Epithelial Healing and Visual Outcomes Using Omega-3 Therapy Before and After Photorefractive Keratectomy (PRK) Surgery
Condition: Refractive Error
MeSH terms: Refractive Errors
Study type: Interventional

Summary: 
      The purpose of this study is to demonstrate that omega-3 supplement can be use as an adjunct
      therapy for PRK patients. The investigators believe that omega-3 supplement will reduce the
      size of persistent epithelial defects (PEDS) and eventually hasten the corneal
      reepithelialization after PRK surgery. If the outcome of this study proves to be effective,
      then PRK would be a more attractive option to those seeking refractive treatment.
    

Detailed description: 
      Dry eye and persistent epithelial defects (PEDS) following LASIK and PRK are one of the most
      common conditions encountered by refractive surgeons and their patient's today.¹-⁴ They are
      associated with significant clinical morbidity in patients resulting in minor problems such
      as discomfort, to extreme debilitation such as visual loss. There is no accepted definition
      of persistent epithelial defect (PED) that includes a time period of recovery. We favor the
      definition given in one text "… when the epithelium fails to re-grow over a defect within the
      expected time course.⁵ The causes of PED are diverse, with several definite etiologies'
      including dry eyes, limbal stem cell deficiency, diabetes mellitus and neurotrophic problems.
      A variety of treatment modalities have been described for PED. The elimination of
      predisposing associated risk remains a key factor in the management process. Therefore, to
      prevent and manage this common disorder it is important to have an understanding of the
      pathophysiology of dry eye after LASIK and PRK. This includes and understanding of the
      relationship and interaction between inflammation, sensory denervation and essential fatty
      acid pathways. Reports of clinical efficacy of anti-inflammatory therapies for treatment of
      dry eye disease provide direct proof of the principle that inflammation is involved in the
      etiology of dry eye disease. Research has shown that the omega-3 polyunsaturated fatty acids
      are some of the most effective natural anti inflammatory agents available. The active
      ingredients in omega 3, EPA ( Eicosapentanoic acid ) which is a 20 carbon omega 3-fatty acid
      with 5 double-bonds , and DHA ( docosahexanoic acid )which is 22 carbon omega-3 fatty acid
      with 6 double bond, both found in certain fish oils enhance the conversion of COX (
      cyclooxygenase) to prostaglandin E3. A natural anti inflammatory agent, prostaglandin E3
      competitively inhibits the effects of the arachidonic acid conversion to prostaglandin E2, a
      highly inflammatory substance. Prostaglandin E3 also inhibits the synthesis of TNFα and
      IL-1β, both of which are inflammatory leukotrienes, also by competitive inhibition.⁶ʹ⁷ By
      decreasing inflammation and stimulating aqueous tear production in rabbits cAMP has been
      shown to stimulate aqueous tear secretion in dry eye. Furthermore, by decreasing inflammation
      and augmenting oil and water layers of the tear film, omega-3 supplementation with fish oil
      rich in EPA may improve both the lipid and aqueous component of the tear film. This may
      improve surgical outcomes by stabilizing the tear film, reducing epithelial defects and
      promoting wound healing
    

Intervention name(s): Omega-3 Fatty Acid Supplements
Intervention type(s): Dietary Supplement
Intervention description(s): Twenty patients labeled as group A (Control Group) will not receive the omega-3 supplement. The Control Group will be treated in the same standard professional way as our normal refractive patients, while another 20 patients labeled as group B (Treatment group) will be given omega- 3 supplements 1 capsule 3 x a day for 2 weeks pre op and 1 month post op plus the regular post op medications. From these supplements, this will be equivalent to 750 mg of omega 3 fatty acids (both EPH and DHA), 1000 mg of Flaxseed oil, and about 183 IU of vitamin E per day. Patients will be asking to follow up postoperatively after 2 days, 4 days, 1 week, 3 months and 6 months
Other intervention name(s): TheraTears; Omega 3
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Supportive Care
Keywords: Refractive Surgery; PRK; Photorefractive Keratectomy; Omega 3 Fatty Acids; Cornea