Photorefractive keratectomy with mitomycin C for the management of a LASIK flap complication following a penetrating keratoplasty

OBJECTIVE: To evaluate the safety and efficacy of photorefractive keratectomy (PRK) with mitomycin C (MMC) following a buttonhole secondary to attempted laser in situ keratomileusis (LASIK) in an eye that had undergone a prior penetrating keratoplasty (PKP). METHODS: Case report and review of the literature. A 26-year-old man underwent PRK with MMC following a buttonhole flap complication after LASIK in an eye that had undergone a PKP for keratoconus. RESULTS: Three months following the procedure, the patient demonstrated a clear cornea and a best-corrected visual acuity of 20/20. CONCLUSION: To our knowledge, this is the first case report of buttonhole during LASIK following a PKP and the use of PRK to treat a LASIK flap complication following a successful PKP. In addition, this is the first case report of prophylactic use of MMC to prevent corneal haze with PRK following PKP. A buttonhole is a rare complication following LASIK for residual refractive error following PKP, which can be successfully managed with PRK and prophylactic MMC.     

Wavefront-guided surface ablation with prophylactic use of mitomycin C after a buttonhole laser in situ keratomileusis flap

PURPOSE: To describe the surgical outcome of a patient who had a previous buttonhole after laser in situ keratomileusis (LASIK) and 3 months later, had wavefront-guided photorefractive keratectomy (PRK) with topical mitomycin C 0.02%. METHODS: A 38-year-old man underwent bilateral LASIK for correction of myopic astigmatism. A buttonhole in his right eye LASIK flap occurred, but the surgeon decided to proceed with ablation due to the small size of the buttonhole. After LASIK, the patient complained of monocular diplopia in his right eye with 20/30 best spectacle-corrected visual acuity. Wavefront analysis showed a large amount of higher order aberrations, especially coma. Slit-lamp examination revealed a moderate buttonhole scar. Three months after LASIK, the patient underwent wavefront-guided PRK with application of topical mitomycin C 0.02% on the stromal bed, for a duration of 2 minutes. RESULTS: One month after wavefront-guided PRK, his uncorrected visual acuity was 20/25 in the right eye, with no symptoms. Best spectacle-corrected visual acuity in the right eye was 20/15 with +0.25 -0.50 x 110 degrees. No haze or scar was seen on slit-lamp examination. Wavefront analysis showed a decrease in higher order aberrations, especially coma and spherical aberration. CONCLUSIONS: Wavefront-guided PRK with prophylactic topical mitomycin C was effective in treating a patient with visual symptoms and loss of BSCVA after a LASIK flap buttonhole. No delayed epithelial healing, side effects or complications were noted due to mitomycin C.     

Prophylactic use of mitomycin-C in the management of a buttonholed LASIK flap

We report a case in which prophylactic mitomycin-C (MMC) was used to prevent haze and scarring after photorefractive keratectomy (PRK) in an eye with a previous laser in situ keratomileusis flap buttonhole. During the patient's primary procedure, a 3.5 mm central buttonhole was created during the microkeratome pass. The flap was repositioned without laser application. Follow-up examinations revealed a moderate central buttonhole scar. Twelve months later, the patient had PRK with adjunctive MMC 0.02% application in the eye. At the 1-year examination, the uncorrected visual acuity was 20/20 and the cornea was clear with no evidence of scarring or haze.     

Transepithelial phototherapeutic keratectomy/photorefractive keratectomy with adjunctive mitomycin-C for complicated LASIK flaps

PURPOSE: To evaluate the efficacy of transepithelial phototherapeutic keratectomy/photorefractive keratectomy (PTK/PRK) with prophylactic mitomycin-C for the treatment of refractive errors and maintenance of corneal clarity following flap complications in laser in situ keratomileusis (LASIK). SETTING: Outpatient tertiary care center, Chicago, Illinois, USA. METHODS: Ten eyes of 10 patients with LASIK flap complications had transepithelial PTK/PRK for correction of ametropia. Mitomycin-C 0.02% was applied to the stroma for 2 minutes following laser ablation. Postoperative uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refractions, and slitlamp examinations were obtained. RESULTS: Preoperatively, the mean UCVA was 20/400 (range 20/40 to counting fingers), the mean BSCVA was 20/28.5, and the spherical equivalent refractive errors ranged from +4.00 to -10.75 diopters (D). After the procedure, the mean UCVA was 20/28, the mean BSCVA was 20/21, and the spherical equivalent refractive errors ranged from +0.37 to -1.00 D. The mean follow-up ranged from 8 to 28 months. No patient experienced delayed reepithelialization, haze, or other signs of toxicity. CONCLUSION: Mitomycin-C can be a useful adjunctive therapy for the prevention of haze when applying surface excimer laser therapy to a cornea following LASIK flap complications.     

丝裂霉素C在LASIK术后角膜上皮植入手术治疗中的应用

目的:探讨丝裂霉素C(mitomycin C,MMC)在准分子激光原位角膜磨镶术(laserin situkeratomileusis,LASIK)术后角膜上皮植入手术治疗中应用的临床疗效。方法:在31例31眼LASIK术后角膜上皮植入患者手术治疗中应用0.2g/L MMC,观察术后裸眼视力及角膜瓣愈合情况。结果:术后6mo裸眼视力平均为0.82±0.19,较术前明显提高(P<0.05)。绝大部分患者角膜瓣愈合良好,4例患者角膜瓣边缘部分融解,但中心视力无明显影响。结论:在LASIK术后角膜上皮植入手术治疗中应用0.2g/LMMC可以取得良好的临床疗效。     

Photorefractive keratectomy retreatment after LASIK

PURPOSE: To study the results of late photorefractive keratectomy (PRK) in corneas originally subjected to LASIK. METHODS: Seven eyes of seven patients who had LASIK for myopia were retreated with PRK at least 2 years after LASIK. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), refraction, and haze were evaluated before and after LASIK and after retreatment by PRK. RESULTS: Photorefractive keratectomy retreatment improved BSCVA in six (86%) of seven eyes, and one (14%) eye showed no changes. None of the eyes lost lines of BSCVA. Five of seven eyes developed mild haze, which disappeared before the last postoperative follow-up. CONCLUSIONS: Photorefractive keratectomy retreatment performed at least 2 years after LASIK can improve visual acuity. We hypothesize that LASIK-induced corneal nerve damage disturbs corneal wound healing by increasing the tendency for development of haze.     

The safety and efficacy of photorefractive keratectomy after laser in situ keratomileusis

PURPOSE: To determine the safety and efficacy of performing photorefractive keratectomy (PRK) in corneas previously treated with laser in situ keratomileusis (LASIK) surgery. METHODS: Fifteen eyes of 14 patients who had initially received LASIK for the treatment of myopia and compound myopic astigmatism were evaluated. Variables included existence of and/or type of flap complication associated with the original LASIK procedure, refractions before and after (3 and 6 months) PRK, uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and the development of complications after PRK such as haze, scarring, double vision, or ghosting. RESULTS: All 15 eyes were available for analysis at 6 months. Eleven eyes had experienced flap complications during the initial LASIK procedure and 4 eyes had experienced complications in the LASIK postoperative period. Characteristics prior to performing PRK included 11 myopic and 4 hyperopic eyes. By 6 months after PRK treatment, 87% of eyes had UCVA > or = 20/40, 53% had > or = 20/25, and 40% had > or = 20/20. All eyes had BSCVA of > or = 20/30, with 73% being > or = 20/20. No eye had lost 2 lines of BSCVA and only 1 eye lost 1 line of BSCVA. Sixty percent of eyes were within 1.0 diopters (D) of emmetropia, and 40% were within 0.5 D of emmetropia. A trend towards undercorrection and surgical induction of astigmatism as confirmed by vector analysis was noted. No eye developed significant haze or scarring. CONCLUSIONS: Photorefractive keratectomy may be a safe procedure to perform in corneas previously treated with LASIK surgery. Results show good reduction of refractive error and improvement of UCVA and BSCVA. A significant undercorrection of astigmatism was attributed to surgically induced astigmatism. Further studies are necessary to determine the long-term safety and stability of outcomes.     

Epithelial ingrowth after LASIK treatment with scraping and phototherapeutic keratectomy

PURPOSE: To evaluate the effect of phototherapeutic keratectomy (PTK) in combination with manual scraping when removing epithelial ingrowth under a LASIK flap. MATERIAL AND METHODS: Three patients, who had undergone several surgeries following LASIK in order to remove epithelial ingrowth that was threatening vision, were treated with a flap lift, manual abrasion and PTK. The PTK was performed on both the stromal and the flap side with the aim of eliminating the threat and improving vision. Two patients underwent primary surgery to remove epithelial ingrowth with manual abrasion and PTK. The influence on vision, topography and cell recurrences was evaluated. RESULTS: Uncorrected visual acuity (UCVA) and best spectacle-corrected visual acuity (BSCVA) improved in four cases and remained good in the fifth case. The refraction did not change significantly. Topography disclosed changes in the irregular astigmatism, explaining the improved BSCVA. Central epithelial ingrowth did not recur, whereas peripheral ingrowth did. The peripheral ingrowth did not progress, except in case 1, where a cyst formed that required surgery. CONCLUSIONS: It is our belief that adding PTK to manual scraping improves the prognosis for eyes with epithelial ingrowth. It is mainly the central ingrowth that is positively affected. Improved adhesion between the stroma and the flap is one possible explanation.     

Results of phototherapeutic keratectomy in the management of flap striae after LASIK

OBJECTIVE: To evaluate the efficacy of phototherapeutic keratectomy (PTK) in reducing or resolving visually significant surface irregularities resulting from flap striae after LASIK. DESIGN: Retrospective, noncomparative case series. PARTICIPANTS: Twenty-three eyes of 22 patients with flap striae after LASIK and reduced best-corrected visual acuity or visual symptoms that resolved with diagnostic contact lens fitting treated between January 2001 and April 2002 with at least 1 month of follow-up. The mean follow-up interval was 134 days (range, 30-354 days). INTERVENTION: Transepithelial PTK. MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA), resolution or reduction of preoperative symptoms, corneal haze, and best spectacle-corrected visual acuity (BSCVA). RESULTS: Mean BSCVA and UCVA improved significantly from 20/32 and 20/48 to 20/22 and 20/33 (P<0.0001 and P = 0.027), respectively, after PTK. There was a significant mean hyperopic shift of 0.88 diopters (D; P = 0.002, range, -1.38 to +3.88 D). Fourteen eyes (61%) were clinically clear, 6 eyes (23%) had trace haze, and 3 eyes (16%) had 1+ haze at the last follow-up visit. Mean spherical equivalent refractive error before LASIK was -7.23 D (range, -2.88 to -13.55 D). Twenty-two of 23 eyes had significant qualitative resolution or reduction of preoperative visual symptoms. CONCLUSIONS: In cases of visually significant LASIK flap striae, PTK is effective in improving best-corrected visual acuity and reducing visual symptoms. High myopia may be a risk factor for development of visually significant microstriae. Development of anterior stromal haze did not exceed 1+ density and was not correlated to either the number of laser pulses or the length of the follow-up period.     

Phototherapeutic keratectomy with mitomycin C for corneal haze following photorefractive keratectomy for myopia

PURPOSE: To evaluate the safety and efficacy of phototherapeutic keratectomy (PTK) with single application of mitomycin C for patients with severe corneal haze following photorefractive keratectomy (PRK) for high myopia. METHODS: Eight eyes of seven patients were treated with PTK and intraoperative topical application of mitomycin C (0.02%) for severe corneal haze (grade 3) following PRK for myopia. RESULTS: All patients' visual performance improved significantly. Mean preoperative visual acuity (20/200 for both UCVA and BSCVA) improved significantly to 20/33 (0.6) and 20/30 (0.7) for UCVA and BSCVA, respectively. Six eyes (85.7%) had improved UCVA to 20/40 or better and gained five or more lines of UCVA. The corneal haze score decreased from grade 3 initially (for all eyes prior to PTK and mitomycin C) to a final mean haze score of 0.3 (range 0 to 0.5). Mean final spherical equivalent refraction achieved was -1.30 +/- 1.60 D (range -3.75 to +1.25 D). One eye gained only three lines of visual acuity due to regression and residual haze. No adverse effects related to the use of mitomycin C were recorded. CONCLUSION: PTK with a single intraoperative application of mitomycin C was safe and effective in reducing corneal haze and improving visual acuity in patients with severe corneal haze following PRK.     

PTK联合PRK治疗LASIK术中角膜瓣并发症

目的：观察PTK联合PPK治疗LASIK术中角膜瓣并发症的疗效。方法：对我院1997年7月至2000年7月间LASIK术中发生角膜瓣并发症的13例病人即刻进行PTK联合PRK治疗，13例病人平均年龄25.1岁（19-32），均为中低度近视（-2.00～-5.75D)，未进行散光治疗，术后随访时间平均为15个月。结果：术后12个月所有病人的裸眼视力均较术前明显提高，除一例病人术后裸眼视力较术前的矫正视力降低一行外，其他病人的裸眼视力均达到术前的矫正视力。结论：对LASIK术中发生角膜瓣并发症的病人即刻进行PTK联合PRK治疗是安全的，可行的。     

LASIK后严重角膜上皮植入并角膜瓣融解的处理

目的：探讨ＬＡＳＩＫ术后严重角膜上皮内生所致角膜瓣融解缺损的治疗方法。病例和方法：ＬＡＳＩＫ术后经本院确诊为角膜上皮内生合并角膜瓣融解的１２例１３眼,根据角膜瓣厚度及角膜瓣融解的程度,９眼接受翻开角膜瓣清除层间上皮的治疗,３眼行异体角膜磨镶术,１眼去除角膜瓣。结果：翻开角膜瓣清除膜上皮的９眼中,２眼复发,但再次治疗后正常愈全。异体角膜磨镶术组的３眼角膜瓣均正常愈合。去除角膜瓣的１眼角膜上皮正常,但     

Photorefractive keratectomy for treatment of flap complications in laser in situ keratomileusis

PURPOSE: To present the results of photorefractive keratectomy (PRK) for treatment of laser in situ keratomileusis (LASIK) flap complications. METHODS: Compilation of case reports through solicitation on Kera-net, an Internet surgery discussion site. RESULTS: PRK was performed on 13 patients from 2 weeks to 6 months after LASIK flap complications. The technique used for the PRK varied. Epithelial removal was performed using no-touch phototherapeutic keratectomy (PTK) in six of the 13 patients and manual debridement in the other seven patients. A dilute solution of 20% ethanol was used to facilitate manual debridement in five of the seven patients. In two of these five patients, the epithelium was replaced as in laser-assisted subepithelial keratomileusis (LASEK). A solution of 0.02% mitomycin C was used after laser ablation to prevent haze formation in three patients. After an average 7 months of follow-up, uncorrected visual acuity was 20/20 in six patients, 20/25 in four patients, and 20/30 in two patients. The visual acuity in one patient was 20/80, purposely left undercorrected for monovision. Best spectacle-corrected visual acuity was 20/20 in 10 of 13 patients. Three patients were 20/25, losing one line of best spectacle-corrected visual acuity. On slit-lamp examination, at last follow-up appointment, stromal haze was graded from trace to none in all patients. CONCLUSIONS: Photorefractive keratectomy is a safe and effective technique for treatment of patients with LASIK flap complications.     

Photorefractive keratectomy with mitomycin C versus LASIK in custom surgeries for myopia: a bilateral prospective randomized clinical trial

PURPOSE: To compare photorefractive keratectomy (PRK) with prophylactic use of mitomycin C (MMC) and LASIK in custom surgeries for myopic astigmatism. METHODS: Eighty-eight eyes of 44 patients with a minimum estimated ablation depth of 50 microm were randomized to receive PRK with MMC 0.002% for 1 minute in one eye and LASIK in the fellow eye. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), cycloplegic refraction, slit-lamp microscopy, contrast sensitivity, specular microscopy, aberrometry, and a subjective questionnaire were evaluated. Forty-two patients completed 6-month follow-up. RESULTS: Mean spherical equivalent refraction error before surgery and mean ablation depth were -3.99+/-1.20 diopters (D) and 73.09+/-14.55 microm in LASIK eyes, and -3.85+/-1.12 D and 70.7+/-14.07 microm in PRK with MMC eyes, respectively. Uncorrected visual acuity was significantly better in PRK with MMC eyes 3 months (P=.04) and 6 months (P=.01) after surgery. Best spectacle-corrected visual acuity and spherical equivalent refraction did not differ significantly in the groups during follow-up (P>.05). Significant haze was not observed in any PRK with MMC eye. Mean higher order aberration was lower in PRK with MMC eyes postoperatively compared with LASIK eyes (P=.01). Better contrast sensitivity was observed in PRK with MMC eyes than LASIK eyes (P<.05). The endothelial cell count did not differ significantly between groups (P=.65). In terms of visual satisfaction, PRK with MMC eyes were better rated. CONCLUSIONS: Photorefractive keratectomy with MMC appears to be more effective than LASIK in custom surgery for moderate myopia. During 6-month follow-up, no toxic effects of MMC were evident. Long-term follow-up is necessary to attest its safety.     

Partial dislocation of laser in situ keratomileusis flap by air bag injury

PURPOSE: A patient developed significant corneal complications from air bag deployment, 17 months after laser in situ keratomileusis (LASIK). METHODS: Case report, slit-lamp microscopy, and review of the medical literature. RESULTS: A 37-year-old woman underwent bilateral LASIK with resultant 20/20 uncorrected visual acuity. Seventeen months later, she sustained facial and ocular injuries from air bag deployment during a motor vehicle accident. Examination revealed bilateral corneal abrasions, partial dislocation of the right corneal LASIK flap, and a hyphema in the right eye. The LASIK flap was realigned, but recovery was complicated by a slowly healing epithelial defect and flap edema. One month following the injury, epithelial ingrowth beneath the LASIK flap was noted. Surgical elevation of the flap and removal of the epithelial ingrowth was performed. Eight months later, epithelial ingrowth was absent and the visual acuity was 20/40. Residual irregular astigmatism necessitated rigid gas permeable contact lens fitting to achieve 20/20 visual acuity. CONCLUSIONS: Air bags may cause significant ocular trauma. The wound healing response of LASIK allows corneal flap separation from its stromal bed for an indeterminate time after surgery. Discussion of the possible risk of corneal trauma as part of informed consent prior to LASIK may be appropriate.     

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.     

Management of irregular astigmatism following rotationally disoriented free cap after LASIK

PURPOSE: To illustrate the challenges associated with a misaligned free flap (cap) and to report the outcome of applying wavefront-guided customized photorefractive keratectomy (PRK) followed by conventional PRK ablation to correct residual refractive error and aberrations after LASIK free cap complications. METHODS: The clinical course and surgical interventions of two patients with free cap complications from LASIK surgery were reviewed. The first patient underwent a total of six interventions after the initial LASIK procedure, and the second patient underwent a total of five interventions. Interventions included cap lift, cap rotation, custom PRK, and conventional PRK enhancement with prophylactic topical mitomycin C (MMC). RESULTS: Customized PRK treatment and subsequent enhancements with prophylactic topical MMC led to the recovery of best spectacle-corrected visual acuity (BSCVA), neutralization of higher and lower order aberrations, and astigmatic neutrality. Symptoms related to higher order aberrations resolved in both patients. CONCLUSIONS: Wavefront-guided custom PRK for higher order aberrations followed by conventional PRK enhancement for residual lower order aberrations, both with topical MMC application, represents an efficacious strategy for treating patients with loss of BSCVA and visual symptoms due to LASIK free cap complications.     

Management of severe flap wrinkling or dislodgment after laser in situ keratomileusis

PURPOSE: To review the management and results of cases with severe flap wrinkling or dislodgment after laser in situ keratomileusis (LASIK). SETTING: University Eye Center, Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, The Chinese University of Hong Kong. METHODS: Four patients with severe flap wrinkling or dislodgment after LASIK are described. Surgical repositioning of the flap was performed in all cases. Flap status, refractive changes, and final uncorrected and best corrected visual acuities were used to evaluate the outcome of flap repositioning. RESULTS: Flap repositioning required suturing in 2 patients, 1 of whom developed severe epithelial ingrowth with melting of the corneal flap and stromal bed and eventually required flap removal. The stromal inflammation resolved, and the corneal surface re-epithelialized after flap excision. In 2 other patients, wedge-shaped tissue excision (1.0 x 1.5 mm) from the superior portion of the corneal flap was necessary to allow better flap realignment. In 1 of these patients, the corneal flap was eventually converted to a free cap to correct residual wrinkling. At a mean follow-up of 15 months, the postoperative uncorrected visual acuity ranged from 20/20 to 20/60, and the best spectacle-corrected visual acuity (BSCVA) was 20/30 or better in all patients. In 1 patient, BSCVA decreased by 1 line. CONCLUSIONS: Flap dislodgment and wrinkling are serious postoperative complications of LASIK. Early recognition of these complications and prompt surgical management are crucial to achieve a successful surgical and visual outcome.     

Epithelial scraping for corneal epithelial ingrowth after laser in situ keratomileusis

BACKGROUND: Laser in situ keratomileusis (LASIK) is an effective method for correcting a wide range of myopia. However, complications sometimes occur. We report here a case treated with epithelial scraping two years and 4 months after surgery for epithelial ingrowth in the central cornea after LASIK. CASE: A 32 year-old woman who had undergone LASIK one year and 4 months before visited our hospital because of visual loss. At the first examination in our clinic, her best-corrected visual acuity was 20/60 in the right eye and 20/15 in the left eye. Epithelial ingrowth was observed in both eyes, but in the right eye, the epithelial ingrowth had reached the central cornea leading to the visual loss. The increased corneal stromal opacity decreased the visual acuity to 20/400. The patient decided to undergo epithelial scraping. The corneal flap was dissected again and epithelial scraping was performed on the stromal bed and back of the corneal flap. The visual acuity was improved from 20/400 to 20/40. However, the stromal opacity and the corneal astigmatism still remained. CONCLUSION: This case suggests that epithelial scraping should be performed immediately when ingrowing epithelium after LASIK begins to invade the central cornea.     

Immunohistology of corneal wound healing after photorefractive keratectomy and laser in situ keratomileusis. wachtlin@ukbf.fu-berlin.de.

PURPOSE: The aim of the study was to compare corneal wound healing after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) using conventional, immuno- and enzymohistologic methods. METHODS: Sixteen white Russian rabbits in each group underwent PRK or LASIK. Keratocyte density was recorded from 1 week to 6 months post-operatively on conventional histological sections. Immunohistologic cellular fibronectin and tenascin were used as markers of early epithelial and stromal wound healing in the cornea. The cell damage was demonstrated enzymohistologically using alkaline phosphatase. RESULTS: The reaction was similar in quality with both methods and occurred at sites of simultaneous epithelial and stromal injury. Mild scarring was found around the edge of the flap after LASIK; PRK-treated corneas developed a central subepithelial haze and scarring. A hypocellular region was found in the anterior part of the ablation zone shortly after PRK. Fibroblast migration later led to hypercellularity and subsequent clinical haze formation. After LASIK this reaction was limited to the peripheral entry point of the microkeratome blade around the edge of the corneal flap, where cellular fibronectin and tenascin reactions were positive. An acellular zone was found anterior to the interface after LASIK. The keratocyte damage visualized by alkaline phosphatase was more extensive after PRK than after LASIK. CONCLUSION: The stromal reaction to surgery was more extensive after PRK than after LASIK. A cytokine-mediated interaction between the epithelium and stroma was suggested as the cause of keratocyte cell migration and scar formation.