Lasting Effects: Seven Year Results of the Castrop Nomogram for Femtosecond Laser-Assisted Paired Corneal Arcuate Incisions

ABSTRACT

Purpose

Long-term results of arcuate incisions are rarely reported. This is unfortunate as long-term stability of astigmatic correction is of great interest to surgeons performing astigmatic correction. This study investigates the 7 year stability of results after application of femtosecond laser-assisted arcuate incisions with the Castrop nomogram.

Methods

Prospective interventional case series at the Augen- und Laserklinik, Castrop-Rauxel, Germany. Single site, single surgeon study. Seven year results of cataract patients with low to moderate corneal astigmatism receiving femtosecond laser‐assisted arcuate incisions using a TechnolasVictus SW 2.7 (Bausch & Lomb Inc, Dornach, Germany) were assessed and compared to 1 year results. Outcome evaluation was based on astigmatic vector analysis, manifest refraction, and visual acuity.

Results

The study analyzed 19 eyes of 19 patients 7 years after surgery. Ocular residual astigmatism changed from −0.26 to −0.39 D. Preoperative corneal astigmatism was −1.51 D. Correction Index changed from 1.0 to 1.16. The magnitude of difference vector changed from 0.26 to 0.39 D. The index of success changed from 0.20 to 0.29. Spherical equivalent remained stable. A slight tendency to change toward astigmatic overcorrection was mainly observed for patients with preoperative with the rule astigmatism, but not with patients with against the rule astigmatism.

Conclusions

The Castrop nomogram showed stable results 7 years after surgery. Similar to toric IOL surgery, it is advisable to be less aggressive when correcting with the rule astigmatism, to avoid overcorrection over a long period.

KEYWORDS:

• Arcuate incision
• astigmatism
• femtosecond laser
• keratotomy
• castrop nomogram

Financial disclosures

Dr. Hoffmann reports personal fees from Alcon, personal fees from Bausch & Lomb and personal fees from Johnson & Johnson that were received outside the submitted work. He has no consulting function in any of the aforementioned companies. Dr. Findl is scientific advisor to Alcon, Carl Zeiss Meditec AG, Croma, Johnson & Johnson and Merck. There are no further conflicts of interest.

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article. Raw data of this study are available from the corresponding author, upon reasonable request.

Additional information

Funding

This study was investigator initiated. Some material presented in this manuscript was provided by Bausch & Lomb Technolas. The authors received no financial support for the research, authorship, and/or publication of this article. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. Therefore, Dr. Hoffmann did not get financial support from Bausch & Lomb Technolas for the conduct of the study. The study was registered here: https://clinicaltrials.gov/ct2/show/NCT01752218?term=arcuate+incisions&draw=2&rank=6