Abstract
Background
A modified implantable collamer lens (ICL) with a central hole (diameter, 0.36 mm), a “Hole-ICL”, was created to improve aqueous humour circulation. The aim of this study was to investigate the fluid dynamic characteristics of aqueous humour in a Hole-ICL using computational fluid dynamics.
Methods
Fluid dynamics simulation using an ICL was performed with thermal-hydraulic analysis software FloEFD V5 (Mentor Graphics Corp.). For the simulation, three-dimensional eye models based on a modified Liou–Brennan model eye with conventional ICL (Model ICM, STAAR SURGICAL) and a Hole-ICL were used. Both ICLs were −9.0 diopters (D) and 12.0 mm in length, with an optic of 5.5 mm. The vaulting was 0.50 mm. The quantity of aqueous humour produced by the ciliary body was set at 2.80 μl/min. Flow distribution between the anterior surface of the crystalline lens and the posterior surface of the ICL was also calculated, and trajectory analysis was performed.
Results
The flow velocity 0.25 mm in front of the centre of the crystalline lens was 1.52 × 10-1 mm/sec for the Hole-ICL and 1.21 × 10-5 mm/sec for the conventional ICL. Outward flow from the hole in the Hole-ICL was confirmed by trajectory analysis.
Conclusion
These results suggest that Hole-ICLs improve the circulation of aqueous humour to the anterior surface of the crystalline lens.
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Acknowledgement
This study was supported by a grant from the Kitasato University School of Allied Health Sciences (Grant-in-Aid for Research Project, No. 2010–1029) (T.K.), a Kitasato University Research Grant for Young Researchers 2010–2011) (T.K.), and a Grant-in-Aid for Young Scientists (B) (T.K.). The authors thank KOZO KEIKAKU ENGINEERING Inc. (Mr. Osamu Kuwahara, Mr. Soichi Masuda, and Dr. Tsuyoshi Yamada) for technical support, and American journal experts for critical reading of the manuscript.
Financial disclosure
Takushi Kawamorita, None; Hiroshi Uozato, None. Dr. Shimizu received a consulting fee from STAAR.
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An earlier version of this paper was presented at the 34th Annual Meeting of the Japanese Society of Ophthalmic Surgeons, Kyoto, January 28, 2011.
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Kawamorita, T., Uozato, H. & Shimizu, K. Fluid dynamics simulation of aqueous humour in a posterior-chamber phakic intraocular lens with a central perforation. Graefes Arch Clin Exp Ophthalmol 250, 935–939 (2012). https://doi.org/10.1007/s00417-011-1850-2
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DOI: https://doi.org/10.1007/s00417-011-1850-2