Jay J. Meyer

Corneal profile analysis after Descemet stripping endothelial keratoplasty and its relationship to postoperative hyperopic shift

PURPOSE: To evaluate changes in the corneal profile after Descemet stripping endothelial keratoplasty (DSEK) using anterior segment optical coherence tomography (AS‐OCT) analysis and to describe its relationship to a dynamic postoperative hyperopic shift. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, USA. METHODS: In this retrospective observational study, 9 eyes had DSEK and were followed with manifest refractions and AS‐OCT analysis. To assess changes in the thickness of the cornea, measurements for each AS‐OCT image were taken at the vertex of the cornea, at 1.5 mm on each side of the vertex, and at the distal edges of the graft. RESULTS: Patients were followed for a mean of 134 days (range 46 to 228 days). Monthly Graft thinning rates were 5.2 μm per month at the vertex, 7.9 μm per month 1.5 mm from the vertex, and 26 μm per month at the edges, with the edges thinning significantly faster than the cornea vertex (P = .0024) and the points on either side of the 3.0 mm visual axis (P = .0018). The mean spherical equivalent (SE) showed an initial hyperopic shift that decreased over the ensuing 100 to 200 days postoperatively. The mean monthly postoperative SE change was −0.25 diopter (D) with a mean preoperative to postoperative SE change of +1.26 D. CONCLUSIONS: The donor graft underwent changes after DSEK, which may account for the induced hyperopia and its diminishment over time via changes in the posterior corneal curvature. Results suggest that intraocular lenses be targeted to −1.00 to −1.25 D of myopia for combined DSEK and cataract procedures.

Effect of Iris Registration on Outcomes of LASIK for Myopia With the VISX CustomVue Platform

PURPOSE To compare visual outcomes after LASIK using the VISX STAR S4 CustomVue, with and without Iris Registration technology. METHODS In this retrospective study, LASIK was performed on 239 myopic eyes, with or without astigmatism, of 142 patients. Iris registration LASIK was performed on 121 eyes and non-iris registration LASIK was performed on 118 eyes. Primary outcome measures were uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), and manifest refraction. RESULTS At 6 months, the mean values for UCVA (logMAR) were 0.00 +/- 0.09 in the iris registration group and -0.01 +/- 0.11 in the non-iris registration group (P = .587). Seventy-nine percent of eyes in the iris registration group had UCVA of 20/20 or better compared to 78% in the non-iris registration group (P = .518). Ninety-two percent of eyes in the iris registration group and 90% in the non-iris registration group were within +/- 0.50 diopters (D) of emmetropia (P = .999). Mean postoperative absolute change in total root-mean-square higher order aberrations in the iris registration group and non-iris registration group was 0.22 microm and 0.19 microm, respectively (P = .6). At 3 months, the mean magnitude of error of surgically induced astigmatism was -0.09 in the iris registration group and -0.04 in the non-iris registration group (P = .25). CONCLUSIONS Wavefront-guided LASIK with the VISX STAR S4 CustomVue laser system, independent of iris registration status, is effective, safe, and predictable. Under well-controlled surgical conditions, this study did not find any statistical significance supporting the better achievement of visual acuity, astigmatism correction, or the lesser induction of higher order aberrations using iris registration in comparison to a non-iris registration system.

Prospective randomized trial of wavefront-guided laser in situ keratomileusis with the CustomCornea and CustomVue laser systems

PURPOSE: To compare visual function, safety, and higher‐order aberrations (HOAs) after wavefront‐guided laser in situ keratomileusis (LASIK) with the LadarVision CustomCornea (Alcon Laboratories, Inc.) and Star S4 CustomVue (Visx) laser systems. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: Seventy‐eight eyes of 39 patients with myopia with or without astigmatism were randomized for LASIK treatment in 1 eye with the CustomCornea laser; the other eye was treated with the CustomVue laser. Patients were followed for 6 months after surgery. The primary outcome measures were uncorrected visual acuity (UCVA), best spectacle‐corrected visual acuity (BSCVA), manifest refraction, and changes in HOAs. RESULTS: At 6 months, the mean logarithm of the minimum angle of resolution (logMAR) UCVA was −0.0135 ± 0.07 (SD) in the CustomVue group and 0.0417 ± 0.12 in the CustomCornea group (P = .023). Eighty‐eight percent of eyes in the CustomVue group had 20/20 or better UCVA compared with 67% in the CustomCornea group (P<.02). At 6 months, 91% of eyes in the CustomVue group and 79% in the CustomCornea group were within ±0.50 diopter (D) of emmetropia (P<.1); 88% and 50%, respectively, were within ±0.25 D (P<.001). Both platforms led to a small increase in total HOAs. The CustomVue system reduced trefoil and induced less of an increase in total HOAs, whereas the CustomCornea platform increased trefoil but induced less of an increase in spherical aberrations and coma. CONCLUSIONS: Both laser systems were effective, safe, and predictable. Wavefront‐guided LASIK with the CustomVue system resulted in better visual acuity, with more eyes having 20/20 acuity than in the CustomCornea group.

The Risk of Capsular Breakage from Phacoemulsification Needle Contact With the Lens Capsule: A Laboratory Study

PURPOSE To determine capsular breakage risk from contact by phacoemulsification needles by machine and tip type. DESIGN Experimental laboratory investigation. METHODS Infiniti (Alcon, Inc.) with Intrepid cartridges and Signature (Abbott Medical Optics, Inc.) phacoemulsification machines were tested using 19- and 20-gauge sharp and rounded tips. Actual and unoccluded flow vacuum were determined at 550 mm Hg, bottle height of 75 cm, and machine-indicated flow rate of 60 mL/minute. Breakage from brief tip contact with a capsular surrogate and human cadaveric lenses was calculated. RESULTS Nineteen-gauge tips had more flow and less unoccluded flow vacuum than 20-gauge tips for both machines, with highest unoccluded flow vacuum in the Infiniti. The 19-gauge sharp tip was more likely than the 20-gauge sharp tip to cause surrogate breakage for Signature with micropulse and Ellips (Abbott Medical Optics, Inc.) ultrasound at 100% power. For Infiniti using OZil (Alcon, Inc.) ultrasound, 20-gauge sharp tips were more likely than 19-gauge sharp tips to break the membrane. For cadaveric lenses, using rounded 20-gauge tips at 100% power, breakage rates were micropulse (2.3%), Ellips (2.3%), OZil (5.3%). Breakage rates for sharp 20-gauge Ellips tips were higher than for rounded tips. CONCLUSIONS Factors influencing capsular breakage may include active vacuum at the tip, flow rate, needle gauge, and sharpness. Nineteen-gauge sharp tips were more likely than 20-gauge tips to cause breakage in lower vacuum methods. For higher-vacuum methods, breakage is more likely with 20-gauge than with 19-gauge tips. Rounded-edge tips are less likely than sharp-edged tips to cause breakage.

Multifocal osteomyelitis due to Mycobacterium szulgai in a patient with chronic lymphocytic leukemia

Mycobacterium szulgai is a pathogenic organism that most frequently causes pulmonary infection and may rarely result in disseminated disease in immunocompromised individuals. We report a case of multifocal osteomyelitis and cutaneous lesions due to M. szulgai in a patient with chronic lymphocytic leukemia. The successful treatment of multifocal osteomyelitis was accomplished using isoniazid, rifampin, and ethambutol.

Risk for uveitis after laser in situ keratomileusis in patients positive for human leukocyte antigen-B27

PURPOSE: To assess the incidence of, risk for, and visual outcomes of acute anterior uveitis (AAU) in human leukocyte antigen (HLA)‐B27 positive patients who had laser in situ keratomileusis (LASIK). SETTING: University‐based center. METHODS: This study comprised 46 eyes of 23 HLA‐B27 positive patients with a 5‐year follow‐up. Data on episodes of uveitis were reviewed retrospectively and the incidence rates calculated for LASIK and non‐LASIK eyes. Kaplan‐Meier survival probabilities were calculated for uveitis occurring during the final 36 to 60 months of the study. Survival probabilities between LASIK and non‐LASIK eyes were compared. RESULTS: Twenty eyes (10 patients) had LASIK a mean of 36 months ± 2 (SD) after the diagnosis of HLA‐B27. In the HLA‐B27 positive patients, the incidence rates of uveitis between eyes that had and eyes that did not have LASIK were not significantly different. The incidence rates of uveitis after LASIK did not differ significantly between eyes with and eyes without episodes of uveitis before LASIK (P = .135). The probability of an eye having no episode of uveitis in the fourth and fifth year of follow‐up was not significantly different between eyes that had LASIK and those that did not (P = .668). CONCLUSIONS: The occurrence rate of post‐LASIK AAU in the HLA‐B27 positive population was not higher than the general incidence in a similar HLA‐B27 population without previous LASIK. A previous episode of uveitis did not appear to increase the risk for uveitis after LASIK in HLA‐B27 positive patients.

Pseudomonas Scleritis Resistant to Fourth-Generation Fluoroquinolones in a Patient Without Prior Trauma or Surgery

Purpose: To describe a case of necrotizing scleritis due to Pseudomonas aeruginosa resistant to fourth-generation fluoroquinolones. Methods: Case report. A 50-year-old woman with no history of trauma or surgery presented with pain and redness of the left eye. Results: The patient did not respond to empiric treatment and developed scleral edema with a nummular area of avascular sclera nasally. Histopathologic examination revealed necrotizing scleritis and cultures grew P. aeruginosa resistant to fourth-generation fluoroquinolones. Conclusions: A high index of suspicion for an infectious etiology must be maintained in cases not responding to conventional noninfectious scleritis therapy and in cases with unusual presentations. Resistance to commonly used empiric antibiotics may further complicate the diagnosis and management of infectious scleritis.

A comparison of three methods for trephining donor corneal buttons: endothelial cell loss and microscopic ultrastructural evaluation.

Purpose: To evaluate the ultrastructure of the cut edge and associated endothelial cell loss following donor cornea trephination with a standard punch, vacuum punch, and vacuum trephine and artificial anterior chamber system. Materials and Methods: This laboratory investigation compared trephinations (8.0 mm) performed on human corneas using either a standard posterior punch (n = 12), vacuum posterior punch (n = 12), or vacuum trephine and artificial anterior chamber system (n = 12). Specular microscopy was performed before and after trephination to determine central endothelial cell density. Light and scanning electron microscopy were performed to evaluate the structure of the trephined edge. Endothelial cell-free distances from the trephinated edges were measured on light microscopy sections. Results: Central endothelial cell loss (cells/mm2) after trephination was –14.0 ± 49.9 (SD) for the standard posterior punch, –85.6 ± 87.0 for the vacuum posterior punch, –116.0 ± 223.1 for the vacuum trephine and artificial anterior chamber system. Endothelial cell-free distances from the trephined margin were 63 ± 22 μm, 85 ± 13 μm, and 123 ± 48 μm for the three respective methods. The edges of grafts cut with anterior trephination were inward sloping from the epithelial to endothelial surfaces, while both posterior punches created outward sloping edges. Increased fibrillar disruption at edges was seen following anterior trephination. Conclusion: Different trephination methods produce distinct cut morphologies with the anterior trephination approach, resulting in more irregular margins. The anterior approach was associated with increased variability and greater endothelial cell loss than the studied posterior approaches. The use of corneal scissors may contribute to the morphologic features of the corneal button seen following anterior trephination.