AcrySof Toric Intraocular Lens Research Articles

Which Keratometer is Most Reliable for Correcting Astigmatism with Toric Intraocular Lenses?

PurposeTo evaluate the accuracy of preoperative keratometers used in cataract surgery with toric intraocular lens (IOL).MethodsTwenty-five eyes received an AcrySof toric IOL implantation. Four different keratometric methods, a manual keratometer, an IOL master, a Pentacam and an auto keratometer, were performed preoperatively in order to evaluate preexisting corneal astigmatism. Differences between the true residual astigmatism and the anticipated residual astigmatism (keratometric error) were compared at one and three months after surgery by using a separate vector analysis to identify the keratometric method that provided the highest accuracy for astigmatism control.ResultsThe mean keratomeric error was 0.52 diopters (0.17-1.17) for the manual keratometer, 0.62 (0-1.31) for the IOL master, 0.69 (0.08-1.92) for the Pentacam, and 0.59 (0.08-0.94) for the auto keratometer. The manual keratometer was the most accurate, although there was no significant difference between the keratometers (p > 0.05). All of the keratometers achieved an average keratometric error of less than one diopter.ConclusionsManual keratometry was the most accurate of the four methods evaluated, although the other techniques were equally satisfactory in determining corneal astigmatism.

AcrySof toric intraocular lens for post-keratoplasty astigmatism

We report a 63-year-old male who had undergone left eye optical penetrating keratoplasty for central leucomatous corneal opacity 10 years earlier. The eye had clear donor graft with residual astigmatism of –6.50 diopter cylinder (DC) at 30°. The patient underwent clear corneal phacoemulsification with implantation of +6.0 D spherical equivalent AcrySof SN60T9 intraocular lens (IOL). Postoperatively, at 10 months, the patient had distance corrected visual acuity of 20/30 with –2.00 DC at 20°. AcrySof toric IOL offers an effective treatment option for post-keratoplasty high corneal astigmatism in patients with cataract.

Results of the AcrySof Toric intraocular lenses implantation

SummaryBackgroundThe expectations of post-removal cataract surgery patients are extremely high, and best vision acuity is expected. The best refractive results are influenced by two factors – cataract surgical removal and the corneal astigmatism correction. Currently, the two most often applied corneal astigmatism removal methods are laser surgery and toric intraocular lens implantation, with the latter method being both more stable and more reversible. This study aimed to estimate the surgical astigmatism correction efficiency after AcrySof Toric intraocular lens implantation in patients with corneal astigmatism.Material/MethodsWe used the AcrySof Toric IOL 1-part hydrophobic acrylic lenses. The retrospective research covered 30 eyeballs in 28 cataract and corneal astigmatism patients, with the AcrySof Toric lens implanted by one surgeon.ResultsIn our test group 92.31% of post-surgical patients (phacoemulsification and toric lenses implantation) gained the best uncorrected visual acuity, range 0.6–1.0; and in 7.69% of patients the acuity was 0.4–0.6. Lens rotation was examined three weeks after the surgical procedure and a 3.24±3.41 degree axial displacement was observed; however, this lens rotation was clinically unimportant.Based on the analysis of post-surgical results, the corneal astigmatism was 84.2% lower than before the procedure.ConclusionsWe noticed clinically and statistically important vision acuity improvement in the corneal astigmatism patients. The patients’ high satisfaction was conditioned by proper pre-surgery qualification. Astigmatism correction by cataract removal surgery is a safe and effective surgical solution. In the future, we expect the use of toric intraocular lenses will become widespread and significant.

Rotational stability of a toric intraocular lens: Influence of axial length and alignment in the capsular bag

To evaluate the rotational stability of a toric intraocular lens (IOL) using purpose-designed software and to determine the influence of axial length (AL) and in-the-bag IOL alignment on IOL rotation. Iladevi Cataract & IOL Research Centre, Ahmedabad, India. Prospective observational case series. This study enrolled eyes that had AcrySof toric IOL implantation. The AL was measured using optical coherence biometry or immersion A-scan biometry. Corneal astigmatism was determined by manual keratometry and topography. The IOL alignment was vertical, horizontal, or oblique. Rotational stability was measured using the purpose-designed software, and the mean absolute difference was determined. The effect of AL and IOL alignment on rotational stability was determined 6 months postoperatively. The study evaluated 168 eyes (168 patients). The mean AL was 23.86 mm ± 1.63 (SD), (range 19.50 to 29.03 mm). The median IOL rotation was 0.3 degree from baseline to 1 week, 1.0 degree from 1 week to 1 month, 0.2 degree from 1 to 3 months, and 0.1 degree from 3 to 6 months. The maximum rotation occurred between 1 week and 1 month. There was a strong correlation between AL and IOL rotation at 6 months (r = 0.93, P<.001). The mean absolute difference at 6 months was not significantly different between the 3 axis placement categories when correlated with the rotation (P=.102, analysis of variance). Toric IOL rotation was greater in eyes with a longer AL. Alignment of the IOL in the capsular bag had no influence on rotation.

Refractive lens exchange using SN60T5 AcrySof Toric intraocular lens in stage 2 keratoconus

Relatamos o caso de uma senhora de 45 anos de idade, portadora de ceratocone grau 2 e consequente anisometropia, submetida à extração do cristalino transparente, e uso da lente intraocular modelo SN60T5 AcrySof Toric para o olho esquerdo. Facoemulsificação seguida pelo implante da lente intraocular tórica no olho esquerdo. No pós-operatório, resultados refracionais e visuais satisfatórios foram alcançados. O uso de lentes intraoculares tóricas pode se constituir em opção terapêutica para casos selecionados de ceratocone grau 2. Extração do cristalino [...]

Erratum: Combined 23-gauge microincisonal vitrectomy surgery and phacoemulsification with AcrySof toric intraocular lens implantation: a comparative study

Correction to: Eye (2011) 25, 1327–1332; doi:10.1038/eye.2011.168; published online 15 July 2011 Since the publication of the above article, the authors have noticed that the diopter (D) range given for spherical IOL correction in the third paragraph of the Patients and methods section was incorrect. The correct details are given below.

Surgical and refractive outcomes of cataract surgery with toric intraocular lens implantation at a resident-teaching institution

To evaluate the refractive and surgical outcomes of cataract surgery with toric intraocular lens (IOL) implantation performed at a teaching institution. Miami Veterans Affairs Medical Center, Miami, Florida, USA. Retrospective case series. All data were obtained by a retrospective chart review and entered into a standard computerized database for analysis. Main outcome measures included refractive and surgical outcomes after Acrysof toric IOL placement, including the deviation from the expected spherical and cylindrical correction and the incidence of ocular complications. The study comprised 94 eyes (80 patients). The mean deviation from the anticipated spherical correction (94 eyes) was +0.06 diopter (D) ± 0.8 (range -2.6 D to +3.6 D), with 80% of eyes achieving a spherical equivalent within ±1.00 D of the target refraction. The postoperative refractive cylinder was significantly reduced from baseline, with 79% of eyes having at least a 0.50 D improvement in astigmatism after surgery (P<.0005). The mean deviation from the anticipated refractive cylinder (85 eyes) was -0.48 ± 1.2 D (range -5.0 to +2.8 D). The IOL was placed in an incorrect position in 2 patients, requiring a reoperation with IOL rotation into the proper axis. The mean follow-up was 7 months (range 1 to 28 months). The added complexity associated with toric IOL placement resulted in spherical and astigmatic improvements without compromising patient safety beyond a level inherent in resident-based cataract surgery.

Phacoemulsification with corneal astigmatism correction with the use of a toric intraocular lens in a case of megalocornea

We report the case of a 49-year-old patient with megalocornea and coexisting corneal astigmatism. The corneal diameter in the right eye was 15.0 mm and in the left eye, 14.9 mm. In both eyes, a nuclear sclerotic cataract developed, with the tendency toward cortical mass swelling in the right eye. The aim of surgical treatment was to remove the cataract with simultaneous correction of corneal astigmatism by implanting an Acrysof toric intraocular lens (IOL). Intraocular lens stabilization was obtained by suturing it to an capsular tension ring (CTR) in the anterior chamber. The IOL-CTR complex was rotated into the lens capsule and aligned with the steep meridian of corneal astigmatism. The surgical technique provides a stable refractive and functional effect in patients with megalocornea and coexisting cataract and corneal astigmatism.

Combined 23-gauge microincisonal vitrectomy surgery and phacoemulsification with AcrySof toric intraocular lens implantation: a comparative study

To compare AcrySof toric intraocular lens (IOL) and non-toric IOL in patients who had combined 23-gauge microincisional vitrectomy surgery (MIVS) and phacoemulsification for vitreoretinal diseases and cataract with pre-existing corneal astigmatism. This is a prospective comparative study comprised of 30 patients (30 eyes) who had combined 23-gauge MIVS and phacoemulsification for vitreoretinal diseases and cataract with pre-existing regular corneal astigmatism greater than 1 diopters (D). In all, 15 eyes had AcrySof toric IOL (Alcon Laboratories) and 15 eyes had non-toric IOL (Akreos AO MI60; Bausch & Lomb) implantation. Main outcome measures were uncorrected visual acuity (UCVA), refractive cylinder, surgically induced astigmatism (SIA), and IOL misalignment during 6 months. The mean UCVA of the toric IOL group was better than the non-toric IOL group at postoperative months 1, 3, and 6 (P<0.001, respectively). The mean absolute residual refractive cylinder of the toric IOL group at postoperative week 1, and months 1, 3, and 6 was less than the non-toric IOL group (P=0.008, <0.001, <0.001, and <0.001, respectively). There was no difference in the mean SIA between the two groups (P>0.05, respectively). The mean toric IOL axis rotation was 3.52 ± 2.75°, which was within 5° in 66.7% of the toric IOL group and within 10° in 100%. Combined 23-gauge MIVS and phacoemulsification with AcrySof toric IOL implantation is an effective method of correcting vitreoretinal diseases and cataract and pre-existing corneal astigmatism, and the toric IOL showed good rotational stability, even in vitrectomized eyes for 6 months.

Results of higher power toric intraocular lens implantation

To evaluate the efficacy, predictability, and safety of coaxial microincision phacoemulsification and toric intraocular lens (IOL) implantation in eyes with high corneal astigmatism. Two eye clinics in Germany. Case series. Routine cataract extraction using 2.2 mm coaxial phaco equipment and Acrysof toric IOL (3.00 to 6.00 diopters [D] cylinder) implantation were performed. Examinations included optical biometry, Haigis IOL calculation, topography, and objective and subjective refractions. Retroillumination images were used to evaluate IOL alignment. Postoperative examinations were scheduled at 1 week and 3 months. The study enrolled 40 eyes (30 patients). The mean preoperative keratometric cylinder was 3.55 ± 0.73 D (range 2.64 to 5.39 D) and the mean 3-month postoperative subjective cylinder, 0.67 ± 0.32 D. The mean logMAR uncorrected distance visual acuity improved from 0.93 to 0.20 and the mean logMAR CDVA, from 0.41 to 0.09. The mean prediction error (spherical equivalent) was +0.14 ± 0.44 D. The mean IOL rotation between 1 week and 3 months was 0.23 ± 1.9 degrees clockwise. The mean surgically induced astigmatism was 0.08 ± 0.41 D. The alignment error was below 10 degrees in 97.5% of cases. The mean vector change in refractive cylinder between 1 week and 3 months was 0.31 ± 0.19 D. The Alpins correction index was +1.01, indicating a slight tendency toward overcorrection. Coaxial microincision phacoemulsification with toric IOL safely and predictably reduced high corneal astigmatism and improved surgical outcomes. Thorough planning and precise execution are necessary.

Vector analysis of astigmatic changes after cataract surgery with toric intraocular lens implantation

To analyze the astigmatic changes after cataract surgery with toric intraocular lens (IOL) implantation and determine the relationship between these changes and the final visual outcomes. Vissum-Instituto de Oftalmológico de Alicante, Alicante, Spain. Prospective case series. This study comprised eyes with visually significant cataract that had surgery with Acrysof toric IOL implantation. Refractive, corneal topography, internal astigmatism, and contrast sensitivity outcomes were evaluated over 6 months. The Alpins vectorial method was used to analyze the target (TIA) and surgically (SIA) induced astigmatism, difference vector, magnitude of error, flattening effect, and torque. The study enrolled 27 eyes (21 patients). Postoperatively, there was a significant reduction in refractive cylinder (P < .01) with an associated visual improvement (P < .01). The magnitude of the SIA vector was significantly lower than the TIA 1 month and 6 months after surgery (P < .01). The mean magnitude of the difference vector was 0.91 diopter (D) ± 0.45 (SD) at 6 months, with no significant differences between postoperative visits (p > 0.19). The mean magnitude of torque vector was 0.59 ± 0.42 D at 6 months. There was a significant negative correlation between refractive cylinder and the magnitude of torque (r ≤ -0.54, P < .01) and the difference vector (r = -0.98, P < .01). The toric IOL restored distance visual function in eyes with cataract and significant corneal astigmatism, although there was a small trend toward undercorrection related to misalignment of treatment. No author has a financial or proprietary interest in any material or method mentioned.

Distance vision after bilateral implantation of AcrySof toric intraocular lenses: a randomized, controlled, prospective trial.

To evaluate the distance vision of Chinese patients with cataracts and corneal astigmatism after implantation of bilateral AcrySof toric intraocular lens (IOL) versus bilateral AcrySof spherical IOL. This study randomized 60 patients into equal groups to receive toric IOL or spherical IOL. IOL powers targeting emmetropia were selected for 93% of toric IOL patients and for 90% of spherical IOL patients. Assessments included monocular and binocular distance vision, with and without best correction. Patients also completed surveys about their distance vision. Preoperatively, the two study groups were similar in age, in distance visual acuity, and in the magnitude of corneal astigmatism. At 6 months postoperative, binocular uncorrected distance vision was 0.06±0.14 logMAR in the AcrySof toric IOL group, significantly better than the 0.14±0.11 logMAR in the spherical IOL group (P<0.05). For eyes with emmetropia as a target, the equivalent of 20/20 uncorrected vision was more likely (P<0.001) in the toric IOL group (36% of eyes) than in the spherical IOL group (4% of eyes). No patients in the emmetropia/toric IOL group used distance glasses, as compared to 52% of patients in the emmetropia/spherical IOL group. All patients were satisfied or highly satisfied. Quality of distance vision was rated higher by toric IOL patients than by spherical IOL patients (P<0.05). Bilateral AcrySof toric IOL is superior to bilateral spherical IOL in providing uncorrected distance vision to cataract patients with corneal astigmatism.

Functional and refractive results after one month of AcrySof toric intraocular lens implantation

Purpose To describe the functional and refractive results obtained with the implantation of toric intraocular lens (IOL) in a private clinic, and verify and compare these results with other similar studies. Methods Retrospective evaluation of patients implanted with SN60AT toric IOL. Patients undergoing cataract surgery and corneal astigmatism (CA) higher than 0.75 D were included in the study. Preoperative and postoperative uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), subjective refraction and preoperative keratometry were recorded and analyzed statistically. Results The study included 68 eyes (52 patients). Thirty eyes were implanted with SN60T3, 11 with SN60T4 and 28 with SN60T5. Mean BCVA gain was of 1.9 ± 1.67 logMAR lines. Comparing the preoperative BCVA versus postoperative UCVA, the improvement was of 0.89 ± 2 logMAR lines. The postoperative refractive astigmatism was −0.37 ± 0.37 D; 75.5% of the eyes had a refractive astigmatism lower than 0.50 D and 98.6% lower than 1.00 D. The expected cylinder supplied by the manufacturer showed a good agreement with the postoperative subjective results (−0.03 ± 0.47 D). Conclusions The implantation of SN60T toric IOL in patients with CA higher than 0.75 D is a safe, predictable and effective way of reducing refractive astigmatism in patients undergoing cataract surgery.

In vivo Assessment of Higher-Order Aberrations after Acrysof Toric Intraocular Lens Implantation: A Comparative Study

To compare higher-order aberrations (HOAs) and optical quality in eyes implanted with AcrySof SN60TT toric intraocular lens (IOL) or with non-toric AcrySof SN60AT IOL (Alcon Laboratories, Inc., Fort Worth, TX). This was a prospective, consecutive, nonrandomized, interventional, comparative study. One hundred eyes with cataract in 56 patients were included (SN60TT group, n=50; SN60AT group, n=50). Patients underwent phacoemulsification through a 2.2-mm temporal corneal incision. Postoperative HOAs, point spread function (PSF) and modulation transfer function (MTF), residual objective refractive astigmatism, and IOL alignment were evaluated using Optical Path Difference (OPD)-Scan II (Nidek, Gamagori, Japan). A novel technique to calculate IOL axis alignment was introduced. One year postoperatively, no statistical difference in corneal, intraocular, and total HOAs, Strehl ratio, and MTF based on HOAs was found between groups. Toric IOL patients had a net residual refractive astigmatism (M) of 0.44 D±0.47; the difference between expected and obtained astigmatism (M) was 0.043 D (p=0.16). Toric IOL axis misalignment was 2.65±2.39 degrees and no correlation with HOAs was found. AcrySof SN60TT determines HOAs comparable to the non-toric version providing a good optical quality, and predictably corrects corneal cylinder with a stable postoperative alignment. The OPD-Scan II might be regarded as a fast and reliable method of toric IOL analysis.

The AcrySof Toric Intraocular Lens in Subjects with Cataracts and Corneal Astigmatism: A Randomized, Subject-Masked, Parallel-Group, 1-Year Study

To compare the AcrySof Toric intraocular lens (IOL) and an AcrySof spherical control IOL and to investigate rotational stability of the AcrySof Toric IOL (Alcon Laboratories, Inc., Fort Worth, TX) in subjects with cataracts and preexisting corneal astigmatism. Randomized, subject-masked, parallel-group, multicenter, 1-year study. We included 517 subjects (Toric IOL, n = 256; control IOL, n = 261). Unilateral implantation of an AcrySof Toric or AcrySof spherical control IOL (spherical powers, 12.00-25.00 diopters [D]; cylinder powers 1.50, 2.25, or 3.00 D for corneal astigmatism correction of 0.75 to < 1.50, ≥ 1.50 to <2.00, and ≥ 2.00 D with no upper limit, respectively). No limbal relaxing incisions were permitted. Visual acuity outcomes, IOL position, patient-reported spectacle use, and safety. One year postoperatively, best spectacle-corrected distance visual acuity of ≥ 20/20 was 77.7% (Toric IOL) versus 69.2% (control IOL). Uncorrected distance visual acuity of 20/20 or better was 40.7% (Toric IOL) versus 19.4% (control IOL; P<0.05). Mean absolute residual refractive cylinder was 0.59 D (Toric IOL) versus 1.22 D (control IOL; P<0.0001). Mean rotation was < 4° (range, 0°-20°) for the Toric IOL. Six-month spectacle freedom was 61.0% (Toric IOL) and 36.4% (control IOL; P < 0.0001). Complications in both groups were few and were as would be expected with cataract surgery. Favorable efficacy, rotational stability, distance vision spectacle freedom, and safety results support the use of the AcrySof Toric IOL for patients with cataracts and corneal astigmatism. Proprietary or commercial disclosure may be found after the references.

Short-term observation of Acrysof Toric intraocular lens for correction of preoperative astigmatism in patients having cataract surgery

To evaluate the results of Toric intraocular lens (IOL) for correction of preoperative astigmatism in patients having cataract phacoemulsification. It was a prospective case series study. Seventy-one eyes (60 patients) had implantation of Acrysof Toric IOL. logMAR uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), preexisting corneal astigmatism, residual refractive sphere and cylinder, and toric IOL axis were measured. Four residual astigmatism models were compared according to their axis postoperatively: neutral, against-the-rule (ATR, 180 ± 15 degrees), with-the-rule (WTR, 90 ± 15 degrees) and oblique (OB, 45/135 ± 30 degrees). Rank sum test and Friedman test was used to analyze these data. Three months postoperatively, the median distant UCVA increased significantly from 0.80 to 0.20, residual refractive astigmatism decreased significantly from 2.02 D to 0.67 D. The mean Toric IOL axis rotation was 1.63 ± 1.83 degrees, with rotation less than 5.00 degrees in 96% of eyes. For uncorrected near visual acuity, group ATR fared the best results and the difference between group ATR and groups WTR, neutral and OB was statistically significant. For UCVA, there was no statistically significant difference between group ATR and groups neutral and OB. Acrysof Toric IOL implantation is a predictable, safe and effective method to correct preexisting corneal astigmatism in patients having cataract phacoemulsification. A pseudophakic eye after Acrysof Toric IOL implantation with low residual ATR myopic astigmatism is beneficial for obtaining a better uncorrected near and distant visual acuities.

Clinical Outcomes of Complex and Uncomplicated Cataractous Eyes After Lens Replacement with the AcrySof Toric IOL

to compare outcomes for uncomplicated versus complex eyes after implantation of AcrySof toric intraocular lenses (IOLs) (Alcon Laboratories Inc) in a retrospective series of cataractous astigmatic eyes. toric IOLs were implanted in 230 eyes of 162 adult patients. Approximately half (52%, n=120) the eyes had no complications (uncomplicated group). The other 110 (48%) eyes (complex group) had a variety of complexities, including retinal or macular problems (eg, age-related macular degeneration), angle or pressure problems (eg, glaucoma), or high astigmatism that required adjunctive limbal relaxing incisions (LRIs). Outcomes were retrospectively assessed approximately 6 weeks after surgery. preoperative corneal astigmatism was 1.60 ± 1.20 diopters (D) overall (1.40 ± 0.70 D in the uncomplicated group and 1.90 ± 1.60 D in the complex group). Residual cylinder was 0.40 ± 0.60 D overall (P<.01 compared to baseline) and was significantly lower (P<.01) for the uncomplicated group (0.30 ± 0.40 D) than for the complex group (0.50 ± 0.80 D), which contained the adjunctive LRI subgroup (residual cylinder 0.80 ± 0.70 D). A larger percentage of uncomplicated eyes (26%) than complex eyes (16%) had at least 20/20 uncorrected distance visual acuity (UDVA) (P=.05). Excluding eyes with intentionally targeted myopic postoperative spherical equivalent, no eyes lost Snellen lines of UDVA, and the average improvement in UDVA was 0.8 ± 0.6 logMAR. Corrected distance visual acuity of the retinal/macular subgroup was poorer than the uncomplicated group pre- and postoperatively but was significantly improved by the surgery (P<.001; average improvement approximately 3 Snellen lines). AcrySof toric IOLs reduced cylinder and improved UDVA in both complex and uncomplicated eyes with cataractous astigmatism.

Visual function and patient experience after bilateral implantation of toric intraocular lenses

To evaluate the efficacy, stability, predictability, and patient-reported outcomes of bilateral toric intraocular lens (IOL) implantation in cases of cataract with preexisting astigmatism. Fourteen universities, hospitals, or private practices, Canada. Patients with cataracts and corneal astigmatism from 1.00 to 2.50 diopters (D) were included in a prospective study of bilateral AcrySof toric IOL implantation. Binocular uncorrected distance visual acuity (UDVA), manifest refraction, and IOL rotational stability were assessed 1 day and 1, 3, and 6 months postoperatively. Patients completed a questionnaire that assessed spectacle independence, visual disturbances, and satisfaction with vision (1 = completely unsatisfied; 10 = completely satisfied) preoperatively and 3 and 6 months postoperatively. The study included 117 patients (234 eyes). The binocular UDVA was 20/40 or better in 99% of patients and 20/20 or better in 63% of patients. The mean residual refractive astigmatism was 0.4 D +/- 0.4 (SD). The spherical equivalent was within +/-0.5 D of target in 77% of eyes. At last observation, IOL alignment was within +/-5 degrees in 91% of eyes and within +/-10 degrees in 99%. Sixty-nine percent of patients reported never using distance spectacles. The frequency and severity of halos and glare were significantly reduced from preoperatively to postoperatively. Satisfaction with vision was rated 7 or higher by 94% of patients. Bilateral implantation of toric IOLs yielded excellent and stable visual outcomes that patients rated as highly satisfactory. No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

Comparison of clear corneal on-axis and temporal incisions for Acrysof Toric intraocular lens implantation

To investigate whether there are some differences in the accuracy of Acrysof Toric intraocular lens (IOL) implantation and the ability to correct astigmatism between 2 types of clear corneal incisions used in phacoemulsification: the on-axis (i.e on the steeper corneal meridian) and the temporal clear corneal incision (OCCI and TCCI, respectively). In this prospective study, thirty-nine eyes with cataract and mild to moderate corneal astigmatism (1.00 - 2.26 diopters on corneal curvature) were recruited and divided into OCCI group (20 eyes) and TCCI group (19 eyes) respectively. All of these patients underwent phacoemulsification and an Acrysof Toric IOL implantation (single surgeon, 3.2 mm incision). Main outcome measurements included uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), corneal curvature, surgically induced astigmatism (SIA), deviation of lens axis (LAD), index of corrected astigmatism (CAI) and accuracy of astigmatism correction (ACA) at 3 months postoperatively. At 3 months postoperatively, simple algebraic difference showed a mean increase in the astigmatism magnitude of (0.28 + or - 0.27) D in the TCCI group and a mean reduction in the astigmatism magnitude of (0.31 + or - 0.26) D in the OCCI group (t = 5.756, F = 0.000). The average LAD was 0 degrees + or - 0 degrees in the OCCI group and 2.22 degrees + or - 2.99 degrees in the TCCI group(t = 3.860, P = 0.000). The average CAI were 1.04 + or - 0.27 and 0.59 + or - 0.44 respectively (t = 3.187, P = 0.004). The ACA were 0.838 and 0.484 respectively (Z = 1.970, P = 0.049). Compared with the TCCI, the OCCI could correct some corneal astigmatism and reduce IAD induced by the SIA shift. As a result, the OCCI could improve the accuracy of Acrysof Toric lens implantation and the ability to correct astigmatism.

Assessment of toric intraocular lens alignment by a refractive power/corneal analyzer system and slitlamp observation

To assess the validity of an internal optical path difference map of a refractive power/corneal analyzer system in determining the alignment of toric intraocular lenses (IOLs). Private practices, Spring Hill, Brisbane, and Chermside, Australia. This retrospective study comprised patients with more than 1.5 diopters of preexisting corneal astigmatism who had phacoemulsification and AcrySof toric IOL implantation. Preoperatively, the surgical eye was marked at the slitlamp microscope using a 4-point technique. The desired IOL orientation was marked with a Mendez marker based on the steep corneal axis. The toric IOL axis was measured 3 weeks postoperatively by rotating the slitlamp beam to align with the IOL axis indicator marks and using the Internal OPD Map on the Nidek OPD-Scan system. Uncorrected (UDVA) and corrected (CDVA) distance visual acuities, residual refractive sphere, and residual keratometric and refractive cylinders were also measured at 3 weeks. Postoperatively, the mean UDVA was 0.17 logMAR +/- 0.18 (SD) and the mean CDVA, -0.01 +/- 0.12 logMAR; 88.2% of eyes had a UDVA of 0.3 or better, and no eye lost lines of visual acuity. There was an 82.33% reduction in defocus equivalent and a 64.62% reduction in refractive cylinder. The mean IOL misalignment measured by slitlamp was 2.55 +/- 2.76 degrees and by the internal map, 2.65 +/- 1.98 degrees. The correlation between the 2 methods was highly significant (r = 0.99, P<.001). Both refractive power/corneal analyzer system and slitlamp observation were reliable and predictable methods of assessing IOL alignment. The 4-point preoperative marking technique yielded clinically acceptable, accurate toric IOL alignment.