1. Unusual Presentations of Post-LASIK Sterile Keratitis Unusual Presentations of Post-LASIK Sterile Keratitis Farid Karimian, MD 2002

2. Case no. 1 S.H., 26 year old engineer referred for correction of his refractive error Glasses & refraction were stable for over 3years There was no h/o contact lens wearing nor any positive attitude to its use Past medical history: negative for any systemic disease Pre-op Refraction OD- 4.00-0.50x 180° OS- 4.25-0.25x180°

3. Case no. 1… cont. Pre-op Topography: OU unremarkable Sim K OD 43.5/43.0 OS 43.0/43.0 Central pachy OD 560µ OS 545µ Operation Data: Standard LASIK procedure Excimer machine: Nidek EC-5000 Microkeratome: Moria CB Complication: None

4. Post-op Course: Day 1 CC: No pain, No photophobia, SLE OU: Trace interface infiltration at periphery (GradeI) OU: Mid-stromal infiltration peripheral to flap Trace AC reaction RX: Beta OU q4h + Chloramphenicol OU q6h Day 2: OU: Peripheral infiltration increased, No CED, stable interface infiltrates RX:-  Beta OU q2h -  Chramphenicol OU q2h Case no. 1… cont.

6. Post-op Course….cont. Day 3: OU(OD>OS): Peripheral circumferential infiltration, became dense, No CED RX:  Beta OU q1h Prednisolone 75mg PO qd started Day 5: Peripheral infiltrations markedly decreased Day 7: Tapering topical and systemic steroid started 1rst month: Faintly visible peripheral infiltration Clean interface and flap UCVA OU 20/20 with non-significant refractive error

7. Pros and Cons Pros Cons Pros and Cons Pros Cons Short interval after LASIK Minimal discomfort Intact epithelium Appropriate response to steroid treatment bilaterality Unusual pattern of infiltration Not present peripheral to hinge are

8. Case no. 1 Peripheral circumferential Post-LASIK sterile keratitis

9. Case no. 2 R.C., 38 year old female seeking refractive surgery for correction of her refractive error Positive history of contact lens wearing discontinued years ago Stable glasses and refraction > 10 years Negative history of any systemic disease Cormeal and ophthalmic exam: unremarkable Refraction OD-2.00-5.00 x 170° OS –1.50-5.00 x 10°

10. Intraoperative events OD: operated first developed inferior paracentral ˜ 3mm CED during microkeratome pass, she was proposed to postpone 2 nd eye surgery OS: Tetracaine epithelial toxicity? supposed  LASIK performed with only one drop Intraoperative epithelial loosening occurred: no CED

11. Postop Course Day 1: CC: pain, photophobia OU SLE: OU: - Bilateral inferior paracentral CED - minimal infilteration under CED RX: - Beta OU bid - Chloramphenicol OU q6h Day 2: CC:  pain and photopobia Exam: - OU stable CED -  infiltration, confined to area of CED - mild AC reaction RX: - Beta was D/C - Ciprofloxacin OU q2h started

13. Post-op Course Day 3: CC, Mild  pain Exam: OU: - CED began to improve - infiltration spread outward  DLK?! RX: - prednisolone 50mg (1mg/kg) started -  ciprofloxacin OU q4h Day 5: CC, marked improvement Exam: OU: - pseudodendrite, no CED’s - infiltration involved all over interface (gradeII) RX: -  prednisolone 75mg (1.5mg/kg) -  Ciprofloxacin OU q6h - Beta OU q4h started

15. Post-op Course 2 weeks: - completely improved CED - resolved interface infiltration - improved flap edema RX: topical and systemic steroids tapered and discontinued 1 month: UCVA OD 20/25 OS 20/25 Refraction OD –0.25-0.75 x 180° OS –0.50-0.50 x 180° SLE OU: no CED - OS: small 1x1mm epithelial pearl at interface - Up to 6 months follow-up, condition unstable

16. Epithelial Erosions: are not benign complications associated with:  Increase risk of epithelial ingrowth  Induced astigmatism  Flap edema  Over or undercorrection  DLK  Flap melt

17. Epithelial erosion: Causes Tangential shearing effect of friction on the epithelium Excessive topical anesthetic Improper draping Rough corneal marking Poor blade edge quality Epithelial basement membrane dystrophy aging

18. Case no. 2 Post-LASIK interface keratitis mimicking infectious cause

19. Case no. 3 “ Refractory DLK ” M.M., 48 year old gentleman was operated for his myopia about 2 months ago Pre-operative history and evaluations were unremarkable except –7.00 D myopia in both eyes LASIK: bilateral simultaneous, uncomplicated Early postop: developed DLK Grade II in both eyes (OS>OD) Intensive and aggressive steroid therapy: Beta OU q1h, prednisolone 100mg PO qd

20. Case no 3 … cont. In September 2001, he was referred due to poor contolled DLK since surgery Medications: Beta OU q2h, Prednisolone 50mg PO qd CC: blurred vision and ocular pain OU UCVA OD 20/60/ OS 20/50 with +4.00 D hyperopia in refraction SLE OU: limbus- to-limbus microcystic coreal epithelial edema (ground-glass appearance) - minimal flap interface infiltration with haziness - TA OD 68 mmHg/ OS 54 mmHg - Fundus OU: pink discs with 0.5C/D ratio

21. Case no 3..cont. Management: Steroids: topical; was DC Systemic: rapid tapering and discontinued Antiglaucoma: timolol OU q12h Acetazolamide 250mg PO q6h

22. Case no. 3 … cont Follow up course After 1 wk: IOP OU decreased to Mid 20’s After 1 mo: UCVA OU 20/30 with + 0.50 D hyperopia IOP: OD 20 mmHg / OS 18 mm Hg with antiglaucoma medication - Acetazolamide was D/ C

23. Case no 3 … cont - After 3 mo: - UCVA OU 20/30 with + 0.5 hyperopia - IOP OU 18 mm Hg with timolol OU q12h - Automated VF OU = borderline GHT - Timolol was discontinued - After 6 mo: - condition was the same - Follow up with IOP and VF

24. Case no. 3 “Refractory DLK “ or “ Pseudo – DLK” Was in fact secondary to very high interaocular pressures due to “ steroid – responsiveness”