Search

* 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?

A THC:YAG laser (thulium, holmium, chromium-doped YAG crystal) was used to create 93 thermal sclerostomies ab externo in 81 glaucomatous eyes of 76 patients. Pulse energies of 80 to 120 mJ were used, with a repetition rate of 5 pulses per second. Total energy levels to produce full-thickness sclerostomies ranged from 1.4 to 7.2 J. Estimated probability of success was 0.66 at 12 months and 0.57 up to 30 months. The mean intraocular pressure in the successful cases was 12.8 ± 4.0 mm Hg.

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.

We conducted a randomized, double-masked, paired comparison of 0.1% thymoxamine vs placebo for the reversal of phenylephrine-induced mydriasis. Mydriasis was induced with 2.5% phenylephrine in each eye of 74 subjects (148 eyes). Each subject then received 0.1% thymoxamine in one eye and placebo in the other eye. Pupillary measurements were obtained at regular intervals during the ensuing 8 hours. At all intervals, a greater percentage of thymoxamine-treated eyes returned to baseline pupillary diameters compared with placebo-treated eyes (P less than or equal to .01). For subjects in whom both pupils returned to baseline, thymoxamine-treated eyes returned to baseline in a mean of 2.2 hours, vs 5.2 hours for placebo (P less than .0001). Among thymoxamine-treated eyes, those with light irides responded more rapidly than those with dark irides, returning to baseline in 1.6 vs 2.8 hours, respectively (P = .0046). After constriction to baseline pupillary diameter had been achieved, no patients experienced a rebound dilation.

To evaluate whether baseline visual field data and asymmetries between eyes predict the onset of primary open-angle glaucoma (POAG) in Ocular Hypertension Treatment Study (OHTS) participants.A new index, mean prognosis (MP), was designed for optimal combination of visual field thresholds, to discriminate between eyes that developed POAG from eyes that did not. Baseline intraocular pressure (IOP) in fellow eyes was used to construct measures of IOP asymmetry. Age-adjusted baseline thresholds were used to develop indicators of visual field asymmetry and summary measures of visual field defects. Marginal multivariate failure time models were constructed that relate the new index MP, IOP asymmetry, and visual field asymmetry to POAG onset for OHTS participants.The marginal multivariate failure time analysis showed that the MP index is significantly related to POAG onset (P0.0001) and appears to be a more highly significant predictor of POAG onset than either mean deviation (MD; P = 0.17) or pattern standard deviation (PSD; P = 0.046). A 1-mm Hg increase in IOP asymmetry between fellow eyes is associated with a 17% increase in risk for development of POAG. When threshold asymmetry between eyes existed, the eye with lower thresholds was at a 37% greater risk of development of POAG, and this feature was more predictive of POAG onset than the visual field index MD, though not as strong a predictor as PSD.The MP index, IOP asymmetry, and binocular test point asymmetry can assist in clinical evaluation of eyes at risk of development of POAG.

This special issue contains original review articles by researchers from the University of California and the Secretariat of Health of Mexico. The articles on epidemiology prevention and health care services review available published data and selected unpublished data on Mexican migrants in California specifically and across the United States. These articles identify research and intervention needs and where available document effective methods of outreach and interventions with the Mexican migrant population. An article addressing the issue within Mexico outlines the emerging data on the vulnerability of Mexicans migrating to the United States with regard to HIV sexually transmitted diseases and associated behaviors. Lastly a concluding article presents an analysis of policies that serve as barriers or facilitators of prevention and care for Mexican migrants in California. All the articles offer compelling evidence for integrating tailored outreach prevention and health care services for the Mexican migrant population into the overall health care infrastructure of communities in California and Mexico. (excerpt)