Low-energy linear-incision neodymium: YAG laser iridotomy versus linear-incision argon laser iridotomy. A prospective clinical investigation.
When the Q-switched neodymium: YAG (Nd: YAG) laser is focused through the Wise 103-diopter (D) iridotomy-sphincterotomy lens (103-D lens) at low energy levels, the peripheral iris fibers can be cut individually across the iris tension lines to produce large iridotomies of controllable size. Thirty patients had linear-incision Nd:YAG laser iridotomy in one eye and linear-incision argon laser iridotomy in the other. Two-hour post-laser IOP rises averaged 7.33 mmHg for the Nd:YAG laser and 8.64 mmHg for the argon laser. The argon laser produced lens burns in 9 of 30 eyes, including 7 of 9 blue eyes. No lens damage occurred with the Nd:YAG laser. No corneal or retinal damage was seen with either laser. Local oozing of blood inhibited optical breakdown and required a pause before completion in 5 of 30 eyes with Nd:YAG iridotomy, including 4 of 6 dark brown thick irides. Because the iris fibers must be cut by direct contact with the laser plasma, serial cutting of iris fibers by multiple low-energy plasmas is safer than a single-shot, high-power plasma occupying the full thickness of the iris. Because it is effective and because it avoids the hazards of argon laser iridotomy and of high-power Nd:YAG laser iridotomy, linear incision Nd:YAG laser iridotomy is recommended as the safest method of iridotomy.
Wise
J B
JB
Department of Ophthalmology, Baptist Medical Center of Oklahoma, Oklahoma City.
D001128:Argon; D002056:Burns; D002986:Clinical Trials as Topic; D005901:Glaucoma / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure; D007498:Iris / Q000473:pathology / Q000601:surgery*; D053685:Laser Therapy / Q000009:adverse effects / Q000379:methods*; D007908:Lens, Crystalline / Q000293:injuries; D011184:Postoperative Period; D011446:Prospective Studies
D001128:Argon