Surface Ablation After Corneal Surgery: Management of Haze Helen K. Wu, MD New England Eye Center Tufts University School of Medicine Boston, MA
Financial Disclosures Travel Stipend/Honoraries: IOP Ophthalmics
Case Presentation 65 year old Caucasian man presents in September 2013 for evaluation of possible epithelial cells under LASIK flap OS He underwent LASIK OU many years prior He had a PRK enhancement OS in June 2012 for astigmatic correction (+1.00 225 2.25 x 110) MMC was not used
Case Presentation Initially, he saw very well, but his vision slowly diminished after about 3-6 months His optometrist had noted increasing astigmatism OS in the last half year 9/12 +0.25-0.25 x 110 1/13 +0.25-175 1.75 x 120 8/13 +2.50-3.25 x 113
Case Presentation
Haze after PRK Enhancement
Haze after PRK Enhancement
Management Underwent PTK OS in September 2013 Transepithelial approach, followed by PRK for astigmatism (no touch technique) Mitomycin C 0.02% applied for two minutes after laser surgery with chilled BSS pre and post procedure Slow steroid taper (prednisolone acetate 1%) UCVA 20/20 3 months later with no visible haze in cornea
Three Months Post PTK with MMC
PRK Enhancement for Regressed Myopic LASIK 17 eyes with history of high myopia treated with PRK at least 6 months after LASIK 14 eyes (82.3%) developed severe grade 3-4 haze with further myopic regression and loss of BCVA 2-6 lines No correlation with ablation depth No difference between eyes with regression and eyes intentionally undercorrected Carones F, et al. Ophthalmology 2001;108:1732 1737
Possible Contributing Factors Wilson described PTK followed by PRK for treatment of flap complications 2-4 weeks after LASIK (AJO 98, Refr Surg Outlook 2001) Jain and colleagues reported successful transepithelial ih lprk immediately in 7 eyes of 14 patients with flap complications (Jain VK et al, JRS 2002) Weisenthal postulated that timing may play a role He also speculated apoptosis may also play a role in haze formation, with greater apoptosis seen after LASIK than after a flap alone (Helena MC et al, IOVS 1998) Weisenthal RW et al, Cornea 22(5): 399 404, 2003.
Role of MMC in Surface Ablation after LASIK Transepithelial PTK with MMC for flap complications (Muller LT et al, JCRS 2005 and Weisenthal RW et al, Cornea 2003) PRK with MMC for residual myopia or regression after LASIK (Shaikh NM et al, JRS 2005 and Srinivasan S et al, JRS 2008) In these reports, MMC was used for a minimum of 30 seconds
Duration of MMC Exposure Clinically significant haze seen in post LASIK patient treated with PRK 8 years later for regression and MMC 0.02% used for 15 seconds Liu A and Manche EE, J Cataract Refract Surg 2010; 36:1599 1601
MMC and PTK/PRK Enhancements after Other Corneal Procedures Rdilk Radial keratotomy (20-40 (2040 sec) Penetrating keratoplasty (20-60 sec) PTK Post PRK haze (2 minutes) Post flap amputation Recurrent Reis-Buckler dystrophy Recurrent Avellino dystrophy Salzmann s nodules Santhiago MR et al, Cornea 2012;31:311 321
Corneal Keloids eods 38 year old Caucasian man s/p PRK for -7.0D OU in 1998 History of keloids after surgery on abdomen Ud Undercorrected tdand enhancement done OU with PRK one year later PTK with MMC for haze OS one year later Had repeat PTK in 2005 with MMC x 30 seconds, ETOH used to remove central 7 mm epithelium Had another PTK with thiotepa oep as swell
PTK and Corneal Keloids Patient seen by me in 2008 UCVA 20/20 OD and 20/100 OS BCVA 20/20 OD with -1.75 +2.50 x 125 and 20/80 OS with -1.75 175+350x80 3.50 Pachy 535 OD and 680 OS Treated with topical cyclosporine A for dry eye and meibomian dysfunction OU
PTK and Keloid Treated with a total of 600 pulses with excimer laser 234 pulses to remove epithelium (breakthrough at 160) and 202 pulses in stroma with masking agent 6.5 mm OZ and 0.1 transition zone MMC 0.2 mg/ml used for full two minutes Patient treated with prednisolone acetate every 1-2 hours initially, slow taper over 8 months Maintained UCVA 20/20 with 3 small patchy haze spots peripherally Five years later, has ring of haze with slight hyperopic shift
Recommendations for Prevention of Haze Prophylactic MMC may be useful in deep ablations with primary PRK procedures, but optimal dosing remains to be determined (10-120 seconds) Use MMC as adjunct for at least 30 seconds or more when doing PRK over any previous corneal surgery
Recommendations for Treatment of Haze Removal of epithelium best achieved with alcohol or laser Use 1-2 minutes of MMC 0.02% after removing corneal haze with PTK/ PRK Treat aggressively with steroids postoperatively and taper slowly Treat dry eye aggressively UV protection
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