Meridional differences in internal dimensions of the anterior segment in human eyes evaluated with 2 imaging systems

Abstract

This study suggests that the internal geometry of the anterior segment of human eyes does not constitute a circle. This may have significant relevance for the accurate sizing of phakic intraocular lenses.

Sulcus anatomy and diameter in pseudophakic eyes and correlation with biometric data: Evaluation with a 50 MHz ultrasound biomicroscope

“…Several studies [15][16][17][18][19] have evaluated the relationship between WTW and STS diameters in an effort to select adequately sized posterior phakic IOLs. Using different devices to measure the STS and the WTW, they showed a weak correlation (r Z 0.406 to r Z 0.597) between these 2 values.…”

“…In 11 eyes (22%), 1 of the oblique diameters was the largest. Werner et al 19 evaluated the sulcus diameter with the Artemis device in postmortem eyes and in a clinical trial. In the postmortem eyes, the mean vertical diameter was larger than the horizontal diameter, while in the clinical study the horizontal diameter was larger than the vertical diameter.…”

“…Surprisingly, to our knowledge, no data on the STS diameter in pseudophakic patients have been published. In contrast, many studies [15][16][17][18][19][20][21] report the sulcus anatomy in young phakic patients with the goal of optimizing the sizing and vault of posterior chamber phakic IOLs. Other studies 22,23 report the sulcus anatomy in aphakic eyes with a scleral-fixated IOL to evaluate and optimize the IOL position.…”

Assessment of a single-piece hydrophilic acrylic IOL for piggyback sulcus fixation in pseudophakic cadaver eyes

“…After gross measurements performed with a digital metric ruler (Absolute Digimatic, Mitutoyo Corp.), the anterior segment of each eye was imaged under a very-high-frequency ultrasound system (Artemis, Arcscan, Inc.), which has expected axial resolution and lateral resolution of 35 mm and 65 mm, respectively. 15 Special attention was directed to documenting the overall position of the primary IOL and to measuring the sulcus diameter in each eye in the horizontal meridian. The corneal epithelium was then removed with a blade, and the corneal surface was immersed in a hypertonic solution (dextran) in an attempt to restore corneal clarity.…”

Three-year stability of an angle-supported foldable hydrophobic acrylic phakic intraocular lens evaluated by Scheimpflug photography

“…All models have a 6.00 mm meniscus (convex-concave) optic and are available in 0.50 D increments from À6.00 to À16.50 D. In this study, the overall size of the IOL was determined using intraoperative WTW caliper measurements plus 0.5 mm. 25,26 The pIOL power was calculated using a formula originally derived by van der Heijde 27 and refined by Holladay. 28…”