James A. Davison

Bio: James A. Davison is an academic researcher from University of Utah. The author has contributed to research in topics: Intraocular lens & Intraocular pressure. The author has an hindex of 4, co-authored 4 publications receiving 400 citations.

History and development of the apodized diffractive intraocular lens.

Abstract: The ReSTOR intraocular lens presents a unique apodized diffractive design within a refractive foldable acrylic optic, which makes an unprecedented level of mulifocal optical performance available. We describe the history and principles of diffractive optics used in the development of this refractive-diffractive IOL.

Clinical performance of Alcon SA30AL and SA60AT single-piece acrylic intraocular lenses.

Abstract: Purpose: To report the clinical performance characteristics of single-piece acrylic Alcon SA30AL and SA60AT intraocular lenses (IOLs). Setting: A private practice in Marshalltown, Iowa, USA. Methods: In a review of 2630 consecutive cases operated on from January 2000 through July 2001, ease of IOL insertion and integrity of the haptic architecture were evaluated in a prospective fashion at implantation. Subgroups of cases were studied prospectively to evaluate 3 factors: same-day incision competence after implantation (postoperative intraoperative pressure [IOP], 107 cases); 2- to 5-week A-constant validation (200 cases); 1-day, 2-week, and 1- and 5-month descriptions of optic centration with respect to pupil and capsule anatomy (79 cases); and a 1-day versus 9-month photographic comparison of IOL centration (70 cases). A retrospective evaluation of the population’s diagnostic codes tabulated complications including increased postoperative iritis, cystoid macular edema, neodymium:YAG (Nd:YAG) laser intervention for posterior capsule opacification, and pseudophakic dysphotopsia. A retrospective review of a subgroup of 140 consecutive cases was done to categorize postoperative optic clarity. Results: Overall, the IOLs were easy to implant with no haptic or optic damage using a forceps or the Monarch® injector. Subgroup studies confirmed good performance in the following parameters: There were no cases of incision incompetence evidenced by an abnormally low postoperative IOP. The lowest postoperative IOP was 6 mm Hg, with the overall mean IOP increasing to 29 mm Hg from the 17 mm Hg measured a mean of 102 minutes after surgery. The manufacturer’s published A-constant was almost identical to that obtained in review (118.4 versus 118.38 for the SA30AL and 118.35 for the SA60AT). In verbal descriptions, IOL optic centration was assessed to be within 0.4 mm of perfect in 75 (95%) of 79 cases. Slitlamp photographs showed that 52 (98%) of 53 IOLs were in the same position 9 months after surgery as on the day of surgery. One IOL optic appeared to rotate 14 degrees. There were no cases of decentration greater than 1.0 mm in either optic centration subgroup. Given a normal postoperative topical steroid regimen, there were no cases of substantially increased or prolonged iritis. There were 17 cases (0.65%) of macular edema. An Nd:YAG laser posterior capsulotomy was performed in 0.64% (13/2044) in the SA30AL group over a mean of 9 months (range 2 to 23 months) and in 0.34% (2/586) in the SA60AL group over a mean of 5.5 months (range 5 to 6 months). Pseudophakic dysphotopsia was diagnosed in 26 eyes of 18 patients (1% of 2630 cases), with 1 patient requiring an IOL exchange. Optic glistenings were observed in 11 (11%) of 100 SA30AL cases at a mean follow-up of 8 months. No glistenings in 40 cases were seen in the SA60AT group at a mean follow-up of 3 months. Conclusions: The single-piece acrylic lenses performed well in all regards. Although not as intense as observed with the earlier 3-piece designs, pseudophakic dysphotopsia occurred in a few patients with the single-piece acrylic lens. Intraocular lens exchanges with single-piece IOLs may be accomplished with less difficulty early rather than late.

Cumulative tip travel and implied followability of longitudinal and torsional phacoemulsification

Abstract: Purpose To compare surgeon-generated tip travel and surgical time of longitudinal and torsional phacoemulsification with straight and angled tips. Setting Private practice, Marshalltown, Iowa, USA. Method The study analyzed surgical videos of 46 phacoemulsification cases performed by 1 surgeon. Based on the tip and type of ultrasound (US) used, the cases were prospectively assigned to 1 of 4 groups and operated on consecutively: straight tip/longitudinal US, straight tip/torsional US, angled tip/longitudinal US, and angled tip/torsional US. Digital Video Measurement System software (Caltex Scientific) was used to measure the phacoemulsification tip's travel during the removal of all 4 nuclear quadrants and the removal of quadrants 2 and 3 (2+3) and to determine surgical time. The cumulative travel distance and surgical time of the 4 groups were compared using analysis of variance. Results The angled tip/torsional US combination reduced tip travel by more than 40% compared with the straight tip/longitudinal US when comparing travel to aspirate all 4 quadrants and quadrants 2+3. Surgical time in the removal of all 4 quadrants and quadrants 2+3 was significantly lower in the angled tip/torsional US group than in the other groups. Conclusions Torsional phacoemulsification using an angled tip required less surgeon-generated tip travel and less time, suggesting that nuclear material may be more efficiently approximated to and aspirated through the tip aperture throughout the phacoemulsification process. Shorter cumulative tip travel and less procedure time imply increased nuclear followability, fewer reacquisition movements, and increased phacoemulsification efficiency and safety.

Ultrasonic power reduction during phacoemulsification using adjunctive NeoSoniX technology.

Abstract: Purpose To compare the phacoemulsification times and powers used in 3 phacoemulsification machine configurations. Setting Wolfe Eye Clinic, Marshalltown, Iowa, USA. Methods A randomized prospective study of 410 consecutive cases was conducted. All cases were performed using the Alcon Legacy 20000 phacoemulsification machine. Configurations were the Standard Legacy 20000 machine (n = 165), Advantec upgraded Legacy 20000 (n = 112), and Advantec upgraded Legacy 20000 with NeoSoniX (n = 133). Preoperative measurements included the patient's age and cataract grade using the nuclear color (NC) scale of the Lens Opacities Classification System III (LOCS III). Intraoperative measurements included machine-measured phacoemulsification time and average percentage of maximum power expenditure. An independent statistician performed analysis of covariance on NC for each of the machine configurations. Results The mean age in years and the NC value were similar in each group. There was no significant difference in phacoemulsification time in minutes among the 3 machines: Standard = 1.17, Advantec = 1.12, NeoSoniX = 1.16. The average percentage of maximum power consumption was similar for Standard Legacy 20000 at 38.00% and Advantec Legacy 20000 at 37.97% but significantly less for Advantec Legacy 20000 with NeoSoniX at 27.56% (P Conclusions The addition of 15% amplitude NeoSoniX rotational energy reduced total ultrasonic power expenditure by 27.5% for all cataract nuclear densities.

Multifocal intraocular lenses in cataract surgery: literature review of benefits and side effects.

Abstract: This literature review looks at the current status of multifocal intraocular lenses (IOLs) in cataract surgery. The results of implantation of multifocal IOLs of diffractive, refractive, and hybrid diffractive–refractive design are described with regard to uncorrected near and distance visual acuity and spectacle independence. The occurrence of photic phenomena and contrast sensitivity loss with multifocal IOLs are also addressed. Financial Disclosure Neither author has a financial or proprietary interest in any material or method mentioned.

Design and qualification of a diffractive trifocal optical profile for intraocular lenses

Abstract: PURPOSE: To theoretically and experimentally assess a new aspheric diffractive trifocal intraocular lens (IOL). SETTING: Centre Spatial de LiLiBelgium. DESIGN: Evaluation of diagnostic test or technology. METHODS: The theoretical profile of the IOL was designed using software simulation and validated by optical calculation software tools that enabled complete theoretical characterization. These data resulted in a new aspheric diffractive trifocal IOL. The IOL theoretically allows improved intermedi- ate vision without impairing near and far vision and favors distance vision in mesopic conditions without increasing halos or glare perception under dim light or large pupil conditions. The theoret- ical findings were compared with those of in vitro testing on the optical bench. RESULTS: There was good agreement between the theoretical profile and achieved IOL profile. The simulated and achieved light distribution and focus distribution showed good concordance. The FineVision aspheric trifocal IOL provided intermediate addition at 1.75 diopters. CONCLUSION: The combination of 2 diffractive profiles to achieve far, intermediate, and near correction is validated. Further clinical investigations are required to validate these principles. Financial Disclosure: Dr. Houbrechts has no financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes. J Cataract Refract Surg 2011; 37:2060-2067 Q 2011 ASCRS and ESCRS

A Comparative Evaluation of a New Generation of Diffractive Trifocal and Extended Depth of Focus Intraocular Lenses

Abstract: Purpose To evaluate and compare the performance of two diffractive trifocal and one extended depth of focus (EDOF) intraocular lenses (IOLs). Methods In this 6-month, single-center, prospective, randomized, comparative study, patients undergoing routine cataract surgery were randomized to receive one of two trifocal IOLs (AcrySof IQ PanOptix; Alcon Laboratories, Inc., Fort Worth, TX, or FineVision Micro F; PhysIOL SA, Liege, Belgium) or an EDOF IOL (TECNIS Symfony; Abbott Medical Optics, Inc., Abbott Park, IL). There were 20 patients in each group. The primary outcome was binocular and monocular uncorrected distance (UDVA), intermediate (UIVA), and near (UNVA) visual acuity. The secondary outcomes were quality of vision and aberrometry. Results There was no statistically significant difference between groups in either monocular (P = .717) or binocular (P = .837) UDVA. Monocular and binocular UNVA were statistically and significantly better for both trifocal lenses than for the EDOF IOL (P = .002). The percentage of patients with J2 UNVA was 52.5% monocularly and 70% binocularly for the TECNIS Symfony IOL, 81.5% monocularly and 100% binocularly for the AcrySof IQ PanOptix IOL, and 82.5% monocularly and 95% binocularly for the FineVision Micro F IOL. There was no significant difference in binocular UIVA between groups; VA was better than 0.6 in 55%, 53%, and 35% of patients with the TECNIS Symfony, AcrySof IQ Pan-Optix, and FineVision Micro F IOLs, respectively. Overall, 90% patients achieved spectacle independence. There were no differences in visual symptoms and aberrometry among groups. Conclusions All three IOLs provided good visual acuity at all distances, a high percentage of spectacle independence, and little or no impact of visual symptoms on the patients' daily functioning. Near vision was statistically better for both trifocal IOLs compared to the EDOF IOL. [J Refract Surg. 2018;34(8):507-514.].

Prospective visual evaluation of apodized diffractive intraocular lenses.

Abstract: Purpose To evaluate distance, intermediate, and near visual performance in patients who had multifocal apodized diffractive intraocular lens (IOL) implantation. Setting Fernandez-Vega Ophthalmological Institute, Oviedo, Spain. Methods The best corrected distance visual acuity, best distance-corrected near visual acuity, intermediate visual acuity, distance contrast sensitivity under photopic and mesopic conditions, and patient satisfaction were measured in 325 patients and 335 patients who had bilateral implantation of the model SA60D3 IOL (AcrySof ReSTOR, Alcon) and model SN60D3 IOL (AcrySof Natural ReSTOR), respectively. Results At the 6-month postoperative visit, binocular best corrected distance acuity with the ReSTOR IOL and the Natural ReSTOR IOL was 0.034 logMAR ± 0.004 (SD) and 0.019 ± 0.020 logMAR, respectively (∼20/20). Binocular best distance-corrected near acuity was 0.011 ± 0.012 logMAR and 0.035 ± 0.013 logMAR, respectively (∼20/20). Intermediate visual acuity with both IOL models worsened significantly as a function of the distance of the test ( P P >.1). A patient satisfaction questionnaire showed that both IOLs performed well and were comparable in satisfaction regarding distance, intermediate, and near activities under different lighting conditions. Conclusions The AcrySof ReSTOR IOL and AcrySof Natural ReSTOR IOL provided good visual performance at distance and near under photopic and mesopic conditions. Intermediate vision with both models was reduced compared with distance and near vision.