Walter J. Stark

Risk Factors for Corneal Graft Failure and Rejection in the Collaborative Corneal Transplantation Studies

PURPOSE To evaluate comprehensively the magnitude of suspected risk factors for corneal graft failure from any cause, failure from rejection, and immunologic reaction in patients at high risk for graft failure after corneal transplantation. METHODS The records of the 457 participants in the Collaborative Corneal Transplantation Studies were reviewed. All participants had at least two quadrants of stromal vascularization and/or a history or previous graft rejection. Patients were followed for 2 to 5 years. Characteristics of the patient, study eye, donor, donor-recipient histocompatibility, and surgical procedure were examined for their association with the graft outcomes of failure from any cause, rejection failure, and immunologic reaction. Multivariate survival analysis techniques were used to estimate rates of graft outcome events and to estimate the magnitude of risk factors. RESULTS Many apparent risk factors did not maintain their association with graft outcomes after adjustment for other risk factors. Young recipient age, the number of previous grafts, history of previous anterior segment surgery, preoperative glaucoma, quadrants of anterior synechiae, quadrants of stromal vessels, a primary diagnosis of chemical burn, and blood group ABO incompatibility were among the strongest risk factors identified for graft failure. Donor and corneal preservation characteristics had little influence on graft outcome. CONCLUSIONS Risk of graft failure varies substantially, even within a high-risk population. The number of risk factors present should be considered by the patient and surgeon when contemplating transplantation and planning follow-up.

Transforming growth factor-β in human aqueous humor

The transforming growth factor-βs are peptide growth factors known to play a central role in wound healing. Using a specific, in vitro assay of cell growth inhibition, we have detected transforming growth factor-β (TGF-β) in 24/24 aqueous humor specimens from eyes undergoing cataract extraction with intraocular lens implantation. The amount of TGF-β ranged from 2.3 to 8.1 ng/ml (mean ± SD = 4.5 ± 1.7 ng/ml), with 61% present in the active form.Subtyping of TGF-β was performed by addition of antibodies specific for the s1 and s2 isoforms to the growth inhibition assay, and confirmed with a sandwich enzyme-linked immunosorbent assay. None of the TGF-β detected was of the s1 isoform; in contrast, the s2 isoform was present in every sample, implying that it might have originated from ocular tissues. The presence of this potent modulator of tissue repair in aqueous humor suggests a role in the healing processes following intraocular surgery, including glaucoma filtration surgery.

National Outcomes of Cataract Extraction: Increased Risk of Retinal Complications Associated with Nd.-YAG Laser Capsulotomy

PURPOSE The authors studied 57,103 randomly selected Medicare beneficiaries who underwent extracapsular cataract extraction in 1986 or 1987 to determine the possible association between performance of neodymium (Nd):YAG laser capsulotomy and the risk of subsequent retinal break or detachment. METHODS Cases of cataract surgery were identified from Medicare claims submitted in 1986 and 1987 and were followed through the end of 1988. Episodes of cataract surgery, posterior capsulotomy, and retinal complications were ascertained based on procedure and diagnosis codes listed in physician bills and hospital discharge records. Lifetable and Coxs proportional hazards models were used to analyze the risk of retinal detachment or break in patients undergoing and not undergoing capsulotomy during the period of observation. RESULTS Of the 57,103 persons identified as having undergone extracapsular cataract extraction in 1986 or 1987, 13,709 subsequently underwent Nd:YAG laser capsulotomy between 1986 and 1988. A total of 337 persons had aphakic or pseudophakic retinal detachments between 1986 and 1988 and an additional 194 underwent repair of a retinal break. Proportional hazards modeling shows a 3.9-fold increase in the risk of retinal break or detachment among those who underwent capsulotomy (95% confidence interval: 2.89 to 5.25). Younger patient age, male sex, and white race also were associated with increased risk of retinal complications after extracapsular cataract extraction. CONCLUSION The authors conclude that there is a statistically significant increase in the risk of retinal detachment or break in those patients who undergo capsulotomy after cataract extraction. Therefore, capsulotomy should be deferred until the patients impairment caused by capsular opacification warrants the increased risk of retinal complications associated with performance of capsulotomy.

The FDA Report on Intraocular Lenses

Clinical studies of intraocular lenses (IOLs) as investigational devices have been regulated in the United States by the Food and Drug Administration (FDA) since 9 February 1978. As of August 1982, data have been collected on more than one million IOLs implanted. During the last 12 months of the study, 409 000 IOLs were implanted. Visual acuity of 20/40 or better at one year after surgery was present in 85% of over 45 000 cases reviewed. Increasing patient age, surgical problems, postoperative complications, and adverse reactions were factors that reduced the visual acuity. The current trend in the USA is for implantation of posterior chamber and anterior chamber IOLs.

Results of the Prospective Evaluation of Radial Keratotomy (PERK) Study One Year After Surgery

The Prospective Evaluation of Radial Keratotomy (PERK) study is a nine-center, self-controlled clinical trial of a standardized technique of radial keratotomy in 435 patients who had physiologic myopia with a preoperative refraction between -2.00 and -8.00 diopters. The surgical technique consisted of eight incisions using a diamond micrometer knife with blade length determined by intraoperative ultrasonic pachymetry and the diameter of central clear zone determined by preoperative refraction. At one year after surgery, myopia was reduced in all eyes; 60% were within +/- 1.00 diopter of emmetropia; 30% were undercorrected and 10% were overcorrected by more than 1.00 diopter (range of refraction, -4.25 to +3.38 D). Uncorrected visual acuity was 20/40 or better in 78% of eyes. The operation was most effective in eyes with a refraction between -2.00 and -4.25 diopters. Thirteen percent of patients lost one or two Snellen lines of best corrected visual acuity. However, all but three eyes could be corrected to 20/20. Ten percent of patients increased astigmatism more than 1.00 diopter. Disabling glare was not detected with a clinical glare tester, but three patients reduced their driving at night because of glare. Between six months and one year, the refraction changed by greater than 0.50 diopters in 19% of eyes.

Neodymium: YAG lasers. An FDA report.

Analysis of data from four neodymium:YAG laser manufacturers submitted to the Food and Drug Administration (FDA) on over 17,000 cases indicate the procedure is safe and effective for cutting opaque posterior lens capsules. A successful opening in the pupillary membrane was achieved in 98% of the cases, and vision improved in 84% of the cases. Clinically significant risks include: a rise in intraocular pressure two to four hours after treatment, damage to the intraocular lens, and rupture of the anterior hyaloid face.

Posterior chamber intraocular lens implantation in the absence of posterior capsular support.

Because of the high incidence and great variety of complications associated with anterior chamber intraocular lenses, we have developed a technique for the implantation of a posterior chamber intraocular lens in the absence of posterior capsular support. The posterior chamber IOL is placed in the ciliary sulcus by suturing the superior haptic to the iris and the inferior haptic to the sclera at the ciliary sulcus. We have used this technique successfully in both complicated extracapsular surgery and secondary intraocular lens implantation.

Topical retinoid treatment for various dry-eye disorders

We evaluated the clinical efficacy of treating various dry-eye disorders using 0.01% and 0.1% (weight/weight) topical all-trans retinoic acid ointment. Twenty-two patients were selected and classified into four major groups: keratoconjunctivitis sicca (6 patients; 11 eyes), Stevens-Johnson syndrome (9 patients; 17 eyes), ocular pemphigoid or drug-induced pseudopemphigoid (3 patients; 6 eyes), and surgery or radiation-induced dry eye (4 patients; 4 eyes), based on the criterion that they remained symptomatic even under maximum tolerable conventional medical and/or surgical therapies. The results indicated that squamous metaplasia with mucin deficiency secondary to goblet cell loss and keratinization may be the basis for the development of clinical symptoms and morbidities, as these epithelial abnormalities were invariably present before treatment. After treatment, all patients demonstrated clinical improvements in symptoms, visual acuity, rose Bengal staining, or Schirmer test. Most importantly, this topical vitamin A treatment caused the reversal of squamous metaplasia as evidenced by impression cytology. Therefore, this treatment may represent the first nonsurgical attempt to treat these disorders by reversing diseased ocular surface epithelium.

Combined phacoemulsification, intraocular lens implantation, and vitrectomy for eyes with coexisting cataract and vitreoretinal pathology ☆

PURPOSE To report the preoperative, intraoperative, and postoperative outcomes of combining phacoemulsification and posterior chamber intraocular lens (IOL) implantation with pars plana vitrectomy in eyes with significant cataract and coexisting vitreoretinal pathology. DESIGN Retrospective, consecutive, interventional case series. METHODS Charts of patients undergoing combined procedures at the Wilmer Ophthalmologic Institute between March 1995 and May 2000 were reviewed. RESULTS In all, 122 eyes of 111 patients were identified. Patient ages ranged from 27 to 89 years (mean 65). Forty-three eyes had diabetic retinopathy; 11 had undergone vitrectomy previously. Macular pathology (hole, membrane, choridal neovascularization) was present in 69 eyes. The most common indications for surgery were diabetic vitreous hemorrhage, macular hole, epiretinal membrane, and retinal detachment. In all cases, phacoemulsification and IOL implantation were performed before vitreoretinal surgery. Preoperative vision ranged from 20/30 to light perception and postoperative vision ranged from 20/20 to no light perception. In 105 patients vision improved, in 7 there was no change, and in 10 vision decreased. Postoperative complications included opacification of the posterior capsule, increased intraocular pressure, corneal epithelial defects, vitreous hemorrhage, retinal detachment and iris capture by the IOL. CONCLUSIONS Combined surgery is a reasonable alternative in selected patients. Techniques that may simplify surgery and reduce complications include: careful, limited, curvilinear capsulorhexis; in-the-bag placement of IOLs; use of IOLs with larger optics; suturing of cataract wounds before vitrectomy; use of miotics and avoidance of long-acting dilating drops in patients with intravitreal gas; and use of wide-field viewing systems.

The Efficacy and Safety of Combined Trabeculectomy Cataract Extraction, and Intraocular Lens Implantation

The safety and efficacy of combined trabeculectomy, extracapsular cataract extraction (ECCE), and posterior chamber intraocular lens (PC IOL) implantation were evaluated by retrospectively analyzing 108 consecutive operations. Postoperatively, 89% of eyes achieved 20/40 or better visual acuity when preoperative macular and optic nerve diseases were excluded. Mean follow-up was 16.8 months. Intraocular pressure (IOP) control (less than or equal to 21 mmHg) was achieved in 92% of eyes; 57% required no medications. Capsulotomy (20%) and transient hyphema (15%) occurred significantly more often (P less than 0.001) than in a comparison group. These results suggest that the combined procedure gives excellent visual rehabilitation and IOP control in the majority of patients included in this analysis.