Alan N. Carlson

Trends in the indications for penetrating keratoplasty, 1980-2001.

Purpose: To study the leading indications and changing trends for penetrating keratoplasty (PK) over the past 3 decades. Methods: This is a retrospective review of 696 cases of PK. The indications for PKs performed at the Duke University Eye Center during the years 1980-1981, 1990- 1991, and 2000-2001 were tabulated to determine trends over the past 3 decades. The main outcome measures were indications for PK. Results: During this study, 696 PKs were performed. The leading indications for PK and their respective frequencies during 1980-1981, 1990-1991, and 2000-2001 were failed grafts (10.8%, 19.0%, 27.0%, respectively), pseudophakic bullous keratopathy (PBK)/aphakic bullous keratopathy (ABK) (19.4%, 20.6%, 16.7%, respectively), Fuchs dystrophy (15.6%, 13.0%, 23.8%, respectively), keratoconus (13.4%, 8.2%, 11.8%, respectively), and corneal scar (7.0%, 8.9%, 10.7%, respectively). The number of PKs for failed grafts and Fuchs dystrophy increased over time. Conclusions: In this study, failed graft has gradually become the leading indication for PK, whereas most other studies have reported PBK as the leading indication. Unlike many other studies, Fuchs dystrophy was a common indication for PK.

Sutured Retropupillary Posterior Chamber Intraocular Lenses for Exchange or Secondary Implantation: The 12th Annual Binkhorst Lecture, 1988+

The histopathologic findings of four eyes obtained postmortem with iris-sutured posterior chamber intraocular lenses (PC IOLs) are described. These IOLs were implanted as exchange procedures. In most instances, the loops were not situated in the ciliary sulcus but rather were suspended behind the iris and ciliary body. Therefore, the primary mechanism of fixation of iris-sutured PC IOLs appears to be the sutures themselves rather than adherence to the ciliary tissues. This report of four eyes is preliminary, but the pathologic analysis, showing few significant lesions attributable to the IOL, provides a reason for optimism for using this technique. A long-term clinical study comparing the results of sutured PC IOLs with those of anterior chamber IOLs (AC IOLs) used in secondary or exchange implantation, as well as collection and analysis of more pathologic specimens, should provide a more definitive answer as to the preferred procedure.

Refractive change after descemet stripping automated endothelial keratoplasty surgery and its correlation with graft thickness and diameter.

Purpose: The purpose of this study was to evaluate the refractive change after Descemet stripping automated endothelial keratoplasty (DSAEK) surgery and its correlation with graft thickness and diameter. Methods: We retrospectively analyzed the refractive outcomes of 45 cases of DSAEK surgery that were performed at Duke University Eye Center between August 2005 and December 2006. We divided our study groups into DSAEK triple cases and pseudophakic DSAEK cases. We measured manifest refraction preoperatively and postoperatively in each group and compared the difference between the preoperative and the postoperative spherical equivalent. We evaluated the correlation of the refractive change with graft thickness and diameter. Results: Forty-five DSAEK cases in 44 patients (27 women and 17 men) were evaluated and analyzed. Mean age of the patients at surgery was 67.6 years (15-81 years, SD 10.7 years). Forty cases were treated for Fuchs endothelial dystrophy and 5 for pseudophakic bullous keratopathy/bullous keratopathy. Seventeen cases were DSAEK triple cases and 28 pseudophakic DSAEK cases. In the DSAEK triple group, the mean change in refraction at an average of 4 months postoperatively was +1.15 D (range −0.02 to 2.87, SD 1.15). In the pseudophakic DSAEK group, the mean change in refraction at an average of 5 months postoperatively was +0.71 D (range −1.75 to 3.0, SD 1.11). The overall refractive change was +0.88 D (range −1.75 to 3.0, SD 1.02). Correlation of refractive change with graft diameter was modest (r = 0.29, P = 0.05), and a small correlation was found with respect to graft thickness (r = −0.16, P = 0.31). Conclusions: Our study of DSAEK grafts demonstrated a hyperopic refractive shift after DSAEK surgery. This observation should be taken into consideration when deciding on the appropriate intraocular lens power in DSAEK triple surgery and may also aid in anticipating refractive outcomes after pseudophakic DSAEK surgery. Further studies to follow these refractive changes over a longer follow-up period and to investigate the mechanism of this refractive change after DSAEK surgery are warranted.

Intraocular Lens Complications Requiring Removal or Exchange

Intraocular lens (IOL)-related complications are caused primarily by mechanical trauma, inflammatory or infectious complications, or optical problems. Complications may occur at the time of surgery or be the result of an ongoing postoperative process. Mechanical and inflammatory injury may produce corneal decompensation, cystoid macular edema, hyphema, uveitis, and glaucoma, causing reduced vision and in some cases chronic pain. Optical problems may be due to a wrong power of the IOL or to postoperative decentration or dislocation of the lens. Ophthalmologists should be aware of the indications for IOL removal or exchange in those patients who have ongoing IOL-induced injury or impairment. Removal or exchange of an IOL frequently involves a complex decision-making process and is often associated with immense technical challenge. Various medical and surgical treatments may be tried to correct IOL problems before the decision is made to remove or exchange the lens.

Endophthalmitis following Nd : YAG laser posterior capsulotomy

We report the development of Propionibacterium acnes endophthalmitis following Nd:YAG laser posterior capsulotomy. The patient previously underwent uncomplicated extracapsular cataract extraction with intraocular lens insertion and was free of inflammation prior to laser capsulotomy. Diagnostic vitrectomy and aqueous tap were performed, and P. acnes was isolated from the aqueous in thiol broth media after nine days of incubation under anaerobic conditions. The patient was managed with topical and systemic antibiotics and steroids. Complete resolution of inflammation with return of vision to 20/25 was achieved without removal of the intraocular lens or lenticular remnants.

Acute corneal endothelial changes after laser in situ keratomileusis.

Purpose. To report the acute effects of laser in situ keratomileusis (LASIK) on the corneal endothelium. Methods. Twenty eyes of 10 consecutive patients (mean age, 38.1 ± 10.84 years) underwent bilateral simultaneous LASIK for myopic astigmatism (spherical equivalent ranging from −1.75 to −7.13 diopters) without any complications. Each eye was evaluated by slit-lamp biomicroscopy and noncontact specular microscopy preoperatively, within 15 minutes after LASIK and 1 day after surgery. Specular microscopy images were then analyzed to calculate endothelial cell density (ECD), coefficient of variation (CV) of cell size, and percentage of hexagonal cells. Results. All corneas demonstrated marked alterations in endothelial cell morphology by slit-lamp biomicroscopy within 15 minutes after surgery that resolved by the first postoperative day. Central corneal endothelial analysis by noncontact specular microscopy confirmed pleomorphism with definite loss of hexagonality. Mean ECD was calculated to be 2,816.3 ± 286.02 cells/mm 2 preoperatively, 2,750.85 ± 327.95 cells/mm 2 on day 0 (p = 0.395), and 2,810.55 ± 218.48 cells/mm 2 on day 1 (p = 0.461). Mean CV was 32.65 ± 7.29 preoperatively, 34.4 ± 6.19 on day 0 (p = 0.412), and 30.9 ± 5.54 on day 1 (p = 0.067). Mean percentage of hexagonal cells was 63.35 ± 10.76 preoperatively, 47.55 ± 9.69 on day 0 (p = 0.000009), and 60 ± 9.3 on day 1 (p = 0.00003). Conclusion. Qualitative and quantitative changes in endothelial cell morphology (i.e., decreased endothelial cell hexagonality) demonstrate that LASIK does induce an acute effect on the corneal endothelium that may represent transient endothelial cell edema.

Ultrasonographic measurement of induced myopia associated with capsular bag distention syndrome

OBJECTIVE To determine the causes of postoperative myopia associated with capsular bag distention syndrome (CBDS) and characterize the associated findings. DESIGN Prospective, multicenter, nonrandomized, comparative (self-controlled) trial. PARTICIPANTS Six eyes from six patients had CBDS develop after phacoemulsification and posterior chamber intraocular lens implantation. METHODS Keratometric values, axial length, visual acuity, and manifest refraction were assessed in each eye. Using 20-MHz (I3SYSTEM-ABD, Innovative Imaging Inc, Sacramento, CA) and 50-MHz (Ultrasound Biomicroscope, Zeiss Humphrey Systems, Dublin, CA) ultrasonographic probes, images and measurements of the anterior segment were obtained. After neodymium:yttrium-aluminum-garnet (Nd:YAG) capsulotomy, these measures were repeated and correlated with predicted and actual refractive changes. MAIN OUTCOME MEASURES Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), manifest refraction, and anterior chamber depth before and after treatment of CBDS. RESULTS Although intended postoperative refraction averaged -0.58 diopters (D) (range, -0.12 to -1.63 D), eyes with CBDS had an average spherical equivalent refraction of -2.35 D (range, +0.13 to -4.50 D), P < 0.05 (one-tailed, paired t test). BCVA averaged 20/24 (range, 20/15-20/40-1), but UCVA averaged 20/133 (range, 20/60 to 20/400). Average distance from the corneal surface to the anterior intraocular lens (IOL) optic surface was 3.55 mm in eyes with CBDS, and 4.30 mm after Nd:YAG capsulotomy. Posterior movement of the IOL optic after capsulotomy accounted for 1.23 D of hyperopic shift or 82% of the CBDS-induced myopia. Treatment of CBDS resulted in both improved UCVA and BCVA. Nd:YAG capsulotomy also released the colloidal suspension within the capsular bag posterior to the IOL optic. The incidence of CBDS was 0.3% in one of the practices reviewed. CONCLUSIONS Capsular bag distention syndrome includes unexpected myopia and poor UCVA after cataract surgery with lens implantation in cases involving a continuous capsulorhexis. A dramatic posterior distention of the posterior capsule is observed, as well as anterior chamber shallowing, tight apposition of the iris to the IOL, and anterior bowing of the iris. A slightly turbid colloidal suspension behind the IOL implant and late posterior capsular fibrosis are also observed. Timely treatment of CBDS can correct unwanted myopia, improve UCVA and BCVA, and restore normal anatomic relationships in the eye.

Fungal scleritis after cataract surgery. Successful outcome using itraconazole.

We report the development of fungal scleritis in a 53-year-old man after uncomplicated cataract surgery. Histopathology and culture identified the organism as Aspergillus flavus. Clinically, the patient worsened on treatment with oral ketoconazole and topical amphotericin B with progression of multifocal scleral nodules and necrosis. Resolution of inflammation was achieved using oral itraconazole, a new triazole antifungal agent. The patient achieved 20/15-2 visual acuity and remains free of symptoms and signs for greater than 2 years after discontinuation of all treatment.

Results of Trabeculectomy Combined With Phacoemulsification Versus Trabeculectomy Combined With Extracapsular Cataract Extraction in Patients With Advanced Glaucoma

We compared the results of trabeculectomy combined with phacoemulsification (n = 16) with those of trabeculectomy combined with extracapsular cataract extraction (n = 18). There was no significant difference between the two groups in terms of early or chronic postoperative intraocular pressure (IOP) control or in terms of the number of glaucoma medications prescribed postoperatively. However, by 12 weeks postoperatively, bleb height and extent were significantly greater in the phacoemulsification group. There was no significant difference between the groups in terms of postoperative spheroequivalent, astigmatism, or cylindrical axis. The mean final visual acuity, however, was less in the extracapsular group. We conclude that phacoemulsification combined with trabeculectomy offers a safe and effective technique to control postoperative IOP in patients with glaucoma.

Effect of Cornea Donor Graft Thickness on the Outcome of Descemet Stripping Automated Endothelial Keratoplasty Surgery

PURPOSE To determine whether Descemet stripping automated endothelial keratoplasty (DSAEK) donor cornea graft thickness impacts measurements of best spectacle-corrected visual acuity (BSCVA), refractive error and intraocular pressure (IOP). DESIGN Retrospective chart review in a tertiary care center at Duke University Eye Center. METHODS We studied 460 eyes that had undergone DSAEK surgery. They were segregated into three groups based on the thickness of the donor graft: <100 μm (n = 67 eyes); 100-150 μm (n = 316 eyes); and >150 μm (n = 77 eyes). The three graft-thickness groups were assessed at about 6 months postoperatively for measurement of BSCVA, spherical equivalent, and IOP. RESULTS Baseline demographics were similar in the three groups. All groups experienced significant improvement in BSCVA (mean ± SD = -0.34 ± 0.50 logMAR); mild hyperopic shift (mean ± SD = 0.48 ± 1.7 D); and stability in IOP measurements (mean ± SD = 0.19 ± 4.8 mm Hg). There were no significant differences in groups according to donor graft thicknesses with respect to change in BSCVA (P = 0.8); hyperopic shift (P = 0.76); or IOP measurement (P = 0.56). CONCLUSIONS DSAEK significantly improves BSCVA. DSAEK graft thickness may not play an important role in the final BSCVA, refractive error, or accuracy of IOP measurement. The ideal DSAEK graft thickness to minimize graft-related complications remains to be determined.