Toric intraocular lens versus monofocal intraocular lens implantation and photorefractive keratectomy: a randomized controlled trial

Toric Monofocal Intraocular Lenses for the Correction of Astigmatism during Cataract Surgery: A Report by the American Academy of Ophthalmology

PURPOSE

To review the published literature evaluating the visual and refractive outcomes and rotational stability of eyes implanted with toric monofocal intraocular lenses (IOLs) for the correction of keratometric astigmatism during cataract surgery and to compare those outcomes with outcomes of eyes implanted with nontoric monofocal IOLs and other astigmatism management methods performed during cataract surgery. This assessment was restricted to the toric IOLs available in the United States.

METHODS

A literature search of English-language publications in the PubMed database was last conducted in July 2022. The search identified 906 potentially relevant citations, and after review of the abstracts, 63 were selected for full-text review. Twenty-one studies ultimately were determined to be relevant to the assessment criteria and were selected for inclusion. The panel methodologist assigned each a level of evidence rating; 12 studies were rated level I and 9 studies were rated level II.

RESULTS

Eyes implanted with toric IOLs showed excellent postoperative uncorrected distance visual acuity (UCDVA), reduction of postoperative refractive astigmatism, and good rotational stability. Uncorrected distance visual acuity was better and postoperative cylinder was lower with toric IOLs, regardless of manufacturer, when compared with nontoric monofocal IOLs. Correcting pre-existing astigmatism with toric IOLs was more effective and predictable than using corneal relaxing incisions (CRIs), especially in the presence of higher magnitudes of astigmatism.

CONCLUSIONS

Toric monofocal IOLs are effective in neutralizing pre-existing corneal astigmatism at the time of cataract surgery and result in better UCDVA and significant reductions in postoperative refractive astigmatism compared with nontoric monofocal IOLs. Toric IOLs result in better astigmatic correction than CRIs, particularly at high magnitudes of astigmatism.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Outcomes of preloaded toric intraocular lens implantation in eyes undergoing phacoemulsification

Purpose

To evaluate the clinical outcomes of preloaded toric intraocular lens (IOLs) implantation in eyes undergoing phacoemulsification.

Methods

This prospective study included 51 eyes of 51 patients with visually significant cataracts and corneal astigmatism ranging between 0.75 and 5.50 D. All patients underwent phacoemulsification with SupraPhob toric intraocular lens implantation under topical anesthesia. The main outcome measures were uncorrected distance visual acuity (UDVA), residual refractive cylinder, spherical equivalent, and IOL stability at 3 months follow-up.

Results

At 3 months, 49% (25/51) of patients had UDVA equal to or better than 20/25 with 100% of eyes achieving better than 20/40. Mean logMAR UDVA improved from 1.02 ± 0.39, preoperatively to 0.11 ± 0.10 at 3 months follow-up (P < 0.001, Wilcoxon signed-rank test). The mean refractive cylinder improved from - 1.56 ± 1.25 D preoperatively to - 0.12 ± 0.31 D at 3 months follow-up (P < 0.001) while the mean spherical equivalent value changed from - 1.93 ± 3.71D preoperatively to - 0.16 ± 0.27D (P = 0.0013). The mean root mean square value for higher order aberrations was 0.30 ± 0.18 μm while the average contrast sensitivity value (Pelli-Robson chart) was 1.56 ± 0.10 log unit, at the final follow-up. The mean IOL rotation at 3 weeks was 1.7 ± 1.61 degrees, which did not change significantly at 3 months (P = 0.988) follow-up. There were no intraoperative or postoperative complications.

Conclusion

SupraPhob toric IOL implantation is an effective method for addressing preexisting corneal astigmatism in eyes undergoing phacoemulsification with good rotational stability.

Refractive surprise of irregular astigmatism following cataract surgery in two patients with neglected subclinical corneal ectasia: two case reports

BACKGROUND

Corneal ectatic diseases are a group of corneal disorder characterized by the steepening and thinning of the cornea. Older people are not a high-risk population for corneal ectatic diseases; due to the lack of typical preoperative topographic manifestations, there is a high possibility that corneal ectasia is undetected.

CASE PRESENTATION

Two patients with subclinical corneal ectasia and senile cataracts presented with irregular astigmatism after steep-axis incision during cataract surgery. The two cases presented in this case report are rare because both patients experienced tremendous changes in astigmatism after cataract surgery.

CONCLUSION

This case report may shed some light on astigmatism-correcting steep-axis incisions in cataract surgeries.

Comparison of Visual Outcomes Between Toric Intraocular Lenses and Clear Corneal Incisions to Correct Astigmatism in Image–Guided Cataract Surgery

Purpose

To compare the astigmatism correction effects of toric intraocular lenses (IOL) and clear corneal incisions during image-guided cataract surgery.

Methods

All patients with regular corneal astigmatism of 0.75–1.5 D underwent cataract surgery and astigmatism correction using the Callisto eye image-guided system. One group had implantation of an AcrySof toric IOL. Another group had implantation of aspheric IOL with 3.0 mm single clear corneal incision (SCCI) on the steep axis. Uncorrected and best-corrected spectacle visual acuity, refraction, and toric IOL axis were evaluated at 1, 4, and 12 weeks postoperatively.

Results

Sixty-eight eyes of 68 patients were included. The mean residual refractive cylinder was 0.34 ± 0.40 D in the toric group and 0.64 ± 0.57 D in the SCCI group. There were no significant differences in residual refractive cylinder, spherical equivalent, uncorrected distance visual acuity (UDVA), and best-corrected spectacle visual acuity (BCSVA) between groups. The percentage of the residual cylinder within ± 0.50 D was 75 and 56% for toric and SCCI cases, respectively (p &gt; 0.1). The mean surgical induced astigmatism vector was 0.61 ± 0.29 D in the SCCI group and 1.04 ± 0.38 D in the toric group. The mean magnitude of error was negative (−0.54 ± 0.48 D) and the correction index was &lt;1.0 (p &lt; 0.05) in SCCI group. At 3 months, all toric IOL alignment errors were within 5 degrees from the intended axis.

Conclusions

Both toric IOL and SCCI can correct low and medium astigmatism effectively with the help of a precise image-guided system.

Correction of pre-existing astigmatism with phacoemulsification using toric intraocular lens versus spherical intraocular lens and wave front guided surface ablation

Background

This study aimed to evaluate toric intraocular lens to correct of pre-existing astigmatism at the time of phacoemulsification compared to using of spherical intraocular lens followed by wavefront guided surface ablation.

Results

The patients were classified into three groups: Group A with 20 eyes of 19 patients having phacoemulsification with spherical intraocular lens only as a control group, group B with 20 eyes of 14 patients had phacoemulsification with toric intraocular lens and group C with 20 eyes of 16 patients had phacoemulsification with spherical intraocular lens and wavefront guided PRK three months later. Comparison pre-operative data for all groups showed no statistically significant difference regarding UCVA, BCVA, MRSE, and refractive astigmatism (P>0.05). Post operatively, there was a statistically significant difference for UCVA, BCVA, MRSE, and refractive astigmatism for group A compared to group B (P<0.05) and group A compared to group C but there was no statistically significant difference for group B compared to C regarding all these parameters (P>0.05).

Conclusion

In this study, we found similar effects for both techniques in astigmatism corrected groups while both differed from the control group that was not corrected. Correcting preexisting astigmatism during cataract surgery should be in mind in every case to improve visual outcomes. Longer period of follow up are required to evaluate stability of these techniques and possibility of regression.

Clinical outcomes, predictability and rotational stability following implantation of Eyecryl toric versus TECNIS toric intraocular lenses-A comparative study

PURPOSE

To compare the visual outcomes, predictability and rotational stability following implantation of Eyecryl toric versus TECNIS toric intraocular lenses.

METHODS

This retrospective study included 100 eyes of 78 eligible patients who underwent phacoemulsification followed by implantation of either Eyecryl Toric IOL or TECNIS Toric IOL (n = 50 eyes in each group), using an intraoperative image-guided marker less system. All toric IOL implantations were performed under balanced salt solution. At 2 weeks, 3 months and 6 months, uncorrected (UDVA) and corrected distance visual acuity (CDVA), spherical equivalent refraction, residual astigmatism, and rotational stability of the toric IOL was evaluated and compared. Rotational stability was assessed using ray tracing.

RESULTS

Mean age of the participants was 67.8 ± 9.26 years in Eyecryl toric group and 64 ± 11 years in TECNIS toric group. The mean pre-op corneal astigmatism was 1.75 ± 0.62 D and 2.00 ± 0.71 D in the Eyecryl and TECNIS group, respectively (p = 0.07). At 2 weeks and at 6 months post-op, there was no statistically significant difference between the UDVA, CDVA, and residual astigmatism between the two groups (p < 0.05). Mean post-operative toric IOL rotation was 3.94 ± 2.27 degrees in the Eyecryl Toric group, and 4.44 ± 2.77 degrees, in the TECNIS Toric group, respectively, the difference was not statistically significant (p = 0.32). One IOL in the Eyecryl group and two IOLs in the TECNIS group required re-positioning for significant post-op rotation at 1 week post-op.

CONCLUSION

At 6 months, both Eyecryl toric and TECNIS toric IOLs showed comparable post-operative outcomes in terms of UDVA, CDVA, residual astigmatism and rotational stability.

Clinical outcomes and rotational stability following implantation of Eyecryl toric intraocular lens - Results of a 12-months prospective study

Purpose:

To evaluate the clinical performance and rotational stability after implantation of Eyecryl Toric monofocal IOL following cataract surgery.

Methods:

Patients undergoing phacoemulsification for age-related cataract and satisfying the eligibility criteria were implanted with Eyecryl Toric IOL. All implantations were done under balanced salt solution. A marker-less system Callisto Eye (Carl Zeiss Meditec, Germany) was used to guide the intra-operative alignment of the toric IOL.

Results:

A total of 50 eyes from 39 patients with mean age of 68.2 ± 8.7 years were included in the study. At 12 months, 82% (41) eyes had cumulative UDVA of 20/20 or better. Post-op SE refraction accuracy was within ± 0.50 D for 94% (n = 47) eyes and refractive cylinder accuracy was within ≤0.50 D in 98% (n = 49) eyes. Average post-op rotation at 1 year was 4.06 ± 2.15 degrees. Eighty-four percent of eyes were within 5 degrees and 16% were within 6-10 degrees of intended axis. Two eyes required IOL re-positioning due to significant rotation of the toric IOL (>10 degrees), identified within the 1^st week after surgery.

Conclusion:

Eyecryl toric IOL demonstrated the ability to achieve a significant reduction in astigmatism, improved UDVA outcomes, high levels of spectacle independence, low rates of intra-operative injector related complications and good rotational stability at 12 months post-op.

Toric intraocular lens versus limbal relaxing incisions for corneal astigmatism after phacoemulsification

BACKGROUND

Cataract is the leading cause of blindness in the world, and clinically significant astigmatism may affect up to approximately 20% of people undergoing cataract surgery. Pre-existing astigmatism in people undergoing cataract surgery may be treated, among other techniques, by placing corneal incisions near the limbus (limbal relaxing incisions or LRIs) or by toric intraocular lens (IOLs) specially designed to reduce or treat the effect of corneal astigmatism on unaided visual acuity.

OBJECTIVES

To assess the effects of toric IOLs compared with LRIs in the management of astigmatism during phacoemulsification cataract surgery.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register; 2019, Issue 9); Ovid MEDLINE; Ovid Embase and four other databases. The date of the search was 27 September 2019.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing toric IOLs with LRIs during phacoemulsification cataract surgery.  DATA COLLECTION AND ANALYSIS: We used standard methods expected by Cochrane. We graded the certainty of the evidence using GRADE. Our primary outcome was the proportion of participants with postoperative residual refractive astigmatism of less than 0.50 dioptres (D) six months or more after surgery. We also collected data on mean residual refractive astigmatism. Secondary outcomes included: uncorrected distance visual acuity, vision-related quality of life, spectacle independence and adverse effects including postoperative lens rotation requiring re-alignment. To supplement the main systematic review assessing the effects of toric IOLs compared with LRIs in the management of astigmatism during phacoemulsification cataract surgery, we sought to identify economic evaluations on the subject.

MAIN RESULTS

We identified 10 relevant studies including 517 people (626 eyes). These studies took place in China (three studies), UK (three), Brazil (one), India (one), Italy (one) and Spain (one). The median age of participants was 71 years. The level of corneal astigmatism specified in the inclusion criteria of these studies ranged from 0.75 D to 3 D. A variety of toric IOLs were used in these studies, in all but one study, these were monofocal. Studies used three different nomograms to determine the size and placement of the LRI. Two studies did not specify this. None of the studies were at low risk of bias in all domains, but two studies were at low risk of bias in all domains except selective outcome reporting, which was unclear. The remaining studies were at a mixture of low, unclear or high risk of bias. People receiving toric IOLs were probably more likely to achieve a postoperative residual refractive astigmatism of less than 0.5 D six months or more after surgery (risk ratio (RR) 1.40, 95% confidence interval (CI) 1.10 to 1.78; 5 RCTs, 262 eyes). We judged this to be moderate-certainty evidence, downgrading for risk of bias. In the included studies, approximately 500 eyes per 1000 achieved postoperative astigmatism less than 0.5 D in the LRI group compared with 700 per 1000 in the toric IOLs group. There was a small difference in residual astigmatism between the two groups, favouring toric IOLs (mean difference (MD) -0.32 D, 95% CI -0.48 to -0.15 D; 10 RCTs, 620 eyes). Although all studies favoured toric IOLs, the results of individual studies were inconsistent (range of effects -0.02 D to -0.71 D; I² = 89%). We considered this to be low-certainty evidence, downgrading for risk of bias and inconsistency. People receiving a toric IOL probably have a small improvement in visual acuity at six months or more after surgery compared to people receiving LRI, but the difference is small and probably clinically insignificant (MD -0.04 logMAR, 95% CI -0.07 to -0.02; 8 RCTs, 474 eyes; moderate-certainty evidence). Low-certainty evidence from one study of 40 people suggested little difference in vision-related quality of life measured using the Visual Function Index (VF-14) (MD -3.01, 95% CI -8.56 to 2.54). Two studies reported spectacle independence and suggested that people receiving toric IOLs may be more likely to be spectacle independent (RR 1.56, 95% CI 1.14 to 2.15; 100 people; low-certainty evidence). There were no cases of lens rotation requiring surgery (very low-certainty evidence). Five studies (320 eyes) commented on a range of other adverse effects including corneal oedema, endophthalmitis and corneal ectasia. All these studies reported that there were no adverse events with the exception of one study (40 eyes) where one participant in the LRI group had a central de-epithelisation which recovered over 10 days. We found no economic studies that compared toric IOLs with LRIs.

AUTHORS' CONCLUSIONS

Toric IOLs probably provide a higher chance of achieving astigmatism within 0.5 D after cataract surgery compared with LRIs. There may be a small mean difference in postoperative astigmatism, favouring toric IOLs, but this difference is likely to be clinically unimportant. There was no evidence of an important difference in postoperative visual acuity or quality of life between the techniques. Evidence on adverse effects was uncertain. The apparent shortage of relevant economic evaluations indicates that economic evidence regarding the costs and consequence of these two procedures is currently lacking.

Phacoemulsification With 3.0 and 2.0 mm Opposite Clear Corneal Incisions for Correction of Corneal Astigmatism

PURPOSE

To compare the effect of 3.0 and 2.0 mm opposite clear corneal incisions (OCCIs) in phacoemulsification on reduction of preexisting corneal astigmatism, and their impact on corneal aberrations.

METHODS

This study is a prospective randomized controlled study that included 140 patients with age-related cataract and regular corneal astigmatism ≥0.75 diopter (D). Phacoemulsification was performed using on-meridian 3.0 or 2.0 mm corneal incision with or without an OCCI. Cases were divided into 4 groups: 3.0 mm OCCIs, 3.0 mm single clear corneal incision (3.0 mm SCCI), 2.0 mm OCCIs, and 2.0 mm SCCI. Keratometry and topography were performed at 3 months postoperatively. The variations in corneal astigmatism and aberrations were recorded. Surgically induced astigmatism was calculated using vector analysis.

RESULTS

The corneal astigmatism reduction was 0.61 ± 0.38 D in the 3.0 mm OCCIs group, significantly higher than the other groups (P ≤ 0.004); and 0.29 ± 0.29 D in the 2.0 mm OCCIs group. The mean surgically induced astigmatism was 1.07 ± 0.51 D in the 3.0 mm OCCIs group, higher than 0.61 ± 0.35 D in the 2.0 mm OCCIs group (P = 0.001). The root mean square values of corneal trefoil, spherical aberration, and total higher order aberrations increased at 3 months postoperatively, but there were no significant differences between OCCI and SCCI groups.

CONCLUSIONS

On-meridian 3.0 mm OCCIs are effective for correcting mild-to-moderate corneal astigmatism during cataract surgery, exerting no additional impact on corneal aberration compared with SCCI.

Two-stage procedure in the management of selected cases of keratoconus: clear lens extraction with aspherical IOL implantation followed by WFG-PRK

AIM

To assess the objective and subjective results of a two-stage procedure for management of keratoconus: clear lensectomy with aspherical intraocular lens (IOL) implantation followed by wave front-guided photorefractive keratotomy (WFG-PRK).

METHODS

This prospective interventional non-randomized study included patients aged 35 years old or more with grade I and II stable keratoconus, a clear visual axis, minimal corneal thickness (MCT) 420 µm or more and average keratometric reading (K) less than 54 diopter (D). Refraction of all selected eyes should be -8.00 D sphere or more with less than -6.00 D cylinder and could be corrected two lines or more with spectacles or contact lenses. All studied eyes underwent a two-stage approach treatment: first refractive lens exchange and aspherical IOL implantation followed, after at least 3mo, by WFG-PRK. Pre and postoperative complete ophthalmological examination were performed. Topographical, visual and aberrometric results were recorded and evaluated during 6mo follow up period. Moreover, patient satisfaction and other subjective outcomes were also analyzed.

RESULTS

The 13 eyes of 11 patients diagnosed with stable keratoconus and aged from 39 to 49y (42.4±6.2y) were enrolled in the study. At baseline, 8 eyes had grade I and 5 eyes had grade II keratoconus. The manifest sphere was -10.3±4.2 D (ranged from -8.0 to -14.0 D) and the manifest cylinder was -4.2±1.2 D (ranged from -1.75 to -5.50 D). After the two-stage procedure, sphere and cylinder reduced significantly to -0.43±0.22 D and -1.3±0.72 D respectively (P<0.001). There was also a highly significant improvement in the mean uncorrected distance visual acuity (UDVA) from logMAR 1.41±0.49 preoperatively to 0.51±0.16 postoperatively (P<0.001) and the mean corrected distance visual acuity (CDVA) from 0.76±0.24 preoperatively to 0.49±0.13 after the operation (P<0.001). All aberrometric and mesopic vision parameters and most of the topographical indices demonstrated highly significant improvement that remains stable until the end of follow up. All recorded subjective data revealed a high degree of patient satisfaction.

CONCLUSION

Two-stage approach (clear lens exchange with monofocal IOL followed by WFG-PRK) in selected cases of keratoconus is a safe, effective and highly predictable procedure with satisfactory visual and refractive results.

Improving the Toric Intraocular Lens Calculation by Considering Posterior Corneal Astigmatism and Surgically-induced Corneal Astigmatism

PURPOSE

To investigate the effect of surgically induced corneal astigmatism (SICA) and total corneal astigmatism (TCA) estimation on the anterior corneal astigmatism (ACA)-based toric intraocular lens (IOL) calculation.

METHODS

Data from preoperative and postoperative corneal astigmatism, postoperative visual acuities, and refractive outcomes were collected. The incision was superior in with the rule anterior corneal astigmatism (WTRA) eyes and temporal in against the rule anterior corneal astigmatism eyes. The following five methods of calculating the toric IOL were compared: (1) ACA only and estimated SICA; (2) ACA with a fixed posterior corneal astigmatism (PCA) and estimated SICA; (3) ACA with a fixed PCA value and actual SICA; (4) and (5) TCA derived from the regression equations of ACA and actual SICA. The residual astigmatism was simulated. The Alpins method was used to analyze the astigmatism.

RESULTS

Sixty eyes from 46 patients were enrolled. Thirty eyes had WTRA and the other thirty had against the rule anterior corneal astigmatism. The vector and arithmetic means of the difference vector decreased when the information regarding the actual SICA and PCA was added to the calculation (from 0.59 diopters [D] @ 87.5° to 0.15 D @ 48.5°, and from 0.95 ± 0.53 to 0.71 ± 0.63 D, respectively; p < 0.001). The mean difference vector across the whole sample was lowest using model 5. The correction index was significantly closest to 1.0 in the WTRA group.

CONCLUSIONS

Researchers may improve the accuracy of post-implantation predictions by calculating toric IOL using exact SICA and TCA, with consideration of the PCA derived from the regression equation of ACA.

Comparison of two techniques for toric intraocular lens implantation: hydroimplantation versus ophthalmic viscosurgical devices

Background

To compare the results between hydroimplantation of a single-piece, acrylic foldable toric intraocular lens (IOLs) and conventional implantation using an ophthalmic viscosurgical device (OVD).

Methods

In this study, 60 eyes with cataract and preexisting regular corneal astigmatism of 1.0 to 3.0 diopters (D) underwent the implantation of the AcrySof toric IOLs (Alcon Laboratories, Inc.). The patients were randomly assigned to a conventional implantation technique with an OVD or a hydroimplantation technique. Comparison of preoperative and postoperative parameters was performed using paired Student t tests, and independent Student t test was used to compare between the two groups.

Results

Three months postoperatively, the mean subjective astigmatism was 0.45 D ± 0.24 (SD) in the OVD group and 0.49 ± 0.29 D in the hydroimplantation group (P = 0.492). The mean endothelial cell density (ECD) loss was 7.54% ± 0.82% and 7.32% ± 0.59%, respectively (P = 0.117). The mean absolute IOL rotation was 4.77 ± 2.32 degrees and 4.70 ± 1.95 degrees, respectively (P = 0.334). The mean time for IOL implantation was 71.50 ± 8.10 s and 37.60 ± 3.90 s, respectively (P < 0.001). Two hours, 1 day, 1 week, 1 month, and 3 months postoperatively, there was no significant difference in IOP between the two groups (P > 0.05), although IOP two hours postoperatively seemed to be a little higher in the OVD group.

Conclusions

Compared with the use of OVDs for toric IOLs implantation, the hydroimplantation technique provided advantages of increased efficiency, reduced surgical time and cost, and no concerns of OVD-induced elevated IOP.

Trial registration

Current Controlled Trials ISRCTN55696872, Retrospectively registered (Date of registration: 25 March 2018).

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.

Prevalence of corneal astigmatism before cataract surgery in Indian population

The purpose of the study was to assess the prevalence of corneal astigmatism before cataract surgery in Indian population. The setting of this study was at the Sant Sarwan Dass Charitable Eye Hospital, Jalandhar, India. This is a clinic-based retrospective study. Charts of patients who underwent cataract surgery over a two-year period were retrospectively reviewed, and preoperative keratometric measurements were collected and analyzed. The mean age of 2316 patients (2502 eyes) was 59.54 ± 10.96 years. The corneal astigmatism was less than 1.0 Dioptre (D) in 796 eyes (59.37 %), 1.0-1.99 D in 716 eyes (28.62 %), 2.0-2.99 D in 187 eyes (7.47 %) and more than 3.0 D in 114 eyes (4.56 %). The mean corneal astigmatism was 1.04 ± 1.04 D and showed a gradual increase with age after the fourth decade. The astigmatism was with-the-rule in 709 (28.34 %), against-the-rule in 1298 (51.88 %), and oblique in 598 (23.9 %) eyes. There was a shift in astigmatism from with-the-rule to against-the-rule with increase in age. Over 40 % of the Indian patients undergoing cataract surgery have more than 1.0 D of corneal astigmatism and may benefit from the use of toric intraocular lenses. These data can be useful in planning to make this technology available for the patients.