Corneal Endothelial Count Research Articles

Phaco-chop versus stop-and-chop nucleotomy for phacoemulsification

To perform a comparative evaluation of phaco-chop versus stop-and-chop nucleotomy techniques of phacoemulsification. Dr. Rajendra Prasad Center for Ophthalmic Sciences, New Delhi, India. Forty eyes of 40 patients with immature senile cataract were included in the study. Twenty eyes each were randomly assigned to have phaco-chop (Group 1) or stop-and-chop (Group 2) nucleotomy during phacoemulsification. The main parameters were corneal endothelial count, effective phaco time, volume of infusion fluid used, central corneal pachymetry, best corrected visual acuity (BCVA), and intraoperative complications during nucleotomy. Follow-up visits were scheduled at 1, 4, and 12 weeks. The mean effective phaco time was 27 seconds +/- 18 (SD) in Group 1 and 28 +/- 16 seconds in Group 2. The mean corneal endothelial cell loss was 6.89% and 7.17%, respectively, at the end of 12 weeks. The difference between groups was not significant. An anterior capsule tear occurred in 3 eyes in Group 1 and 1 eye in Group 2. All eyes achieved a BCVA of 20/20 at the end of 4 weeks. There were no significant between-group differences in any intraoperative or postoperative parameter. The phaco-chop and the stop-and-chop nucleotomy techniques were equally efficacious for nuclear management during phacoemulsification.

Double-masked prospective ocular safety study of a lens epithelial cell antibody to prevent posterior capsule opacification

To evaluate the intraocular safety of an immunoconjugate (MDX-RA) developed to prevent posterior capsule opacification (PCO) in human eyes. St. Thomas's Hospital Eye Department, London, United Kingdom. Twenty-six patients had phacoemulsification and implantation of an intraocular lens (IOL). All were randomly allocated at the end of surgery to receive a 0.1 mL placebo or 0.1 mL of the immunotoxin MDX-RA intracamerally. Two doses of the drug were tested: 8 patients with a low dose (50 units), 9 patients with a high dose (100 units), and 9 with placebo. Follow-up at days 1, 14, 30, 60, 90, and 180 consisted of visual acuity measured by the Early Treatment of Diabetic Retinopathy Study test, contrast sensitivity, aqueous flare, specular microscopy of the IOL's anterior surface, and corneal endothelial counts. The percentage area of PCO was measured from retroillumination images of the posterior capsule. There was no decrease in corneal endothelial cell count in toxin-treated patients. Early postoperative flare, anterior chamber cell count, and corneal pachymetry were higher in toxin-treated patients. The median percentage area of PCO at 1 year was 32.0 in the placebo group, 3.8 in the low-dose group, and 7.4 in the high-dose group (P = .06). This prospective, randomized, placebo-controlled trial confirmed that MDX-RA is safe for intraocular use and is of potential value for further clinical trials of the prevention of PCO.

The Effect of Intracamerally Injected Ethacrynic Acid on Intraocular Pressure in Patients with Glaucoma

We studied the effect of ethacrynic acid on intraocular pressure in eyes with advanced open-angle glaucoma. Five to 15 microliters of ethacrynic acid (3.3 to 9.8 micrograms) was injected intracamerally after retrobulbar anesthesia was achieved in five eyes of five patients with advanced glaucoma. Intraocular pressure before treatment ranged from 26 to 46 mm Hg with maximal medical treatment. A reduction in intraocular pressure from 9 to 31 mm Hg was observed in all patients three to 24 hours after treatment, and this effect lasted for three days, with a gradual return of intraocular pressure to pretreatment values one week after treatment. No acute corneal or anterior chamber side effects were observed and results of corneal endothelial cells counts were essentially unchanged two months after treatment. We suggest that ethacrynic acid may represent a new class of antiglaucoma medication. Intracameral administration of ethacrynic acid or a derivative might be contemplated in the future at the time of other ocular surgical procedures to treat short-term intraocular pressure increase.

Inhibition of Posterior Capsule Opacification by 5-Fluorouracil in Rabbits

An extracapsular cataract extraction was performed on both eyes of 24 rabbits. Irrigation for 10 min of the capsular bag of the left (test) eye with 8-12 cm3 of 1 litre of BSS-plus to which had been added 50 mg of 5-fluorouracil significantly inhibited proliferation of the anterior capsular epithelium as compared with the right (control) eyes identically treated except for the omission of 5-fluorouracil (p less than 0.001). Corneal endothelial counts did not differ significantly. A reduction in opacification of the posterior capsule is expected from 5-fluorouracil treatment.

Use of hyaluronate sodium v air in extracapsular cataract extraction.

A total of 17 patients underwent extracapsular cataract extraction with artificial lens implantation by one surgeon. Eight were given hyaluronate sodium (Healon) during the procedure, while nine received only air. Corneal thickness and endothelial cell counts were obtained one day prior to surgery and 90 days postoperatively. There were mean cell losses of 10.5% and 11.2% in the Healon and air groups, respectively. This is a mean difference of 0.7%, which is not significant statistically. Therefore, despite several studies that demonstrate the protective value of hyaluronate sodium on the corneal endothelium during anterior segment surgery, this study showed no such difference in the protective effects between the two.

Change Article Title

<i>To the Editor</i>.–I write about the article entitled "Corneal Endothelial Changes with Long-Term Topical Epinephrine Therapy" by Waltman et al that appeared in theArchives(95:1357-1358, 1977). I believe that this article should have been entitled "Corneal Endothelial Count Asymmetries Associated With Long-Term Asymmetrical Topical Epinephrine Therapy." In no part of the report is there an endothelial cell count before epinephrine therapy and a subtraction of a later count from this to produce a difference which is what a change is. The concept is certainly worthy of further study but this article has not documented a change.