Injectable 1-piece hydrophilic acrylic toric intraocular lens for cataract surgery: Efficacy and stability

Toric intraocular lens: A literature review

Toric intraocular lenses (IOLs) are universally recommended in cataract cases with preoperative corneal astigmatism ≥1.5 D. An optimal surgical outcome depends on careful patient selection, complete preoperative evaluation, accurate IOL power calculation, precise marking of the axis, meticulous intraoperative approach, and methodical postoperative care. Understanding the importance of posterior corneal astigmatism, surgically induced astigmatism, and effective lens position in IOL power calculation and newer techniques to measure them directly have resulted in better postoperative refractive outcomes. We present a brief overview of toric IOLs along with the preoperative evaluation, IOL power calculation, different marking methods, intraoperative approach, and postoperative outcomes. Functional and anatomical outcomes, including uncorrected visual acuity, residual refractive astigmatism, and postoperative IOL misalignment, which have been reported for both toric IOLs and multifocal toric IOLs, are reviewed.

Comparison of clinical outcomes of Eyecryl toric and Alcon toric intra-ocular lenses - A real world study

Purpose

To compare the visual outcomes and residual astigmatism following implantation of Eyecryl toric versus Alcon AcrySof IQ toric intra-ocular lenses (IOLs).

Methods

This retrospective, observational study included 143 eyes of 141 patients who underwent phaco-emulsification, followed by implantation of Eyecryl toric IOL (n = 83 eyes) or Alcon toric IOL (n = 60 eyes) in an eye hospital in South India from 2018 to 2021. At 1 month post-op, the uncorrected distance visual acuity (UCVA), best corrected distance visual acuity (BCVA), and residual astigmatism of the toric IOL were compared and analyzed.

Results

The mean pre-op corneal astigmatism was 2.02 ± 0.81 D and 1.70 ± 0.68 D in the Alcon and Eyecryl groups, respectively (P = 0.005). The mean post-op corneal astigmatism at 1 month was 0.50 ± 0.51 D and 0.36 ± 0.42 D in the Alcon and Eyecryl groups, respectively, with no statistically significant difference between them (P = 0.87). The mean post-op UCVA in logarithm of minimum angle of resolution (logMAR) at 1 month was similar between the groups at 0.17 ± 0.18 and 0.17 ± 0.16 in the Alcon and Eyecryl groups, respectively (P = 0.98). The mean post-op BCVA in logMAR at 1 month was 0.06 ± 0.09 and 0.03 ± 0.10 in the Alcon and Eyecryl groups, respectively (P = 0.02).

Conclusion

Both Eyecryl toric and Alcon AcrySof IQ toric IOLs showed comparable post-operative outcomes in terms of UCVA and residual astigmatism. The post-op BCVA was clinically similar between groups but statistically better in the Eyecryl toric group.

Impact of Material and Lens Design on Repositioning Surgery of Toric Intraocular Lenses: A Single-Arm Meta-Analysis

Aim

To analyze the pooled incidence rate in repositioning surgery by considering different materials and designs.

Methods

All published studies investigating the repositioning surgery of toric intraocular lenses (IOLs) before September 1, 2020, were searched and evaluated. The R3.5.2 software was used to extract the data, and a single arm meta-analysis was performed.

Results

19 cases from 18 published studies articles were included in the meta-analysis. The pooled incidence rate in repositioning surgery was 2% (I² = 53%, P_{heterogeneity}<0.01). Plate and silicone IOLs had significantly higher incidence rates (6% for each) than loop (2%) and hydrophobic acrylate (2%). Incidence rates of Acrysof, Staar, TECNIS, PhysIOL SA, T-flex 623T, and Microsil 6116TU groups were 1% (95% CI [1%–2%]), 6% (95% CI [4%–9%]), 3% (95% CI [2%–4%]), 1.40% (1/71), 3.03% (1/33), and 4.76% (1/21), respectively.

Conclusions

The pooled incidence rate of repositioning surgery in IOLs was 2%. Materials and designs would be risk factors for the rotational stability of the toric IOLs. Pooled incidence rates of the hydrophobic acrylate and loop group were lower than those of the silicone and plate group. Product identity is the main driver of heterogeneity.

Refractive outcomes of femtosecond laser-assisted cataract surgery with arcuate keratotomy and standard phacoemulsification with toric intraocular lens implantation

PURPOSE

Femtosecond laser arcuate keratotomy (FS-AK) and toric intraocular lens (IOL) implantation are effective for the correction of eyes with corneal astigmatism. In this study, the postoperative refractive outcomes of patients receiving femtosecond laser-assisted cataract surgery (FLACS) with FS-AK and patients receiving standard phacoemulsification with toric IOL implantation were evaluated.

METHODS

This retrospective study reviewed the postoperative outcomes of patients undergoing FLACS with FS-AK (the FS-AK group) and patients undergoing standard phacoemulsification with toric IOL implantation (the toric IOL group). The main outcome measures were uncorrected and corrected visual acuities, keratometric and refractive astigmatism, and vector analysis.

RESULTS

The FS-AK group included 41 eyes with preoperative keratometric astigmatism of - 1.64 ± 0.42 diopters (D), and the toric IOL group included 53 eyes with preoperative keratometric astigmatism of - 2.29 ± 0.91 D (P < 0.001). Postoperative refractive astigmatism was comparable between the two groups. Compared with the FS-AK group, postoperative uncorrected visual acuity was significantly better (P = 0.005) and corrected visual acuity was marginally better in the toric IOL group (P = 0.051). The absolute angles of error were 9.95° ± 9.57° and 5.08° ± 4.94° (P = 0.02) in the FS-AK and the toric IOL groups, respectively.

CONCLUSION

Both FLACS with FS-AK and standard phacoemulsification with toric IOL implantation are safe and effective methods for astigmatism correction during cataract surgery. Standard phacoemulsification with toric IOL implantation achieves better visual acuity than FLACS with FS-AK at the 6-month follow-up.

Toric Intraocular Lens Implantation in the Correction of Moderate-To-High Corneal Astigmatism in Cataract Patients: Clinical Efficacy and Safety

Methods

A total of 57 cataract patients (57 eyes) with regular corneal astigmatism (≥2.57 D) were enrolled in this retrospective cohort study. Phacoemulsification with toric IOL implantation was performed for all patients. The uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) were recorded before and one year after surgery, and statistical analysis of preoperative corneal astigmatism, postoperative residual astigmatism, aberrations, IOL rotation, and related factors was performed to evaluate the efficacy, safety, and stability of toric IOLs in correcting moderate-to-high corneal astigmatism.

Results

One year after surgery, visual acuity was significantly improved compared with that before surgery (preoperative log MAR 0.87 ± 0.34 vs. postoperative log MAR 0.31 ± 0.26, p < 0.001), and the self-reported spectacle independence rate was 68.42%. The total residual astigmatism was 1.18 ± 0.85 D, which was significantly less than the preoperative value (3.41 ± 0.99 D) (p < 0.001). The degree of toric IOL rotation was 4.93 ± 3.02°, and 54.39% of patients had a lens rotation of less than 5°. The IOLs of 5.26% (3 eyes) of patients rotated more than 10°, and these patients received glasses instead of undergoing IOL repositioning.

Conclusions

Toric IOL implantation provided optimal vision outcomes and low spectacle dependence during a one-year follow-up period. The results from our study show that toric IOL implantation is a safe and effective option for cataract patients with moderate-to-high corneal astigmatism.

A randomised, prospective study of 'off-the-shelf' use of toric intraocular lenses for cataract patients with pre-existing corneal astigmatism in the NHS

BACKGROUND/OBJECTIVES

To compare visual and refractive outcomes of monofocal intraocular lenses (IOLs) with limbal relaxing incisions (LRI) with 'off-the-shelf' use of toric IOLs (TIOLs), with a fixed 2-dioptre cylinder (DC) correction, for cataract patients with pre-existing corneal astigmatism in a public-sector setting.

SUBJECTS/METHODS

Seventy-seven patients (77 eyes, first treated eye) with visually significant cataract and pre-operative corneal astigmatism ≥2.00 DC were randomised to receive either 'off-the-shelf' TIOLs, with a fixed 2.00 DC cylinder correction (39 eyes), or monofocal IOLs (38 eyes) with LRIs. The concept of fixing the cylindrical correction was to minimise costs, allow a full TIOL bank to be available and eliminate the need for individual TIOL ordering. Outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA) and refraction. Astigmatic changes were evaluated using the Alpins vector method.

RESULTS

Mean UDVA improved from logMAR 0.88 (SD 0.56)[~20/150] pre-operatively to 0.18 (SD 0.19)[~20/30] post-operatively in TIOL group, versus 0.82 (SD 0.55)[~20/130] to 0.27 (SD 0.15)[~20/40] in monofocal/LRI group (P = 0.02; 95% CI: -0.17, -0.01). Mean CDVA improved from logMAR 0.40 (SD 0.26)[~20/50] to 0.01 (SD 0.12)[~20/20] in TIOL group, and 0.41 (SD 0.38)[~20/40] to 0.06 (SD 0.12)[~20/25] in LRI group (P = 0.07; 95% CI: -0.11, 0.01). Average post-operative refractive cylinder in TIOL group was 1.35 DC (SD 0.84 DC) and in LRI group 1.91 DC (SD 1.07 DC) (P = 0.01; 95% CI: -1, -0.12). Mean difference vector magnitude was 1.92 DC (SD 1.08 DC) in LRI group and 1.37 DC (SD 0.84 DC) in TIOL group (P = 0.02; 95% CI: 0.11, 0.99).

CONCLUSIONS

TIOLs with a fixed 2.00 DC correction during cataract surgery may improve UDVA, reduce post-operative cylinder and result in a more reliable astigmatic correction compared with monofocal IOLs with LRIs.

Visual and autorefraction outcomes following toric intraocular lens insertion without calculation of posterior corneal astigmatism in the UK National Health Service

OBJECTIVE

To ascertain visual and refractive outcomes following toric intraocular lens (IOL) implantation in the UK National Health Service (NHS) without posterior corneal astigmatism calculation, with multiple surgeons of different grades, pooled input and output pathways and autorefraction as the refractive outcome measure.

METHODS

Preoperative and 1-month post-operative data were analysed retrospectively in 114 eyes (95 patients) receiving a toric IOL between 2014 and 2016 at Imperial College NHS Trust. Preoperative keratometric astigmatism was ≥2 dioptres (D).

RESULTS

Mean preoperative best-corrected visual acuity (BCVA) was 0.50 logMAR (±0.46), improving to a mean uncorrected VA (UCVA) of 0.35 logMAR (±0.36) postoperatively (p < 0.001) with 65% of eyes attaining a UCVA ≤ 0.30 logMAR. Excluding 33 eyes with pre-existing visual comorbidities and one targeting monovision, mean post-operative UCVA was 0.24 logMAR (±0.29) (p < 0.001), and 85% had UCVA ≤ 0.30 logMAR, 62% UCVA ≤ 0.20 logMAR. Mean refractive astigmatism improved from 3.04 D (±1.46) to 1.36 D (±1.13) (p < 0.001). In total, 52% of eyes had post-operative refractive astigmatism ≤1.00 D. The Alpins correction index was 1.05 (±0.22), indicating a tendency to overcorrect. Toric IOL misalignment was noted in two eyes, and two cases of posterior capsule rupture were converted to a non-toric IOL.

CONCLUSIONS

Visual outcomes of toric IOL implantation in our pooled pathway are comparable to single-surgeon case series where posterior corneal astigmatism has not been accounted for. However, with 1-month post-operative autorefraction, only 52% of eyes had ≤1 D refractive astigmatism, which is lower than previously published series, but may be standard for 1-month autorefraction outcomes.

Postoperative rotation of supplementary sulcus-supported toric intraocular lenses

We describe 7 cases in which supplementary sulcus-based toric intraocular lenses (IOLs) rotated postoperatively, requiring surgical realignment. The initial rotation was identified clinically between 3 months and 36 months postoperatively. All eyes had keratoconus, with and without prior keratoplasty, and 6 had longer than average axial lengths. No preceding trauma could be identified for 5 of the eyes. One eye had 3 episodes of postoperative IOL rotation, eventually requiring suture fixation to stabilize the IOL. This series indicates that postoperative rotation of a supplementary sulcus-based toric IOL may occur in eyes with or without preceding trauma. Eyes with keratoconus are at risk for postoperative rotation of the IOL, and suture fixation may be required to obtain stability.

Efficacy of toric intraocular lens implantation with high corneal astigmatism within the United Kingdom's National Health Service

OBJECTIVES

To determine the efficacy of toric intraocular lens (TIOL) implantation in cataract surgery patients with high levels of pre-operative corneal astigmatism and ocular co-morbidities in a state funded, National Health Service (NHS) hospital.

METHODS

Retrospective cohort study involving consecutive cases of TIOL implantation in cataract surgery with over 3.00DC of pre-operative corneal astigmatism. Subjects were implanted with the Tecnis TIOL (Abbot Medical Optics) with capsular tension ring stabilisation using the Callisto system (Carl Zeiss Meditec). Visual acuity and refraction were assessed at 4-6 weeks post-operatively. Vector analysis was used to calculate the intended refractive correction, surgically induced refractive correction (SIRC), correction ratio (CR), error of magnitude (EM) and error vector (EV).

RESULTS

Sixty-six eyes of forty-seven subjects aged 73.8 ± 11.9 were included. Eyes with ocular co-morbidities included dry age-related macular degeneration (n = 13), amblyopia (n = 7), high myopia (n = 7), glaucoma (n = 6), previous corneal transplantation (n = 2), nanophthalmos (n = 2) and corneal scarring (n = 1). Pre-operative corneal astigmatism was 4.25 ± 1.69DC (range 3.00-12.00), post-operative refractive astigmatism was 1.31 ± 1.05DC (range 0.00-6.50DC) and post-operative unaided visual acuity was 0.25 ± 0.19 LogMAR. Vector analysis demonstrated an SIRC of 4.08 ± 1.39DC, CR = 1.1 ± 0.3, EM -0.4 ± 1.0 and EV of 1.23 ± 0.72.

CONCLUSIONS

The results demonstrate the efficacy of TIOL implantation in patients with high corneal astigmatism and provide strong evidence advocating their use in cataract surgery within a state funded hospital eye service. Refractive astigmatism was significantly lower than the pre-operative corneal astigmatism and a low error vector was achieved relative to the magnitude of correction.

Rotational stability and refractive outcomes of a single-piece aspheric toric intraocular lens with 4 fenestrated haptics

PURPOSE

To assess the outcomes of implantation of a single-piece toric intraocular lens (IOL) with 4 fenestrated haptics.

SETTING

IRCCS Fondazione Bietti, Rome, Italy.

DESIGN

Prospective case series.

METHODS

All patients who had implantation of the Mini Toric Ready IOL were consecutively enrolled. Intraoperatively, the IOL was aligned using an automated system. Follow-up visits were performed at 1 day, 1 week, and 1, 3, and 6 months. At each visit, retroillumination pictures were taken to assess IOL orientation; visual acuity and refraction were also measured.

RESULTS

The final analysis comprised 63 eyes (63 patients). From the first to the last follow-up, the mean arithmetic rotation was -0.2 degrees ± 3.5 (SD) (range -13 to +10 degrees) and the mean absolute rotation was 1.6 ± 3.1 degrees. Intraocular lens rotation from the first to the last examination was within 5 degrees in 92.1% of eyes and on consecutive visits, within 5 degrees in 98.4% or more of eyes. By 6 months, 10 IOLs (15.9%) had rotated clockwise and 10 counterclockwise. Linear regression did not show a statistically significant relationship between rotational stability and the axis of placement with any preoperative parameter (eg, axial length). The mean magnitude of preexisting corneal astigmatism was 1.9 ± 0.7 diopters (D) (range 0.76 to 3.72 D). At the last follow-up, the mean magnitude of refractive astigmatism was 0.5 ± 0.4 D (range 0.0 to 1.5 D); the difference was statistically significant (P < .05).

CONCLUSION

The toric IOL showed good rotational stability and is an option for correcting corneal astigmatism at the time of cataract surgery.

Real-world refractive outcomes of toric intraocular lens implantation in a United Kingdom National Health Service setting

BACKGROUND

With increasing availability of toric intraocular lenses (IOL) for cataract surgery, real-world refractive outcome data is needed to aid the counselling of patients regarding lens choice. We aim to assess the outcomes of toric intraocular lens use in the non-specialist environment of a typical United Kingdom NHS cataract service.

METHODS

A retrospective cohort study conducted at the Oxford Eye Hospital, Oxford University Hospitals NHS Foundation Trust, UK. All patients who received a toric IOL implant over a 10 months period. Patients underwent pre-operative corneal marking, phacoemulsification and toric IOL implantation. Biometry was obtained using a Zeiss IOLMaster 500 and the toric IOLs were selected using the manufacturers' online calculators. Post-operative refractions were obtained from optometrist's manifest refraction or by autorefraction. The outcome measures were post-operative unaided visual acuity (UVA), spherical equivalent refraction, cylindrical correction and all complications.

RESULTS

Thirty-two eyes of 24 patients aged 21-86 years (mean 66.4, SD 14.5) were included. UVA was superior to pre-operative best-corrected visual acuity (BCVA) in 81% of eyes, same in 16% and inferior in 3%, resulting in a median improvement of 0.20 LogMAR (IQR 0.10 to 0.30). 56%, 81%, 94% and 100% of eyes were within ±0.5, ±1.0, ±1.5 and ±2.0 D of predicted spherical equivalent, respectively. Three (9%) eyes required further surgery to rectify significant IOL rotation.

CONCLUSIONS

Reduced cylindrical correction and improved UVA could be expected in the majority of patients undergoing toric IOL implantation. Patients should be counselled about the risk of lens rotation.

Optimizing outcomes with toric intraocular lenses

Toric intraocular lenses (IOLs) are the procedure of choice to correct corneal astigmatism of 1 D or more in cases undergoing cataract surgery. Comprehensive literature search was performed in MEDLINE using “toric intraocular lenses,” “astigmatism,” and “cataract surgery” as keywords. The outcomes after toric IOL implantation are influenced by numerous factors, right from the preoperative case selection and investigations to accurate intraoperative alignment and postoperative care. Enhanced accuracy of keratometry estimation may be achieved by taking multiple measurements and employing at least two separate devices based on different principles. The importance of posterior corneal curvature is increasingly being recognized in various studies, and newer investigative modalities that account for both the anterior and posterior corneal power are becoming the standard of care. An ideal IOL power calculation formula should take into account the surgically induced astigmatism, the posterior corneal curvature as well as the effective lens position. Conventional manual marking has given way to image-guided systems and intraoperative aberrometry, which provide a mark-less IOL alignment and also aid in planning the incisions, capsulorhexis size, and optimal IOL centration. Postoperative toric IOL misalignment is the major factor responsible for suboptimal visual outcomes after toric IOL implantation. Realignment of the toric IOL is needed in 0.65%–3.3% cases, with more than 10° of rotation from the target axis. Newer toric IOLs have enhanced rotational stability and provide precise visual outcomes with minimal higher order aberrations.

Toric Intraocular Lenses Versus Peripheral Corneal Relaxing Incisions for Astigmatism Between 0.75 and 2.5 Diopters During Cataract Surgery

PURPOSE

To compare the outcomes after toric intraocular lens (tIOL) or peripheral corneal relaxing incisions (PCRI) for keratometric astigmatism (K_A) between 0.75 and 2.5 diopters (D) during cataract surgery.

DESIGN

Prospective randomized clinical trial.

METHODS

Eighty eyes (80 participants) received either tIOL or PCRI and were assessed preoperatively, 1, 3, 6, and 12 months postoperatively.

PRIMARY OUTCOME MEASURE

Uncorrected (UCDVA) and best-corrected distance logMAR visual acuity (BCDVA) at 12 months.

SECONDARY OUTCOME MEASURES

Uncorrected near visual acuity (UCNVA), manifest refraction, K_A and mean keratometry (K_M), corneal aberrometry, tIOL rotation, and quality-of-life questionnaire.

RESULTS

Comparing tIOLs vs PCRIs, there was no significant difference in the UCDVA, BCDVA, and UCNVA. At 12 months, 61% vs 53% had UDCVA of 20/25 or better, 100% vs 76% gained ≥1 lines, and 59% vs 43% were within ±0.13 D spherical equivalent. In the PCRI group, anterior K_A decreased at 1 month and remained stable thereafter; there was a nonsignificant trend toward a flatter posterior K_A and steeper posterior K_M and the total corneal Z₂^-2 was low at 1 and 12 months. Over 12 months, there were changes in posterior corneal tilt, coma, and hexafoil in the PCRI group. The mean rotation of the tIOLs at 12 months was 1.8 ± 1.4 degrees. tIOL patients were happier and were glad to use the nonprescription sunglasses.

CONCLUSION

There was no difference in visual acuity, although more tIOL patients gained ≥1 line and were within ±0.13 D. After PCRIs, the anterior K_A decreased in the early postoperative period and remained stable thereafter and posterior corneal aberrations changed constantly over 12 months.

Refractive and Quality of Vision Outcomes with Toric IOL Implantation in Low Astigmatism

Purpose. To evaluate the refractive and the quality of vision outcomes of toric IOL implantation in patients with low astigmatism. Design. Prospective study of single-arm. Methods. Patients with corneal astigmatism range from 0,75 D to 1,5 D and cataract that underwent cataract surgery with toric IOL. The measurements were performed preoperatively and 6 weeks after the surgery. Patients were evaluated for visual acuity with and without correction, contrast sensitivity, static and dynamic refraction, and quality of life questionnaire. Pre- and postoperative values were compared and their variations were evaluated for linear correlation. Results. 21 eyes of 21 patients. Postoperative mean uncorrected visual acuity was 0.80 ± 0.19, and the best corrected visual acuity was 0.97 ± 0.15. p < 0.001 compared to preoperative values. The average postoperative refractive cylinder was −0.34 ± 0.39. The questionnaire's total value before and after surgery was, respectively, 43.20 ± 15.76 and 79.70 ± 10.11 (p < 0.001). The correlation coefficients between the values of the questionnaire variation and the UCVA, BCVA, and CS variation were, respectively, 0.548 (p = 0.005), 0.508 (p = 0.009), and 0.409 (p = 0.033). Conclusion. Patients with low astigmatism who underwent phacoemulsification with toric IOL implantation experienced significant decrease in refractive astigmatism and improvement in their quality of life.

Anterior stromal puncture with staining: A modified technique for preoperative reference corneal marking for toric lenses and its retrospective analyses

Introduction:

Toric intraocular lenses (IOLs) are an effective way of compensating preexisting corneal astigmatism during cataract surgery. To achieve success, it is imperative to align the toric IOLs in desired position and preoperative reference marking is one among the three important steps for accurate alignment. To make the marking procedure simpler and effective, we have modified the conventional three-step slit lamp-based technique.

Materials and Methods:

Patient is seated in front of the slit lamp and asked to keep the chin over chin rest. A 26-gauge bent needle with tip stained by sterile blue ink marker is used to make anterior stromal puncture (ASP) at the edges of horizontal 180° axis near the limbus.

Results:

A total of 58 eyes were retrospectively evaluated. Mean (+/-SD) IOL deviation on day 1 and day 30 was 5.7 ± 6.5° and 4.7 ± 5.6°, respectively. Median IOL misalignment on day 1 and day 30 was 3°. Redialing of IOL was required in 2 (3.4%) eyes only, all of which were performed within 1 week of surgery. In total, 2 (3.7%) eyes had a residual astigmatism of − 0.5 Dcyl and − 1.0 Dcyl, respectively.

Conclusion:

ASP is an effective technique for reference marking, technically simpler and can be practiced by most of the surgeons. It avoids the necessity of high-end sophisticated machinery and gives a better platform for the reference corneal marking along with the benefit of reproducibility and simplicity.

Corneal Astigmatism in Patients After Cataract Surgery: A 10-Year Follow-up Study

PURPOSE

To report the long-term outcomes of corneal astigmatism after cataract surgery.

METHODS

The study included 55 eyes of 46 patients who underwent cataract surgery with temporal 3-mm clear corneal incisions from January 2001 to December 2003. All patients underwent complete ophthalmological examination including keratometry at the preoperative visit and at 2 months and 10 years after surgery. Only those eyes that underwent a follow-up of 10 years or longer from the time of cataract surgery were enrolled. Arithmetic and vector analyses were performed to obtain the change in corneal astigmatism with advancing age.

RESULTS

The mean age of the patients was 59.11 ± 12.33 years (range: 18 to 75 years), and 58.7% of the patients were women. The mean follow-up period was 131.28 ± 14.36 months. The average magnitudes of surgically induced astigmatism and long-term astigmatism change were 0.66 ± 0.42 and 0.57 ± 0.47 diopters (D), respectively. The vector difference was 0.56 ± 0.55 D at 90° ± 0° between the preoperative and 2-month visits. However, there was no difference in vector values between postoperative 2 months and 10 years (0.00 ± 0.74 D at 0° ± 0°).

CONCLUSIONS

Patients with corneal astigmatism who underwent cataract surgery did not show a long-term against-the-rule change in corneal astigmatism during a 10-year follow-up. These results provide useful information when planning toric intraocular lens implantation in patients with corneal astigmatism. [J Refract Surg. 2016;32(6):404-409.].

Comparison of clinical outcomes among 3 marking methods for toric intraocular lens implantation

PURPOSE

To compare the clinical outcomes of 3 marking methods for toric intraocular lens (IOL) implantation in cataract patients.

METHODS

This study included 48 eyes of 48 cataract patients who underwent cataract surgery with toric IOL implantation. The rotational errors of 3 marking methods-the iris pattern marking method (iris pattern group), the pendulum marking method (pendulum group), and the 3-point marking method (3-point group)-were assessed.

RESULTS

The respective rotational errors were 4.0° ± 3.1° (mean ± SD), 5.3° ± 4.1°, and 7.3° ± 6.0°. The iris pattern group had significantly (P = 0.048) smaller rotational errors than did the 3-point group; no significant difference was found between the iris pattern and pendulum groups. However, the differences in postoperative uncorrected distance visual acuity and astigmatism did not reach significance among the 3 groups.

CONCLUSION

The refractive and visual results of toric IOL implantation using the 3-point marking method were comparable to the other methods evaluated in this study, although the accuracy of the axis alignment of the toric IOLs was significantly lower than that obtained with the iris pattern method.

Astigmatism management in cataract surgery with Precizon(®) toric intraocular lens: a prospective study

Purpose

The purpose of this study was to evaluate the visual and refractive outcomes and rotational stability of the new aspheric Precizon^® toric intraocular lens (IOL) for the correction of corneal astigmatism in cataract surgery.

Setting

Department of Ophthalmology, Hospital Geral de Santo António – Centro Hospitalar do Porto, EPE and Hospital de Pedro Hispano, Matosinhos, Portugal.

Design

This was a prospective clinical study.

Patients and methods

A total of 40 eyes of 27 patients with corneal astigmatism greater than 1.0 diopter (D) underwent cataract surgery with implantation of Precizon^® toric IOL. IOL power calculation was performed using optical coherence biometry (IOLMaster^®). Outcomes of uncorrected (UDVA) and best-spectacle corrected distance visual acuities (BCDVA), refraction, and IOL rotation were analyzed at the 1st week, 1st, 3rd, and 6th month’s evaluations.

Results

The median postoperative UDVA was better than preoperative best-spectacle corrected distance visual acuity (0.02 [0.06] logMAR vs 0.19 [0.20] logMAR, P<0.001). At 6 months, postoperative UDVA was 0.1 logMAR or better in 95% of the eyes. At last follow-up, the mean spherical equivalent was reduced from −3.35±3.10 D to −0.02±0.30 D (P<0.001) with 97.5% of the eyes within ±0.50 D of emmetropia. The mean preoperative keratometric cylinder was 2.34±0.95 D and the mean postoperative refractive cylinder was 0.24±0.27 D (P<0.001). The mean IOL rotation was 2.43°±1.55°. None of the IOLs required realignment.

Conclusion

Precizon^® toric IOL revealed very good rotational stability and performance regarding predictability, efficacy, and safety in the correction of preexisting regular corneal astigmatism associated with cataract surgery.

Decompensation of ocular torsion following malrotation of a toric intraocular lens

Toric intraocular lenses (IOLs) are being increasingly used to correct corneal astigmatism in cataract surgery. A quarter of patients that undergo cataract surgery may benefit from a toric rather than a spherical IOL. However, these implants must be positioned accurately, because postoperative rotation of the toric IOL can have clinically significant consequences. We present the first documented case of a 78-year-old woman who presented with diplopia as a result of exacerbation of a preexisting torsion following toric lens implantation.

Vector Analysis, Rotational Stability, and Visual Outcome After Implantation of a New Aspheric Toric IOL

PURPOSE

To evaluate vector analysis, rotational stability, and refractive and visual outcome of a new toric intraocular lens (IOL) for correction of preexisting corneal astigmatism during routine cataract surgery.

METHODS

In this prospective, interventional case series, 30 toric, aspheric Bi-Flex T toric IOLs (Medicontur Medical Engineering Ltd., Inc., Zsámbék, Hungary) were implanted in 20 consecutive patients with topographic corneal astigmatism between 1.50 and 4.00 diopters (D) and evaluated within the first year after implantation. Appropriate IOL-toric alignment was facilitated by combined imaging/eye tracking technology. Postoperative evaluation included refraction and uncorrected and corrected distance visual acuities (UDVA, CDVA). For each visit, photodocumentation in retroillumination was performed to evaluate toric alignment and potential toric IOL rotation. Vector analysis of refractive astigmatism was performed using the Alpins method.

RESULTS

At 12 months postoperatively, a reduction of the refractive astigmatism from 1.93±0.90 D (range: 0.50 to 4.00 D) to 0.28±0.61 D (range: 0.00 to 1.50 D) could be found, with patients achieving a mean UDVA of 0.06±0.16 logMAR (range: -0.18 to 0.40 logMAR; Snellen 20/20). Intraoperative to 12-month postoperative comparison of IOL axis alignment showed low levels of rotation (0.2°±2.41°; range: +4° to -5°). Vector analysis showed target induced astigmatism of 0.60 D @180°, surgically induced astigmatism of 0.80 D @177°, correction index of 1.02±0.25, and a difference vector of 0.30 D @82°.

CONCLUSIONS

Implantation of the new Bi-Flex T IOL was a safe, stable, and effective method to correct preexisting regular corneal astigmatism during cataract surgery.

Comparison Between Digital and Manual Marking for Toric Intraocular Lenses: A Randomized Trial

To compare the clinical outcome of digital and manual marking for toric intraocular lens (IOL) alignment. This is a prospective clinical study that included 60 eyes of 60 patients undergoing cataract surgery with coexisting corneal astigmatism more than 1 diopter (D). The eyes were randomly assigned to either digital image guidance using VERION digital marker (Alcon Laboratories, Ft. Worth, TX) or manual slitlamp-assisted preoperative marking using pendulum-attached marker. Tecnis toric IOL (Abbott Medical Optics, Inc, Santa Ana, CA) was implanted in all cases. The mean postoperative uncorrected distance visual acuity (UCDVA) for the digital-marking group was 0.12 + 0.12 logMAR, and for the manual-marking group was 0.18 + 0.14 logMAR (P = 0.104). The mean deviation from targeted induced astigmatism (TIA) for the first group was 0.10 + 0.08 D and for the second group was 0.20 + 0.14 D (P = 0.001). The mean postoperative toric IOL misalignment measured by the slitlamp was 2.4° + 1.96° for the first group and was 4.33° + 2.72° for the second group (P = 0.003). Accurate alignment of the toric IOL is important to achieve the desired astigmatism correction. VERION system has the advantage of preoperative planning and intraoperative digital guidance of the toric IOL alignment. The use of VERION system resulted in less postoperative deviation from TIA and showed less postoperative toric IOL misalignment than using manual-marking technique.

Transscleral suture fixation following recurrent toric intraocular lens rotation

We describe a surgical technique of transscleral suture fixation for recurrent rotation of a double-loop hydrophilic acrylic toric intraocular lens (IOL) in the capsular bag. Two 9-0 polypropylene sutures are placed in the proximal and distal angulations of 1 of the IOL haptics through the capsular bag. The clockwise and counterclockwise traction provided by these sutures prevents rotation of the IOL in either direction. This technique can be used in cases of spontaneous postoperative IOL rotation to achieve stabilization. In the case we describe, the IOL remained stable 11 months following transscleral suture fixation at the desired axis.

The use of toric intraocular lens to correct astigmatism at the time of cataract surgery

Background:

To evaluate the visual and refractive outcomes of cataract surgery with toric intraocular lens (IOL) implantation at a teaching hospital of the United Kingdom.

Design:

Prospective interventional case series.

Materials and Methods:

This study compared the outcome of 3 groups of patients: Group 1 included 25 eyes with cataract and more than 2.5 diopters (D) of corneal astigmatism receiving a toric monofocal IOL; Group 2 had 18 patients with cataract and more than 2.5 D of astigmatism but receiving a non-toric monofocal IOL; while Group 3 had 25 patients with cataract and less than 1.5 D of astigmatism and receiving a non-toric monofocal IOL. Data collected included uncorrected (UDVA) and corrected (CDVA) distance visual acuities, refraction and corneal keratometry. Postoperative examinations were scheduled at 1 and 6 weeks.

Results:

Postoperatively the mean UDVA was LogMAR 0.27 ± 0.20 (equivalent snellen acuity of 20/37) in Group 1, 0.54 ± 0.22 (20/69) in Group 2 and 0.16 ± 0.20 (20/29) in Group 3. The mean CDVA was LogMAR 0.08 ± 0.13 (20/24) in Group 1, 0.23 ± 0.16 (20/34) in Group 2 and 0.04 ± 0.13 in Group 3 (20/22). The mean preoperative keratometric cylinder was 3.78 ± 1.0 D in Group 1, 3.41 ± 1.47 D in Group 2 and 0.97 ± 0.43D in Group 3; the mean postoperative subjective cylinder was 1.2 ± 0.68 D in Group 1, 3.23 ± 1.41 D in Group 2 and 0.95 ± 0.58 D in Group 3. The difference was statistically significant for the postoperative refractive cylinder values when comparing Group 1 to Group 2 (P = <0.0001) but the difference was insignificant between Group 1 and Group 3 (P = 0.23).

Conclusion:

Toric IOL implantation is an effective option to manage corneal astigmatism at the time of cataract surgery and to optimise visual outcomes for astigmatic patients when comparing to outcomes for their non-astigmatic counterparts.

Influence of the overall intraocular lens diameter on rotational stability

PURPOSE

To evaluate the rotational stability of two intraocular lenses (IOLs) of similar design and material but with a difference of 1 mm in overall length.

METHODS

In this prospective study patients with age-related cataract were included. An IOL with an overall diameter of 12 mm (ACR6 = small-diameter IOL) was compared to an IOL with an overall diameter of 13 mm (IDEA 613 XC = large-diameter IOL).

RESULTS

In total, 60 patients were included in this study. Absolute rotation in the small- and large-diameter groups was 4.4° (SD: 4.0; range: 0.3-17.8) and 3.0° (SD: 2.4; range: 0.1-7.8), respectively. The differences between the two IOLs were not found to be statistically significant.

CONCLUSION

The effect of the overall length of an IOL appears to have little impact on early rotation after cataract surgery.

Clinical outcomes of TECNIS toric intraocular lens implantation after cataract removal in patients with corneal astigmatism

PURPOSE

To evaluate safety and effectiveness of the TECNIS toric intraocular lenses (IOLs).

DESIGN

Prospective, multicenter, 2-armed, bilateral, 6-month clinical trial following the American National Standards Institute (ANSI) standard for Toric IOLs.

PARTICIPANTS

Subjects implanted with a TECNIS toric IOL (n = 172) or a TECNIS 1-piece control IOL (ZCB00; n = 93).

METHODS

Subjects underwent standard cataract surgery with IOL implantation. The randomized control arm consisted of subjects requiring cylinder correction of 0.75 to 1.50 diopters (D) who were implanted with either toric (ZCT150) or nontoric (ZCB00) IOLs. The open-label arm (OLA) consisted of subjects requiring cylinder correction of 1.50 to 3.62 D and implanted with ZCT225, ZCT300, or ZCT400 IOLs.

MAIN OUTCOME MEASURES

Assessments were at 1 day, 1 week, and 1, 3, and 6 months and included uncorrected distance visual acuity (UCDVA) and best-corrected distance visual acuity (BCDVA), manifest refraction, keratometry, adverse events, spectacle use, and photographic documentation of IOL rotational stability.

RESULTS

Mean percent reduction in cylinder (± standard deviation) was statistically significantly greater (P < 0.0001) for ZCT150 eyes (74.53 ± 72.25%) versus ZCB00 eyes (31.61 ± 78.73%). In the OLA, mean percent reduction in cylinder was 76.27 ± 33.09%. A UCDVA of 20/20 or better was achieved by 43.6% (44/101) of ZCT150 eyes and by 23.7% (22/93) of ZCB00 eyes (P = 0.0026). In the OLA, 38.0% (27/71) achieved 20/20 or better UCDVA. Mean UCDVA was 0.10 ± 0.14 for ZCT150 eyes and 0.16 ± 0.16 for ZCB00 eyes (P = 0.0009); in the OLA, mean UCDVA was 0.11 ± 0.12. The BCDVA was 20/40 or better for all eyes. Mean absolute lens rotation between visits for toric eyes pooled was less than 3°. Lens rotation of 5° or less occurred in 92.9% of toric eyes between 1 and 3 months and in 94.1% between 3 and 6 months, exceeding the ANSI standard for stability (≥ 90% of eyes with ≤ 5° of rotation between visits). Four lenses (2.3%) were repositioned during the study.

CONCLUSIONS

The TECNIS toric IOLs successfully reduce ocular astigmatism and are a safe and effective treatment for cataract patients with corneal astigmatism.

Technology and Intraocular Lenses to Enhance Cataract Surgery Outcomes-Annual Review (January 2013 to January 2014)

PURPOSE

This article is aimed to provide a clinical update on recent developments in cataract surgical techniques, with specific focus on femtosecond laser technology. The article also focuses on recent improvements in the technology used in implanting intraocular lenses (IOLs).

DESIGN

Literature review.

METHODS

The authors conducted a review of literature available in the last 12 months in the English language using PubMed. The period used to conduct the literature search was from January 1, 2013, to December 31, 2013. The following search terms were used during the PubMed search: phacoemulsification, femtosecond laser, toric IOLs, multifocal IOLs, multifocal toric IOLs, manual small-incision cataract surgery, outcomes, surgically induced astigmatism, rotational stability, trifocal IOLs, laser cataract surgery, safety, and efficacy.

RESULTS

This review incorporates selected original articles that provide fresh insights and updates on the fields of toric and multifocal IOLs, femtosecond laser cataract surgery, and manual small-incision cataract surgery. Particular attention has been paid to observational, randomized controlled clinical trials, experimental trials, and analyses of larger cohorts with prospective and retrospective study designs. Letters to the editor, unpublished works, and abstracts do not fall under the purview of this review.

CONCLUSIONS

This review is not designed to be all-inclusive. It highlights and provides insights on literature that is most useful and applicable to practicing ophthalmologists.

Rotational performance and corneal astigmatism correction during cataract surgery: aspheric toric intraocular lens versus aspheric nontoric intraocular lens with opposite clear corneal incision

PURPOSE

To compare the astigmatism-reducing effect of an aspheric toric intraocular lens (IOL) and an aspheric nontoric IOL with an opposite clear corneal incision (OCCI) in cataract surgery.

SETTING

Vienna Institute for Research in Ocular Surgery, Hanusch Hospital, Vienna, Austria.

DESIGN

Prospective randomized clinical study.

METHODS

Patients with low to moderate corneal astigmatism scheduled for cataract surgery received an aspheric toric IOL (Lentis L-312T) or an aspheric nontoric IOL (Lentis L-312) combined with an OCCI. Keratometry and corneal tomography were performed 1 hour, 1 week, 3 months and 9 months postoperatively. Postoperative residual astigmatism was measured using an autorefractor. Rotational toric IOL stability was analyzed using retroillumination photography.

RESULTS

Fifty-five patients were included. Three months postoperatively, the mean reduction in corneal astigmatism was 0.67 diopter (D) ± 0.58 (SD) in the toric group and 0.18 ± 0.52 D in the nontoric-OCCI group. The mean uncorrected distance visual acuity was 0.29 ± 0.30 logMAR and 0.09 ± 0.18 logMAR, respectively (P=.02). The mean refractive astigmatism was 1.02 ± 0.54 D and 0.68 ± 0.52 D, respectively (P=.05). One hour, 3 months, and 9 months postoperatively, the mean absolute IOL misalignment of toric IOLs was 4.99 ± 4.66 degrees, 13.59 ± 11.29 degrees, and 19.90 ± 14.48 degrees, respectively.

CONCLUSIONS

The toric IOL tended to rotate significantly postoperatively. Visual acuity was good in both groups. Residual refractive cylinder was significantly lower in the toric IOL group.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.

The visual and functional impacts of astigmatism and its clinical management

PURPOSE

To provide a comprehensive overview of research examining the impact of astigmatism on clinical and functional measures of vision, the short and longer term adaptations to astigmatism that occur in the visual system, and the currently available clinical options for the management of patients with astigmatism.

RECENT FINDINGS

The presence of astigmatism can lead to substantial reductions in visual performance in a variety of clinical vision measures and functional visual tasks. Recent evidence demonstrates that astigmatic blur results in short-term adaptations in the visual system that appear to reduce the perceived impact of astigmatism on vision. In the longer term, uncorrected astigmatism in childhood can also significantly impact on visual development, resulting in amblyopia. Astigmatism is also associated with the development of spherical refractive errors. Although the clinical correction of small magnitudes of astigmatism is relatively straightforward, the precise, reliable correction of astigmatism (particularly high astigmatism) can be challenging. A wide variety of refractive corrections are now available for the patient with astigmatism, including spectacle, contact lens and surgical options.

CONCLUSION

Astigmatism is one of the most common refractive errors managed in clinical ophthalmic practice. The significant visual and functional impacts of astigmatism emphasise the importance of its reliable clinical management. With continued improvements in ocular measurement techniques and developments in a range of different refractive correction technologies, the future promises the potential for more precise and comprehensive correction options for astigmatic patients.

Cataract surgery with toric intraocular lens for correction of high corneal astigmatism

OBJECTIVE

To analyze the outcomes of cataract surgery with high-power toric intraocular lens (IOL) implantation in patients with high corneal astigmatism.

DESIGN

Retrospective case series.

PARTICIPANTS

Twelve eyes of 9 patients.

METHODS

Patients with idiopathic, pathologic, or postsurgical corneal astigmatism and a visually significant cataract were included in the study. Cataract extraction with implantation of a custom-made high-power toric IOL was performed on all patients. Outcomes included uncorrected and best corrected distance visual acuity (UDVA and BCDVA), manifest refraction, and mean and steepest keratometry. Analysis of astigmatic vectors was also performed.

RESULTS

The mean follow-up time was 3.75 months. At the last follow-up visit, there was a significant improvement of UDVA (1 ± 0.64 vs 0.39 ± 0.21 logMAR; p < 0.05), cylindrical refraction (-4.72 ± 1.13 vs -1.81 ± 1.10 D; p < 0.01), and refractive spherical equivalent (-4.56 ± 5.58 vs -0.36 ± 1.19 D; p < 0.05). The BCDVA improvement did not reach statistical significance. Astigmatism on the target axis was reduced by an average of 5 D (p < 0.01).

CONCLUSIONS

Cataract surgery with implantation of a high-power toric IOL was safe and effective in correcting high values of corneal astigmatism.

Rotational stability of a single-piece toric acrylic intraocular lens: a pilot study

PURPOSE

To evaluate the visual performance and rotational stability of the Tecnis Toric 1-piece intraocular lens (IOL) during the first 3 postoperative months.

DESIGN

Prospective, single-center study.

METHODS

In this study, patients with age-related cataract and corneal astigmatism of 1.0 to 3.0 diopters measured with the IOLMaster 500 (Carl Zeiss Meditec AG) were included. Before surgery, rotating Scheimpflug scans (Pentacam HR; Oculus) were performed and the cornea was marked in the sitting position at the slit lamp. Patients received a single-piece toric hydrophobic acrylic IOL (Tecnis Toric; AMO). Immediately and 3 months after surgery, retroillumination photographs were obtained to assess the rotational stability of the IOL. Additionally, Autorefraction (Topcon), subjective refraction, uncorrected and distance-corrected visual acuity, keratometry, and Scheimpflug and ocular wavefront (WASCA, Carl Zeiss Meditec AG) measurements were performed at the 3-month follow-up.

RESULTS

Thirty eyes of 30 patients were included in this study. Mean absolute difference between the IOL axis at the 3-month and 1-hour follow-up was 2.7 degrees (standard deviation, 3.0 degrees). The IOL rotation was less than 3 degrees and less than 6 degrees in 62% and 95% of all cases, respectively.

CONCLUSIONS

The Tecnis Toric 1-piece IOL is rotationally stable and shows excellent capsule bag performance and refractive outcomes.

Comparison of Toric Intraocular Lenses and Arcuate Corneal Relaxing Incisions to Correct Moderate to High Astigmatism in Cataract Surgery

PURPOSE

To compare toric intraocular lens (IOL) implantation with arcuate corneal relaxing incisions for moderate to high corneal astigmatism during cataract surgery.

DESIGN

A retrospective comparison study.

METHODS

This 12-month single-surgeon study compared eyes with cataract and preexisting astigmatism of 1.75 diopters (D) or greater (range, 1.75-5.25 D) receiving corneal arcuate relaxing incisions or toric IOL implantation. Main outcome measures were visual acuity, refractive results, and IOL axis determination.

RESULTS

There were 45 and 20 eyes in the toric IOL and arcuate incision groups, respectively. Preoperative data were not significantly different between the 2 groups; the mean preoperative astigmatism was 2.16 ± 0.93 D in the toric IOL group and 2.41 ± 0.76 D in the incisional group. At 6 months postoperatively, the mean residual astigmatism was 0.75 and 1.33 D (P = 0.000), respectively; 82.2% and 44.4% of eyes were 1.00 D or less (P = 0.000), and 35.7% and 16.7% of eyes were 0.50 D or less (P = 0.000), respectively. Uncorrected distance visual acuity improved in both groups; eyes in the toric IOL group were more likely to be 20/30 or better (87% vs 29%, P = 0.008). Following surgery, all eyes had best corrected visual acuity of 20/40 or greater, and no eye lost a line of vision. The mean toric IOL rotation was 2.6 ± 1.7 degrees (range, 0-6 degrees).

CONCLUSIONS

Both toric IOLs and arcuate corneal incisions reduce moderate to high preexisting corneal astigmatism during cataract surgery; however, toric IOL implantation was more effective and predictable.

Toric intraocular lenses: historical overview, patient selection, IOL calculation, surgical techniques, clinical outcomes, and complications

We present an overview of currently available toric intraocular lenses (IOLs) and multifocal toric IOLs. Relevant patient selection criteria, IOL calculation issues, and surgical techniques for IOL implantation are discussed. Clinical outcomes including uncorrected visual acuity, residual refractive astigmatism, and spectacle independency, which have been reported for both toric IOLs and multifocal toric IOLs, are reviewed. The incidence of misalignment, the most important complication of toric IOLs, is determined. Finally, future developments in the field of toric IOLs are discussed.

Efficacy and stability of AT TORBI 709 M toric IOL

PURPOSE

To describe the intraocular rotational stability and refractive results of the toric AT TORBI 709 M (former AT.Comfort 464 TLC) intraocular lens (IOL) (Carl Zeiss Meditec AG, Jena, Germany).

METHODS

Forty-eight eyes of 32 consecutive patients with cataract and greater than 1 diopter of corneal astigmatism were included. Implantation of the toric IOL was performed after phacoemulsification. Uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), residual refractive sphere, residual keratometric and refractive cylinders, and toric IOL axis were measured before and 1, 3, and 6 months after surgery.

RESULTS

Mean logMAR UDVA and CDVA improved significantly after surgery (P < .05). UDVA was 20/40 or better in 88.1% of eyes and 20/25 or better in 61.9%. CDVA was 20/40 or better in 100% of eyes and 20/25 or better in 90.2%. Mean refractive cylinder decreased significantly from -2.23 ± 1.72 before to -0.43 ± 0.53 after surgery (P < .05). Vector analysis of attempted versus achieved correction showed 100% of eyes within ± 1.00 D and 95.2% within ± 0.50 D for J and 100% of eyes were within ± 1.00 D and 95.2% within ± 0.50 D for J. Mean toric IOL axis rotation was 4.42 ± 4.31 degrees (range: 0 to 16 degrees) and 86% of the lenses rotated less than 10 degrees.

CONCLUSIONS

The AT TORBI 709 M IOL has proved to be a predictable and effective device with good rotational stability for the correction of preexisting astigmatism during cataract surgery.

Results of cataract surgery with Z-flex hydrophilic acrylic toric IOL

PURPOSE

To report the outcome of cataract surgery with implantation of the Z-flex 690TA hydrophilic acrylic toric intraocular lens (IOL).


METHODS

We enrolled consecutive patients who had 1.75 D or more of preexisting corneal astigmatism. Patients had cataract extraction surgery with implantation of a Z-flex 690TA toric IOL (Medicontur, Hungary). Refractive outcomes, keratometry, correction ratio (CR), and error of magnitude (EM) were evaluated.

RESULTS

Nineteen eyes of 13 patients were evaluated. Mean follow-up time was 4.3 ± 2.3 months. Mean preoperative keratometric astigmatism was 3.05 ± 0.74 D. Mean postoperative deviation from the anticipated spherical equivalent was +0.23 ± 0.39 D, with 100% of eyes achieving a spherical equivalent within ± 1.00 D of the target refraction. Mean deviation from the anticipated refractive cylinder was 0.46 ± 0.47 D. Mean IOL misalignment was 5.67 ± 6.45 degrees. Mean CR was 1.02 ± 0.22, and the mean EM was -0.09 ± 0.55 D.

CONCLUSION

The Z-flex 690TA hydrophilic acrylic toric IOL implantation was safe, effective, and predictable in correcting corneal astigmatism during cataract surgery.

Analysis of corneal astigmatism in cataract surgery candidates at a teaching hospital in Shanghai, China

PURPOSE

To describe and quantify the pattern of corneal astigmatism in cataract surgery candidates and to provide information for cataract surgeons and intraocular lens (IOL) manufacturers.

SETTING

Zhongshan Hospital, Fudan University, Shanghai, China.

DESIGN

Cross-sectional study.

METHODS

The datasets of cataract surgery candidates acquired between November 1, 2009, and November 30, 2011, were collected and analyzed. Keratometry values were optically measured by partial coherence interferometry (IOLMaster) before cataract extraction. Spearman rank correlation coefficients were used to estimate bivariate correlations. The power vector method, J(0) and J(45) values, and linear regression models were used to assess the association between age and astigmatism.

RESULTS

The study evaluated the keratometry values in 1430 eyes (827 patients) with a median age of 75 years (range 16 to 98 years). The corneal astigmatism was 1.00 diopter (D) or higher in 45.45% of eyes. The magnitude of corneal astigmatism was positively correlated with age (ρ = 0.126, P = .000). A trend toward increasing against-the-rule astigmatism with age was found by linear regression models; the per-year increase in age was associated with a J(0) decrease of 0.016 D in right eyes and 0.018 D in left eyes (both P = .000). No association was found between age and J(45).

CONCLUSIONS

Most eyes having corneal astigmatism of 1.00 D or greater could be covered by the range of the cylindrical power of the toric IOLs available on the market. Against-the-rule corneal astigmatism of relatively younger cataract surgery candidates should be managed more aggressively.

FINANCIAL DISCLOSURE

No author has a financial or proprietary interest in any material or method mentioned.