This year's survey of the members of the International Society of Refractive Surgery and American Academy of Ophthalmology shows refractive surgeons becoming more conservative in some areas—they're leaning toward thinner flaps each year—but becoming more daring in others, such as performing bilateral lens procedures. The use of phakic lenses and the Intralase are both up, as well. To find out more, read on.


Each year, the survey is conducted by Mobile, Ala., surgeon Richard Duffey and Palm Springs, Calif., ophthalmologist David Leaming. For this year's survey, 248 surgeons, or 18 percent of the 1,407 surveyed, responded. Here are the highlights:


 
• Procedures being performed. More surgeons are performing refractive lens exchange and phakic intraocular lens procedures than a year ago. The percentage doing RLE jumped 10 percent, from 58 to 68 percent, and the proportion implanting phakic lenses climbed from 30 to 38 percent.


Also, LASIK volume is down. The percentage of surgeons who say they do more than 75 cases per month is down to 13 percent, from a high of 27 percent in 2001. The number of surgeons who do at least 25 cases per month is also down, having steadily declined to 33 percent from its highest point (54 percent) in 2001.



Though LASIK is approved for +6 D, surgeons don't think highly of it for patients in that range. "For even the 3-D hyperope, refractive lens exchange is increasing [at 18 percent now]," says Dr. Duffey. "The FDA may have approved 6 D of hyperopic correction, but nobody's doing +6 D with the laser. It's too unpredictable and there are too many night-vision problems. They end up with very unstable corneas. When you try to make a cornea that steep, even with excellent centration, a little decentration can be a problem." The number of surgeons doing +5-D corrections bears this out; only 13 percent of surgeons say they'd choose LASIK for this level of correction, compared to 60 percent for RLE and even 19 percent for "waiting."


 
• Custom is king. In 2003, only 5 percent of the survey's respondents said they used custom LASIK for 76 to 100 percent of their patients. Now, that number is 66 percent. "It just keeps getting better," says Dr. Duffey.


 
• Bilateral lens surgery. "At least 10 percent of surgeons who implant phakic IOLs say they're comfortable with doing them bilaterally at the same OR visit," notes Dr. Duffey. "This really surprises me, because, in the United States, any doctor who does a bilateral intraocular procedure and gets an endophthalmitis that affects both eyes, or a cystoid macular edema that affects both, he's dead in the water from a medicolegal standpoint. There's no defense for it."


 
• Making a flap. Most surgeons (72 percent) use some sort of mechanical microkeratome to make the flap, though the percentage of surgeons reporting that they use the Intralase laser is up to 28 percent from 20 percent last year. Thirty-three percent of doctors use either the Bausch & Lomb Hansatome (28 percent) or the Zyoptix XP microkeratome (5 percent). "I keep expecting Intralase to take over," says Dr. Duffey. "Yes, it keeps going up, but it's still only at 28 percent. I think there are just too many Hansatomes out there that are expensive to get rid of, and Moria users also represent about 23 percent of all the flap-making devices used. I think Intralase will continue to increase, but I think you'll have as many people using mechanical microkeratomes as you have Intralase. The only way I see that changing is if you get a medicolegal climate in which Intralase makes it very difficult to use a microkeratome with its warrants that its laser is so much safer."


 
• Tracking topographers. Many surgeons in the survey have multiple topographers, an average of 1.43 topography units per surgeon. "New technology comes on board and volume goes up," says Dr. Duffey. "We have a Zeiss and Orbscan and an EyeSys. So, when we buy new units, we eventually go to the next level of technology; my next one will probably be a Pentacam."


 
• Presbyopia surgery. Interestingly, with all the hubbub over presbyopic IOLs, monovision and modified monovision are still the procedures of choice for 61 percent of surgeons. Sixteen percent would choose the ReSTOR lens, 10 percent like the ReZoom, and 9 percent prefer the Crystalens. "The mono numbers dropped a little from last year, and the presbyopic lens numbers either stayed the same or went up a little. I think the trend is that the mono numbers will get lower as we get more accommodative and multifocal technologies.



"Monovision is still popular because [surgeons] don't think the multifocals are the end-all, be-all," adds Dr. Duffey. "If someone comes in wearing monovision contact lenses successfully and they have cataracts, do you really want to introduce a whole new subject or just take them back to where they were before? They understand monovision immediately and tolerate it, et cetera." He says some of the affinity for monovision probably is because it's cheaper, though it's still effective.


 
• Preferred flap thickness. Surgeons are definitely moving toward thinner flaps. Three years ago, around 35 percent of surgeons used LASIK flaps of between 150 and 160 µm, with the same percentage using 120- to 130-µm flaps. Only 11 percent made 100-µm flaps. Now, however, 49 percent say they use 120 to 130-µm flaps, and 27 percent make 100-µm ones. The 150 to 160 group is down to 20 percent. "Some of this is Intralase, but some of it is even microkeratome users who've learned they can cut thinner flaps," says Dr. Duffey. As to where this trend might lead, he says it's probably limited by the variability of the devices. "The problem is, whether it's an Intralase or the best microkeratome, there's still a range of about 30 to 40 µm. So, if you're shooting for 90, some will be 70 µm, and some will be 110. And if you get too much below 70, into the 65 and 60s, you're starting to get into Bowman's layer, if not epithelium. I measure corneal thickness on all my PRK patients before and after epithelial debridement, and the average epithelial thickness by subtraction method is about 65 µm. So, if you start getting below that, you're going through Bowman's layer and into epithelium and you'll get a scar. So I think 90 is getting to your limit."


All of the survey results are available on Dr. Duffey's website at
duffeylaser.com