Jared M. Emery

Complications of Phacoemulsification

Charles Kelman performed the first phacoemulsification operation in 1967, but it was not until 1971 that the technique had been sufficiently refined to allow its use by others. Now over 2,000 surgeons have been trained in the technique, and more than 100,000 cases have been performed. However, extended follow-up in any given series has been difficult because of the wide geographic distribution of patients, and interpretation is hampered by the frequent insertion of intraocular lenses in these patients. The present series attempts to carefully document operative and postoperative complications encountered in a consecutive series of patients whose senile cataracts were treated by phacoemulsification.

Secondary intraocular lens implantation

ABSTRACT We conducted a retrospective study of our first 75 consecutive patients receiving secondary intraocular lens implants. Ninety‐seven percent had postoperative visual acuities of ≥ 20/40; 86%, ≥ 20/25. Four percent of patients lost two or more lines of vision. Complications included retinal detachment (4%), transient cystoid macular edema (3%), transient corneal edema (3%), pupillary block glaucoma (1%), and progression of an epiretinal membrane (1%). Patients requiring anterior vitrectomy had the least favorable outcome, with a 28% incidence of retinal complications. Overall, these data show secondary intraocular lens implantations to be safe and effective. However, greater caution is recommended for patients who will require anterior vitrectomy because of the higher rate of retinal complications.

Inhibition of posterior capsule opacification with an immunotoxin specific for lens epithelial cells: 24 month clinical results

Purpose: To assess the safety and effectiveness of an immunotoxin, MIX‐RA, designed to inhibit posterior capsule opacification (PCO). Setting: eleven private practices in the United States. Methods: This study comprised 63 eyes of 63 patients having extracapsular cataract extraction by phacoemulsificaton; these patients were enrolled in a Phase l/ll clinical investigation of the immunotoxin MDX‐RA. At the close of surgery, 21 patients were treated with placebo, 23 patients with 50 units of the immunotoxin, and 19 patients with 175 units of the immunotoxin as an aqueous solution. The patients were monitored for 24 months after primary cataract surgery using external eye and slitlamp examinations, visual acuity assessment,‐ophthalmoscopy, pachymetry, tonometry, endothelial cell counts and lens capsule photography. Posterior capsule opacification, recorded on lens capsule photographs, was graded independently by a committee of 3 cataract surgeons. The incidence of neodymium:YAG (Nd:YAG) capsulotomy was projected from the opacification results. Results: The immunotoxin,‐ at the 50 unit dose, was well tolerated and effective in inhibiting PCO. At the 175 unit dose, there was a trend toward increased postoperative inflammation that was transient with no residua. From 6 to 24 months postoperatively, the 50 unit dose significantly inhibited PCO compared with the placebo (P < .05). This significant reduction in PCO translated into a significantly lower projected need for Nd:YAG capsulotomy in the 50 unit than the placebo group (P < .004). About 60% in the placebo group and 4% in the 50 unit group were projected to need an Nd:YAG capsulotomy by 3 years postoperatively. Conclusion: The immunotoxin was well tolerated and was effective in reducing PCO for up to 24 months after cataract surgery. Although these preliminary results are encouraging, a larger study is underway to determine whether the reduction in PCO by the immunotoxin decreases the need for Nd:YAG capsulotomy.

Comparison of the accuracy of computerized videokeratography and keratometry for use in intraocular lens calculations.

ABSTRACT We compared the accuracy of keratometry and computerized videokeratography (CVK) for use in intraocular lens calculations. We studied 48 eyes of 45 patients having phacoemulsification and posterior chamber lens implantation. Computerized videokeratography was performed with the EyeSys Corneal Analysis System™ (ECAS™). Using the SRK II, SRK/T, and Holladay formulas, we evaluated predictive accuracy calculated with keratometric values and four values derived from ECAS measurements. For each formula, the use of one of the CVK parameters resulted in lower mean absolute errors between actual and predicted postoperative refractive errors and higher percentages of cases with power prediction errors <0.5 and <1.0 diopters. Computerized videokeratography may provide a more accurate corneal curvature value than keratometry for use in intraocular lens calculations.

Inhibition of cell proliferation on lens capsules by 4197X-ricin A immunoconjugate+++

Purpose: To evaluate the cytotoxicity of immunotoxin 4197X‐ricin A (4197X‐RA) and its ability to inhibit protein synthesis and human lens epithelial cell (LEC) proliferation on the inner surface of the lens capsule. Setting: Houston Biotechnology, Inc., The Woodlands, Texas. Methods: A cell culture system was established using human LECs as a model for the proliferation of remnant LECs that occurs during posterior capsule opacification (PCO) after extracapsular cataract extraction. The LEC culture system was also used in vitro for testing compounds that might inhibit this process in vivo. Human LECs were cultured on the surface of the original lens capsule fixed to collagen. Variability was reduced by dissecting each lens capsule into equivalent halves and exposing the segments to immunotoxin 4197X‐RA. Results: Protein synthesis and LEC proliferation were almost completely inhibited at relatively low 4197X‐RA concentrations after short exposure. The inhibitory effects persisted up to 3 weeks after withdrawal of the immunotoxin and after several media exchanges. Conclusion: Immunotoxin 4197X‐RA may help prevent PCO after primary cataract surgery.

Glare following posterior chamber intraocular lens implantation

ABSTRACT We performed glare tests on patients following uncomplicated extracapsular cataract extraction and posterior chamber intraocular lens implantation and on noncataractous phaldc patients. Three types of lenses were implanted to compare the effect of optic asphericity and ultraviolet filtration on glare. Glare testing was performed using the Miller‐Nadler GlareTester and Baylor Visual Function Tester. The glare scores of the pseudophaldc and phakic patients were statistically similar. In the pseudophaldc patients, factors associated with decreased glare performance were posterior capsular opacification and increased pupil size; the intraocular lens type did not significantly affect glare scores.

Mathematical model to predict the need for neodymium: YAG capsulotomy based on posterior capsule opacification rate.

Purpose: To evaluate a model to project the estimated time required before patients having primary phacoemulsification require neodymium:YAG (Nd:YAG) laser capsulotomy. Setting: Eleven private practices in the United States. Methods: Projections of time to capsulotomy were based on assessment of the early development of posterior capsule opacification (PCO) over Me. The PCA date were collected during a clinical study to evaluate MDX‐RA, an investigational immunotoxin designed to limit epithelial cell growth, preventing postsurgical PCO. From the PCO data, the estimated time to Nd:YAG capsulotomy in a placebo‐treated group was compared with the actual time to capsulotomy in a cohort of patients from general practice who had had phacoemulsification. Resut: By 6 months, the mean Opacification Index in the MDX‐RA‐group was significantly lower than that in the placebo group(P < .05) and remained significantly lower at 12 (P < .001), 18 (P < .001), and 24 (P < .016) months. The rate of POO in the MOX‐RA group was approximately.6 tames lower ttrXi the in the placebo group (P < .0004). Fifty‐seven percent in the Placebo group and 4% in the MDX‐RA group were projected to require an Nd YAG capsulotomy within.3 years of primary cataract surgery. Projected values for the placebo group were similar to actual values observed in the population‐based cohort. Conclusions: This technique could be used to predict the need for NdNAG capsulotomy using early measurements of PCO.

Complications of implanting three-piece C-loop posterior chamber lenses in the anterior chamber

We have examined a total of four eyes in three patients who had undergone implantation of three-piece C-loop posterior chamber intraocular lenses into the anterior chamber. All four eyes exhibited four or more of the following complications: 1) loop encapsulation by peripheral anterior synechiae; 2) recurrent iritis; 3) central loop displacement with corneal endothelial touch; 4) progressive endothelial cell loss and corneal edema; 5) glaucoma; and 6) cystoid macular edema. Intraocular lens removal was required in all four eyes, and penetrating keratoplasty was performed in one. We believe that these complications are attributable to the inherent fallacies of fixating three-piece open-loop lenses in the anterior chamber angle.

High altitude corneal endothelial decompensation.

A 77-year-old patient with low endothelial cell countssustained acute unilateral endothelial decompensation when he traveled to an elevation of 12,500 feet. The corneal edema gradually increased after his return to sea level, and penetrating keratoplasty was required to restore vision. To our knowledge, this is the first reported case of hypoxia-induced corneal endothelial decompensation.

Flexible anterior chamber intraocular lens expulsion

We report a case of presumed traumatic expulsion of an anterior chamber intraocular lens two weeks postoperatively. The 59-year-old patient presented complaining of foreign-body sensation; we found the intraocular lens in his superior conjunctival fornix.