March 2007

 

ASCRS ASOA PREVIEW

 

Innovation to prevail at ASCRS•ASOA Symposium and Congress


by Michelle Dalton EyeWorld Contributing Editor

 

 

Numerous presentations will highlight advances in ophthalmology at this year’s annual symposium.

Dr.Pfaeffl’s step-by-step guide of the flaporhexis technique:

Step 1. Enter the side cut with the short hook side of the Seibel-IntraLASIK Flap lifter (Rhein Medical Tampa,Florida) or similar instrument at the 9 o'clock or 3 o'clock position and push down vertically into the gap.

Step 2. Turn the tip by 90 degrees to widen the gap of the sidecut.

Step 3. Make a swing to the contra lateral side all around the edge of the flap following the tip inside the edge of the gutter all the way down to the hinge. Go back to the entrance site and open the side cut back to the hinge.

Step 4. Use a pair of Baraquer forceps or the special designed Flaporhexis forceps (GEUDER, Heidelberg,Germany G-SO2424) to firmly grab the flap at the opened 6o'clock position.

Step 5: Tlift the flap with a strong and determined pull back to the hinge, just as opening a fish can: the flap will be peeled off the stroma very easy, since the main resistance at the side cut already has been overcome.

Source: Wolfgang Pfaeffl, M.D.

Image 1: Hinge opening technique: unwanted complication when entering the preformed interface at the hinge.

Source: Wolfgang Pfaeffl, M.D.

Flaporhexis: Alternative way to make a femtosecond laser corneal flap Using a femtosecond laser to lift a corneal flap—a technique dubbed “flaporhexis,” Wolfgang Pfaeffl, M.D., Ph.D., evaluated 304 eyes of 155 patients. These patients underwent femtosecond LASIK with the IntraLase FS30 (now Advanced Medical Optics, AMO, Santa Ana, Calif.), with an intended flap thickness of 100 microns.

“The surgical approach of flaporhexis we will talk about is derived from what is commonly called a ‘can opener technique’,” Dr. Pfaeffl said. Flaporhexis was developed to reduce the mechanical trauma associated with separating the corneal tissue by taking advantage of the cornea’s natural anatomy. The anterior part of the cornea tends to be stronger, thereby allowing tearing (greek “rhexis”) along the preformed cuts of the femtosecond photodisruption, he said.

Where flaporhexis differs, he said, is by opening the flap from the opposite side of the hinge. If performed correctly, the surgeon will find a virgin, uniform, dry stromal bed, he said. Additionally, Dr. Pfaeffl said flaporhexis contrasts to what is described as a “hinge opening technique” used to access the stromal bed. The major advantage of flaporhexis is the lack of instrument manipulation Less stress to the central cornea, leaves the optical passageway to the pupil entrance untouched. He does caution that well known effects of vertical or horizontal breakthrough, occasionally encountered in femtosecond photodisruption forms an opaque bubble layer of softened tissue. Weakend tissue is prone to corneal stress or complications when an instrument intrudes this area. (See image 1) In Dr. Pfaeffl’s study, no patients lost best corrected visual acuity (BCVA) as a result of flap complications. The easiness of this techinque has been greatly improved by the Geuder flaporhexis forceps. Dr. Pfaeffl has created corneal flaps via the flaporhexis technique to create flaps as thin as 60 microns, as measured by online optical coherence pachymetry. “With the improved quality of tissue dissection by the newer technology of the 60 Hz femtosecond lasers, flaporhexis is an even safer and easier approach to make a flap,” he said. “We believe the technique is appealing for any surgeon who is involved in wavefront-guided treatments of the cornea.” Dr. Pfaeffl is slated to discuss complications associated with this technique at the upcoming 2007 ASCRS•ASOA Symposium & Congress in San Diego. His presentation, “Flaporhexis: Alternative way to make a femtosecond laser corneal flap” will be given Monday, April 30, during Keratorefractive: Femtosecond Flap, running from 1:00-2:30 p.m.

Editors’ Note: Dr. Pfaeffl has no financial interests related to his comments.

Contact Information

Pfaeffl: +49 160 97981000; pfaeffl@msn.com

Long-term retrospective study of endoscopic cyclophotocoagulation in refractory glaucomas

Francisco E. Lima, M.D. evaluated results from a retrospective review of 539 eyes of 485 patients who had undergone endoscopic cyclophotocoagulation (ECP) and had at least five years follow-up. Inclusion criteria included at least intraocular glaucoma surgery and an IOP of at least 35 mm Hg on maximum tolerated therapy or eyes with advanced glaucomatous damage and an IOP greater than target pressure with a visual acuity better than light perception. Exclusion criteria included eyes that had undergone previous cyclodestructive procedures, eyes that did not perceive light, eyes that had a retinal or choroidal detachment or eyes with a failed corneal graft. Success was defined as an IOP between 5 mm Hg and 22 mm Hg at last follow-up with or without maximum tolerated topical glaucoma medications. Failure was defined as an IOP of at least 22 mm Hg during three consecutive follow-ups, eyes that went to phthisis bulbi and eyes that had to undergo another surgical intervention to control IOP. Limbal and pars plana ECP was performed for 210 degrees with scleral depression of the ciliary body, Dr. Lima said. In this long-term evaluation, the mean pre-op IOP was 37.9 mm Hg, which decreased to 15.7 mm Hg at the final follow-up. Success after one year was 92.6%, which decreased to a success rate of 78.8% at the 5-year mark. Complications associated with ECP included fibrin exudate, failed corneal graft, hyphema, immediate post-op IOP spike, choroidal detachment, phthisis, retinal detachment and hypotony. “These outcomes surpass the historical results of tube implantation,” Dr. Lima said. The ECP effect on neovascular glaucoma is “very interesting,” he told EyeWorld. “Most of the cases who went to phthisis had neovascular glaucoma.” Neovascular glaucoma is characterized by diminished aqueous production; it should have less ciliary body photocoagulated when compared with the other types of glaucoma, he said. Because the secondary congenital glaucoma is the most refractory, Dr. Lima said, at least three applications of ECP are needed to control IOP. “Even with all 360 degrees of ciliary body treated the IOP comes back high,” he said. “Or it usually goes to phthisis in the third intervention.”

The ECP effects and complications are more related to aqueous production in neovascular glaucoma and congenital glaucoma, Dr. Lima said. He suggested the cause in eyes with congenital glaucoma may involve a “kind of regeneration of ciliary epithelium associated with aqueous formation.”

Dr. Lima is slated to present “Long-term retrospective study of endoscopic cyclophotocoagulation in refractory glaucomas” on Tuesday, May 1, during the Glaucoma: Surgical Treatment session, running from 1:00-2:30 p.m.

Editors Note: Dr. Lima has no financial interests related to his comments.

Contact Information

Lima: +55 62 2855566; flimacbco@uol.com.br

Innovation to prevail at ASCRS•ASOA Symposium and Congress Innovation to prevail at ASCRS•ASOA Symposium and Congress
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