Korean J Ophthalmol.  2007 Mar;21(1):1-5. 10.3341/kjo.2007.21.1.1.

Comparison of Surgically Induced Astigmatisms after Clear Corneal Incisions of Different Sizes

• Moon SC
• Mohamed T
• Fine IH

• KMID: 1105022
• DOI: http://doi.org/10.3341/kjo.2007.21.1.1

Abstract

PURPOSE: This study was performed to assess efficiency and stability of astigmatic change by incision size after cataract surgery. METHODS: This work was designed as a retrospective, comparative, nonrandomized interventional study. A total of 121 cases of cataract surgery were reviewed in 98 patients performed by one surgeon at the Oregon Eye Institute in Eugene, OR, USA with 3-year follow-ups. All procedures were performed with the temporal approach of self-sealing incisions. The serial change in surgically induced astigmatisms were examined in all cases of three groups: Group A, cartridge injection of a foldable IOL through a 2.5 mm self-sealing incision; Group B, cartridge injection of a foldable IOL through a 3.0 mm self-sealing incision; Group C, cartridge injection of a foldable IOL through a 3.5 mm self-sealing incision. Keratometric data were obtained preoperatively, and 3 weeks, 3 months, 6 months, 9 months, 12 months, 24 months and 36 months postoperatively. Polar value analysis was performed to calculate the surgically induced astigmatism. RESULTS: The astigmatic change decreased over time in Group B (P<0.05). The other groups tended to remain in induced astigmatism. All groups showed anticlockwise torque at 3 weeks following surgery. Group B showed a decrease in deviation, but the other groups showed increases in their torque value at postoperative 12 months (P<0.05). CONCLUSIONS: The 3.0 mm incision size correlated with the least surgically induced astigmatism.

Keyword

Cataract surgery; Incision size; Surgically induced astigmatism

MeSH Terms

Retrospective Studies
Phacoemulsification
Lens Implantation, Intraocular
Humans
Cornea/*surgery
Cataract Extraction/*adverse effects/*methods
Astigmatism/*etiology

Figure

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  Fig. 1 SIA by incision size.

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  Fig. 2 Axis deviation after surgery by incision size.

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  Fig. 3 SIA; individual values in Group A at 12 months. In the upper figure, each point represents a single induced astigmatism uniquely characterized by a pair of polar values in the form of ΔAKP and ΔAKP (+45). All points inside the ellipse are within the 95% distribution of the observations. In the lower figure, the same phenomenon is displayed as net astigmatisms in a polar plot. The dashed line connecting the single point of polar values to the two equivalent net astigmatisms below illustrates this phenomenon.

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  Fig. 4 SIA; individual values in Group B at 12 months.

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  Fig. 5 SIA; individual values in Group C at 12 months.

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