Jan Venter
University of California, San Francisco
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Journal of Cataract and Refractive Surgery | 2013
Jan Venter; Martina Pelouskova; Barrie M. Collins; Steven C. Schallhorn; Stephen J. Hannan
Purpose To report the effectiveness, patient satisfaction, and complication rate with a zonal refractive intraocular lens (IOL) in a high volume of patients. Setting Private clinic, London, United Kingdom. Design Case series. Methods Retrospective data of patients with binocular Lentis Mplus IOLs were analyzed. The main outcome measures were uncorrected distance visual acuity (UDVA), uncorrected near visual acuity (UNVA), corrected distance visual acuity, manifest refraction, patient satisfaction, and complications. One‐month, 3‐month, and 6‐month data were analyzed. Results The study comprised 9366 eyes of 4683 patients. The mean spherical equivalent changed from +1.73 diopters (D) ± 3.37 (SD) preoperatively to −0.02 ± 0.60 D at 3 months and +0.03 ± 0.60 D at 6 months. Ninety‐five percent of patients achieved a binocular UDVA of 6/7.5 (0.1 logMAR) or better 3 months postoperatively. The mean binocular UNVA was 0.155 ± 0.144 logMAR and 0.159 ± 0.143 logMAR at 3 months and 6 months, respectively. Severe dysphotopsia requiring an IOL exchange occurred in 55 eyes. Patient satisfaction was high, with 97.5% of patients willing to recommend the procedure. Conclusions The zonal refractive IOL provided excellent distance and near visual acuity. The postoperative complication rate was clinically acceptable, and patient satisfaction high. Financial Disclosure Dr. Schallhorn is a consultant to Abbott Medical Optics, Inc. No author has a financial or proprietary interest in any material or method mentioned.
Journal of Refractive Surgery | 2009
Jan Venter
PURPOSE To assess the safety, efficacy, predictability, and refractive outcome of implanting Ophtec Artisan phakic intraocular lenses (pIOLs) in eyes with keratoconus. METHODS In this retrospective study, 18 eyes of 11 patients diagnosed with keratoconus who underwent toric or myopic pIOL implantation were followed for 1 year postoperatively. Mean patient age was 41+/-10.97 years (range: 23 to 64 years). Preoperative manifest refractive sphere was -4.64+/-2.74 diopters (D) (range: -9.75 to 0.00 D) and cylinder was -3.07+/-2.04 D (range: -7.75 to -0.50 D). Inclusion criteria were preoperative best spectacle-corrected visual acuity (BSCVA) of 0.30 or better and stable refraction (</=0.50-D change in manifest refraction spherical equivalent [MRSE] yearly). Refractive outcomes and endothelial cell counts were analyzed primarily for 6-month follow-up and when available for 1-year follow-up. RESULTS The mean postoperative MRSE was -0.46+/-0.60 D (range: -1.88 to 0.13 D). Twenty-two percent (4/18) of eyes had an uncorrected visual acuity (UCVA) of 1.0 or better and 94% (17/18) of eyes had a UCVA of 0.63 or better. Sixty-one percent (11/18) of eyes had an MRSE within +/-0.50 D of the intended correction and 72% (13/18) of eyes gained one or more lines of BSCVA and no eyes lost lines of BSCVA. Mean endothelial cell counts decreased by 23 cells/mm(2) at 6 months postoperatively. CONCLUSIONS The implantation of Artisan iris-fixated pIOLs in patients with stable keratoconus for correction of astigmatism and myopia is safe, predictable, and effective with minimal complications. Due to the progressive nature of keratoconus, proper patient counseling is necessary.
Journal of Refractive Surgery | 2013
Jan Venter; Rodney Blumenfeld; Steve Schallhorn; Martina Pelouskova
PURPOSE To report the outcomes of the correction of mixed astigmatism with non-penetrating femtosecond laser intrastromal astigmatic keratotomy in patients with previous refractive surgery. METHODS One hundred twelve eyes that had low mixed astigmatism after excimer laser surgery, refractive lens exchange, or phakic intraocular lens implantation underwent intrastromal astigmatic keratotomy using paired symmetrical non-penetrating intrastromal arcuate keratotomies created 60 μm from the surface to 80% depth at 7 mm diameter. Outcome measures included uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), subjective refraction, and keratometry. A coupling ratio was calculated to assess the change in spherical equivalent. Average follow-up was 7.6 ± 2.9 months. Patients were divided into two groups: no excimer laser corneal ablation and previous excimer laser surgery. Preoperative and postoperative data were compared between groups and analyses were performed on the whole group of eyes. RESULTS Overall, the mean UDVA improved significantly from 0.18 ± 0.14 to 0.02 ± 0.12 logMAR (6/9 to ≈6/6 Snellen) (P < .01). The mean absolute subjective cylinder decreased significantly from 1.20 ± 0.47 diopters (D) preoperatively to 0.55 ± 0.40 D postoperatively (P < .01). Subjective sphere decreased significantly from +0.61 ± 0.33 to +0.17 ± 0.36 D (P < 0.01). The mean CDVA was -0.03 ± 0.08 logMAR (≈ 6/6 Snellen) preoperatively and -0.05 ± 0.09 logMAR (≈ 6/5 Snellen) postoperatively (P = .06). The coupling ratio was 0.92 ± 0.45. There was no statistically significant difference in the preoperative and postoperative sphere, cylinder, UDVA, CDVA, and coupling ratio between groups. No surgical complications occurred. CONCLUSIONS Femtosecond laser intrastromal astigmatic keratotomy was effective at reducing refractive error in patients where other surgical options were exhausted. Predictability and efficacy could be improved with nomogram refinement.
Journal of Refractive Surgery | 2013
Steven C. Schallhorn; Mitch Brown; Jan Venter; David Teenan; Keith A Hettinger; Hiromi Yamamoto
PURPOSE To provide an initial retrospective evaluation of early postoperative outcomes after wavefront-guided myopic LASIK using a new-generation Hartmann-Shack wavefront sensor. METHODS A noncomparative, retrospective study of 243 eyes of 126 patients that underwent primary wavefront-guided LASIK, using wavefront data obtained with a new Hartmann-Shack aberrometer (iDesign Advanced WaveScan aberrometer; Abbott Medical Optics, Inc., Santa Ana, CA). Visual acuity, refraction, and patient satisfaction were evaluated 1 month after surgery. RESULTS The manifest spherical equivalent was reduced from -3.28 ± 1.79 diopters (D) (range: -9.88 to -0.38 D) before surgery to -0.03 ± 0.29 D (range: -1.00 to +1.25 D) 1 month after surgery. The manifest spherical equivalent was within 0.50 and 1.00 D of target in 93.0% and 99.6% of eyes, respectively. Manifest astigmatism preoperatively (-0.72 ± 0.67 [range: 0.0 to -5.00 D]) was reduced to -0.14 ± 0.20 (range: 0.0 to -1.00 D) at 1 month and the vector-derived correction ratio (surgically induced refractive change/intended refractive correction) was 1.02 ± 0.30. Uncorrected distance visual acuity of 20/16, 20/20, and 20/25 or better was achieved in 79.0%, 93.4%, and 96.7% of eyes, respectively. No eyes lost two or more lines of corrected distance visual acuity, whereas a gain of one or more lines was observed in 14.0%. Most patients (98.5%) reported that they were satisfied with the outcome of their procedure. CONCLUSIONS Wavefront-guided LASIK using the new aberrometer in this retrospective evaluation was effective, safe, and predictable in the early postoperative time period for the correction of myopia with high patient satisfaction.
Journal of Cataract and Refractive Surgery | 2013
Jan Venter; Martina Pelouskova
Purpose To evaluate the refractive outcomes and rotational stability after implantation of a multifocal toric intraocular lens (IOL) with a surface‐embedded near section. Setting Private center, London, United Kingdom. Design Case series. Methods This study evaluated eyes with more than 1.50 diopters (D) of preexisting corneal astigmatism. After phacoemulsification, Lentis Mplus toric IOLs were implanted in all cases. The main outcome measures were refraction, uncorrected (UDVA) and corrected (CDVA) distance visual acuities, uncorrected near visual acuity (UNVA), keratometry, and IOL position. Three‐month postoperative data are presented. Results The study enrolled 89 eyes (58 patients). The mean monocular postoperative UDVA and UNVA were 0.03 logMAR ± 0.11 (SD) and 0.17 ± 0.14 logMAR, respectively. The mean refractive cylinder decreased from 2.90 ± 1.31 D preoperatively to 0.50 ± 0.39 D postoperatively (P<.001). The mean difference between the planned axis of implantation and the actual axis postoperatively was 2.53 ± 2.27 degrees. Conclusion The multifocal toric IOL with a surface‐embedded near section effectively corrected preexisting corneal astigmatism. The IOL was stable in the capsular bag, there were no visually significant complications, and there was no significant rotation out to 3 months postoperatively. Financial Disclosure Neither author has a financial or proprietary interest in any material or method mentioned.
Journal of Refractive Surgery | 2014
Jan Venter; Dean Barclay; Martina Pelouskova; Claire E.L. Bull
PURPOSE To assess efficacy, safety, predictability, and patient satisfaction after refractive lens exchange with a new refractive rotational asymmetric multifocal intraocular lens. METHODS One hundred six eyes of 53 patients after bilateral refractive lens exchange with the SBL-3 lens (Lenstec, Inc., Christ Church, Barbados) implantation were evaluated. The mean preoperative refractive sphere was +1.06 ± 2.63 diopters (D) (range: -8.25 to +5.00 D) and the mean refractive cylinder was -0.51 ± 0.46 D (range: -2.00 to 0.00 D). Monocular and binocular uncorrected and corrected distance visual acuity, uncorrected and distance-corrected intermediate visual acuity, uncorrected and distance-corrected near visual acuity, defocus curve, and patient satisfaction were evaluated 3 months postoperatively. RESULTS At 3 months, 84.9% (90 eyes) were within ±0.50 D of emmetropia. The mean postoperative uncorrected distance visual acuity was -0.03 ± 0.09 logMAR (6/6 Snellen) monocularly and -0.08 ± 0.08 logMAR (6/4.8 Snellen) binocularly. The mean monocular and binocular uncorrected near visual acuity were 0.12 ± 0.12 and 0.08 ± 0.10 logMAR (6/7.5 Snellen), respectively. Defocus curve showed a slight drop off for vergences equivalent to intermediate vision. Although some night vision phenomena were reported, overall satisfaction was high. No intraoperative or postoperative complications occurred in this study. CONCLUSIONS The new refractive rotationally asymmetric intraocular lens provided good range of vision for near, intermediate, and distance. Long-term follow-ups are necessary to evaluate the performance of this intraocular lens.
Journal of Refractive Surgery | 2014
Steven C. Schallhorn; Mitch Brown; Jan Venter; Keith A Hettinger; Stephen J. Hannan
PURPOSE To determine the relationship between low-light pupil size and patient-reported outcomes 1 month after wavefront-guided LASIK in young patients with myopia. METHODS Retrospective case series of 10,944 eyes of 5,563 young patients with myopia who underwent wavefront-guided LASIK (6.0-mm optical zone). Preoperative pupil size was measured under low-light conditions with an infrared pupillometer. Visual and refractive outcomes were evaluated at 1 month postoperatively. A questionnaire was administered to assess patient-reported outcomes including satisfaction with the procedure, night driving, and glare and halo visual symptoms. RESULTS The average patient age was 29.8 years (range: 18 to 40 years). The mean preoperative manifest spherical equivalent of -3.49 diopters (D) (range: -0.50 to -11.75 D) was reduced to -0.04 ± 0.29 D at 1 month, with 94% of eyes achieving an uncorrected distance visual acuity of 20/20 or better. The mean low-light pupil diameter was 6.6 mm (range: 4 to 9 mm) and 1,514 patients (27.2%) had a diameter of 8 mm or larger. No correlation between pupil diameter and patient-reported outcomes was found (r range: -0.02 to 0.07). Logistic regression analysis identified postoperative uncorrected distance visual acuity and postoperative manifest refraction as significant predictors of night halo complaints after wavefront-guided LASIK (P < .01). CONCLUSIONS In this large series of young patients with myopia treated with wavefront-guided LASIK, low-light pupil diameter was not predictive of surgery satisfaction, ability to perform activities, or visual symptoms at 1 month postoperatively.
Journal of Cataract and Refractive Surgery | 2015
Jan Venter; Martina Pelouskova; Claire E.L. Bull; Steven C. Schallhorn; Stephen J. Hannan
Purpose To evaluate the efficacy, safety, predictability, and patient satisfaction after refractive lens exchange with a zonal refractive intraocular lens (IOL) with an inferior reading addition in emmetropic patients. Setting Optical Express, London, United Kingdom. Design Retrospective case series. Methods Emmetropic presbyopic patients who had implantation of a Lentis Mplus LS‐313 MF30 IOL were evaluated. Inclusion criteria were sphere between −0.50 diopter (D) and +1.00 D with no more than 0.75 D of refractive cylinder and an uncorrected distance visual acuity (UDVA) of 6/6 or better in each eye. The main outcome measures were monocular and binocular UDVA, uncorrected near visual acuity (UNVA), corrected distance visual acuity (CDVA), and patient satisfaction. Three months data are presented. Results Four hundred forty eyes of 220 patients were evaluated. The mean monocular UDVA changed from −0.04 logMAR ± 0.06 (SD) preoperatively to −0.04 ± 0.11 logMAR postoperatively (P = .39). The mean CDVA was −0.10 ± 0.05 logMAR preoperatively and −0.09 ± 0.06 logMAR postoperatively (P = .06). At 3 months, 99.7% of eyes were within ±1.00 D of emmetropia. The mean UNVA was 0.13 ± 0.14 logMAR monocularly and 0.10 ± 0.12 logMAR binocularly. On the patient satisfaction questionnaire, 91.9% of patients said the refractive procedure improved their lives and 93.5% were willing to recommend it to friends and family. Three patients requested IOL exchange because of severe night‐vision phenomena or unsatisfactory quality of vision. Conclusion Refractive lens exchange with this zonal refractive IOL was safe in emmetropic presbyopic patients. Financial Disclosure Dr. Schallhorn is a consultant to Abbott Medical Optics. No other author has a financial or proprietary interest in any material or method mentioned.
Clinical Ophthalmology | 2015
Steven C. Schallhorn; Jan Venter; Stephen J. Hannan; Keith A Hettinger
Purpose The purpose of this study was to evaluate the refractive and visual outcomes of wavefront-guided laser in situ keratomileusis (LASIK) in eyes with myopic astigmatism and cylindrical component ≥2.0 diopter (D). Methods In this retrospective study, 611 eyes that underwent LASIK for simple or compound myopic astigmatism were analyzed. Preoperative refractive cylinder ranged from −2.00 D to −6.00 D (mean −2.76±0.81 D), and the sphere was between 0.00 D and −9.75 D (mean −2.79±2.32 D). Predictability, visual outcomes, and vector analysis of changes in refractive astigmatism were evaluated. Results At 3 months after LASIK, 83.8% of eyes had uncorrected distance visual acuity of 20/20 or better, 90.3% had manifest spherical equivalent within ±0.50 D, and 79.1% had residual refractive cylinder within ±0.50 D of intended correction. The mean correction ratio for refractive cylinder was 0.92±0.14, the mean error of angle was −0.45°±2.99°, and the mean error vector was 0.37±0.38 D. A statistically significant correlation was found between the error of magnitude (arithmetic difference in the magnitudes between surgically induced refractive correction and intended refractive correction) and the intended refractive correction (r=0.26, P<0.01). Conclusion Wavefront-guided LASIK for the correction of myopic astigmatism is safe, effective, and predictable.
Journal of Refractive Surgery | 2009
Jan Venter
PURPOSE To compare refractive outcomes and higher order aberrations of eyes that underwent LASIK for myopia with astigmatism with or without active cyclotorsion error correction. METHODS This was a contralateral eye study of 48 eyes of 24 patients who underwent LASIK using the NIDEK Advanced Vision Excimer laser platform (NAVEX), treating one eye with active cyclotorsion error correction (TEC eyes) and the fellow eye without active cyclotorsion error correction (without TEC eyes). Postoperatively, the refractive outcomes, including postoperative astigmatism and higher order aberrations were compared between groups using the t test. A P value <.05 was considered statistically significant. Three-month postoperative outcomes are presented. RESULTS Preoperative manifest refraction spherical equivalent was -3.59+/-1.60 diopters (D) (range: -1.25 to -6.75 D) for the TEC group and -3.82+/-1.89 D (range: -1.38 to -8.63 D) for the without TEC group. No statistically significant differences were noted in postoperative visual acuity between groups (P>.05). The TEC eyes had statistically significant lower postoperative cylinder (0.28+/-0.27 D [range: 0 to -0.75 D] for the TEC group vs 0.49+/-0.30 D [range: 0 to -1.00 D] for the without TEC group; P=.02). A mean decrease in root-mean-square (RMS) of higher order aberration was noted in the TEC eyes, and a mean increase was noted in RMS of higher order aberration for the without TEC eyes at both 5- and 6-mm pupil diameters. The TEC eyes had statistically significantly lower RMS of higher order aberration (P<.01). CONCLUSIONS Active torsion error correction with the NIDEK NAVEX platform statistically significantly increases the predictability of astigmatism correction and reduces the induction of higher order aberrations of eyes undergoing LASIK.