Corneal edema following Corneal edema following Photorefractive Photorefractive

Keratectomy (PRK)Keratectomy (PRK)Gerald W Zaidman, MD, FAAO,FACSGerald W Zaidman, MD, FAAO,FACS

Professor of OphthalmologyProfessor of OphthalmologySarah E. Eccles Brown, BA Sarah E. Eccles Brown, BA Westchester Medical CenterWestchester Medical CenterNew York Medical CollegeNew York Medical College

Valhalla, NYValhalla, NY

THE AUTHORS DO NOT HAVE ANY FINANCIAL THE AUTHORS DO NOT HAVE ANY FINANCIAL INTEREST IN THIS PRESENTATIONINTEREST IN THIS PRESENTATION

The purpose of this poster is to present The purpose of this poster is to present a case of a patient with nearly total a case of a patient with nearly total loss of endothelial cells and loss of endothelial cells and subsequent corneal edema following subsequent corneal edema following PRK with mitomycinPRK with mitomycin

Case ReportCase ReportA 49 year old fireman underwent A 49 year old fireman underwent

refractive surgery in May 2005refractive surgery in May 2005He had had flash burns to his eyes so he He had had flash burns to his eyes so he

had no eyelashes or eyebrowshad no eyelashes or eyebrowsHis preoperative refraction wasHis preoperative refraction was

OD -4.75 – 2.50 x 40OD -4.75 – 2.50 x 40OS -5.50 – 1.00 x 110OS -5.50 – 1.00 x 110

Case ReportCase ReportCorneal pachymetry was 503 OD and 502 OSCorneal pachymetry was 503 OD and 502 OSTherefore his surgeon chose PRK + mitomycin Therefore his surgeon chose PRK + mitomycin

–surgery completed without complication–surgery completed without complicationHis exam in November, 2005 –His exam in November, 2005 –

VA, OD 20/40; Rx +0.75 – 0.75 x 30VA, OD 20/40; Rx +0.75 – 0.75 x 30VA, OS 20/25+; Rx planoVA, OS 20/25+; Rx plano

PRK enhancement + mitomycin was PRK enhancement + mitomycin was performedperformed

Case ReportCase Report5 days after enhancement cornea OD 5 days after enhancement cornea OD

became acutely inflamedbecame acutely inflamedPatient referred-exam showed corneal Patient referred-exam showed corneal

stromal edema without ulceration – Figure stromal edema without ulceration – Figure 11

Eye healed; residual scarring and corneal Eye healed; residual scarring and corneal thinning – VA = 20/200thinning – VA = 20/200

Pacyhmetry = 391 OD, 467 OS; Pacyhmetry = 391 OD, 467 OS; endo cell count OS=2700endo cell count OS=2700

PKP performed OD 5 months laterPKP performed OD 5 months later

Figure 1

PathologyPathologyExcised corneal button demonstrated Excised corneal button demonstrated

chronic stromal keratitis, loss of chronic stromal keratitis, loss of Bowman’s membrane, intact Bowman’s membrane, intact Descemet’s membrane, Descemet’s membrane, severe severe hypocellularityhypocellularity (almost (almost complete absence) complete absence) of of endothelial cellsendothelial cells

DiscussionDiscussion►Myopic PRK may induce corneal Myopic PRK may induce corneal

scarringscarring►Mitomycin – C used since 2000 to Mitomycin – C used since 2000 to

prevent corneal haze following PRKprevent corneal haze following PRK►Mitomycin toxicity has been reported Mitomycin toxicity has been reported

after pterygium surgery but rarely after pterygium surgery but rarely after PRKafter PRK

Mitomycin toxicity after Mitomycin toxicity after PTK/PRKPTK/PRK

Pfister-after PTK, 6 day use of topical mito-C led Pfister-after PTK, 6 day use of topical mito-C led to corneal edemato corneal edema

Torres- mito-C seen in AC after PRK, after Torres- mito-C seen in AC after PRK, after epithelial debridementepithelial debridement

Chang-rabbit study demonstrated dose Chang-rabbit study demonstrated dose dependent increase of corneal thickness after dependent increase of corneal thickness after mito-c applied to corneas debrided of mito-c applied to corneas debrided of epitheliumepithelium

Morales-patients treated with mito-C after PRK Morales-patients treated with mito-C after PRK had a significant loss of endothelial cellshad a significant loss of endothelial cells

ConclusionsConclusions►Mitomycin – C can penetrate into the Mitomycin – C can penetrate into the

anterior chamberanterior chamber►Mitomycin – C in the anterior chamber Mitomycin – C in the anterior chamber

can be toxic to endothelial cellscan be toxic to endothelial cells►Ophthalmologists should be careful Ophthalmologists should be careful

about the use of Mitomycin – C in thin about the use of Mitomycin – C in thin corneas with debrided epithelium corneas with debrided epithelium because of because of an increased risk of an increased risk of endothelial toxicityendothelial toxicity

ReferencesReferences

►Pfister RR. Cornea 2004; 23: 744-7.Pfister RR. Cornea 2004; 23: 744-7.►Torres RM, et al. JCRS 2006; 32: 67-71.Torres RM, et al. JCRS 2006; 32: 67-71.►Chang SW. JCRS 2004; 30: 1742-1750.Chang SW. JCRS 2004; 30: 1742-1750.►Morales AJ, et al. AJO 2006; 142: 400-Morales AJ, et al. AJO 2006; 142: 400-

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