Many research teams worldwide vigorously pursue higher-resolution retinal imaging using AO, optical coherence tomography (OCT), and lasers with exotic optics. In addition, improved surgical techniques with lasers could result in faster healing and less scarring.
FREMONT, CA: Lasers are important surgical tools for ophthalmologists. Surgeons can treat vision-robbing diseases such as macular degeneration, glaucoma, and diabetic retinopathy with these devices. They can also make the patient's vision crisp and clear.
Several laser-based procedures alleviate glaucoma. For example, one laser iridotomy surgery treats narrow-angle glaucoma—a severe, acute form of the disease. In this type of glaucoma, the eye's iris is pushed forward; thereby, the channel that normally allows aqueous fluid to drain is blocked. A resulting spike in intraocular pressure causes an acute glaucoma attack that permanently damages the optic nerve.
A risk factor for narrow-angle glaucoma is hyperopia (farsightedness) in which the eye is shorter, front to back, than average. Crystalline lenses of hyperopic people thicken due to normal aging. As a result, they may crowd the small eyes and interfere with the trabecular meshwork of the iris, which normally regulates fluids in the eyeball.
Ophthalmologists can use Nd:YAG laser to drill a tiny hole in the iris to relieve some fluid pressure inside the eyeball in a laser iridotomy. Ophthalmologists generally start the surgery using an argon laser to spur coagulation in the hole area and finishes with the Nd:YAG laser. However, as the Nd: YAG laser does not aid coagulation, there is some risk of bleeding during the procedure.
In some cases, the ophthalmologist must perform an iridoplasty with an argon laser and a larger spot size (200 to 400 m). This causes the iris tissue to contract and creates a larger hole.
Open-angle glaucoma is a chronic, silent thief of sight, characterized by a gradual decrease in aqueous fluid outflow despite an open anterior chamber. However, once the condition has progressed beyond the point where eyedrops or pills can control it, an ophthalmologist can perform an argon laser trabeculoplasty (ALT), which involves punching 50-m-size holes in the angle (the region where the cornea and iris meet). The procedure stimulates the tissue, causing it to drain the intraocular fluid more effectively.
In recent years, scientists have refined this surgery into selective laser trabeculoplasty (SLT), which uses 532-nm Nd: YAG light with a spot size of roughly 400 µm to increase drainage trabecular mesh. SLT proponents claim that it causes less tissue damage to the angle, although some studies have shown that both procedures have equal success rates with patients.
Tomorrow's patients will enjoy clear, comfortable vision because of today's Imaging and surgical research.