[Anterior segment analysis using OCT3]

[Spectral-domain optical coherence tomography in anterior segment imaging: the 3rd dimension]

PURPOSE

Anterior segment imaging using optical coherence tomography (OCT) time domain technology has been used for many years. When it appeared, it was a promising technique in the analysis of the anterior segment, making it possible to reach a definition of the ocular structures comparable with histology. Now with new-generation OCT, it is possible to perform high-definition and three-dimensional imaging.

MATERIAL AND METHOD

A 3D OCT-1000 (Topcon, Tokyo, Japan) parameterized to obtain high-definition and 3D imaging of the iridocorneal structures.

RESULTS

We present a collection of images obtained using this technique.

DISCUSSION

Based on a very sophisticated tool for retinal and glaucoma imagery, it is now possible to obtain very-high-quality imaging of the anterior segment, which, with its great versatility, increases the value of acquiring this type of device.

CONCLUSIONS

The potential of 3D OCT-1000, already a very good exam for the posterior segment, and the only one to perform anterior segment three-dimensional imaging in a single acquisition, should not be neglected.

[Arcuate keratotomy for postkeratoplasty astigmatism by femtosecond laser]

OBJECTIVE

Evaluation of the effectiveness of arcuate keratotomy performed with femtosecond laser for correction of postkeratoplasty astigmatism.

METHODS

This retrospective clinical study included 11 eyes. All cases underwent arcuate keratotomy using femtosecond laser. Outcome measures included visual acuity and endothelial cell density as well as refractive, keratometric, and topographic astigmatism. The incision depth was also evaluated by OCT-3.

RESULTS

With a mean follow-up of 7.4+/-6.7 months, uncorrected visual acuity was not modified and the mean best corrected visual acuity significantly improved from 1.68+/-1.59 lines (p=0.007). The mean preoperative refractive cylinder was 5.18+/-1.15D, decreasing to 3.41+/-1.93D (p=0.045) after laser-arcuate keratotomy. The reduction of preoperative keratometric (7.79+/-3.69D) and topographic (7.98+/-2.41D) astigmatism was higher, with a decrease to 4.81+/-2.52D (p=0.021) and 4.36+/-2.59D (p=0.005) postoperatively. Endothelial cell density was not modified after surgery. The difference between achieved and planned incision depth was -10.7+/-63.5mum. All cases were uncomplicated.

DISCUSSION

Arcuate keratotomies performed with the femtosecond laser were effective in reducing postkeratoplasty astigmatism and has a number of advantages over conventional techniques. However, efficacy could be improved by a more accurate nomogram.

CONCLUSION

Arcuate keratotomy performed with femtosecond laser is a relatively easy, safe, and effective means of treating postkeratoplasty astigmatism. Given our small sample, much larger series are needed to provide more confident estimates of astigmatism reduction proportions and to adjust correction parameters.