J Korean Ophthalmol Soc.  2012 Nov;53(11):1603-1608.

The Efficacy of KR-1W Aberrometer in Assessing the Astigmatism after Toric Intraocular Lens Implantation

• Kim SW
• Han SY
• Lee KH

Abstract

PURPOSE
To evaluate the efficacy of the KR-1W aberrometer in assessing the astigmatism and the achieved axis after AcrySof Toric intraocular lens (IOL) implantation.
METHODS
Thirty-nine patients (48 eyes) that had undergone phacoemulsification and AcrySof Toric IOL implantation were included in the present study. At postoperative 1 month, ocular aberrations of all the eyes were measured using the KR-1W aberrometer before mydriasis and the achieved axis of AcrySof Toric IOL was measured by slit lamp examination after mydriasis. The achieved axis measured by slit lamp examination and the astigmatism of the implanted AcrySof Toric IOL were compared with the KR-1W.
RESULTS
The mean achieved lens axis after mydriasis measured by slit lamp examination and KR-1W was 86.43 +/- 47.49 degrees and 88.93 +/- 41.22 degrees, respectively. The correlation coefficient of the 2 methods was 0.992 (p < 0.001). The measured astigmatism according to the AcrySof Toric IOL model was 1.11 +/- 0.47D in SN60T3, 1.71 +/- 0.51D in SN60T4, and 3.32 +/- 0.78D in SN60T5.
CONCLUSIONS
Without the need to directly evaluate the axis of implanted Toric IOL after mydriasis, the achieved lens axis can be measured by the KR-1W without mydriasis. The AcrySof Toric IOL model could be assessed by the KR-1W without information about the AcrySof Toric IOL model.

Keyword

Aberrometer; AcrySof; Astigmatism; KR-1W; Toric Intraocular Lens

MeSH Terms

Astigmatism
Axis, Cervical Vertebra
Eye
Humans
Lens Implantation, Intraocular
Lenses, Intraocular
Mydriasis
Phacoemulsification

Figure

• 

  Figure 1 Postoperative estimation of toric intraocular lens (IOL) position using slit lamp and KR-1W. Pictures taken at the slit lamp is analyzed by Photoshop program for axis of toric IOL (Top left). Astigmatism of "internal" value is axis of toric IOL measured by KR-1W (Bottom left).

• 

  Figure 2 Time course of uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA). Both post-operative UCVA and BCVA were significantly improved when compared with pre-operative values (p-value < 0.001, Paired t-test) and remained stable, with no significant change for 6 months of follow-up (p = 0.362, p = 0.417 by Repeated-measures ANOVA).

• 

  Figure 3 The changes of mean astigmatism. Post-operative cylinder power was significantly improved when compared with pre-operative values (p < 0.013 by Paired t-test). There were no significant differences in post-operative cylinder power during the follow-up period of 6 months (p = 0.269 by Repeated-measures ANOVA).

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  Figure 4 Refractive outcomes. Mean spherical equivalent significantly improved compared to preoperative values during all follow-up periods. D = diopter.

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  Figure 5 Relationship between astigmatic axis measured by slit lamp and astigmatic axis measured by KR-1W. Linear regression model was used to estimate the relationship. The results showed strong positive association between the 2 methods.

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  Figure 6 Comparison of measured astigmatism by KR-1W. The measured astigmatism according to AcrySof Toric Intraocular Lens model were 1.11 ± 0.47D in SN60T3, 1.71 ± 0.51D in SN60T4, and 3.32 ± 0.78D in SN60T5.

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