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Jay S Pepose

Publications and source records attributed to Jay S Pepose.

At least 19 recordsLinked to original sources
PubMed2007

Determining corneal power using Orbscan II videokeratography for intraocular lens calculation after excimer laser surgery for myopia.

PURPOSE: To assess the accuracy of Orbscan II slit-scanning videokeratography for intraocular lens (IOL) calculation in eyes with previous photorefractive surgery for myopia. SETTING: Private practice, St. Louis, Missouri, USA. METHODS: Corneal power (K) was measured by manual keratometry, Placido-based videokeratography (Atlas), slit-scanning videokeratography (Orbscan II), and contact lens overrefraction in 21 post-photoablation eyes having cataract surgery. Postoperative data collected after phacoemulsification were used to back-calculate corneal power (BCK). The BCK values were statistically compared at 3.0 to 6.0 mm central Orbscan II curvature and power measurements, including total axial power, total tangential power, total mean power, and total optical power. Similar comparisons were made to Atlas curvature at the 0.0 to 10.0 mm zones. RESULTS: The mean corneal power after refractive surgery based on BCK values using the Holladay 2 formula (BCK H2) was 39.35 diopters (D) +/- 2.58 (SD). The mean manual value (40.52 +/- 1.95 D) and Atlas-based values were statistically higher than BCK H2 values (P<.001). The mean corneal power calculated from historical data was 39.33 +/- 2.70 D (P = .83 to BCK H2; n = 19) and from contact lens overrefraction, 41.38 +/- 3.11 D (P = .19; n = 5). Orbscan II parameters (n = 21) of the total mean power (3.0 mm, 39.10 +/- 2.63 D), total tangential power (3.0 mm, 39.11 +/- 2.60), total axial power (5.0 mm, 39.19 +/- 2.55 D), and total optical power (3.0 mm, 39.08 +/- 2.78 D; 4.0 mm, 39.39 +/- 2.76 D) were statistically similar to both the historical and BCK H2 values (P>.11). If used prospectively, 80.9% of eyes would have been within +/-0.50 D of the targeted refraction using a 4.0 mm total optical power, 76.2% using a 5.0 mm total axial power, and 42.1% using the historical method. CONCLUSION: The Orbscan II 5.0 mm total axial power and 4.0 mm total optical power can be used to more accurately predict true corneal power than the history-based method and may be particularly useful when pre-LASIK data are unavailable.

Cataract↗
PubMed2006

Changes in corneal biomechanics and intraocular pressure following LASIK using static, dynamic, and noncontact tonometry.

PURPOSE: To compare the preoperative and postoperative measurement of corneal biomechanical properties and intraocular pressure (IOP) using Goldmann applanation tonometry (GAT), the ocular response analyzer (ORA), and the Pascal dynamic contour tonometer (PDCT) in eyes undergoing myopic laser in situ keratomileusis (LASIK). DESIGN: Prospective, nonrandomized clinical trial. METHODS: IOP was measured in 66 myopic eyes before and after LASIK by GAT, ORA, and PDCT in a randomized sequence. Metrics of corneal biomechanical properties (corneal hysteresis [CH], corneal resistance factor [CRF], and ocular pulse amplitude [OPA]) were recorded. RESULTS: After LASIK, there was a reduction in mean corneal pachymetry of 90.2 mum and in IOP measurements with GAT (Delta = -1.8 +/- 2.8 mm Hg; P < .01), ORA-Goldmann (Delta = -4.6 +/- 2.8 mm Hg, P < .01), and ORA-corneal compensated (Delta - 2.1 +/- 2.6 mm Hg; P < .05). However, there was no statistically significant difference between preoperative and postoperative IOP measurements taken by PDCT (Delta = -0.5 +/- 2.6 mm Hg). Postoperatively, CRF decreased by 28.6% (P < .01), CH by 16.2% (P < .01), and OPA by 1.8% (P = .32). CONCLUSIONS: Measurement of IOP with PDCT appears to be relatively immune to changes in corneal biomechanics and pachymetry after LASIK, in comparison to GAT and ORA measures of IOP. PDCT and ORA both showed statistically lower variation in measurement than GAT. LASIK produced a marked decline in CH and CRF, which may reflect respective changes in the viscous and elastic qualities of the post-LASIK cornea. In contrast, there was no statistical change in OPA.

Adult↗
PubMed2006

Ocular herpes simplex: changing epidemiology, emerging disease patterns, and the potential of vaccine prevention and therapy.

PURPOSE: To review the changing epidemiology of herpes simplex virus infection, emerging patterns of herpetic ocular disease, and the challenges and promise of herpes simplex virus vaccine therapy. DESIGN: Perspective. METHODS: Literature review. RESULTS: An epidemic increase in genital herpes simplex type 2 infection is reflected in a 30% increase in HSV-2 antibodies in the United States since 1976. Approximately one in four people in the United States over age 30 is infected with HSV-2. Primary acquisition of herpes simplex type 1 is becoming progressively delayed in many industrialized countries, in contrast to developing nations where the virus is acquired early in life and is ubiquitous. Changes in sexual behavior among young adults have been associated with a recent increase in genital HSV-1 infection, resulting from oral-genital rather than genital-genital contact. Clinical trials of HSV vaccines using selected herpes simplex virus type 2 proteins mixed in adjuvant have shown limited efficacy in seronegative women, but not in men. CONCLUSIONS: The recent epidemic of genital herpes simplex type 2 infection is likely to result in an increase in neonatal ocular herpes and in delayed cases of acute retinal necrosis syndrome. The increase in genital HSV-1 may lead to industry production of vaccines that contain components of both HSV-1 and HSV-2 targeted toward limiting genital disease and transmission. As newer herpes simplex vaccines become available, ophthalmologists must be vigilant that a boost in immunity against HSV does not have a paradoxical effect in exacerbating break-through cases that develop immune-mediated herpes simplex stromal keratitis.

Herpes Simplex Virus Vaccines↗
PubMed2006

Development of late-onset subepithelial corneal haze after laser-assisted subepithelial keratectomy with prophylactic intraoperative mitomycin-C Case report and literature review.

We present a case of dense, visually significant reticular haze that developed approximately 17 months after uneventful laser-assisted subepithelial keratectomy with mitomycin-C (MMC). The patient was successfully treated with manual debridement coupled with phototherapeutic keratectomy and intraoperative MMC.

Adult↗
PubMed2005

Optical performance of 3 intraocular lens designs in the presence of decentration.

PURPOSE: To study the theoretical optical performance of 3 intraocular lens (IOL) designs in the presence of IOL decentration. SETTING: Optics Center, Bausch & Lomb, Rochester, New York, USA. METHODS: A ray-tracing program was used to evaluate the effect of IOL decentration on the optical performance of 3 silicone IOLs (LI61U, Bausch & Lomb; Tecnis Z9000, Advanced Medical Optics; and a new aberration-free IOL [SofPort AO, Bausch & Lomb]) in an experimental model eye. The study was done using pupil diameters of 3.0 mm, 4.0 mm, and 5.0 mm and IOL decentrations of 0 mm, 0.25 mm, 0.50 mm, 0.75 mm, and 1.00 mm. The modulation transfer functions were computed and plotted. A Monte Carlo simulation analysis with 1000 trials with IOL decentration randomly varying for each pupil size was performed. RESULTS: Decentration of LI61U and Tecnis Z9000 IOLs led to asymmetrical higher-order aberrations that adversely affected the optical performance of the model eye; performance was not affected with the aberration-free IOL because it lacks inherent spherical aberration. Optical performance with the aberration-free IOL was better than with the LI61U IOL as the former has less spherical aberration and did not introduce other aberrations when decentered. Performance with the aberration-free IOL was better than with the Tecnis Z9000 IOL for 3.0 mm, 4.0 mm, and 5.0 mm pupils when decentration exceeded 0.15 mm, 0.30 mm, and 0.38 mm, respectively. Performance with the LI61U IOL was better than with the Tecnis Z9000 IOL for 3.0 mm, 4.0 mm, and 5.0 mm pupils when decentration exceeded 0.3 mm, 0.5 mm, and 0.5 mm, respectively. Monte Carlo simulations showed the expected postoperative results of the LI61U IOL and aberration-free IOL would be repeatable and predictable, whereas the outcomes with the Tecnis Z9000 IOL would vary widely. CONCLUSIONS: The optical performance of the model eye was not affected by decentration of an aspheric IOL designed to have no inherent spherical aberration. With decentration, the performance with the new IOL was better than with a conventional spherical IOL and an aspheric IOL designed to offset the spherical aberration of an average cornea.

Biocompatible Materials↗
PubMed2005

Topographic and biomechanical differences between hyperopic and myopic laser in situ keratomileusis.

PURPOSE: To evaluate the size, shape, and uniformity of the videokeratographic functional optical zone (FOZ) after laser in situ keratomileusis (LASIK) in 2 cohorts of patients with equivalent amounts of preoperative myopic or hyperopic astigmatism. SETTING: Pepose Vision Institute, St. Louis, Missouri, USA. METHODS: Eyes with myopic or hyperopic astigmatism (n=27 in each group) that had LASIK with the Visx Star S3 laser were retrospectively selected to match for level of preoperative refractive error. Slit-scanning videokeratography was performed preoperatively and 6 months postoperatively and analyzed using custom software. The FOZ was calculated by analyzing refractive power maps using a region-growing algorithm. Difference maps were generated from slit images and compared for interval change in corneal elevation, tangential curvature, and refractive power. The difference maps were also averaged (mean difference maps) for each target population. A Zernike decomposition of corneal first-surface elevation was performed to compare postoperative values with baseline parameters. RESULTS: The mean postoperative refractive sphere at 6 months was -0.17 diopter (D) +/- 0.66 (SD) and +0.25 +/- 0.85 D in the myopia group and hyperopia group, respectively, and the mean postoperative astigmatism, -0.49 +/- 0.32 D and -0.65 +/- 0.52 D, respectively (P=.11). Based on the refractive power maps, the mean preoperative and postoperative myopic FOZ was 33.09 +/- 7.30 mm(2) and 30.94 +/- 5.43 mm(2), respectively, and the mean hyperopic FOZ, 33.19 +/- 7.96 mm(2) and 37.99 +/- 6.88 mm(2), respectively. After LASIK, there was an increase in magnitude of negative anterior corneal surface spherical-like Zernike values in the myopia group (P<.0001) and an increase in magnitude of positive spherical-like Zernike values in the hyperopia group. Postoperatively, significant induction of corneal surface horizontal coma was noted in hyperopic eyes (P<.0001). Hyperopic eyes, on average, had larger topographic FOZs after LASIK, but with less uniformity of curvature and power change than myopic eyes. CONCLUSIONS: Hyperopic LASIK, which involves more transition points along the ablation diameter, produced a less uniform topographic FOZ than typical myopic treatments. Less predictable biomechanical changes from the circumferential release of tension on collagen bundles after midperipheral hyperopic ablation and greater variation in beam centration and the angle of incidence may contribute to the greater variability in corneal curvature and power in hyperopic LASIK than in myopic LASIK.

Astigmatism↗
PubMed2004

The effect of punctal occlusion on wavefront aberrations in dry eye patients after laser in situ keratomileusis.

PURPOSE: To compare the wavefront aberrations in post-laser in situ keratomileusis (LASIK) dry eye patients before and after punctal occlusion. DESIGN: Prospective, comparative, nonrandomized study. METHODS: Wavefront aberrometry was performed on 16 eyes of eight patients with dry eyes after LASIK surgery. Wavefront measurements were taken before and 1 month after punctal plug placement and compared with 10 eyes of post-LASIK patients without clinically dry eyes measured twice 1 month apart. Student t tests were used to assess the statistical significance of differences between pre- and post-punctal plug measurements. RESULTS: Punctal occlusion in the post-LASIK dry eye patients significantly reduced total, lower, and higher order wavefront aberrations by 47% to 63% (P <.01). Among higher-order aberrations, there were significant reductions in coma and spherical aberration but not in trefoil, after punctal occlusion. The reduction of wavefront aberrations by punctal occlusion in post-LASIK dry eye patients resulted in a significant improvement in quantitative visual acuity assessed using an Early Treatment of Diabetic Retinopathy Study chart and in subjective qualitative vision, confirmed by convolutional analysis using image simulation. No statistically significant differences in any of these metrics were found in the post-LASIK control group without clinically dry eyes measured twice at a similar time interval. CONCLUSIONS: Wavefront aberrometry provides a useful, objective assessment of post-LASIK dry eye patients before and after punctal plug placement. Aggressive treatment of dry eyes may be important before obtaining wavefront measurements that serve as the basis for planning refractive corneal laser treatments and retreatments.

Adult↗
PubMed2003

Human corneal endothelial cell expression of Na+,K+-adenosine triphosphatase isoforms.

OBJECTIVE: To determine the expression of alpha subunits and different isozymes of Na+,K+-adenosine triphosphatase (ATPase) in human corneal endothelial cells (HCECs). METHODS: Immunoblot and RNA analysis of Na+,K+-ATPase alpha subunit expression were performed in preparations from HCECs that had been immortalized by transformation with simian virus 40. Na+,K+-ATPase activity was determined by constructing dose-response curves for the ouabain inhibition of Na+,K+-ATPase activity in human corneal endothelial cells. RESULTS: Both messenger RNA analysis and immunoblot studies indicated that HCECs express ATPase catalytic alpha1 and alpha3, but not alpha2 and alpha4, subunits. A limited amount of alpha3 subunit was expressed in HCECs compared with the alpha1 subunit. Biochemical analyses of Na+,K+-ATPase activity revealed 2 independently active Na+,K+-ATPase isoenzymes, a low-affinity site with a kinetic parameter for ouabain inhibition constant (Ki) in the micromolar range and a high-affinity site with a constant Ki in the nanomolar range. These 2 sites may be associated with alpha1 and alpha3 isoforms, respectively, expressed in HCECs. CONCLUSIONS: Human corneal endothelial cells express alpha1 and alpha3 isoforms of Na+,K+-ATPase, and both polypeptides are catalytically competent in these cells. Defining the components of Na+,K+-ATPase in HCECs is an important step toward elucidating the mechanisms that regulate corneal endothelial ionic pump function as well as the pathogenesis of corneal diseases associated with corneal edema.

Cell Line, Transformed↗
PubMed2003

Correlation of visual and refractive outcomes between eyes after same-session bilateral laser in situ keratomileusis surgery.

PURPOSE: To determine whether between-eye refractive and visual outcomes after same-session laser in situ keratomileusis (LASIK) surgery are correlated, and to determine whether suboptimal visual and refractive outcomes in one eye are predictive of poor results in the fellow eye. DESIGN: Observational case series. METHODS: Retrospective chart review. A total of 484 eyes of 242 patients met inclusion criteria of having undergone same-day LASIK surgery and having 3-month refractive and visual acuity outcomes. Statistical comparisons of outcomes were performed, including between-eye Pearson correlation analysis and logistic regression models for predicting second-eye outcome. Main outcome measures were 1-month, 3-month, and 6-month uncorrected visual acuity and manifest refraction. RESULTS: Refractive outcomes at 1, 3, and 6 months between first (right) and second eyes were not found to be significantly different. No difference in uncorrected or best spectacle-corrected visual acuity was observed between first and second eyes Refractive outcomes of spherical equivalent, sphere, and cylinder and visual outcomes of uncorrected and best spectacle-corrected visual acuity were highly correlated between the two eyes. Analysis of cases with suboptimal outcomes (> or =1 diopter from intended correction or uncorrected acuity equal to or worse than 20/40) suggests that a poor refractive or visual outcome in the first eye increases the risk of a poor outcome in the second eye by approximately 20-fold. CONCLUSIONS: Retrospective analysis of refractive and visual outcomes from patients undergoing same-session bilateral LASIK demonstrates a high correlation of refractive and visual outcome between the eyes.

Adult↗
PubMed2003

Ocular complications of smallpox vaccination.

PURPOSE: To describe the ocular complications of smallpox vaccination and to discuss potential therapeutic options. DESIGN: Review of pertinent medical literature and recent treatment recommendations of the Centers for Disease Control and Prevention. RESULTS: After immunization against smallpox, vaccinia infection of the eyelid, conjunctiva, or ocular surface can result from accidental autoinoculation from a vaccination site before scab formation or from contact with a recently vaccinated individual. While uncommon, corneal involvement can lead to stromal opacification and scarring. Clinical findings of ocular and periocular vaccinia must be differentiated from those produced by other pathogens such as molluscum contagiosum, herpes simplex, varicella zoster, and acanthamoeba infections. Clinical diagnosis can be confirmed by electron microscopy to identify the presence of orthopoxvirus, as well as by virologic culture, polymerase chain reaction, and/or restriction endonuclease analysis of viral isolates. CONCLUSIONS: While the majority of ocular complications of smallpox vaccination in immunocompetent patients are self-limiting, selective cases may require treatment with trifluridine drops, topical corticosteroids and vaccinia immune globulin (VIG). Vaccinia virus does not appear to be sensitive to acyclovir. Specific treatment recommendations are outlined for the spectrum of ocular manifestations.

Centers for Disease Control and Prevention, U.S.↗
PubMed2003

Intraocular lens calculations in patients with corneal scarring and irregular astigmatism.

PURPOSE: To compare various methods of estimating corneal power for intraocular lens (IOL) calculation in patients with irregular corneal astigmatism. SETTING: Pepose Vision Institute, St. Louis, Missouri, USA. Case reports and review of the medical literature. RESULTS: Two patients with irregular corneal astigmatism had an IOL exchange after a "surprise" post-cataract-surgery refraction. In the first case, the patient had a post-cataract-surgery refraction of +5.50 -0.75 x 69 and in the second case, a refraction of -7.00 -1.00 x 180. The central corneal power before IOL exchange was assessed using manual keratometry, various computerized videokeratography curvature and power maps, and contact lens overrefraction. The total axial power map (Orbscan(R), Bausch & Lomb), total optical power map (Orbscan), and contact lens overrefraction method provided the most accurate estimates of central corneal power in these 2 patients. CONCLUSION: Computerized scanning-slit videokeratography, which analyzes the anterior and posterior surfaces of the cornea, and the contact lens overrefraction method gave good estimations of corneal power in patients with irregular corneal astigmatism. This type of analysis may improve the accuracy of IOL calculation in patients with corneal pathology and irregular astigmatism.

Adult↗
PubMed2003

Retained contact lens for more than 10 years in a laser in situ keratomileusis patient.

A 49-year-old man with blurred vision in 1 eye and myopic regression had laser in situ keratomileusis (LASIK) in the right eye after having 20/20 uncorrected visual acuity for 2 years. At the conclusion of surgery, a poly(methyl methacrylate) contact lens that had been retained for more than 10 years was discovered in the upper fornix. Although the patient remained asymptomatic, reports of significant complications associated with retained contact lenses are numerous. In addition, retained contact lenses, lid lesions, and periocular masses can induce refractive and topographic changes after LASIK. The retained contact lens may have led to compression-induced changes in corneal curvature, resulting in the need for uniocular enhancement 2 years after the primary LASIK procedure.

Conjunctival Diseases↗
PubMed2002

Implantation of scleral expansion band segments for the treatment of presbyopia.

PURPOSE: To assess the effects of scleral expansion band (SEB) segments on accommodative amplitude (primary measure), along with near and distance vision, refraction, pupil size and function, keratometry, axial length, intraocular pressure, contrast sensitivity, stereopsis, and other parameters (secondary measures) in a cohort of 29 emmetropic, presbyopic patients. DESIGN: Multicenter, prospective, nonrandomized, unmasked clinical trial in which the nonoperated eye served as the control. METHODS: Four polymethylmethacrylate segments were surgically implanted in quadrantic scleral pockets created in the dominant eye of 29 emmetropic patients who were between the ages of 51 and 60 (mean age 54). Patients were examined preoperatively and up to 6 months postoperatively. The aforementioned tests were performed on the operated and control eye of each patient. Data were analyzed using two-sided rank tests. Medians, means, and standard deviations are provided for all measurements. RESULTS: Accommodative amplitude was measured monocularly using a near-point "push" technique from both a 70-cm and 30-cm starting point. An increase in accommodative amplitude of surgical eyes by +1.7 +/- 1.5 diopters and +1.5 +/- 1.2 diopters, at these two testing distances, respectively, was noted at 6 months postoperatively (P <.0001). A smaller increase was also seen in control eyes (+1.2 +/- 1.1 diopters and +1.3 +/- 1.2 diopters, respectively). There was notable intercenter variation in gains in accommodation, with three of seven centers showing significant improvement in near-point accommodative amplitudes relative to the others (P =.0003). There was a median improvement of uncorrected near acuity in surgical eyes by 0.3 logarithm of the minimal angle of resolution (logMAR) at 30 and 40 cm and by 4 lines at 20 cm, with the difference in near acuity improvement at 6 months between SEB eyes and control eyes statistically significant at 20 cm (P <.030). Changes in spherical equivalence, axial length, and central keratometry readings were not statistically significant. There were no reports of anterior segment ischemia or malignant glaucoma. Adverse effects were limited to a transient elevation of intraocular pressure in one patient and misalignment of individual SEB segments, due to inadequate scleral pocket formation, in three patients. Only one SEB segment in one eye was replaced. It appears that the thickness and uniformity of the scleral belt loop is critical to the proper positioning and efficacy of the SEB segments. CONCLUSION: While the safety profile of SEB segments for the treatment of presbyopia was high, a modest improvement in near vision was noted in approximately half the patients using subjective methods of testing. The mechanisms that underlie improvement in near vision in the nonoperated eye await explanation. This may be due to a centrally controlled consensual response, potentiated convergence generating increased intravitreal pressure and hydraulic lift of the vitreo-zonular-lens diaphragm, or artifact from current testing techniques. Future studies of the SEB procedure should address the issue of intercenter variation by further standardizing and automating specific aspects of the surgical technique, as well as incorporating objective testing methods into the study design.

Accommodation, Ocular↗
PubMed2002

Comparison of photorefractive keratectomy, astigmatic PRK, laser in situ keratomileusis, and astigmatic LASIK in the treatment of myopia.

PURPOSE: To determine factors affecting refractive and visual outcomes in patients treated with astigmatic and spherical photorefractive keratectomy (A-PRK and PRK) and laser in situ keratomileusis (A-LASIK and LASIK). SETTING: University referral refractive surgery clinic. METHODS: Refractive and visual acuity results in 619 eyes of 388 consecutive patients having refractive surgery over a 2-year period by a single surgeon were retrospectively analyzed. Patients were divided into mild-to-moderate myopia (spherical equivalent [SE] less than -6.12 diopters [D]) and high myopia (SE -6.12 D or higher). Multivariate and logistic regression analyses were performed. RESULTS: Refractive results in flap-based and PRK-based procedures were comparable in mild-to-moderate myopia patients but were significantly better in high-myopia patients having flap-based procedures. Refractive stability was greater in flap-based procedures than in PRK-based procedures. Elliptical ablations yielded a marked reduction in the astigmatic cylinder in patients having A-LASIK and A-PRK, while spherical PRK induced small amounts of with-the-rule astigmatism. Complications were uncommon in both groups, consisting primarily of epithelial ingrowth in flap-based procedures and haze in PRK-based procedures. Multivariate regression identified the preoperative SE as a significant determinant of PRK outcomes (with higher success for lower myopia) and intraocular pressure as a minor determinant of outcomes in PRK-based and flap-based procedures. Logistic regression suggested that only the preoperative SE was a significant factor in predicting the likelihood of poor outcomes in PRK patients. CONCLUSIONS: Refractive outcomes were almost identical in patients having elliptical or spherical ablations with flap-based or PRK-based procedures. In eyes with mild-to-moderate myopia, there was little difference in refractive or visual outcomes between flap-based and PRK-based procedures; in eyes with high myopia, flap-based procedures offered more predictable refractive outcomes and better visual outcomes.

Adult↗