Strict inclusion criteria apply for using the femtosecond laser flapless intrastromal procedure to treat presbyopia.
Chicago-Strict inclusion criteria apply for using the femtosecond laser flapless intrastromal procedure (IntraCor, Technolas Perfect Vision) to treat presbyopia. However, results from medium-term follow-up show that this procedure has excellent functional outcomes, good safety, and high patient satisfaction when used in appropriate candidates, said Claire Hartnett, MD, at the annual meeting of the American Society of Cataract and Refractive Surgery.
"In addition to patients being carefully selected for the intrastromal presbyopia procedure, those who are eligible candidates must be counseled about a potential for loss of distance visual acuity," said Dr. Hartnett, research fellow, Mater Private Hospital, Dublin, Ireland. "Nevertheless, in our study we found a 91% patient satisfaction rate, and we feel the femtosecond laser intrastromal procedure offers a very good option for presbyopic correction."
Mean near uncorrected visual acuity (UCVA) was N18 preoperatively (range N10 to N36), improved dramatically to N5 at 6 weeks (range N4 to N12), and remained N5 at 24 months. At 12 months, 91% of patients had achieved spectacle independence and were reading N8 or better in good natural lighting conditions, but 60% of patients needed reading glasses in dim lighting conditions.
Preoperatively, mean refraction was +0.34 D SE. Refraction data from follow-up visits showed the treatment caused an early myopic shift that was associated with central corneal steepening, but both changes lessened with time. Mean myopic shift was –0.76 D at 3 months, –0.66 D at 6 months, –0.62 D at 12 months and –0.54 D at 24 months when mean refraction was –0.31 D SE.
At 12 months, there was a mean loss of 1 logMAR line from preoperative distance UCVA, and 16% of patients noticed a reduction in their distance UCVA. However, distance UCVA was generally stable between 12 and 24 months, and at 24 months, 9% of patients had a 1-line gain from baseline distance logMAR UCVA, 32% had no change, 37% had a 1-line loss, 16% lost 2 lines, and 6% lost 3 lines.
About one-fourth of patients reported glare and halos after the procedure, but the symptoms were not debilitating for any patient, and they also improved over time. Other safety data showed no evidence of corneal ectasia on topographic analysis, no loss of binocular depth perception on stereopsis testing, and no change in endothelial cell count.
"We know the femtosecond laser causes photo disruption within the stroma, which raised the question of whether the procedure would affect the endothelium," Dr. Hartnett said. "However, we saw an endothelial cell count loss of only 2.09% over 2 years."
Claire Hartnett, MDE-mail: firstname.lastname@example.org
Dr. Hartnett has no relevant financial interests to disclose.