The effect of anterior chamber depth on endothelial cell count after filtration surgery.

Eighteen patients undergoing glaucoma filtration surgery underwent specular microscopic examination 1 day prior to surgery and 4 to 6 months after surgery. Patients were evaluated postoperatively for the presence of iridocorneal or lenticular-corneal touch, anterior chamber depth, and inflammation. Ten eyes that maintained their anterior chamber following glaucoma filtration surgery did not have a significant decrease in corneal endothelial cell density. However, eight eyes that developed a shallow anterior chamber with iridocorneal touch had a mean (+/- SD) decrease of 265 +/- 185 cells (12.4%) peripherally and 250 +/- 243 cells (11.6%) centrally in corneal endothelial cell count. None of the patients with iridocorneal touch developed corneal edema after a mean follow-up of 44.4 +/- 18.0 months. Iridocorneal touch after glaucoma filtration surgery is associated with loss of endothelial cells yet appears to be well tolerated by the cornea.

Prevention of intraocular pressure elevation following neodymium-YAG laser posterior capsulotomy.

Thirty-two eyes of 32 patients were treated with 0.5% timolol, 2% pilocarpine, or normal saline five and 30 minutes following neodymium-YAG laser posterior capsulotomy in a randomized, double-masked study. Mean maximum intraocular pressure (IOP) elevation was 8 +/- 2 mm Hg following treatment with normal saline, 5 +/- 3 mm Hg following treatment with 2% pilocarpine, and 1 +/- 2 mm Hg following treatment with 0.5% timolol. Fewer patients treated with 0.5% timolol developed an IOP elevation of 5 mm Hg or more than control patients. On aphakic patient treated with 0.5% timolol developed a maximum IOP greater than or equal to 40 mm Hg. We found that treatment with 0.5% timolol after neodymium-YAG laser posterior capsulotomy provides partial protection from IOP elevation.

Intraocular pressure elevation following Nd:YAG laser posterior capsulotomy.

Intraocular pressures (IOP) and tonographic outflow facilities were measured following neodymium (Nd): YAG laser posterior capsulotomy in 13 pseudophakic and 8 aphakic eyes. Mean intraocular pressure (IOP) peaked by three hours with a mean increase of 13 mmHg, remained elevated by 5 mmHg at 24 hours but returned to baseline by one week. Fourteen eyes (67%) had greater than or equal to 10 mmHg elevation and eight (38%) had greater than or equal to 40 mmHg maximum IOP. All the patients who eventually demonstrated a greater than or equal to 10 mmHg elevation within six hours of the capsulotomy initially had an IOP elevation greater than or equal to 5 mmHg at one hour. The mean outflow facility was reduced from 0.18 microl/min/mmHg before capsulotomy to 0.08 microl/min/mmHg (55%, P less than 0.0001) at four hours and was still decreased at 0.13 microl/min/mmHg (27%, P less than 0.05) at one week. Seventy-five percent of aphakic and 15% of pseudophakic patients had maximum IOP greater than or equal to 40 mmHg (P less than 0.01). Measurements should be performed one hour postlaser in all patients for IOP and three to four hours in aphakic patients, glaucomatous patients, patients receiving greater than or equal to 200 mjoules total laser energy, and patients with greater than or equal to 5 mmHg elevation at one hour in order to detect and treat significant IOP elevations.

Effect of sodium hyaluronate on corneal wound healing.

With the development of the use of sodium hyaluronate for endothelial cell protection during anterior segment surgery, we were interested in the effect of sodium hyaluronate on corneal wound healing. Therefore, the following experiment was performed. Corneal incisions were made in both eyes of 14 albino rabbits. Sodium hyaluronate was used to fill the anterior chamber of the test eye, and balanced salt solution was used in the control eye. The wounds were sutured wih 10-0 nylon. On the seventh postoperative day, and strength was measured. After suture removal, the intraocular pressure was raised until the wound burst. Results showed no statistical difference between these and control eye.