Francisco Fantes

Accommodation of an Endocapsular Silicone Lens (Phaco-Ersatz ) in the Nonhuman Primate

In owl monkeys, as a model of endocapsular cataract extraction, the lens material was removed through a small hole in the capsule and was replaced with a silicone polymeric gel. The ability of this endocapsular implant (Phaco-Ersatz) to accommodate was documented when pilocarpine produced an increase in the curvature of the lens surface and a decrease in the anterior chamber depth, just as occurs with the untouched natural lens. Refinements of the surgical technique are required to achieve a controlled degree of filling of the capsular bag and inhibit postoperative epithelial proliferation on the inner capsular surface.

Corneal graft survival and intraocular pressure control after penetrating keratoplasty and glaucoma drainage device implantation

OBJECTIVE To investigate corneal graft survival rates and intraocular pressure (IOP) control in eyes after penetrating keratoplasty (PK) and glaucoma drainage device (GDD) implantation. DESIGN Retrospective, comparative, consecutive case series. PARTICIPANTS All patients who underwent PK and GDD implantation at the Bascom Palmer Eye Institute between January 1, 1993 and October 31, 1998. MAIN OUTCOME MEASURES Graft clarity and IOP control. RESULTS Of the 72 eyes in 72 patients identified, 47 (65%) underwent combined PK and GDD implantation, and 25 (35%) underwent GDD placement after PK (2-30 months after PK; median, 13 months). The GDD type was Baerveldt 350 mm(2) in 57 eyes, Ahmed in 9, Krupin in 2, and other in 4 eyes. The GDD was placed in the anterior chamber in 54 eyes (75%) and in the vitreous cavity in 18 eyes (25%). Preoperative IOP was 11 to 53 mmHg with or without antiglaucoma medications in 16 eyes (30%) with the GDD implanted in the anterior chamber and in 4 eyes (22%) with the GDD placed in the vitreous cavity (P = 0.76). At 1 year after GDD implantation, the graft was clear in 26 eyes (48%) with the GDD in the anterior chamber compared with 15 eyes (83%) with the GDD in the vitreous cavity (P = 0.013). Forty-eight eyes (89%) with the GDD in the anterior chamber and 18 eyes (100%) with the GDD in the vitreous cavity had IOP between 5 and 21 mmHg with or without antiglaucoma medications (P = 0.33). The mean reduction in IOP, 1 year after surgery, was 12 mmHg among eyes with the GDD in the anterior chamber, compared with 17 mmHg among eyes with the GDD in the vitreous cavity (P = 0.13) CONCLUSIONS Corneal graft survival at 1 year is significantly higher among eyes with the GDD implanted in the vitreous cavity compared with those in which the GDD is implanted in the anterior chamber. The IOP was significantly lower at 1 year after surgery compared with before surgery in both groups, and there was no significant difference between the groups in IOP control and amount of IOP reduction. There was no significant difference in corneal graft survival or IOP control between eyes with the GDD implanted concurrently with the PK versus after the PK.

Corneal Wound Healing in Monkeys 18 Months After Excimer Laser Photorefractive Keratectomy

Excimer laser keratomileusis (photorefractive keratectomy, direct corneal ablation) for myopic corrections of 2.00 diopters (n = 1), 4.00 D (n = 4), and 8.00 D (n = 3) was performed on eight corneas of four Rhesus monkeys. All animals were followed for 18 months. The ablations healed normally and no epithelial erosions occurred. Serial slit-lamp microscope examinations revealed that a variable amount of corneal haze developed in all animals; this haze progressively faded during the follow-up period. Histopathology revealed an epithelium of normal thickness, basement membrane abnormalities, increased number and activity of stromal keratocytes, and a variable amount of newly secreted extracellular matrix in the anterior stroma. These findings suggest that excimer laser keratomileusis induces a mild wound healing response in the anterior cornea which displays considerable individual variability and persists up to 18 months.

AMNIOTIC MEMBRANE TRANSPLANTATION FOR BULLOUS KERATOPATHY IN EYES WITH POOR VISUAL POTENTIAL

Purpose: To evaluate the long‐term outcomes of epithelial debridement and amniotic membrane transplantation (AMT) for pain and discomfort relief in patients with symptomatic bullous keratopathy and poor visual potential. Setting: Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, Miami, Florida, USA. Methods: This retrospective study included 18 eyes (18 patients) with bullous keratopathy presenting with intractable pain or discomfort and poor visual potential. After epithelial debridement, all eyes had AMT with the basement membrane side up. During a mean follow‐up of 25.1 months ± 9.6 (SD) (range 12 to 45 months), pain relief, epithelial healing, and visual changes were analyzed. Results: Pain relief was obtained in 88% of patients. Sixty‐six percent of eyes had complete resolution of ocular discomfort starting soon after the first postoperative day. One eye had evisceration for persistent pain 10 months postoperatively. Corneal epithelial healing was complete in all except 1 eye. Remaining complaints included foreign‐body sensation (5%), tearing (11%), and photophobia (5%). Conclusions: Amniotic membrane transplantation was a safe, effective, and long‐lasting treatment modality for intractable pain associated with chronic bullous keratopathy in eyes with poor visual potential. It can be an alternative to conjunctival flaps for the long‐term management of patients with bullous keratopathy in whom corneal transplantation is not indicated. A comparison of the efficacy of AMT with that of other surgical procedures must be performed.

Combined pars plana vitrectomy and glaucoma drainage implant placement for refractory glaucoma

PURPOSE To report visual acuity and intraocular pressure outcomes among patients who have undergone combined pars plana vitrectomy and placement of a glaucoma drainage implant. METHODS The medical records of all patients who underwent combined pars plana vitrectomy and placement of a glaucoma drainage implant at the Bascom Palmer Eye Institute by one of the authors between January 1, 1990, and February 28, 1998, were reviewed. Forty patients (40 eyes) were identified, including 14 patients with neovascular glaucoma secondary to proliferative diabetic retinopathy or central retinal vein occlusion, 15 patients with other posterior segment disease, seven patients with secondary angle-closure glaucoma, and four patients with aphakia with ruptured anterior hyaloid face. Main outcome measures included visual acuity and intraocular pressure at 1 year postoperatively. RESULTS At 1 year postoperatively, 31 (77.5%) of 40 patients had stable or improved visual acuity; three eyes (7. 5%) had a final visual acuity of no light perception and three additional eyes (7.5%) were enucleated (because of chronic pain in two eyes and endophthalmitis in one eye). Mean preoperative intraocular pressure was 34 mm Hg and the median number of preoperative antiglaucoma medications was two. At 1 year postoperatively, mean intraocular pressure was 13 mm Hg and the median number of antiglaucoma medications was zero. Twenty-two patients (55.0%) achieved an intraocular pressure greater than 5 mm Hg and less than or equal to 21 mm Hg without antiglaucoma medication, and an additional seven patients (17.5%) achieved this level of intraocular pressure control with medication. Only one patient (2.5%) underwent further glaucoma surgery for uncontrolled intraocular pressure. CONCLUSIONS Although combined pars plana vitrectomy and placement of a glaucoma drainage implant is often a successful management option in selected patients with refractory glaucoma, visual outcome may be poor because of severe underlying ocular disease and postoperative complications.

Characteristics of optic nerve head drusen on optical coherence tomography images.

BACKGROUND AND OBJECTIVE To describe the characteristics of optic nerve head drusen in optical coherence tomography (OCT) images. PATIENTS AND METHODS Cross-sectional images of the optic nerve were obtained in seven patients with optic nerve head drusen with Stratus and spectral-domain OCT (Carl Zeiss Meditec, Dublin, CA). These were compared to optic disc photographs, autofluorescence, and echography images. For comparison, these tests were performed on four patients with papilledema and three patients with small optic discs. RESULTS Optic nerve head drusen typically elevated the disc surface and appeared as an optically empty cavity, sometimes with a perceptible reflection from the posterior surface. The disc surface was also elevated in cases of papilledema, but had a strong anterior reflectance behind which there was no visible structure. The surface of the small optic nerves was slightly elevated, but with less anterior reflectance. CONCLUSION Optic nerves with drusen showed features in these OCT images that were distinct from cases of papilledema or small optic discs.

Corneal preparation of eye bank eyes for experimental surgery.

Purpose. To evaluate the efficacy of dextran in balanced salt solution (BSS) as a preparation of eye bank corneas for experimental surgeries. Methods. We used 12 eye bank eyes that were unsuitable for transplant. The corneas were removed from the globe and affixed to a Hanna artificial anterior chamber. Four concentrations of dextran–BSS (10%, 15%, 20%, and 30% [± 0.56%]) were used to dehydrate the corneas, and corneal thickness was assessed with an ultrasonic pachymeter (±5 &mgr;m) at varying time-intervals over 3 hours. Results. The corneas were thinned to an average thickness of 477 ± 54 &mgr;m, 430 ± 54 &mgr;m, 406 ± 61 &mgr;m, and 391 ± 52 &mgr;m at average times of 75 ± 0 minutes, 85 ± 23 minutes, 60 ± 12 minutes, and 45 ± 0 minutes for the 10%, 15%, 20%, and 30% concentrations, respectively. Corneal thickness was stabilized in both a 15% and a 20% solution. The data was fit to exponential curves until a minimum value was reached, after which linear regression analysis was used to determine the slopes of the data. The slopes for the 15% and 20% concentrations were not significantly different from 0 (p = 0.5 and p = 0.4, respectively). The slopes for each set of data from the 10% and 30% concentrations were significantly different from each other (p = 0.010 and p = 0.001, respectively). Conclusions. A solution of 20% dextran in BSS is effective for dehydrating eye bank corneas to a quasi-normal physiologic thickness and for maintaining the thickness for a sufficient amount of time. Both the posterior and anterior sides of the cornea should be exposed to the solution for 60 minutes.

Surgical management of patients with combined glaucoma and corneal transplant surgery.

The reasons for having combined glaucoma and corneal transplant surgery are myriad. Patients with corneal transplants have a high frequency of developing secondary glaucoma. Patients with preexisting glaucoma have even higher risk for developing glaucoma refractory to medical management after penetrating keratoplasty. The indication for corneal transplant affects the risk for developing postkeratoplasty glaucoma. The surgical treatment options for treating glaucoma include laser trabeculoplasty, cycloablation, trabeculectomy, and glaucoma drainage implants. In addition, the sequencing of glaucoma surgery relative to penetrating keratoplasty affects the outcome. Newer corneal transplant techniques may have a lower risk for developing secondary glaucoma.

Small peripheral anterior continuous curvilinear capsulohexis

Cataract surgery is routinely performed using an anterior continuous curvilinear capsulorhexis (CCC). A manual surgical technique is described for performing a small (less than 1.5 mm diameter) anterior CCC. This techniques applications extend from Phaco-Ersatz, a cataract surgical technique designed to restore accommodation to pediatric cataract surgery. An experimental rabbit study was conducted to determine the feasibility of the technique. Up to 9 small peripheral anterior CCCs were made in the same lens capsule without the capsule tearing. The mean diameter of the CCCs was 1.1 mm +/- 0.3 (SD). A 30 gauge needle and Utrata capsulorhexis forceps were used to construct the CCC. This technique shows promise for the successful performance of small CCCs in Phaco-Ersatz procedures and pediatric cataract surgery.

Three-Year Follow-up of a Novel Aqueous Humor MicroShunt.

Aims:An observational study to determine the safety and efficacy of filtering surgery employing a microlumen aqueous drainage device (InnFocus MicroShunt), used intraoperatively with Mitomycin C, implanted alone or in combination with phacoemulsification. Materials and Methods:Single-site, prospective, nonrandomized study of 23 eyes that had failed maximum tolerated glaucoma medication, followed for 3 years. A MicroShunt was implanted ab externo through a needle tract under the limbus, draining aqueous from the anterior chamber to the scleral surface. Prespecified outcome measures include: intraocular pressure (IOP) control, with and without supplemental medication, success rate, medication use, and adverse events. Results:Fourteen patients received the MicroShunt alone and 9 with cataract surgery. At 1 (n=23), 2 (n=22), and 3 (n=22) years of follow-up; the qualified success rate (IOP⩽14 mm Hg and IOP reduction ≥20%) was 100%, 91%, and 95%; mean medicated IOP was reduced from 23.8±5.3 to 10.7±2.8, 11.9±3.7, and 10.7±3.5 mm Hg, and the mean number of glaucoma medications/patient was reduced from 2.4±0.9 to 0.3±0.8, 0.4±1.0, and 0.7±1.1, respectively. The most common complications were transient hypotony (13%, 3/23) and transient choroidal effusion (8.7%, 2/23), all resolved spontaneously. There were no leaks, infections, migrations, erosions, persistent corneal edema, or serious long-term adverse events. Conclusion:Surgery with the InnFocus MicroShunt transscleral aqueous drainage tube with Mitomycin C achieved IOP control in the low teens in most subjects up to 3 years of follow-up with only transient adverse events occurring within the first 3 months after surgery.