Arthur Vassiliadis

Retinal Injury Due to Industrial Laser Burns

Ocular industrial lasers burns in seven patients were analyzed as to cause, severity, and type of injury. Ocular damage ranged from minimal retinal burns to extensive areas of damage with commotio retinae and vitreous hemorrhage. Visual loss ranged from complete recovery without residual defect to a profound decrease in central acuity. The kinds of lasers causing these injuries were neodymium YAG, argon, krypton, and rhodamine dye. Severity of injury was related to several factors. Some degree of carelessness was involved in all injuries.

Subconjunctival THC:YAG Laser Thermal Scierostomy

A THC:YAG laser (thulium, holmium, chromium-doped YAG crystal) was used to create thermal sclerostomies in 21 glaucomatous eyes of 19 patients. The laser is a long-pulsed (300 microsec), compact, self-contained, solid state laser operating in the near infrared (2.1 mu). A 1-mm conjunctival stab incision was made 12 mm away from the sclerostomy site to allow entry of a specially designed 22-gauge (712 mu) optic probe that delivers energy at a right angle to the long axis of the fiber. Probe insertion produced minimal disturbance of the conjunctiva. Pulse energies of 80 mJ to 120 mJ were used with a repetition rate of 5 pulses/second. Total energy levels to produce full-thickness sclerostomies ranged from 1.4 to 4.8 J. Subconjunctival 5-fluorouracil injections were administered in 15 eyes. At 3 months the mean intraocular pressure of successful cases (16) was 14 mmHg (range, 9 to 22 mmHg). Of successful cases, the mean intraocular pressure at 6 months was 13 mmHg (range, 2 to 22 mmHg). Five cases failed within the initial 3 months, and 3 additional cases failed by 6 months. The authors conclude that this full-thickness sclerostomy technique may simplify filtering surgery without anterior chamber instrumentation and with minimal conjunctival trauma.

Techniques of Argon Laser Photocoagulation of Diabetic Disk New Vessels

Four argon laser techniques have been evaluated in the eradication of diabetic disk neovascularization: focal (nonfeeder) photocoagulation, feeder-frond photocoagulation alone, panretinal photocoagulation alone, and feeder-frond treatment combined with panretinal photocoagulation. Focal photocoagulation was dangerous and the least effective technique in preventing recurrence of neovascularization. Feeder-frond photocoagulation was effective initially, but was associated with a high incidence of recurrent neovascularization. Panretinal photocoagulation and panretinal photocoagulation combined with feeder-frond treatment produced results superior to those obtained with the two earlier techniques. The best results were obtained with combined feeder-frond and panretinal photocoagulation done concurrently. Early diagnosis, aggressive photocoagulation therapy, and close follow-up were essential in order to obtain good results.