Page 17 - NAME OF CONDITION: REFRACTIVE ERRORS

papillary size. If this be the case, it is interesting to speculate whether the treated area
corrects the aberrations, over the entire spectrum of papillary dilatation and

constriction, which happens during our day to day activities.
5. Limitation of the retina: Even if we correct all the aberrations of the eye, there is a
biological limitation of the retina to see beyond approximately 6/3 vision. It is not clear
whether the neural retina will be able to interpret the improved image.
6. Depth of field: Removing the eye’s higher order aberrations increases optical quality
for objects that lie at the best focus. However, it reduces optical quality for objects that
are far out of best focus. Exactly how this benefits and cost tradeoff functions in
everyday vision has not yet been carefully studied.
7. Change in posture: It has to be understood that the wave front measurements are
taken with the patient in a sitting position, while the treatment is performed in a

patient in a supine position. Since the wave front changes with these postural
alterations, this factor needs to be studied in detail.

Contraindications
• Unstable refraction
• Certain abnormalities of the cornea (e.g., keratoconus or other corneal ectasias,
thinning, edema, interstitial or neurotrophic keratitis, extensive vascularization)
• Insufficient corneal thickness for the proposed ablation depth

• Visually significant cataract
• Uncontrolled glaucoma

• Uncontrolled external disease (e.g., blepharitis, dry eye syndrome, atopy/allergy)
• Uncontrolled connective tissue or autoimmune disease
• Unrealistic patient expectations
Relative Contraindications
• Functional monocularity

• Ocular conditions that limit visual function
• Excessively steep or flat corneas
• Abnormal corneal topography suggestive of forme fruste of keratoconus, keratoconus,
or other corneal ectasias

• Significant irregular astigmatism
• Corneal stromal or endothelial dystrophies
• History of herpes simplex virus (HSV) or varicella zoster virus (VZV) keratitis
• Significant dry eye syndrome
• Prior incisional or lamellar keratorefractive surgery

• Glaucoma
• Diabetes mellitus

• Pregnancy or lactation

• Connective tissue or autoimmune diseases

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