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* BACKGROUND AND OBJECTIVE: This is a follow-up report on 103 THG:YAG (holmium) sclerostomies ab externo performed on 87 eyes of 81 patients. * PATIENTS AND METHODS: The patients received pulse energies of 0.06 to 0.13 J (mean total energy 4.4 ± 3.3 J, range 0.6 to 17.1 J). * RESULTS: The estimated success rates with or without medication, and allowing a second procedure, were 44% at 2 years and 36% at 4 years. The mean preoperative intraocular pressure (IOP) was 29.7 ± 11.4 mm Hg, and the mean postoperative IOP in the successful patients was 13.6 ± 4.6 mm Hg (P < .01). Hypotony and iris incarceration were the most frequent early complications. * CONCLUSIONS: Although holmium laser sclerostomy is a relatively straightforward procedure and offers some advantages over standard trabeculectomy in select cases, it currently has a number of drawbacks that limit its use. [Ophthalmic Surg Lasers 1996;27:823-831.]

CASE REPORT A 73-year-old Hispanic woman with Type II diabetes mellitus for the past 3 years is referred for management of ocular hypertension. Her family history is unremarkable. Slitlamp biomicroscopy reveals no apparent secondary cause for her elevated intraocular pressure (IOP) and both angles are widely open with mild, uniform, trabecular pigmentation. Cup–disc ratios are 0.6 OU, with pink, healthy neural rims without evidence of thinning, notch, nerve fiber layer defect, or localized pallor. Achromatic automated perimetry is unremarkable, and short-wavelength perimetry is unreliable. IOPs range from 23 to 28 mm Hg. Corneal thicknesses are 558 and 560 μm, in the right and left eyes, respectively. 1. Which patients with ocular hypertension should be treated? 2. Should one correct IOP for corneal thickness and if so, how should this be done? 3. How should IOP be measured in eyes with irregular corneal surfaces or following keratorefractive surgery?

Background: Laser sclerostomy can be performed in a less-invasive manner than standard filtering surgery. Longer wavelengths in the infrared range have water-absorptive characteristics that facilitate perforation of the sclera. The goal was to perform laser sclerostomy ab externo to avoid intraocular instrumentation and minimize conjunctival trauma. Methods: A thulium, holmium, chromium-doped:YAG (THC:YAG) crystal laser was used to create thermal sclerostomies in 49 glaucomatous eyes of 46 patients. The laser is a long-pulsed (300-μsecond), compact, self-contained, solid-state laser operating in the near infrared (2.1 μm). Energy was delivered via a specially designed 22-gauge (712-μm) optic probe that emits energy at a right angle to the long axis of the fiber. Pulse energies of 80 to 120 mJ were used. Total energy levels to produce full-thickness sclerostomies ranged from 1.4 to 7.2 J. Subconjunctival 5-fluorouracil (5-FU) injections were administered in 46 eyes. Success was defined as an intraocular pressure (IOP) of less than or equal to 22 mmHg with or without medications. For eyes in which preoperative IOP was less than or equal to 22 mmHg, success was defined as a decrease in IOP of greater than or equal to 30%. Results: Estimated probability of success allowing for one retreatment was 0.75 at 6 months and 0.68 at 12 months. Mean IOP of successful cases was 13.3 mmHg at both 6 and 12 months. Twelve cases failed within the initial 6 months, and two additional cases failed by 12 months. Conclusion: THC:YAG ("holmium") laser thermal sclerostomy is an alternative to other full-thickness filtration procedures. Further evaluation and understanding will define its ultimate role in glaucoma management.

The prevalence of open angle glaucoma is disproportionately high in the African American population. Information about the effectiveness of anti-glaucoma medications in an exclusively African American population is lacking. We treated both eyes of 38 African American patients who have stable open angle glaucoma with either levobunolol b.i.d. or dipivefrin b.i.d. to evaluate the effectiveness of each drug in lowering intraocular pressure. Patients were treated for six weeks following a two week washout period. We measured intraocular pressure levels after one, three, and six weeks. Each medication produced a statistically significant decrease in intraocular pressure by week one. The mean pre-treatment pressure of 24.4 mmHg in the levobunolol was reduced to 17.0 mmHg by week six. The mean pre-treatment pressure of 25.4 mmHg in the dipivefrin treated group was reduced to 18.2 mmHg by week six. There was not a statistically significant difference in the pre-treatment or the final pressure between the two groups. Both levobunolol and dipivefrin produce a statistically significant decrease in intraocular pressure in African American patients with open angle glaucoma.

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 µsec), compact, self-contained, solid state laser operating in the near infrared (2.1 µ). A 1-mm conjunctiva) stab incision was made 12 mm away from the sclerostomy site to allow entry of a specially designed 22-gauge (712 µ) 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 conjunctiva) trauma.

A newly developed compact (40 kg), self-contained contact Neodymium:YAG laser produces high-peak, high-energy (800 mJ/pulse), short (1.0 millisecond) pulses with 1 to 3 pulses/exposure. Energy is delivered via a 320- µm cleaved quartz fiber optic probe. Cyclophotocoagulation was performed in five eyes of three medium-sized Dutch-pigmented rabbits. The eyes received exposures of 1 to 3 pulses/exposure. Energy delivered ranged from 100 to 800 mJ/pulse. Histopathology revealed ciliary body disruption and hemorrhage with no damage to overlying sclera. When used for transscleral cyclodiathermy in the rabbit, the laser created significant ciliary body disruption with minimal scleral injury.

A THC:YAG laser (thulium, holmium, chromium-doped YAG crystal) was used to create thermal sclerostomies in 35 glaucomatous eyes of 33 patients. The laser is a long-pulsed (300 microsecond(s) ec), 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/sec. Total energy levels to produce full-thickness sclerostomies ranged from 1.4 to 7.2 J. Subconjunctival 5-fluorouracil injections were administered in 32 eyes. Success rate was 66% at 6 months and 63% at 12 months. Mean intraocular pressure of successful cases was 14 mmHg at 6 months and 13 mmHg at 12 months. Ten cases failed within the initial six months, and one additional case failed by 12 months. Success and failure were analyzed relative to patient risk factors and clinical experience with the procedure.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Background The prevalence of glaucoma is higher in African American individualsthan in white individuals. Objective To report the safety and efficacy of topical ocular hypotensive medicationin delaying or preventing the onset of primary open-angle glaucoma (POAG)among African American participants in the Ocular Hypertension Treatment Study. Methods Eligibility criteria included age between 40 and 80 years, intraocularpressure between 24 and 32 mm Hg in one eye and between 21 and 32 mm Hg inthe other eye, and no evidence of glaucomatous structural or functional damageby standard clinical measures. Participants were randomized to either theobservation group or medication group. Of the 1636 participants randomized,408 were self-identified as African American. Main Outcome Measure The primary outcome was the development of reproducible visual fieldabnormality and/or reproducible optic disc deterioration attributed to POAG. Results Among African American participants, 17 (8.4%) of 203 in the medicationgroup developed POAG during the study (median follow-up, 78 months) comparedwith 33 (16.1%) of 205 participants in the observation group (hazard ratio,0.50; 95% confidence interval, 0.28-0.90; P = .02). Conclusion Topical ocular hypotensive therapy is effective in delaying or preventingthe onset of POAG in African American individuals who have ocular hypertension.

During the past several years the Neodymium:YAG laser has become increasingly popular for performing peripheral iridotomy. Using energy levels of 2-8 millijoules per shot and 1-3 shots per treatment, most irides can be penetrated in one sitting. Nd:YAG laser iridotomies show very little tendency to close, except in patients with active intraocular inflammation. A small amount of hemorrhage is common following YAG laser iridotomy, but clinically significant hyphema is rare. Significant lenticular or corneal damage is extremely rare. Although longterm follow-up of large numbers of patients is lacking, Nd:YAG laser iridotomy appears to be a safe and effective alternative to Argon laser iridotomy in selected patients.