Lacritin and Heparanase Levels in Human Tears After Laser Refractive Surgery

Inclusion Criteria:

- Active duty US Army Soldiers eligible for care at WRAMC

- Undergoing PRK or LASIK

- Male or female, of any race, and at least 21 years old and not older than 55 years
old at the time of the tear collection. The lower age limit of 21 years is intended
to ensure documentation of refractive stability.

- Appropriately aged individuals who report that their eyes are "normal" and who have
no active eye illness as determined by the principal investigator or
sub-investigator.

- Ability and willingness to understand and provide informed consent to participate in
this study.

- Up to -10.00 diopters of myopia.

- Subject must expect to be located in the greater Washington DC area for a 12 month
period post-operatively.

- Consent of the subject's command (active duty) to participate in the study.

- Access to transportation to meet follow-up requirements.

Exclusion Criteria:

- Any reason to be excluded for PRK or LASIK

- Female subjects who are pregnant, breast-feeding or intend to become pregnant during
the study. Female subjects will be given a urine pregnancy test prior to
participating in the study to rule out pregnancy. [Pregnancy and breastfeeding are
contraindications to refractive surgery in general, including PRK, whether
participating in this study or not]

- Patients with known sensitivity or inappropriate responsiveness to any of the
medications used in the post-operative course.

- Any physical or mental impairment that would preclude participation in any of the
examinations.

- Anterior basement membrane dystrophy

- History of recurrent epithelial erosion

- Significant dry eye (symptomatic with Schirmer <5mm at 5 minutes)

- Other corneal epithelial disorder or healing abnormality

- Individuals with any infectious or inflammatory ocular conditions (e.g. have "pink
eye" or uveitis).

- Individuals diagnosed with dry eye or other ocular surface condition, including but
not restricted to neurotropic keratitis, anterior basement membrane dystrophy, and
recurrent corneal erosions.