LRI by hand or laser, both hold advantages
Addressing astigmatism at the time of cataract surgery optimizes refractive outcomes.
WAIKOLOA, Hawaii — The femtosecond laser method of developing arcuate incisions provides precision in depth and placement of limbal relaxing incisions, continuous curvature and the ability to titrate incisions, Preeya K. Gupta, MD, said at Hawaiian Eye 2019.
Even though her preferred method of correction for low levels of astigmatism is astigmatic keratotomy (AK) with femtosecond laser, Gupta said, “Manual LRI and femto AK are both excellent options. Astigmatism management at the time of cataract surgery is really essential to provide that high quality of uncorrected vision that we talk about with refractive cataract surgery.”
Femtosecond laser incisions are fundamentally different from manual incisions, she said. An incision made with a laser is photodisruptive and removes tissue from the site. Because of this change in wound architecture, a nomogram for a manual incision would tend to overcorrect, although there are nomograms developed for laser incisions as well.
Even so, femtosecond laser adds a layer of precision, Gupta said.
“Unless you’re taking a pachymeter and calculating it out, you don’t know necessarily how deep your blade is going,” she said. “With the laser, there’s actual OCT imaging. Typical incisions are placed at the 9 mm optical zone at 80% depth, and they’re unlikely to perforate given the added precision.”
The continuous incision is another advantage of the femtosecond laser, according to Gupta.
“I would like to think that I make a perfect freehand incision, but it never is as perfectly continuous as a laser,” Gupta said. “You have the ability to titrate the incision, which is very different than the manual incision. You do not have to open the arcuate incision, disrupting the epithelium if you don’t want to.”
Risks associated with arcuate incisions include disruption of the epithelium, which is more common in older patients with anterior basement membrane dystrophy, and decreased corneal sensation, Gupta said. Over time, arcuate incisions can become less effective, and patients may experience a regression of the procedure’s effects. Other risks include perforation of the cornea, especially in high myopes with a thinner peripheral cornea, and infection, “like with anything we do with any procedure,” she said.
“Over 50% of patients with cataracts have more than 0.75 D of clinically significant pre-existing corneal astigmatism,” Gupta said. “We know that astigmatism is really important to address if we’re looking for the most optimal visual outcomes.”
For Gupta, femtosecond laser creation of the LRI has increased her efficiency at the time of cataract surgery. However, she said, “For anybody out there that’s trying to achieve higher refractive outcomes, I think it’s very important to be comfortable with both manual and femto incisions.” – by Scott Buzby
Gupta P. Manual vs. femto arcuate incisions: which is better? Presented at: Hawaiian Eye; Jan. 19-25, 2019; Waikoloa, Hawaii.
For more information:
Preeya K. Gupta, MD, can be reached at Duke Eye Center, 4709 Creekstone Drive, Durham, NC 27703; email: email@example.com.
Disclosure: Gupta reports she is a consultant to Aurea, Kala, TearScience, Shire, Allergan, Bio-Tissue, NovaBay Pharmaceuticals, Johnson & Johnson Vision, Alcon, TearLab, Ocular Science and Zeiss.