Dr. Bharti Kashyap,
K06544, Dr. Birendra Prasad Kashyap
ABSTRACT
PURPOSE:
Our purpose was to compare the visual outcomes of Toric IOLs Vs Verion Assisted FLACS Arcuate Incisions for management of coexisting cataract and corneal astigmatism of 1 D to 1.25 D
METHOD:
Retrospective review of 72 patients who underwent FLACS with toric IOL (Gr 1) and Verion Assisted FLACS Arcuate Incisions with (Gr 2). The main outcomes were 7 days and 90 days post-op UCVA, Spherical Equivalent (SE), Contrast Sensitivity (CS) expressed as Modular Transfer Function.
RESULTS:
Gr 2 yielded better 7 days post operative UCVA (p=0.722), SE (p=0.270) and CS (p=0.614 at 5cpd, p=0.709 at 10cpd) results than Gr 1 but were not significant.
90 days post operative results of UCVA (p=0.027), SE (p=0.019) and CS (p=0.041 at 5cpd, p=0.038 at 10cpd) in Gr 2 were found to be significantly better than Gr 1
CONCLUSION:
Toric IOLs and LenSx arcuate incision reduced astigmatism; but the correction was significantly less effective in Arcuate Incision as compared to Toric IOLs in longer time period
BACKGROUND
Approx 70 % of the general cataract population has at least 0.50 D of astigmatism, and estimated 40 % of the general cataract population has 1.00 D astigmatism
Today, cataract surgery is regarded as a refractive surgery, aiming pseudophakic emmetropia, which makes eliminating corneal astigmatism critical. Correction of astigmatism is a significant differentiator in Verion Assisted Femto Arcuate vs Toric IOL’s.
For achieving long term consistent results, we have compared Verion assisted FLACS Arcuate Incisions & Toric IOLs for management of corneal astigmatism of 1 D to 1.25 D.
INTRODUCTION
This is a prospective non -randomized clinical study. UCVA, spherical equivalent, corneal astigmatism, modular transfer function, corneal topography, aberrometry was done.
Candidates for cataract extraction were non-randomly divided into 2 groups:
- Verion Guided Lensx Femtosecond Assisted Arcuate incisions
- Toric IOL’s
In Femtosecond Group, patients underwent LenSx Pre treatment procedure by fragmentation mode of laser treatment followed by Phacoemulsification by Centurion Vision System and IOL implantation by Autosert injector. The energy used in the fragmentation of nucleus was 12 micro joules with spot and layer separation of 18 microns and 26 microns respectively. 2.3 mm corneal incisions and capsulotomy of 4.9 mm diameter were made by LenSx laser. Energy used for capsulotomy and corneal insicions making was 6 micro joules.
In Phacoemulsfication group, 2.2 mm clear corneal incision were made; after incision, a continuous curvilinear capsulorhexis measuring approximately 5.0 mm in diameter was accomplished with Verion Image Guide System. After hydrodissection, phacoemulsification of the nucleus and cortical aspiration were performed. All surgeries included in the analysis were uneventful and the IOLs were implanted accurately within the capsular bag.
All patients had a baseline pre operative assessment including anterior and posterior segment examination.
Postoperative examinations were performed at 7 days and 90 days. UCVA, Spherical Equivalent, Corneal Astigmatism and Contrast Sensitivity by Modular Transfer Function were determined at each examination.
STATISTICAL ANALYSIS
Results between the Femtosecond Laser assisted Cataract surgery pattern groups and phacoemulsification group were compared using a one way analysis of variance. The results are expressed as Mean ± SD. A p value < 0.05 was considered statistically significant. All statistical calculation was performed using IBM SS statistics Data Editor.
RESULTS
The mean age of patients in FLACS Arcuate Group and Toric IOL were 63.06 ± 4.23 and 62.67± 4.16 respectively (range: 50 to 70) for 38 males and 34 females.
Table 1 shows group statistics of Visual Acuity for Arcuate and Toric Group at 7 days and 90 days
| Group Statistics | |||||
| VAR00001 | N | Mean | Std. Deviation | Std. Error Mean | |
| VA 7 DAYS | ARCUATE | 36 | .1083 | .09673 | .01612 |
| TORIC | 36 | .1000 | .10142 | .01690 | |
| VA 90 DAYS | ARCUATE | 36 | .1639 | .10462 | .01744 |
| TORIC | 36 | .1361 | .10731 | .01789 | |
Table 2:- Shows Topometric cylinder in arcuate group
| INTERVAL | TOPOMETRIC CYLINDER |
| PRE OPERATIVE | 1.087 (± 0.13) Dioptres |
| 7 DAYS POST OPERATIVE | 0.439 (± 0.14) Dioptres |
| 90 DAYS POST OPERATIVE | 0.832 (± 0.22) Dioptres |
The table shows the distribution of topometric cylinder in the Arcuate group preoperatively, at 7 days and at 90 days post operatively.
Table 3:-Shows the Topometric Cylinder difference between the Pre operative and Post Operative at 7 and 90 days respectively in the Arcuate group.
| PERIOD | DIFFERENCE | SIGNIFICANCE |
| PRE OPERATIVE VS 7 DAYS POST OPERATIVE | .663 | 0.000 |
| PRE OPERATIVE VS 90 DAYS POST OPERATIVE | .017 | 0.087 |
The table shows the topometric cylinder that exist at 7 days post operative and 90 days post operatively which indicates that at 7 days the astigmatism was significantly reduced where as in 90 days there is no significance in the Arcuate group.
Table 4 showing Independent Sample Test of uncorrected Visual Acuity for LenSx Arcuate vs Toric Group at 7 days and 90 days
| Independent Samples (T)Test (Table 4) | ||||||||||
| t-test for Equality of Means | ||||||||||
| Visual acuity | F | Sig. | T | Df | Sig.(2-tailed) | Mean
Difference |
Std. Error
Difference |
95% Confidence | ||
| Lower | Upper | |||||||||
| 7 DAYS | Equal variances assumed | .097 | .756 | .357 | 70 | .722 | .00833 | .02336 | -.03825 | .05492 |
| Equal Variance not assumed | .357 | 69.844 | .722 | .00833 | .02336 | -.03826 | .05492 | |||
| 90 DAYS | Equal variances assumed | .089 | .766 | 2.112 | 70 | .027 | .02778 | .02498 | -.02204 | .07759 |
| Equal Variance not assumed | 2.112 | 69.955 | .027 | .02778 | .02498 | -.02204 | .07760 | |||
Uncorrected Visual Acuity in ARCUATE group was 0.108±0.097 and 0.10±0.102 for TORIC group at 7 days, whereas at 90 days these values were 0.164±0.105 and 0.136±0.107 for ARCUATE and TORIC groups (p=0.722, p=0.027 respectively)
By using Independent sample T test in the above groups we found that there is no statistical significant difference between the groups at 7 days, but statistical significance exists at 90 days
Table 5 showing group statistics of Spherical Equivalent for ARCUATE and TORIC Group at 7 days and 90 days
| Group Statistics | |||||
| VAR00001 | N | Mean | Std. Deviation | Std. Error Mean | |
| SE7DAYS | ARCUATE | 36 | .5189 | .20450 | .03408 |
| TORIC | 36 | .4511 | .22942 | .03824 | |
| SE90DAYS | ARCUATE | 36 | .4378 | .23295 | .03882 |
| TORIC | 36 | .4494 | .21674 | .03612 | |
Table 6:- Showing Independent Sample Test Result of spherical equivalent for lensx arcuate vs toric group at 7 days post op and 90 days post op under photopic condition
| Table 6 | ||||||||||
| Spherical Equivalent | F | Sig. | T | Df | Sig. (2-tailed) | Mean Difference | Std. Error Difference | 95% Confidence | ||
| Lower | Upper | |||||||||
| 7 DAYS | Equal variances assumed | .271 | .416 | -.220 | 70 | .827 | -.01167 | .05303 | -.11743 | .09410 |
| Equal Variance not assumed | .220 | 69.639 | .827 | -.01167 | .05303 | -.11744 | .09411 | |||
| 90 DAYS | Equal variances assumed | .393 | .533 | .323 | 70 | .019 | .06778 | .05122 | -.03438 | .16994 |
| Equal Variance not assumed | .323 | 69.095 | .019 | .06778 | .05122 | -.03441 | .16996 | |||
Spherical Equivalent at 7 days in ARCUATE group was 0.519±0.205 and 0.451±0.229 for TORIC group, whereas at 90 days these values were 0.438±0.233 and 0.449±0.217 for ARCUATE and TORIC groups (p=0.270, p=0.019 respectively)
By using Independent sample T test in the above groups we found that there is no statistical significant difference between the groups for Spherical Equivalent at 7 days, but statistical significance exists at 90 days
Table 7 showing the group statistics of Modular Transfer function values for 5 cpd and 10 cpd at 7 days post Op in Photopic Conditions
| 7 DAYS | VAR00001 | N | Mean | Std. Deviation | Std. Error Mean |
| 5 CPD | ARCUATE | 36 | .5258 | .05090 | .00848 |
| TORIC | 36 | .5314 | .04176 | .00696 | |
| 10 CPD | ARCUATE | 36 | .3489 | .02993 | .00499 |
| TORIC | 36 | .3517 | .03291 | .00548 |
Table 8:-Showing Independent Sample Test Result of modular transfer function values for 5 cpd and 10 cpd at 7 days post op under Photopic condition
| Independent Samples Test (Table 8) | |||||||||||
| 7 Days operative | F | Sig. | T | df | Sig. (2-tailed) | Mean Difference | Std. Error Difference | 95% Confidence | |||
| Lower | Upper | ||||||||||
| 5 CPD | Equal variances assumed | 1.282 | .261 | .506 | 70 | .614 | -.00556 | .01097 | -.02744 | .01633 | |
| Equal Variance not assumed | -.506 | 67.425 | .614 | -.00556 | .01097 | -.02745 | .01634 | ||||
| 10 CPD | Equal variances assumed | .183 | .670 | .375 | 70 | .709 | -.00278 | .00741 | -.01756 | .01201 | |
| Equal Variance not assumed | -.375 | 69.380 | .709 | -.00278 | .00741 | -.01757 | .01201 | ||||
In 7 days follow up, we found that Mean and standard deviation of Modular Transfer Function (expressed as variable of contrast sensitivity) in ARCUATE group was 0.526 ±0.051 at 5 cpd and 0.349±0.029 at 10 cpd, whereas these values of MTF in TORIC group was 0.532±0.042 at 5 cpd and 0.352±0.033 at 10 cpd. (p=0.614, p=0.709 respectively)
By using Independent sample T test in the above groups we found that there is no statistical significance difference between the groups at 5 cpd and 10 cpd.
Table 9 showing the group statistics of Modular Transfer Function values for 5 cpd and 10 cpd at 90 days post Op in Photopic Conditions
| Group Statistics | |||||
| 90 days Post Op | VAR00001 | N | Mean | Std. Deviation | Std. Error Mean |
| 5 CPD | ARCUATE | 36 | .4764 | .04223 | .00704 |
| TORIC | 36 | .4919 | .04515 | .00753 | |
| 10 CPD | ARCUATE | 36 | .3447 | .03517 | .00586 |
| TORIC | 36 | .3617 | .03273 | .00546 | |
Table 10 showing Independent Sample Test Result of modular transfer function values for 5 cpd and 10 cpd at 90 days post op under Photopic condition
| Independent Samples Test (Table 10) | ||||||||||
| 90 days Post Operative |
Sig. | df | Sig. (2-tailed) | Mean Difference | Std. Error Difference | 95% Confidence | ||||
| Lower | Upper | |||||||||
| 5 CPD | Equal variances assumed | .826 | .366 | -1.910 | 70 | .041 | -.01556 | .01030 | -.03611 | .00111 |
| Equal Variance not assumed | -1.910 | 69.689 | .041 | -.01556 | .01030 | -.03611 | .00111 | |||
| 10 CPD | Equal variances assumed | 1.169 | .283 | -2.116 | 70 | .038 | -.01694 | .00801 | -.03292 | -.00097 |
| Equal Variance not assumed | -2.116 | 69.641 | .038 | -.01694 | .00801 | -.03292 | -.00097 | |||
In 90 days follow up, we found that Mean and standard deviation of Modular Transfer Function (expressed as variable of contrast sensitivity) in ARCUATE group was 0.477 ±0.042 at 5 cpd and 0.345±0.035 at 10 cpd, whereas these values of MTF in TORIC group was 0.492±0.045 at 5 cpd and 0.362±0.033 at 10 cpd. (p=0.041, p=0.038 respectively)
By using Independent sample T test in the above groups we found that there is statistical significant difference between the groups at 5 cpd and 10 cpd.
Table 11 showing the group statistics of Modular Transfer function values for 5 cpd and 10 cpd at 7 days post Op in Mesopic Conditions
| Group Statistics | |||||
| 7 days Post Operative | VAR00001 | N | Mean | Std. Deviation | Std. Error Mean |
| 5 CPD | ARCUATE | 36 | .4797 | .04488 | .00748 |
| TORIC | 36 | .4775 | .05079 | .00846 | |
| 10 CPD | ARCUATE | 36 | .2878 | .02642 | .00440 |
| TORIC | 36 | .2894 | .02280 | .00380 | |
Table 12 showing Independent Sample Test Result of modular transfer function values for 5 cpd and 10 cpd at 7 days post op under mesopic condition
| Independent Samples Test (Table 12) | ||||||||||
| 7 DAYS POST OP | F | Sig. | T | Df | Sig. (2-tailed) | Mean Difference | Std. Error Difference | 95% Confidence | ||
| Lower | Upper | |||||||||
| 5 CPD | Equal variances assumed | .694 | .408 | .197 | 70 | .845 | .00222 | .01130 | -.02031 | .02475 |
| Equal Variance not assumed | .197 | 68.956 | .845 | .00222 | .01130 | -.02031 | .02476 | |||
| 10 CPD | Equal variances assumed | .373 | .543 | -.287 | 70 | .775 | -.00167 | .00582 | -.01327 | .00993 |
| Equal Variance not assumed | -.287 | 68.533 | .775 | -.00167 | .00582 | -.01327 | .00994 | |||
In 7 days follow up, we found that Mean and standard deviation of Modular Transfer Function (expressed as variable of contrast sensitivity) in ARCUATE group was 0.479 ±0.045 at 5 cpd and 0.288±0.027 at 10 cpd, whereas these values of MTF in TORIC group was 0.478±0.051 at 5 cpd and 0.289±0.023 at 10 cpd. (p=0.845, p=0.775 respectively)
By using Independent sample T test in the above groups we found that there is no statistical significant difference between the groups at 5 cpd and 10 cpd.
Table 13 showing the group statistics of Modular Transfer function values for 5 cpd and 10 cpd at 90 days post Op in Mesopic Conditions
| Group Statistics | |||||
| VAR00001 | N | Mean | Std. Deviation | Std. Error Mean | |
| 5 CPD | ARCUATE | 36 | .4242 | .03290 | .00548 |
| TORIC | 36 | .4408 | .03246 | .00541 | |
| 10 CPD | ARCUATE | 36 | .2875 | .02260 | .00377 |
| TORIC | 36 | .2969 | .02364 | .00394 | |
Table 14 showing Independent Sample Test Result of modular transfer function values for 5 cpd and 10 cpd at 90 days post op under mesopic conditions
| Independent Samples Test (Table 14) | ||||||||||
| 90 days Post Op | F | Sig. | t | df | Sig. (2-tailed) | Mean Diff. | Std. Error Diff. | 95% Confidence | ||
| Lower | Upper | |||||||||
| 5 CPD | Equal variances assumed | .116 | .735 | -2.164 | 70 | .034 | -.01667 | .00770 | -.03203 | -.00130 |
| Equal Variance not assumed | -2.164 | 69.98 | .034 | -.01667 | .00770 | -.03203 | -.00130 | |||
| 10 CPD | Equal variances assumed | .024 | .877 | -2.102 | 70 | .021 | .00056 | .00545 | -.01032 | .00143 |
| Equal Variance not assumed | -2.102 | 69.85 | .021 | .00056 | .00545 | -.01032 | .00143 | |||
In 90 days follow up, we found that Mean and standard deviation of Modular Transfer Function (expressed as variable of contrast sensitivity) in ARCUATE group was 0.424 ±0.033 at 5 cpd and 0.289±0.023 at 10 cpd, whereas these values of MTF in TORIC group was 0.441±0.033 at 5 cpd and 0.296±0.024 at 10 cpd. (p=0.034, p=0.021 respectively)
By using Independent sample T test in the above groups we found that there is statistical significant difference between the groups at 5 cpd and 10 cpd.
CONCLUSION
Both LenSx Arcuate incisions and Toric IOLs reduced astigmatism; but the astigmatism correction was less effective in due course of time in the Lensx Arcuate group as compared to the Toric IOLs.
Toric IOL group achieved significantly better post operative Uncorrected Visual Acuity, and Spherical Equivalent, Contrast Sensitivity as compared to the Lensx Arcuate group at 90 days post op resulting in significantly less number of eyes using spectacles post operatively.
RECOMMENDATIONS:-
Effects of toric IOLs were more predictable and sustained. Under correction was commonly observed in Verion assisted Flacs Arcuate group 3 months postoperatively. The correction in Toric group remained stabled with time (3 months) with no significant regression. Nomogram and cyclotorsion compensation / software upgrades, revision of surgical technique of opening of arcuates needs modification
REFERENCES
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2.Assisting femto incision with nomogram. Eric Donnenfeld, Ophthalmology management.
3.Using laser to manage Astogmatism during cataract surgery. Damien F. Gold berg. Cataract and Refractive surgery Today.
4.Comparison of Toric Intraocular Lenses and Arcuate Corneal Relaxing Incisions to Correct Moderate to High Astigmatism in Cataract Surgery. Roberts TV, Sharwood P, Hodge C, Roberts K, Sutton G. Asia Pac J Ophthalmol (Phila). 2014 Jan-Feb;3(1):9-16. doi: 10.1097/APO.0b013e3182a0af21.
5.The role of femtolaser in cataract surgery. Nagy ZZ, Szaflik JP, Klin Oczna. 2012;114 (4):324-7. Review