lift cases (<15 d after surgery) were identified.

RESULTS

Overall, 25,712 eyes were included, of which 366 (1.42%) underwent early postoperative flap lifting. There was a significant reduction in early postoperative flap lifting rates from 2006 (2.46%) to 2015 (0.92%) (P = 0.001). Reasons for early flap lifting included striae (n = 301, 1.17%), diffuse lamellar keratitis (n = 62, 0.24%), flap dislocation (n = 20, 0.08%), epithelial ingrowth (n = 18, 0.07%), and interface debris (n = 15, 0.06%). There was a significant difference in rates and outcomes of flap relifting among high-volume surgeons (P < 0.001). The flap lift group had a significantly lower final safety index (0.95 ± 0.16 vs. 1.01 ± 0.15, P < 0.001), efficacy index (0.85 ± 0.26 vs. 0.94 ± 0.26, P < 0.001), and a higher distance from target refraction (0.39 ± 0.61 vs. 0.21 ± 0.46 D). In unilateral cases, the study eye had a lower safety index (P < 0.001), efficacy index (P < 0.001), and greater distance from target refraction (P = 0.003) compared with the fellow eye. After intervention, 81.1% of cases achieved full resolution, 10.1% achieved partial resolution, 4.1% required additional flap relifting, and 4.7% were nonresolved by the end of follow-up.

CONCLUSIONS

The main indication for early flap relifting after LASIK was striae, and most cases achieved full resolution. Although refractive and visual outcomes are lower in this group, they are, nevertheless, satisfactory.

Nd:YAG laser for epithelial ingrowth after laser in situ keratomileusis

PURPOSE

To evaluate the efficacy of neodymium:yttrium-aluminum-garnet (Nd:YAG) laser for treatment of epithelial ingrowth after laser in situ keratomileusis (LASIK).

PATIENTS AND METHODS

Fifty-eight patients with epithelial ingrowth presented to Sohag refractive center, Sohag, Egypt, between January 2015 and March 2017. Only 41 patients (18 females and 23 males, mean age: 33.4 years) involving 41 eyes were indicated for treatment by Nd:YAG laser as the rest of the eyes were only under observation. Patients with epithelial ingrowth were recognized at a mean of 6 months after primary LASIK procedure (range: 2-16 months). Four eyes had undergone previous LASIK enhancements. Four eyes had the epithelial ingrowth removed by flap lift and scrapping. The mean intensity of the spots used was 0.8 mJ with variable number of shots depending on the size and density of the epithelial ingrowth area. Twenty-eight eyes showed complete regression after one session, while the rest necessitated 2-3 sessions for complete resolution. Mean follow-up period was 8 months (range 5-12 months).

RESULTS

Epithelial ingrowth was treated successfully in all 41 eyes. The uncorrected visual acuities were 20/20, and there was no evidence of recurrent epithelial ingrowth after 6 months with no complications reported.

CONCLUSION

YAG laser is a simple, effective outpatient procedure for the management of epithelial ingrowth after LASIK.

Epithelial ingrowth following laser in situ keratomileusis (LASIK): prevalence, risk factors, management and visual outcomes

The number of laser in situ keratomileusis (LASIK) procedures is continuing to rise. Since its first application for correcting simple refractive errors over 25 years ago, the role of LASIK has extended to treat other conditions, including postkeratoplasty astigmatism/ametropia, postcataract surgery refractive error and presbyopia, among others. The long-term effectiveness, predictability and safety have been well established by many large studies. However, due to the creation of a potential interface between the flap and the underlying stroma, interface complications such as infectious keratitis, diffuse lamellar keratitis and epithelial ingrowth may occur. Post-LASIK epithelial ingrowth (PLEI) is an uncommon complication that usually arises during the early postoperative period. The reported incidence of PLEI ranged from 0%–3.9% in primary treatment to 10%–20% in retreatment cases. It can cause a wide spectrum of clinical presentations, ranging from asymptomatic interface changes to severe visual impairment and flap melt requiring keratoplasty. PLEI can usually be treated with mechanical debridement of the affected interface; however, additional interventions, such as alcohol, mitomycin C, fibrin glue, ocular hydrogel sealant, neodymium:yttriumaluminum garnet laser and amniotic membrane graft, may be required for recurrent or refractory cases. The aims of this review are to determine the prevalence and risk factors of PLEI; to describe its pathogenesis and clinical features and to summarise the therapeutic armamentarium and the visual outcome of PLEI.

Flap Amputation with Phototherapeutic Keratectomy (PTK) and Adjuvant Mitomycin C for Severe Post-Lasik Epithelial Ingrowth

Purpose

To report a patient with severe post–laser in situ keratomileusis (LASIK) epithelial ingrowth and keratolysis treated with flap amputation and phototherapeutic keratectomy (PTK) with adjuvant intraoperative mitomycin C (MMC).

Methods

Case report.

Results

A 55-year-old woman was referred to our department due to severe post-LASIK epithelial ingrowth with corneal melting 2 years after primary LASIK. The patient had had two previous attempts for epithelial ingrowth treatment (flap lift and epithelial ingrowth manual removal) that were unsuccessful. Slit lamp biomicroscopy and anterior segment optical coherence tomography showed extensive epithelial ingrowth and keratolysis (thinning of the LASIK flap) while the patient had photophobia and could not tolerate contact lenses. Flap amputation with subsequent PTK (in order to smooth out the corneal irregularities caused by the keratolysis and/or variations in flap thickness) and adjuvant intraoperative MMC application for 2 minutes was performed. There were no intra- or postoperative adverse events seen during the follow-up period. Six months after the procedure, uncorrected visual acuity improved to 20/40 compared with 20/50 preoperatively, while best spectacle-corrected visual acuity improved from 20/40 to 20/32. The topographic astigmatism was decreased from 3.24 diopters (D) to 1.00 D.

Conclusions

Flap amputation with PTK and adjuvant intraoperative MMC is an option for the management of severe post-LASIK epithelial ingrowth with keratolysis.

Fibrin adhesive in conjunction with epithelial ingrowth removal after laser in situ keratomileusis: long-term results

PURPOSE

To describe the long-term results of fibrin adhesive use in the management of epithelial ingrowth after laser in situ keratomileusis (LASIK).

SETTING

Private practice, Minneapolis, Minnesota, and an academic medical center, Durham, North Carolina, USA.

DESIGN

Retrospective case series.

METHODS

Patients with a history of LASIK had epithelial ingrowth removal with mechanical debridement and fibrin glue application. Visual outcomes and the presence or absence of epithelial ingrowth were evaluated again after 3 months and at the last follow-up. The main outcome measures were recurrence of epithelial ingrowth and visual acuity.

RESULTS

Thirty-nine eyes of 38 patients were evaluated. After epithelial ingrowth removal and application of fibrin glue, 31 eyes (79.5%) had no recurrence of ingrowth at the final follow-up and 5 eyes (12.8%) had mild epithelial ingrowth not requiring removal. Three eyes (7.7%) had significant epithelial ingrowth at the 3-month follow-up that required subsequent removal and fibrin application. At the 3-month follow-up visit, 76.9% of eyes achieved 20/25 or better corrected distance visual acuity (CDVA) and 69.2% of eyes achieved 20/40 or better uncorrected distance visual acuity (UDVA). At the last follow-up visit (mean 26.6 ± 17.0 months [SD]), 84.6% of eyes had 20/25 or better CDVA and 74.4% of eyes had 20/40 or better UDVA.

CONCLUSIONS

Fibrin adhesive in conjunction with manual epithelial removal prevented a clinically significant recurrence of epithelial ingrowth in the majority of eyes. Larger randomized studies are needed to compare the success of this technique with that of others.

FINANCIAL DISCLOSURE

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

Laser confocal microscopy is a valuable, non-invasive tool for early diagnosis and characterisation of epithelial nests

A 22-year-old woman presented with blurred vision and glare in the right eye, which had been present for three months. The patient had undergone laser-assisted in situ keratomileusis nine months previously and enhancement three months thereafter. On ophthalmological examination, visual acuity was 6/8.6 in the right eye and 6/6 in the left eye. An opaque epithelial nest below the flap with a visible demarcation line was detected along the pupil margin in the right eye. Subsequent laser confocal microscopy revealed the presence of epithelial cells in a whorled pattern with irregular astigmatism on corneal topography. Three months later, the clinical symptoms had worsened and a denser and larger wedge-shaped epithelial nest was observed. The nest was scraped. Six months later, the patient exhibited restored visual acuity (6/6) without glare. Laser confocal microscopy is a valuable, non-invasive tool and provides in vivo pathological images for early diagnosis and localisation of lesion depth in epithelial nests to guide appropriate surgical management.

Nd:YAG laser treatment for epithelial ingrowth after laser refractive surgery

Epithelial ingrowth under refractive surgery flaps occurs in primary treatment and in further flap lift. Nd:YAG treatment was first described in 2008. In the only series published to date, 100% of patients treated had topographic and symptomatic improvement. The authors pictorially illustrate two cases of epithelial ingrowth following laser in situ keratomileusis achieving complete symptomatic relief and marked microscopic improvement following Nd:YAG laser treatment.

Incidence of epithelial ingrowth in primary and retreatment laser in situ keratomileusis

PURPOSE

To analyze the risk for clinically significant epithelial ingrowth after primary laser in situ keratomileusis (LASIK) and flap-lift retreatment LASIK.

SETTING

Private practice, Beverly Hills, California, USA.

METHODS

All cases of primary and flap-lift retreatment LASIK performed by the same surgeon in a single surgical center between January 2004 and June 2007 were retrospectively reviewed. Cases that subsequently developed clinically significant epithelial ingrowth, defined as epithelial ingrowth impeding on the visual axis and negatively affecting uncorrected or corrected distance visual acuity, were identified and analyzed.

RESULTS

Clinically significant epithelial ingrowth occurred in none of the 3866 primary LASIK cases and in 15 (2.3%) of the 646 flap-lift retreatment cases (P<.0001). Clinically significant ingrowth was more frequent when flap-lift retreatment was performed 3 or more years after primary LASIK (7.7% versus 1.0%) (P = .0001). Patient age and sex did not have a statistically significant effect on the epithelial ingrowth rate. There was a nonsignificant trend toward increased epithelial ingrowth after flap-lift retreatment of Automated Corneal Shaper (ACS) microkeratome flaps.

CONCLUSION

Flap-lift retreatment performed 3 or more years after primary LASIK led to a higher risk of clinically significant epithelial ingrowth than primary LASIK or earlier flap-lift retreatment.

FINANCIAL DISCLOSURE

The author has no financial or proprietary interest in any material or method mentioned.

Epithelial ingrowth after femtosecond laser-assisted in situ keratomileusis

PURPOSE

To describe the incidence and clinical features of epithelial ingrowth after femtosecond laser-assisted in situ keratomileusis (LASIK).

METHODS

All eyes with clinically significant epithelial ingrowth were identified from patients who underwent primary femtosecond laser-assisted LASIK and their subset of patients who underwent enhancement procedures from January 2005 to March 2007 at Kudret Eye Hospital. Clinical course in terms of severity, type of epithelial ingrowth, time of appearance, effect on visual acuity, and treatment was described for each patient.

RESULTS

Two eyes of 6415 eyes after primary procedure and 2 eyes of 108 eyes after enhancement procedure developed clinically significant epithelial ingrowth. All eyes were treated with surgical removal of epithelial ingrowth. The epithelial ingrowths in all the patients were seen as solitary islands of cells, with a size ranging between 1 and 3 mm, beneath the flap with no connection with the surface epithelium. There was recurrence of ingrowth in 1 eye.

CONCLUSIONS

Visually significant epithelial ingrowth after femtosecond laser-assisted LASIK is an infrequent complication. The lower incidence of epithelial ingrowth after femtosecond LASIK surgery compared with mechanical microkeratome-assisted LASIK may be attributed to the anatomy of the femtosecond laser-created side cut in contrast to that created with a mechanical microkeratome and the creation of less peripheral trauma at the time of flap creation.

Epithelial ingrowth within the interface following traumatic corneal lamellar laceration

A 45-year-old patient with a traumatic corneal lamellar laceration who was treated conservatively initially developed an epithelial ingrowth within the flap-stroma interface, causing diminished vision. Confocal microscopy revealed highly refractive bodies without cellular elements at the flap-stroma interface. Treatment comprised surgical debridement of the epithelial sheet from the interface with a thorough irrigation of the stromal bed followed by careful realignment of the flap. The diagnosis was confirmed by histologic examination of the scraped specimen. At the last follow-up examination, vision had improved and there was no recurrence of epithelial ingrowth. Proper primary management of a traumatic corneal lamellar laceration can provide good visual outcome and prevent rare complications such as epithelial ingrowth.

Treatment of laser in situ keratomileusis interface epithelial ingrowth with neodymium:yytrium-aluminum-garnet laser

PURPOSE

To evaluate the results obtained with the treatment for interface epithelial ingrowth after laser in situ keratomileusis (LASIK) with neodymium:yytrium-aluminum-garnet (Nd:YAG) laser.

DESIGN

Retrospective, interventional, noncomparative, consecutive case series.

METHODS

Thirty eyes were treated with Nd:YAG laser for clinically significant epithelial ingrowth developed after LASIK. Each impact produced an explosion with evaporation of epithelial cells giving rise to bubbles. The mean intensity of the spots was 0.6 mJ, and they were variable in quantity depending on the size of the epithelial ingrowth area. The patients were followed up for two years.

RESULTS

The opacities caused by the epithelial ingrowth disappeared in 80% of the cases with the Nd:YAG laser treatment. In 40% of the cases, two or more sessions of Nd:YAG laser treatment were necessary to eliminate the epithelial ingrowth areas entirely. In 60% of the cases, visual acuity improved by one or more lines of vision and the corneal topography was more regular. After the treatment, symptoms like glare and halos improved in all cases. The intensity of the laser was adjusted in each case and was focused perfectly on the epithelial ingrowth areas. There were no complications.

CONCLUSIONS

Nd:YAG laser, in our experience, is an easy and effective technique for the treatment of epithelial ingrowth after LASIK.

Treatment of epithelial ingrowth after LASIK enhancement with a combined technique of mechanical debridement, flap suturing, and fibrin glue application

PURPOSE

To report a case of clinically significant post-laser in situ keratomileusis (LASIK) epithelial ingrowth successfully treated with a combined technique of mechanical debridement, flap suturing, and fibrin glue application.

METHODS

A retrospective case report.

RESULTS

A 42-year-old female patient underwent LASIK and an enhancement procedure in 1998 and 2002, respectively. Two years after her enhancement, she developed severe, visually significant epithelial ingrowth. Treatment was undertaken using a combination of mechanical debridement, flap suturing, and fibrin glue application. No recurrence was found during a 15-month follow-up period. No adverse effects were seen with this approach.

CONCLUSION

Severe progressive epithelial ingrowth may be treated successfully with a combination of mechanical debridement, flap suturing, and fibrin glue application.

Ethanol Treatment Induces Significant Cell Death in Porcine Corneal Fibroblasts

PURPOSE

To explore the effect of ethanol treatment on corneal stromal cells.

METHODS

Primary porcine corneal fibroblasts from passages 3 to 5 were treated with ethanol at concentrations of 10%, 15%, 20%, and 50% for 30 seconds. A control group was treated with phosphate-buffered saline (PBS) for 30 seconds. Morphologic changes were documented with phase-contrast microscopy, and the growth curves were examined with a PicoGreen assay. Cellular viability was examined with an ethidium homodimer and calcein-AM stain, whereas cellular apoptosis and/or necrosis were analyzed by a YO-PRO-1 dye/propidium iodide apoptosis assay coupled with flow cytometry and further confirmed with a genomic DNA pattern assay. Cellular toxicity was examined with a lactate dehydrogenase (LDH) assay.

RESULTS

Significant cell rounding and detachment from the culture dish were noticed after 20% ethanol treatment of 30 seconds, despite that the cell morphology remained unchanged in the PBS and 10% and 15% ethanol groups. Twenty percent ethanol induced significant cellular toxicity, causing cell death as shown by ethidium homodimer and calcein-AM stain, YO-PRO-1 dye/propidium iodide apoptosis assay, and LDH assay, although 10% and 15% ethanol caused minimal changes to corneal fibroblasts. Cellular death was most significant 6 hours after the 20% ethanol treatment. The genomic DNA pattern revealed intact DNA in the control, 10% ethanol, and 15% ethanol groups at all times, whereas DNA smearing was noticed at 48 hours after the 20% ethanol treatment. However, none of the DNA examined revealed significant DNA laddering patterns of apoptosis. Fifty percent ethanol treatment of 30 seconds resulted in cell fixation and cell death.

CONCLUSION

Treatment with 20% ethanol for 30 seconds induced significant porcine corneal fibroblast cell death, whereas 10% and 15% ethanol treatment of 30 seconds caused minimal changes. We propose that, when applied for 30 seconds, 20% ethanol is the threshold level that causes cell death in cultured porcine corneal fibroblasts.

Late Traumatic Flap Dislocations After LASIK

PURPOSE

To report the management and outcome of late onset traumatic dislocation of LASIK flaps.

METHODS

This retrospective, interventional case series presents three patients with late onset LASIK flap dislocation following mechanical trauma 1 to 7 years postoperatively.

RESULTS

In all cases, the flap was surgically repositioned. Epithelial ingrowth was removed and diffuse lamellar keratitis was treated with an intensive steroid regimen. All patients returned to their preoperative best spectacle-corrected visual acuity. Aggressive steroid treatment during the perioperative period and meticulous handling of the epithelium are important in preventing further recurrence.

CONCLUSIONS

Laser in situ keratomileusis flaps may experience mechanical dislocation as late as 7 years postoperatively. Diffuse lamellar keratitis and epithelial ingrowth are associated with flap dislodgment.

Corneal Iron Line Following LASIK With Epithelial Ingrowth

PURPOSE

To report a new corneal iron line following keratorefractive surgery.

METHODS

Case report and review of the literature. A 51-year-old man developed epithelial ingrowth after otherwise uneventful LASIK surgery. The patient, satisfied with an uncorrected visual acuity of 20/25 and otherwise asymptomatic, declined to have his flap relifted to treat the ingrowth.

RESULTS

Six months postoperatively a corneal iron line was noted at the leading edge of the epithelial ingrowth. Vision remained stable.

CONCLUSIONS

: Epithelial iron lines have been reported with a number of conditions, including post-refractive procedures. This is the first report of an iron line associated with epithelial ingrowth following LASIK.

Flap suturing with proparacaine for recurrent epithelial ingrowth following laser in situ keratomileusis surgery

PURPOSE

To evaluate the safety and efficacy of flap suturing with proparacaine application for the management of recurrent epithelial ingrowth following laser in situ keratomileusis (LASIK).

SETTING

Private consultation practice and Department of Ophthalmology, Rush University, Chicago, Illinois, USA.

METHODS

Six eyes of 5 patients with recurrent epithelial ingrowth had flap lifting followed by debridement of interface epithelial cells, interface application of proparacaine, and the placement of interrupted 10-0 nylon sutures.

RESULTS

Four eyes achieved a best corrected visual acuity (BCVA) of 20/40 or better. Two eyes required repeat debridement with suturing and were stable with at least a 1-year follow-up. No eye lost more than 1 line of BCVA. Three eyes regained excellent uncorrected visual acuity due to a reduction in induced astigmatism.

CONCLUSIONS

Recurrent epithelial ingrowth following LASIK surgery can be a visually debilitating condition. Flap suturing with interface proparacaine application may be effective in preventing further recurrences of epithelial ingrowth after initial debridement.

Risk Factors in Interface Epithelialization After Laser in situ Keratomileusis

PURPOSE

To identify risk factors associated with primary and recurrent epithelial ingrowth after laser in situ keratomileusis (LASIK) requiring surgical debridement.

METHODS

Charts of patients who required single or multiple surgical debridements of epithelial ingrowth were reviewed retrospectively and analyzed to identify preoperative, intraoperative, and postoperative risk factors.

RESULTS

Fourteen of 22 patients had epithelial ingrowth that required a single surgical removal. These were mostly associated with the surgeon's learning curve, epithelial injury, and enhancement by lifting the flap. Multiple surgical debridements were required in eight patients and some of these were associated with epithelial basement membrane degeneration and a history of type I diabetes.

CONCLUSIONS

Refractive surgeons should be aware of surgical and non-surgical ocular and systemic risk factors associated with both primary and recurrent epithelial ingrowth after LASIK to appropriately consent patients seeking refractive surgery. Type I diabetes may increase the risk of epithelial downgrowth in LASIK.

Advanced epithelial ingrowth 6 months after laser in situ keratomileusis

Epithelial ingrowth is a common complication of laser in situ keratomileusis (LASIK). The cause is thought to be postoperative invasion of surface epithelial cells under the flap. We present a case of advanced epithelial cystic ingrowth that caused a profound reduction in visual acuity 6 months after a second LASIK enhancement.

Characteristic clinical findings and visual outcomes

PURPOSE

To describe a potentially serious complication of laser in situ keratomileusis (LASIK) that can masquerade as a persistent epithelial defect.

SETTING

Refractive surgery centers in academic institutions.

METHODS

Charts of 4 eyes in which epithelial-defect-masquerade syndrome was diagnosed were reviewed to determine the time to diagnosis and the presence of associated features that may have contributed to the delay in diagnosis. Clinical findings and outcomes of medical and surgical intervention were recorded.

RESULTS

All eyes developed an epithelial defect involving the edge of the flap during surgery. The diagnosis of epithelial ingrowth was delayed because of the presence of stromal edema (n = 4), diffuse lamellar keratitis (n = 3), and contraction of the flap leading to gutter widening (n = 4). Epithelial ingrowth was diagnosed 5, 7, 15, and 60 days after LASIK. All eyes satisfied the following criteria: convexity of the peripheral epithelium at the edge of the flap associated with light reflections at the end of the flap, fluorescein pooling in the gutter, stromal edema, reduced best spectacle-corrected visual acuity (<20/60 in 3 eyes), and partial healing of the epithelial defect limited to the flap hinge. One eye developed stromal scarring and ulceration that required fortified antibiotics. Surgical repair included epithelial scraping after the flap was lifted and ironing followed by placement of a contact lens after surgery. The epithelial defect healed 5, 7, 21, and 24 days after surgery. The final uncorrected visual acuity ranged from 20/15 to 20/100.

CONCLUSIONS

Epithelial ingrowth following LASIK-associated epithelial defects may masquerade as stromal edema associated with a persistent epithelial defect. A high index of suspicion for epithelial ingrowth is essential to avoid a delayed diagnosis, which can result in irreversible visual loss due to stromal melting and infectious keratitis.

Fibrin glue for the prevention of epithelial ingrowth after laser in situ keratomileusis

We present 3 cases of recurrent epithelial ingrowth following laser in situ keratomileusis. All patients consented to flap lifting, epithelial ingrowth removal, and placement of fibrin glue (Tisseel(R) VH, Baxter) at the flap edges. Two of 3 eyes had no evidence of recurrent epithelial ingrowth within a relatively short follow-up. One eye that also had had radial keratotomy had a small nest of stable epithelial cells that had not progressed. Fibrin glue may be a useful adjunct to prevent recurrent epithelial ingrowth. There were no complications associated with its use.

PRK for epithelial ingrowth in buttonhole after LASIK

PURPOSE

To evaluate the efficacy of photorefractive keratectomy (PRK) in progressive central epithelial ingrowth after buttonholes after laser in situ keratomileusis (LASIK).

METHODS

Two eyes of two patients with progressive central epithelial ingrowth and fibrosis in flap buttonholes after LASIK underwent PRK 6 months following primary surgery.

RESULTS

Epithelial ingrowth was treated successfully in both eyes. The uncorrected visual acuities were 20/20, and there was no evidence of recurrent epithelial ingrowth after 6 months.

CONCLUSIONS

Photorefractive keratectomy is a useful modality in the treatment of central epithelial ingrowth in buttonholes following LASIK. As a single-step surgery, it offers both therapeutic and optical advantages by simultaneously clearing the corneal opacity and correcting the refractive error in selected cases.

Sporadic diffuse lamellar keratitis (DLK) after LASIK

PURPOSE

To examine the incidence of sporadic diffuse lamellar keratitis (DLK) in a large series of LASIK eyes and to suggest the hypothesis that the etiology of sporadic DLK differs from that of epidemic DLK.

METHODS

The incidence and severity of DLK was noted in 1352 consecutive eyes that had primary LASIK for myopia or hyperopia and 217 consecutive eyes that had LASIK enhancement.

RESULTS

Twelve of the eyes having primary LASIK had stage 1 DLK and 5 had stage 2 DLK (.9% total). No eyes had stage 3 or stage 4 DLK. Three of the 217 eyes (1.4%) that had LASIK enhancement had stage 1 DLK. The difference in the rate of DLK for primary LASIK compared with LASIK enhancement was not statistically significant (p = 0.69). All eyes responded to intensive corticosteroid therapy, with the addition of flap lifting and irrigation for the eyes with stage 2 DLK. Two of the eyes (one primary LASIK and one LASIK-enhancement) had implanted epithelial nests associated with the DLK. None of the cases of DLK occurred in eyes of patients who had surgery on the same operating day in this series. Two other eyes that had epithelial abrasions more than 3 months after LASIK or LASIK enhancement developed stage 1 DLK.

CONCLUSIONS

Many cases of sporadic DLK, including cases associated with epithelial trauma after LASIK, are likely attributable to endogenous factors that trigger inflammation. One trigger is the release of epithelium-derived cytokines such as interleukin-1 that stimulate keratocytes to produce chemokines that are chemotactic to inflammatory cells. Cells likely accumulate at the interface because it is potential space, representing a path of least resistance for cell movement. Some sporadic cases may also be related to exogenous factors such as Betadine. Epidemic DLK is likely associated with exogenous factors that stimulate inflammation, such as endotoxin contaminating sterilizer reservoirs or detergents on instruments.

Twenty percent alcohol toxicity on rabbit corneal epithelial cells: electron microscopic study

PURPOSE

To evaluate 20% ethanol toxicity on the rabbit corneal epithelium, ethanol-treated rabbit corneas were examined with electron microscopy.

METHODS

Rabbit corneas (24 eyes) were treated with 20% ethanol for 30 seconds, 1 minute, and 2 minutes by using LASEK (laser-assisted subepithelial keratectomy) instruments and then washed with sterile water. Zero time, 1, 3, 5 days after ethanol treatment, corneas were excised and examined with scanning and transmission electron microscopy (SEM and TEM).

RESULTS

Widespread partial or total damage of microvilli, focal breaks of intercellular junction, and cellular edema was observed. The damage was more severe in corneas with longer ethanol treatment. In corneas with ethanol treatment more than 1 minute, slough of superficial corneal epithelium occurred and progressed with time. Two-minute ethanol treatment resulted in complete destruction of microvilli and significant separation of intercellular junction. These pathologic changes persisted 5 days after ethanol treatment.

CONCLUSIONS

From these results, increasing exposure time to ethanol more than 1 minute results in significant damage to superficial corneal epithelium and prolongs its normal recovery time.

LASIK complications: etiology, management, and prevention

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