Long-Term Results of Photorefractive Keratectomy: A 13 Years
Prospective Study presented at ARVO 2006
FT. LAUDERDALE May 1, 2006 // Press Release // A long-term study
of photorefractive keratectomy (PRK) to correct myopia indicates
that patients undergoing this procedure maintain improved vision for
at least 13 years, researchers said here at the annual meeting of
the Association for Research in Vision and Ophthalmology (ARVO).
"To our knowledge, this prospective study has the longest
follow-up available on photorefractive keratectomy," said Graziano
Bricola, MD, staff physician, University Eye Clinic of Genoa,
University of Genoa, Genoa, Italy.
The researchers determined that the improvements seen after 3
months in patients treated with photorefractive keratectomy held up
after 13 years "with no evidence of regression." They also found
that ocular haze decreased with time and that patients recovered
best-corrected vision acuity.
The study included 29 patients who had undergone the procedure in
both eyes and 21 patients who had photorefractive keratectomy
performed in just one eye -- or a total of 79 eyes. There were 32
men and 18 women among the 50 patients in the study.
Patients underwent the procedure with a Summit Technology UV200
Eximer laser. Patients were followed 1 day after surgery, then 3 to
6 days later and once every 3 months for a year; every 6 months
until year 2 and the then every other year. Over the 13 years, 19
patients were lost to follow-up. The report was made on the basis of
results in 49 eyes.
"No late complications were found in this study," Dr. Bricola
said in the poster presentation April 30, 2006. By the end of the
study 37 of the 39 corneas were clear; 2 eyes still showed
subjective haze. The haze was described as halos seen by subjects
during night driving or when looking at street lights at night, he
said. The halos were more vivid to patients who underwent greater
vision correction -- more than 6 diopters -- surgery.
"These results confirm other shorter studies and demonstrate the
efficacy and safety of myopic photorefractive keratectomy," Dr.
The researchers said that 4 of the patients developed a temporary
increase in ocular pressure about 1 to 3 months following the
procedure. When the use of steroid was halted, the increase in
pressure returned to normal values, Dr. Bricola said.
"At 13 years, no one had developed glaucoma of ocular
hypertension," he reported.