Diode lasers in ophthalmology

Cyclophotocoagulation as a Minimally Invasive Treatment Option for Glaucoma

Historically, the complications and inadequate efficacy of prior cyclodestructive procedures limited their role in glaucoma management. Recent advances in treatment techniques and parameters for laser cyclophotocoagulation has expanded its role in today's glaucoma practice. This review summarizes the role of different cyclophotocoagulation techniques, including continuous wave transscleral cyclophotocoagulation and micropulse transscleral cyclophotocoagulation, in the management of glaucomatous optic neuropathy.

[Diode and argon trabeculoplasty in primary open-angle glaucoma treatment]

Laser trabeculoplasty is one of the methods used to decrease intraocular pressure (IOP) as part of comprehensive glaucoma treatment. Argon laser trabeculoplasty (ALT) and diode laser trabeculoplasty (DLT) are two of the most widely used laser trabeculoplasty techniques. The mechanism of its hypotensive action is based on the effect that laser emission photocoagulate has on trabecular meshwork and subsequent outflow facilitation, but the difference in wavelength and emission energy determine the difference in direct laser action and the features of postoperative clinical appearance. The efficacy of both methods has been verified in many studies; however, relatively few of them have made comparative analysis of the two techniques. The article reviews publications dedicated to comparing the efficacy of ALT and DLT, including their hypotensive effect, safety, as well as data on laser surgery tolerance and complications.

Lasers in ophthalmology

Laser technology continues to progress with the addition of new lasers, new delivery systems, and new applications. The introduction of lasers to veterinary ophthalmology has radically changed the level of care that we can provide to our patients. The development of the diode laser has particularly had an impact on veterinary ophthalmology. The diode's affordability, portability, and broad applications for veterinary patients have allowed laser surgery to become a routine part of veterinary ophthalmology practice. Educating the public and veterinary community in available laser techniques will generate improved ophthalmic care and provide more data on which to build future applications.

Recurrent hyphema in an aphakic child: Swan syndrome

In 1973, Swan described 3 patients who developed hyphema months to years after uncomplicated cataract surgery. He noted focal vascularization from an ingrowth of episcleral vessels at the cataract wound site, resulting in recurrent intraocular bleeding. Swan syndrome has been reported following intracapsular cataract extraction, extracapsular cataract extraction (including clear corneal incisions), iridocyclectomy, and glaucoma filtering procedures. Patients typically present with sudden painless blurred vision, often upon awakening, which may or may not be preceded by physical strain or trauma. Other patients are asymptomatic and diagnosed with hyphema or anterior chamber red blood cells on routine examination. The hyphema often resolve spontaneously, making later diagnosis difficult. Gonioscopic visualization of the abnormal wound vessels is necessary for diagnosis. Without active bleeding, however, the fibrovascular tuft may be easily overlooked. We report a case of Swan syndrome in a 16-month-old boy after cataract extraction was performed. To our knowledge, Swan syndrome has not been reported in the pediatric population. Children represent a significant proportion of patients undergoing anterior segment surgery and Swan syndrome should be considered in the differential diagnosis of hyphema in this population.

Argon vs diode laser trabeculoplasty

PURPOSE

To compare the efficacy of diode laser and argon laser trabeculoplasty in a randomized prospective study of 11 paired fellow eyes.

METHODS

Fellow eyes of 11 patients, having had no prior laser trabeculoplasty and requiring laser trabeculoplasty to lower intraocular pressure, were randomly assigned prospectively to diode laser trabeculoplasty in one eye and argon laser trabeculoplasty in the other eye.

RESULTS

In the diode laser group, the average baseline intraocular pressure was 21.6 +/- 2.0 mm Hg before trabeculoplasty and 19.6 +/- 2.1 mm Hg (or a 7.7% +/- 11.5% mean pressure reduction) at 1 month, 19.3 +/- 2.6 mm Hg (or a 6.9% +/- 13.5% mean reduction) at 2 months, and 19.0 +/- 3.3 mm Hg (or a 2.4% +/- 16.9% mean reduction) at 3 months postoperatively. In the argon laser group, the average intraocular pressure was 24.4 +/- 3.5 mm Hg before treatment and 17.6 +/- 1.7 mm Hg (or a 24.7% +/- 11.4% mean pressure reduction) at 1 month, 16.8 +/- 2.5 mm Hg (or a 26.7% +/- 15.3% mean reduction) at 2 months, and 15.5 +/- 1.2 mm Hg (or a 30.0% +/- 16.5% mean reduction) at 3 months after laser trabeculoplasty. The difference between argon and diode laser intraocular pressure reduction was statistically significant at 1 month (P < .01), 2 months (P < .01), and 3 months (P < .05) after treatment.

CONCLUSION

Argon laser trabeculoplasty appears to be more effective than diode laser therapy in lowering intraocular pressure during the first 3 months after treatment.