Ointment reduces epithelial disruption
Analyses suggest risk influenced by such factors that include age and rosacea
By Cheryl Guttman Krader
Reviewed by Andrew E. Holzman, MD
McLean, VA – In patients undergoing LASIK with use of a femtosecond laser for flap creation,
pretreatment with a hyperosmotic agent during the week before surgery significantly reduces
the risk of intraoperative corneal epithelial disruption, according to the results of a prospective,
randomized, fellow eye-controlled single-blind study presented by Andrew E. Holzman, MD.
The study included 248 patients undergoing bilateral surgery who had one eye randomly
assigned to bedtime use of sodium chloride hypertonicity ophthalmic solution 5% (Muro 128
5%, Bausch + Lomb) beginning 1 week before surgery and the other eye left untreated. Dr.
Holzman rated epithelial integrity at the end of the case, and the results showed there was a
40%, statistically significant, reduction in the risk of the epithelial disruption associated with
hyperosmotic ointment pretreatment.
Age best predictor
Additional exploratory analyses investigating associations between various patient-related
features and epithelial disruption showed age was the single best predictor. The risk of
epithelial disruption increased by nearly 10% for each 1 year increase in age and was
significantly lower in patients <34 years old compared with their older counterparts, said Dr.
Holzman, medical director of TLC Laser Eye Centers, McLean, VA.
“Epithelial disruption, occurring as a result of flap creation-induced shearing/crushing forces
that can damage the basement membrane, is estimated to occur in 2% to 10% of LASIK cases
and may lead to prolonged recovery time as well as epithelial ingrowth, flap edema, flap
melt, stromal haze, corneal ulcers, recurrent erosion, and decreased BCVA,” Dr. Holzman
said. “Considering these risks, we suggest performing an adhesion test preoperatively.
“Patients whose epithelium is loose should undergo PRK instead of LASIK,” he said. “Based on
the results of this randomized study, I am now pretreating my LASIK patients over age 35 with a
hyperosmotic ointment.”
Dr. Holzman said that he uses a variety of “epithelial-friendly” techniques perioperatively
and postoperatively to minimize the risk of epithelial disruption. These include aggressive
use of viscous lubricants preoperatively, intraoperatively, and postoperatively. He also has
patients keep their eyes closed while waiting for surgery, and instills topical anesthetics only
immediately prior to surgery.
In addition, for the past 10 years, Dr. Holzman has been instructing all patients to apply 5%
NaCl ointment inside the lower lid at bedtime, beginning 1 week prior to surgery. While it was
his anecdotal observation that he’s seen few frank epithelial defects in his IntraLASIK cases
since initiating hyperosmotic ointment pretreatment, he conducted the randomized study to
establish its benefit.
Grading epithelial integrity
Dr. Holzman performed all of the surgeries and was unaware of which was the treated eye.
Epithelial disruption was assessed at the end of surgery by wiping the cornea aggressively with
a semi-moist cellulose sponge; based on the amount of movement observed, epithelial integrity
was graded on a scale of I (normal, no movement) to IV (frank epithelial defect with surface
loss).
The postoperative cornea received a normal grading (I) in 211 (85.1%) eyes pretreated with
the hyperosmotic agent compared with 192 (77.4%) control eyes. There were no grade IV
frank epithelial defects noted in the treatment group but three such defects were noted in
the control, untreated group. The majority of the abnormal grades in both groups were of the
grade II variety (i.e., <1 mm of epithelial movement along the flap edge); these were found
in 27 (11%) eyes pretreated with the hyperosmotic agent and 42 (17%) eyes in the untreated
group.
Covariates explored as possible predictors of epithelial disruption risk included age, gender,
ethnicity, Fitzpatrick skin-type scale, hair color, and rosacea. The analyses suggested the risk of
epithelial disruption was influenced by age and rosacea.
When controlling for the presence of rosacea, there was a 4.5-fold increased risk for epithelial
disturbance among patients older than 34 years old compared with those 34 and younger.
When controlling for age, patients with rosacea had a 2-fold increased risk of epithelial
disturbance relative to the reference group, although the difference was not statistically
significant due to the limited number of those with rosacea.
“It is hard to draw conclusions about the effect of some of the covariates due to small sample
sizes,” Dr. Holzman concluded. “However, there appeared to be an association between loose
epithelium and both rosacea and red hair color.”
Take-Home Message
Results of a prospective, randomized, fellow eye-controlled, observer-masked study support
the use of hyperosmotic ointment pretreatment in patients ages 35 and older undergoing LASIK
with a femtosecond laser to reduce the risk of corneal epithelial disruption.
