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Biomedical subjects

I P Pollack

Publications and source records attributed to I P Pollack.

At least 37 records · Page 2Linked to original sources
PubMed1985

Q-switched neodymium-YAG laser angle surgery in open-angle glaucoma.

In a short-term pilot study, we evaluated Q-switched neodymium-YAG laser angle surgery in 25 eyes from 22 patients with medically uncontrolled open-angle glaucoma. All eyes had unacceptable intraocular pressures (IOPs), despite maximum tolerated medical therapy, argon laser trabeculoplasty, and prior intraocular filtration surgery (eight eyes). Using a pulse energy of 10 millijoules, ten spots were placed approximately 4 degrees apart in the mid-trabecular meshwork using an Nd-YAG laser (Coherent 9900). The mean preoperative and final postoperative IOPs were 30 +/- 6 mm Hg and 21 +/- 8 mm Hg, respectively. The mean follow-up time was five (+/- 3) months (range, two to 14 months). The final postoperative IOP was less than 22 mm Hg in 17 eyes (68%). Holes within the trabecular meshwork were visible in 14 eyes, and laser therapy was associated with the liberation of debris into the anterior chamber in all eyes. Complications included transient postoperative IOP elevation (eight eyes), angle bleeding (six eyes), and posterior displacement of the iris root (four eyes).

Adolescent↗
PubMed1985

Neodymium:YAG laser iridotomy in the cynomolgus monkey.

The histologic effects of various Neodymium:YAG laser energy levels were evaluated after iridotomy formation in cynomolgus monkey eyes. Scanning election microscopy of the corneal endothelium above the treated areas revealed no significant cell loss or pleomorphism when compared to the adjacent untreated areas. Light and phase contrast microscopy demonstrated closure of the iridotomies in most cases by a bridge of iris pigment epithelium. In several specimens, stromal tissue and pigment laden cells were present over the attenuated iris pigment epithelium. There were four lens opacities with rupture of the anterior lens capsule and anterior epithelial cell hyperplasia in one. No damage was apparent in the trabecular meshwork or retina with light microscopy or fluorescein angiography.

Animals↗
PubMed1984

Argon laser trabeculoplasty in younger patients with primary open-angle glaucoma.

We conducted a retrospective comparison of the effectiveness of argon laser trabeculoplasty in controlling increased intraocular pressure in two different age groups treated for medically uncontrolled primary open-angle glaucoma. Of 15 eyes of patients less than 40 years old who had primary open-angle glaucoma, nine (60%) had uncontrolled intraocular pressures postoperatively and needed filtering surgery within two years of argon laser trabeculoplasty. Only two of 29 (7%) eyes in older patients had unacceptably high intraocular pressures during a mean (+/- 1 S.D.) follow-up period of 17 +/- 5 months. Older eyes had greater decreases in intraocular pressure (12 +/- 6 mm Hg) than younger eyes (5 +/- 6 mm Hg) after laser treatment. Failure in young eyes appeared to correlate with a high preoperative intraocular pressure. Thus, argon laser trabeculoplasty is not a reliably effective form of therapy for younger patients with primary open-angle glaucoma.

Adolescent↗
PubMed1984

A comparison of neodymium: YAG and argon laser iridotomies.

A prospective short-term clinical study evaluated argon and Q-switched neodymium:YAG laser iridotomies in 40 eyes of 20 patients with primary chronic angle-closure glaucoma. All patients had bilateral iridotomies with one eye randomly assigned to argon laser and the fellow eye to neodymium:YAG laser therapy. In all eyes a patent iridotomy was created in one treatment session. A mean of 12 +/- 11 and 0.033 +/- 0.025 J were needed for iridotomy formation in argon and neodymium:YAG treated eyes respectively. No neodymium:YAG and six (30%) argon iridotomies had marked closure requiring retreatment. Immediate postoperative intraocular pressure elevation greater than 10 mmHg was seen in seven (35%) argon and six (30%) neodymium:YAG-treated eyes. Nine (45%) eyes treated with the neodymium:YAG laser had bleeding from the iridotomy site. No acute lens damage was found in the neodymium:YAG eyes while seven (35%) lenses in the argon group had focal opacities. Seven (35%) neodymium:YAG and five (25%) argon treated eyes had focal nonprogressive corneal opacities above the iridotomy site. Specular microscopy showed a significant central corneal endothelial loss in argon laser treated eyes. No eyes had detectable retinal damage.

Adult↗
PubMed1984

Nonsteroidal anti-inflammatory agents after argon laser trabeculoplasty. A trial with flurbiprofen and indomethacin.

Seventy glaucomatous eyes received argon laser trabeculoplasty (ALT) to 180 degrees of the trabecular meshwork. Thirty-six eyes were treated with topical .03% sodium flurbiprofen, a nonsteroidal anti-inflammatory agent; 34 eyes received placebo. Eighteen eyes received ALT to 360 degrees of the meshwork; nine of these eyes were treated with topical 1% indomethacin and nine eyes received placebo. Eyes treated with flurbiprofen and indomethacin showed significantly less conjunctival injection following ALT. However, these agents did not significantly alter the anterior chamber reaction after laser therapy compared to placebo. Flurbiprofen-treated eyes showed a significantly smaller percent (32.6%) decrease in intraocular pressure (IOP) one day after ALT as compared to eyes receiving placebo (43.8%). In addition, a higher percentage of placebo treated eyes had a fall in IOP of at least 10 mmHg up to five weeks after ALT. Within the indomethacin protocol, the percentage change in IOP was comparable for both indomethacin and placebo treated eyes. Mild ocular symptoms (itching, burning, foreign-body sensation) developed in 77.8% of flurbiprofen-treated eyes, in 55.6% of indomethacin-treated eyes, and in 20.9% of eyes receiving placebo.

Adult↗
PubMed1984

The Q-switched ruby laser in glaucoma.

A pilot study evaluated the safety and effectiveness of a Q-switched ruby laser in the treatment of both pupillary-block (10 eyes) and open-angle glaucoma (4 eyes). All patients had either poor visual acuity or had previously failed with conventional surgery. We created a patent iridotomy in all eyes, with one pulse in eight. Three of the four eyes with open-angle glaucoma had an intraocular pressure decrease of at least 15 mmHg after angle treatment. The major complication of Q-switched ruby iridotomy was blood and pigment within the anterior chamber obscuring the view of the iris. There were no apparent complications noted with Q-switched ruby angle treatment. The potential advantages, complications, and future uses of Q-switched lasers in glaucoma are discussed.

Adolescent↗
PubMed1984

Use of the neodymium:YAG laser to create iridotomies in monkeys and humans.

In a prospective study the Nd:YAG laser was used to create iridotomies in cynomolgus monkeys, using various levels of energy and pulse-trains of 1 to 9. Although no change occurred in the endothelial cell count of the cornea, opacities of the corneal endothelium and lens did occur. In addition, one eye showed rupture of the anterior lens capsule immediately behind the iridotomy. Most of the iridotomies in these animals closed within 3 to 4 weeks. Attenuated pigment epithelium bridged the gap within 9 days and in many sections it appeared that the iridotomies closed by fibrous contraction or early stromal regeneration. A prospective short-term clinical study evaluated argon and Q-Nd:YAG laser iridotomies in 42 eyes of 21 patients with primary chronic angle-closure glaucoma. In each patient one eye was randomly treated with an argon laser iridotomy and the fellow eye with a Nd:YAG laser iridotomy. In every case a patent iridotomy was created in one session. A mean of 12 +/- 11 and 0.033 +/- 0.025 Joules was required to complete an iridotomy with the argon and Nd:YAG lasers, respectively. Thirty percent of the argon iridotomies became sufficiently closed with pigment to require retreatment; whereas none of the Nd:YAG iridotomies closed. A postoperative rise in IOP greater than 10 mm Hg was seen in 38% argon- and 29% Nd:YAG-treated eyes. Although bleeding around the iridotomy occurred in 48% of eyes, in no case was this of significant consequence. No acute lens damage was observed in the Nd:YAG-treated human eyes, while 43% of lenses in the argon group had focal opacities. Thirty-three percent of Nd:YAG- and 24% of argon-treated eyes had focal, nonprogressive corneal opacities above the iridotomy. Specular microscopy showed a significant central corneal epithelial cell loss in argon laser eyes only. The potential of creating a laser iridotomy with a single burst of energy is extremely attractive and worthy of further investigation.

Animals↗
PubMed1983

Argon laser trabeculoplasty in secondary forms of open-angle glaucoma.

A pilot study evaluated both the safety and the effect on intraocular pressure control of argon laser trabeculoplasty (ALT) in eyes with secondary forms of open-angle glaucoma. All patients included in this study had poor IOP control and were considered surgical candidates. The ALT was considered successful if IOP control was sufficient to avoid conventional filtration surgery. Fifty-five eyes of 46 patients were treated. The mean follow-up was 8 +/- 4 months. The mean IOP decrease was 13 +/- 9 mm Hg. The ALT caused serious complications in none of the 55 eyes and seemed most effective in treating pigmentary, pseudoexfoliation, and angle-closure glaucoma present after iridotomy. The ALT had minimal therapeutic effect in eyes with uveitic, angle-recession, and congenital glaucoma.

Argon↗
PubMed1983

The effect of argon laser trabeculoplasty on the medical control of primary open-angle glaucoma.

Argon laser trabeculoplasty was performed in 33 eyes with primary open-angle glaucoma whose intraocular pressures were poorly controlled on medical therapy. Five eyes (three patients) were failures and underwent trabeculectomy within three months. The remaining 28 eyes were followed up for 18 months and received a complete examination at periodic intervals. Beginning three months after trabeculoplasty, an attempt was made to decrease medications in a prospective manner in order to determine the least treatment required to maintain a pressure of less than 22 mmHg. No medication could be discontinued in 39% of eyes, whereas 18% were "cured" by trabeculoplasty and required no further medical therapy for control. Nine of 14 eyes that had been treated with carbonic anhydrase inhibitors were controlled without these drugs after trabeculoplasty. In 57% of eyes, the miotic could be discontinued. A total of 82% of cases still required some medication for pressure control after laser trabeculoplasty.

Adult↗
PubMed1982

Argon laser peripheral iridotomies in the treatment of primary angle closure glaucoma. Long-term follow-up.

We analyzed the long-term results after argon laser peripheral iridotomy in 98 eyes of 54 patients with primary angle closure glaucoma. During a mean follow-up period of about five years, visual acuity, intraocular pressure, medication changes, and the need for filtration surgery or cataract surgery were used to evaluate the amount of possible damage that had resulted from laser iridotomy. Eyes treated with the argon laser did not appear to differ significantly from those of similar patients, described in other series, in which surgical iridectomy had been used as the therapy of choice. Argon laser peripheral iridotomy appears to be a laser peripheral iridotomy appears to be a safe and effective means of treating primary angle closure glaucoma.

Adult↗
PubMed1982

Histologic studies of angle structures after laser iridotomy in primates.

Each of nine eyes of five cynomolgus monkeys had argon laser peripheral iridotomies performed to investigate the histologic effects on the trabecular meshwork. The laser technique was the same as is used in human eyes. With laser iridotomy, particulate debris was released into the anterior chamber and rapidly accumulated in the angle. The densest initial deposit was in the inferior juxtacanalicular trabecular meshwork. Histologically, pigment was located both extracellularly and within giant vacuoles of the endothelium and Schlemm's canal and intracellularly within trabecular endothelial cells. This finding indicates that this pigment is removed from the anterior chamber both by bulk aqueous flow and by phagocytosis. One year after iridotomy, only a slightly increased pigmentation of the angle was still present. No permanent ultrastructural damage to the angle was detected.

Animals↗
PubMed1982

Argon laser trabeculoplasty: its effect on medical control of open-angle glaucoma.

Twenty persons with primary open-angle glaucoma (POAG) were followed for an average of one year in a prospective study after argon laser trabeculoplasty was performed in one eye. By one month the mean intraocular pressure (IOP) had fallen 39% and was associated with an 80% increase in mean facility of aqueous outflow. Eighteen persons with POAG were evaluated for the possibility of maintaining an IOP of less than 22 mm Hg with less medication than was required prior to laser treatment. One third of these patients required no medication after treatment, and 39% required less; however, 28% of persons who were poorly controlled before treatment required the same regimen to maintain control after laser trabeculoplasty. Six out of nine persons no longer required a carbonic anhydrase inhibitor while six out of eight persons no longer required a miotic. Laser trabeculoplasty failed to produce a sufficiently large fall in IOP in most persons on maximal medication to permit discontinuation of all medication; but it produced its most satisfying response in persons whose glaucoma was less difficult to control.

Carbonic Anhydrase Inhibitors↗
PubMed1980

Biostatistical analysis of the collaborative glaucoma study. I. Summary report of the risk factors for glaucomatous visual-field defects.

A prospective collaborative study was conducted in five centers during a 13-year period to identify factors that influence the development of visual-field defects (GVFDs) of open angle glaucoma. In 5,000 subjects, GVFDs developed in only 1.7% of eyes. Statistical analysis of 26 factors at first examination identified five that were significantly related to the development of GVFDs--outflow facility, age, applanation pressure, cup-disc ratio, and pressure change after water drinking. Their absolute initial value, and not its change with time, was the important predictor. Multivariate analysis showed their collective predictive power to be undesirably poor, indicating that other factors must play an important role in the development of GVFDs. Mortality-table analysis indicated that during a period of five years, 98.54% of eyes with initial pressure less than 20 mm Hg continued to be free from GVFDs as compared with 93.34% of those with pressure of 20 mm Hg or greater.

Aged↗