Офтальмохирургия (Jan 2017)

ASSESSMENT OF ANTERIOR CHAMBER PARAMETERS IN PATIENTS WITH HIGH MYOPIA CORRECTED WITH ANGLE-SUPPORTED PHAKIC INTRAOCULAR LENS USING THE OPTICAL COHERENCE TOMOGRAPHY

  • A. A. Shpak,
  • B. E. Malyugin,
  • N. P. Sobolev,
  • D. F. Pokrovskiy,
  • I. N. Shormaz,
  • K. M. Patakhova

DOI
https://doi.org/10.25276/0235-4160-2016-3-39-43
Journal volume & issue
Vol. 0, no. 3
pp. 39 – 43

Abstract

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Purpose. To assess anatomic topographic parameters of the anterior chamber of the eye in patients with high myopia corrected with the angle-supported phakic intraocular lens (PIOL) of the Cachet design using the anterior segment optical coherence tomography (AS-OCT).Material and methods. Seventeen highly myopic patients (31 eyes) corrected with angle-supported PIOL Cachet (Alcon) were examined in the period from September 2010 to December 2013. Mean age of the patients was 25.8±4.6 years. Mean spherical equivalent was -12.38±3.64D. All patients underwent comprehensive preand post-operative examinations, including the AS-OCT (Visante OCT, Carl Zeiss Meditec AG). Preoperatively the horizontal and vertical anterior chamber diameters (Angle-toAngle, ATA) were measured and the anterior chamber depth (from corneal epithelium and endothelium) using the AS-OCT. Also 3-12 months postoperatively the following parameters were assessed: «PIOL – corneal endothelium» (central), «PIOL – natural lens» (central) and «PIOL edge – corneal endothelium» (temporal and nasal).Results. The mean preoperative horizontal and vertical anterior chamber diameters were 12.07±0.38mm and 12.46±0.44mm, respectively (P<001). The mean preoperative anterior chamber depth values from corneal epithelium and corneal endothelium were 3.88±0.31mm and 3.36±0.33mm, respectively. Mean distance «PIOL – corneal endothelium» was 2.19±0.19mm, «PIOL – natural lens» – 0.92±0.15mm, temporal «PIOL edge – corneal endothelium» – 1.55±0.18mm and nasal «PIOL edge – corneal endothelium» – 1.53±0.18mm. In 10 of 31 eyes (6 of 16 patients) it was found that both the nasal and the temporal «PIOL edge – corneal endothelium» parameters were below 1.5mm. Using the step method of linear discriminant analysis a formula (reliable with P<0.005) and a simplified algorithm were calculated to predict the risk of a «dangerous» Cachet PIOL position in the anterior chamber of the eye. Based on our own clinical material a priori sensitivity and specificity of this formula were 100% and 95%, respectively.Conclusion. The current study showed that the existing patient selection criteria for the Cachet PIOL do not provide its safe position in some cases. The new prediction formula and algorithm allow timely identifying patients at risk early to enhance the efficiency and safety of this high myopia correction method.

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