Publications by authors named "David J Schanzlin"
Purpose: To assess the ability of the WaveScan WaveFront System (VISX Inc, Santa Clara, CA) to measure refractive errors in patients with difficult retinoscopy and to compare results to standard cycloplegic retinoscopy.
Methods: The medical records of patients with an ocular condition that could contribute to difficult or unreliable retinoscopy who underwent nondilated, noncycloplegic evaluation with the WaveScan WaveFront System were reviewed retrospectively. Results were compared to a standard cycloplegic retinoscopy.
Purpose: To test a new method of intraocular lens (IOL) calculation after corneal refractive surgery using Scheimpflug imaging (Pentacam HR) and partial coherence interferometry (PCI) (IOLMaster) that does not require historical data; that is, the Schuster/Schanzlin-Thomas-Purcell (SToP) IOL calculator.
Setting: Shiley Eye Center, San Diego, California, and Walter Reed National Military Medical Center, Bethesda, Maryland, USA.
Design: Retrospective data analysis and validation study.
Purpose: To create an accurate, low-cost optomechanical model eye for investigation of refractive errors in clinical and basic research studies.
Methods: An optomechanical fluid-filled eye model with dimensions consistent with the human eye was designed and fabricated. Optical simulations were performed on the optomechanical eye model, and the quantified resolution and refractive errors were compared with the widely used Navarro eye model using the ray-tracing software ZEMAX (Radiant Zemax, Redmond, WA).
Purpose: To investigate the effect of omega-3 oral nutritional supplementation on corneal reepithelialization, visual acuity, and tear stability after photorefractive keratectomy (PRK).
Methods: This is a prospective, randomized, single-blinded controlled therapeutic trial using omega-3 oral nutritional supplements (TheraTears Nutrition for Dry Eyes; Advanced Vision Research-Akorn, Ann Arbor, MI) conducted at our center. Eighteen healthy patients with refractive error between -1 and -8 diopters were recruited and had bilateral PRK.
Purpose: To evaluate changes in corneal asphericity (Q) and spherical aberrations after refractive surgery using Scheimpflug imaging.
Setting: University of California, San Diego, Shiley Eye Center, La Jolla, California, USA.
Design: Cohort study.
Purpose: To determine whether treatment with oral gabapentin reduces postoperative pain after photorefractive keratectomy (PRK).
Methods: This prospective, randomized, double-blind, placebo-controlled study comprised 40 patients scheduled for bilateral PRK. Exclusion criteria were previous refractive surgery; diseases that could affect epithelial healing; use of antihistamines, nonsteroidal anti-inflammatory drugs, or steroids; and use of mitomycin C during PRK.
The authors report a case of an immunocompetent 38-year-old male who presented with an indolent keratitis that eluded diagnosis after multiple cultures taken over 9 months. He was started initially on medications against Acanthamoeba, after presenting with a nearly complete corneal ring 2 months after trauma. These medications likely partially treated his condition, thereby making laboratory diagnosis more difficult.
View Article and Find Full Text PDFPurpose: To describe a new technique for deep anterior lamellar keratoplasty in the human eye.
Methods: We obtained globes from the San Diego Eye Bank and performed central and peripheral pachymetry measurements at the 8-mm optical zone. We made a radial incision at the edge of the optical zone at 90% depth of central corneal thickness.
Purpose: To compare the clinical outcomes of wavefront-guided laser in situ keratomileusis in eyes in which iris registration was used (IR group) and eyes in which iris registration would not engage (no-IR group).
Setting: Shiley Eye Center, University of California San Diego, La Jolla, California, USA.
Methods: This retrospective analysis comprised 112 eyes of 64 patients who had wavefront-guided LASIK using the Visx CustomVue S4 IR platform (Advanced Medical Optics) for myopia or myopic astigmatism.
Purpose: To assess the efficacy, predictability, and safety of wavefront-guided laser in situ keratomileusis (LASIK) in the treatment of high myopia by using the Visx S4 CustomVue wavefront platform.
Methods: A retrospective analysis of consecutive cases of eyes with high myopia (manifest refraction spherical equivalent >or= -6.00 D) that underwent non-physician-adjusted wavefront-guided LASIK by using the Visx S4 CustomVue wavefront platform.
Purpose: To evaluate the efficacy and safety of photorefractive keratectomy (PRK) for residual refractive errors in patients who had previous insertion of intrastromal corneal ring segments (Intacs, Addition Technology, Inc.) for treatment of low myopia.
Setting: Shiley Eye Center, University of California San Diego, La Jolla, California, USA.
Purpose: To compare the recovery of uncorrected visual acuity (UCVA) following LASIK in patients treated with topical cyclosporine A 0.05% and patients treated with a standard postoperative regimen.
Methods: In this single-center, open-label, retrospective study, a standard refractive workup was performed in 45 patients (85 eyes) who underwent LASIK and did not have preexisting dry eye.
Background: The authors used a retrospective case series to describe the increased frequency of dry eye syndrome in patients who have undergone both laser in situ keratomileusis and blepharoplasty.
Methods: The authors reviewed records from six patients who required surgical correction for exposure keratopathy previously treated by both laser in situ keratomileusis and blepharoplasty.
Results: All six patients developed significant exposure keratopathy postoperatively requiring surgical intervention.
New surgical approaches to the management of keratoconus and post-LASIK ectasia.
Trans Am Ophthalmol Soc
June 2007
Purpose: The objective of this study is to describe the authors' results with intrastromal corneal ring segments (Intacs) and a new variation of lamellar keratoplasty, termed intralamellar keratoplasty (ILK), for the treatment of keratoconus (KCN) and post-laser-assisted in situ keratomileusis (LASIK) ectasia.
Methods: A retrospective review of contact lens-intolerant KCN and post-LASIK ectasia cases that had surgery with either Intacs or ILK was performed. The end points were mean uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), spherical equivalent (SE), manifest and topographic cylinder, and restoration of contact lens tolerance.
Purpose: To compare postoperative pain associated with epi-LASIK versus photorefractive keratectomy (PRK).
Methods: This prospective observer-masked randomized study included 40 eyes of 20 patients with myopia and astigmatism who received epi-LASIK (Moria Epi-K) in one eye and PRK in the contralateral eye. Corneal ablation was done using the NIDEK EC-5000 excimer laser.
Purpose: To analyze in vivo the architecture of clear corneal incisions (CCIs) for phacoemulsification using optical coherence tomography (OCT).
Setting: Anterior Segment Department, Asociacion Para Evitar la Ceguera en Mexico, Hospital Dr Luis Sanchez Bulnes, Mexico.
Methods: A prospective masked study analyzed 20 unsutured CCIs placed superiorly and created in a uniplanar fashion with a 3.
Purpose: To report the first known case of a donor cornea being examined and shipped with a soft contact lens in place.
Methods: Case Report.
Results: Surgery was cancelled, the two involved eye-banks were notified, and the patient underwent successful keratoplasty 2 days later.
Results of late flap removal after complicated laser in situ keratomileusis.
J Cataract Refract Surg
March 2005
Purpose: To evaluate the effect of flap removal on complications after laser in situ keratomileusis (LASIK).
Setting: Three university-based referral centers and 1 private practice.
Methods: This retrospective interventional case series comprised 6 eyes of 6 patients at 4 centers.
Purpose: To compare retinal nerve fiber layer (RNFL) thickness measurements before and after LASIK.
Design: Cohort study.
Participants: Twenty participants undergoing LASIK and 14 normal controls.
Purpose: There are numerous reports of corneal ectasia after laser in situ keratomileusis (LASIK) for myopia without a consistent definition of this condition or a definitive etiology. We conducted a retrospective analysis of published case reports to describe common characteristics of this postoperative event and compared them with findings from a group of successful LASIK patients.
Methods: A MEDLINE search for "LASIK" and "ectasia" yielded 21 relevant articles published before May 2003 (n = 86 eyes, 59 patients).
Objective: To report the histologic characteristics of lamellar channel deposits after polymethyl methacrylate intrastromal corneal ring segments in a human eye.
Methods: A 34-year-old man previously diagnosed with keratoconus received photorefractive keratectomy in his left eye that exacerbated his corneal ectasia. To delay or possibly prevent corneal transplant, the patient elected to have intrastromal corneal segments implanted in the left eye.
Purpose: Laser in situ keratomileusis (LASIK) involves ablation of the corneal stroma, which may induce a change in birefringence. The purpose of this study was to determine the effect of LASIK on corneal birefringence by measuring corneal polarization magnitude (CPM) and axis (CPA).
Study Design: Cohort study.
Proteoglycan alterations in the rabbit corneal stroma after a lamellar incision.
J Cataract Refract Surg
April 2003
Purpose: To investigate proteoglycans under minimally damaged epithelium after a lamellar microkeratome incision.
Setting: Collaborating university departments.
Methods: Anterior lamellar caps were excised from rabbit corneas and then resutured in place.