Managing Post-Operative Complications for LASIK and PRK

Transcription

1 Managing Post-Operative Complications for LASIK and PRK LASIK Flap Complications Epithelial defects o Cause Basement membrane dystrophy Recurrent erosion syndrome Dry eyes Trauma PRK as alternative Pre-treat dry eye disease/ocular surface irregularities Striae o Microstriae Vs. Macrostriae o Cause Poor flap adherence Trauma and Eye Rubbing High myopic ablation Microstriae Dependent upon subjective complaints and objective findings Macrostriae Immediate referral to surgeon to refloat flap and reposition Diffuse lamellar keratitis (DLK) o Multifactorial Cause Stage 1 Topical corticosteroids Stage 2 Topical corticosteroids Vs. Oral corticosteroids Stage 3 Topical corticosteroids Vs. Oral corticosteroids Referral to surgeon Stage 4 Flap amputation o Differential Diagnosis Interface fluid syndrome (IFS) Etiology o Central and/or paracentral accumulation of fluid between the flap and stroma Risk factors o Corticosteroids

2 Clinical Pearls o Central haze and interface fluid gap o Measure intraocular pressure (IOP) in central and peripheral cornea o Central cornea will have very low IOP compared to periphery o Anterior segment optical coherence tomography (OCT) can confirm diagnosis Treatment o Discontinue corticosteroids and start anti-glaucoma medication Pressure-induced interlamellar stromal keratitis (PISK) Etiology o Steroid-induced o Condition that is most easily confused with DLK Clinical Pearls o Measure IOP in presence of aggressive corticosteroid treatment and diffuse corneal haze o Usually presents 1-2 weeks after LASIK o Worsens with increased use of corticosteroids o Differs from IFS in that it is not confined to the central cornea Advanced diagnostics o Anterior segment optical coherence tomography (OCT) Differentiates PISK from IFS Treatment o Discontinue corticosteroids o Employ anti-glaucoma medication Epithelial ingrowth o Etiology Active proliferation or iatrogenic introduction of epithelium at flap edge Flap edge irregularities Iatrogenic o Clinical manifestations Classification systems o Surgical treatment Re-lift and irrigate Close observation Transient light sensitivity syndrome (TLSS) o Signs and Symptoms o High raster bed and side-cut energy Cytokine aggregation Increased keratocyte activity Aggressive topical corticosteroids

3 Infection o Signs and Symptoms o Organisms and timing of onset Gram positive/negative organisms Mycobacterium Fungal Pulse loading of broad spectrum antimicrobial agents that are rapidly bactericidal Fortified vancomycin Amikacin Re-lifting the flap with cultures, scraping and irrigation Flap amputation as last resort Inhibit collagenase production Doxycycline Ectasia Ectatic disorders Specific topographic patterns Residual stromal bed thickness Low pre-operative corneal thickness High myopia Young age Other: Family history and chronic eye rubbing o Prevention Utilizing alternative treatments (ie, Surface ablation, Phakic IOL) Avoid retreatment in cases with a low RSB o Management of postoperative ectasia Spectacles or soft contact lenses Avoid eye rubbing Rigid gas permeable contact lenses Intra-corneal ring segments Corneal collagen cross-linking Corneal transplantation Marginal Sterile Corneal Infiltrates o Pathophysiology Corneal hypersensitivity to bacterial exotoxins colonizing the eyelids Epithelial injury o Clinical diagnosis Occurs 1-5 days post-surgically Localized or circumferential infiltrate peripheral to the flap edge o Clinical management Topical corticosteroid every 1-2 hours

4 Identify patients who are high risk and pretreat them accordingly Acne rosacea Atopic disease Blepharitis Dry eye Dry eye Gender Pre-existing dry eye Hinge properties (ie, Location, Width) Ablation depth o Diagnostic approach Schirmer test I/II, and Phenol red thread TBUT Tear Osmolarity Ocular surface staining Ocular Surface Disease Index (OSDI) Artificial tears Lid scrubs Topical cyclosporine A 0.05% Punctal plugs Oral dietary supplements Omega-3 fatty acids Doxycycline Autologous serum Photorefractive keratectomy (PRK) Corneal haze Classification o Typical transitory haze o Late haze Cause o Ultraviolet exposure o Discontinuation of topical corticosteroids o Delayed epithelial healing o Systemic autoimmune disease Pathophysiology and Grading system o Disruption of basement membrane Keratocyte transformation into activated fibroblasts Risk factors o Depth of ablation/refractive status considerations o Diameter of ablation o Corneal healing time

5 o Irregularity of post-operative stromal surface o Basement membrane integrity o Tear fluid transforming growth factor beta levels Prevention o Mitomycin C o Vitamin C Treatment o Topical corticosteroids o Phototherapeutic keratectomy with mitomycin C 0.02% RCE Pathophysiology o Abnormal basal epithelial cell layer o Abnormal basement membrane Overexpression of proteases and collagenase (MMP-9) o Absent or abnormal hemidesmosomes o Loss of anchoring fibrils Treatment o Medical Hyperosmotic agents Artificial tears Topical corticosteroids Tetracycline class antibiotics o Surgical Anterior stromal micropuncture Surgical keratectomy Phototherapeutic keratectomy