Managing Challenging Cases in Refractive Surgery Missouri Optometric Association Stephen A. Wexler, MD Eric E. Polk, OD, FAAO Outline The presenters will review challenging cases they have managed in refractive surgery. The cases presented are representative of challenges that the affiliate optometrist may experience when co managing refractive surgery. Case Report #1 I) Patient experiences loose epithelium during LASIK surgery. He also experiences diffuse lamellar keratitis and epithelial ingrowth as a result of this complication. Treatment involves intensive steroid treatment and surgery with a YAG laser to treat the epithelial ingrowth. II) Loose Epithelium during LASIK surgery a. Some patients have sub clinical EBMD b. Difficult to screen patients for this problem c. Not apparent on slit lamp exam prior to age 40 d. Risk factors e. Fair skinned patients f. Fitzpatrick skin typing test g. Type 1 3 skin tpe i. Loose Epithelium 1. Frustrating for patient 2. Frustrating for surgeon 3. Loose epithelium with flap creation increases risk for 4. Blurred vision 5. Epithelial ingrowth 6. Infection 7. DLK III) Diffuse Lamellar Keratitis (DLK) i. DLK is a non infectious inflammation that presents with inflammatory cells in the interface between the flap and normal cornea ii. Occurs secondary to response to injury or exaggerated response to surgery
IV) iii. Wash out needed 1/1000 cases iv. Almost always seen on day one but sometimes not seen until day 2 b. DLK Risk Factors i. Epithelial defects ii. Contaminants in interface iii. Heme iv. Highly allergic individuals v. Higher incidence in spring and fall c. Stages i. Grade I in periphery of flap ii. Grade II progresses to center iii. Grade III involves clumping and lining up of the cells iv. Grade IV has central plaque with induced hyperopic astigmatism and loss of BCVA d. Grade 3 or 4 DLK leads to: i. hyperopic astigmatism ii. Irregular astigmatism iii. loss of BCVa iv. flap melts v. lawsuits e. Treatment i. Pred Forte 1% q 1 hour while awake ii. Oral prednisone 40 to 60 mg/day iii. Wash out procedure on day 3 or 4 iv. Almost always very effective Epithelial Ingrowth a. Influx of epithelial cells under the LASIK flap b. Typically do not occur with primary procedure c. Risk factors i. Flap lifts ii. Flap displacement iii. Corneal abrasions d. Epi ingrowth can cause loss of BCVA and flap melt e. Epi ingrowth is much more common following enhancements f. Much less common with Intralase g. May occur when epithelium is loose during surgery
h. Treatment i. Re lift, remove epithelium, replace flap 1. 50% recurrence rate ii. Re lift, remove epithelium, suture flap iii. Re lift, remove epithelium, Tisseel glue V) Case Report: Glare and Halo s following LASIK surgery a. Etiology i. Corneal edema ii. Decentered ablation iii. Post surgical irregular astigmatism iv. Laser ablation v. Pupil Size vi. Optical zone of laser vii. Spherical Aberration b. Does Pupil Size Matter? i. Villa, et al. Night vision disturbances after succesful LASIK Surgery.Br J Ophthalmol 2007;91(8):1031 37 ii. Reports of halo at night were same with large pupils vs normal pupils c. Risk Factors for Night Vision problems i. Amount of correction ii. High myopia iii. High Astigmatism iv. Post operative aberrations v. Spherical Aberration vi. Coma vii. Secondary astigmatism d. Treatment i. Miotics 1. Pilocarpine 1% 2. Alphagan P ii. Spectacles 1. Over minus patient iii. PRK Enhancement 1. Correct spherical aberration iv. Correct residual RX 1. Astigmatism, myopia, hyperopia
VI) Case Report: LASIK Infection a. Serious complication of LASIK surgery b. Can quickly cause degradation of flap tissue and loss of BCVA c. Incidence 0.1% of LASIK surgeries d. Typically presents the first week after corneal refractive surgery i. Healthcare workers, insulin dependent diabetics, dialysis patients, intravenous drug users, patients with dermatologic conditions, and patients with long term indwelling intravascular catheters have higher rates of colonization than the general population. ii. If it occurs in the first two weeks after surgery, be suspicious of gram positive Staphylococcus iii. After two weeks, think of opportunistic organisms like atypical mycobacteria, fungus, or Nocardia. iv. It is logical to suspect MRSA if the patient is a health care worker or has had recent exposure to a hospital, 1. Eric Donnenfed, MD e. Infectious Keratitis i. Methicillin resistant staphylococcus tend to cause the majority of infections ii. Mycobacteria is less of a concern then before iii. Moxifloxacin and gatifloxacin cover the atypical mycobacteria iv. Infections are 6 times more common with PRK than with the femtosecond laser f. Differential Diagnosis of infection i. DLK ii. Sterile Infiltrate iii. Surgical Debris iv. Microbial Keratitis v. Bacterial vi. Mycobacterial vii. Fungal viii. Viral g. Symptoms i. Pain, photophobia and redness ii. Tearing iii. Foreign body sensation
VII) iv. Decreased vision v. Increase of glare and halos h. Presentation of Infection i. Pain and Photophobia ii. Redness iii. Anterior chamber reaction. iv. Epithelial defect over infiltrate. v. Anterior or posterior extension of infiltrate i. Treatment i. Culture ii. Fortified Vancomycin and Gentamycin or fortified Cefazolin iii. Polytrim for MRSA infections or when fortified antibiotics are unavailable iv. Fourth generation fluoroquinolones v. Discontinue steroid if open wound defect vi. Oral Antibiotics vii. Azithromycin or Clarithromycin PO viii. Doxycycline to decrease collagen destruction Conclusion