J Korean Ophthalmol Soc.  2009 Apr;50(4):510-517. 10.3341/jkos.2009.50.4.510.

Changes in the Cornea and Anterior Chamber After LASEK: Pentacam Findings

• Park JH
• Kang JH
• Jin KH

• KMID: 2212250
• DOI: http://doi.org/10.3341/jkos.2009.50.4.510

Abstract

PURPOSE: We evaluated changes in the cornea and anterior chamber after LASEK using Pentacam to search for signs of subclinical keratectasia occurrence.
METHODS
Seventy-one eyes of 36 patients who had received LASEK were enrolled in this study. All eyes were examined for asphericity of the anterior and posterior cornea (Q-value), anterior and posterior corneal displacement, central corneal thickness, anterior chamber depth, angle, and volume using Pentacam before surgery and again one month after the operation.
RESULTS
The postoperative changes in the asphericity of the posterior cornea and posterior corneal displacement were not statistically significant(p=0.668, p=0.101). The anterior chamber depth, angle, and volume decreased by 0.088 mm, 0.983degrees, 7.21 mm3 after LASEK, respectively. (p=0.000) The postoperative changes in asphericity of the anterior cornea, anterior corneal displacement, and central corneal thickness were statistically significant(p=0.000).
CONCLUSIONS
In this study, we compared changes in the anterior chamber and cornea after LASEK using Pentacam. Changes in the anterior cornea were significant; however, the posterior cornea did not change significantly. The anterior chamber depth, anterior chamber angle, and volume were decreased one month after the operation, although further long-term follow-ups will be necessary to verify these findings.

Keyword

Anterior chamber; Cornea; LASEK; Pentacam

MeSH Terms

Anterior Chamber
Cornea
Displacement (Psychology)
Eye
Follow-Up Studies
Humans
Keratectomy, Subepithelial, Laser-Assisted

Figure

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  Figure 1. The scatterplots for corneal asphericity between preoperative and postoperative states (at 1 month after operation). (A) Anterior corneal surface. A prolate anterior corneal surface had changed into an oblate surface after operation. (B) Posterior corneal surface. An asphericity of the posterior cornea was unchanged after operation.

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  Figure 2. The scatterplots for corneal central elevation between preoperative and postoperative states (at 1 month after operation). (A) Anterior corneal surface. Central elevation of anterior corneal surface was lower after operation.(B) Posterior corneal surface. Central elevation of posterior corneal surface was unchanged after operation.

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  Figure 3. The scatterplots for anterior chamber parameters between preoperative and postoperative states (at 1 month after operation). (A) Anterior chamber depth. Anterior chamber depth had become shallow after operation. (B) Anterior chamber angle. Anterior chamber angle had become narrow after operation. (C) Anterior chamber volume. Anterior chamber volume had shrunk after operation.

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  Figure 4. The schematic figures of change of the cornea after LASEK surgery. (A) Section of cornea during LASEK surgery. (B) Magnification of section plane and free body diagram. (C) Magnification of section plane and net force of free body diagram. Net force of free body diagram was directed posterior to anterior through axial plane. (D) Change of cornea and anterior chamber after LASEK surgery. Posterior cornea was not displaced and the anterior cornea was displaced posteriorly. Because of tensile strength, the iris was displaced anteriorly resulting in the anterior chamber angle, volume, and depth was decreased.

Reference

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