Predicting sulcus size using ocular measurements

Abstract

Traditional estimation of sulcus size through limbal measurement is inadequate because limbus size alone cannot predict sulcus size. A general formula using the sphere and the mean corneal power can help predict sulcus size. Corneal power was significantly and negatively correlated with sulcus and limbus size as well as sphere. The standard error of sulcus measurement by UBM was 0.4 mm.

Correcting Interdevice Bias of Horizontal White-to-White and Sulcus-to-Sulcus Measures Used for Implantable Collamer Lens Sizing

“…14 Pop et al used analog ultrasound microscopy to measure STS, where the lateral scan width is insufficient to image sulcus diameters in 1 scan sweep. 13 On the other hand Kawamorita et al examined the agreement of the HiScan and Orbscan devices, and reported a similar correlation between STS and horizontal WTW as reported here. 24 The repeatability of the UBM in our study was worse than reported in the literature; however, using the average of several measures significantly reduced the LoA, making these compatible to limits of repeatability reported with Scheimpflug methods.…”

“…[4][5][6][7][8][9][10][11][12] Despite efforts to improve predictability of vault following ICL implantation, it remains poor; the reasons for this are multiple. 5,[13][14][15][16][17][18][19][20][21][22][23] High-frequency ultrasound biomicroscopy (UBM) with a wide scanning field has enabled direct measurement of horizontal sulcus-to-sulcus (STS) diameter. Poor correspondence (г<0.50) between the horizontal WTW and STS measure has since been reported, however the width of the limits of agreement (LoA) reported between horizontal WTW and STS measures is similar to repeatability limits of STS estimates.…”

Corneal diameter measurements by corneal topography and angle-to-angle measurements by optical coherence tomography: Evaluation of equivalence

“…Different methods have been described for measuring these distances. [13][14][15]20,21 These methods can be divided into 2 groupsdmanual and automatedddepending on the examiner's level of participation in the procedure. Millimeter rules, calipers, gauges, or scales in slitlamp oculars are devices for manual determination of the WTW diameter.…”

“…The determination of sulcus-to-sulcus distance before implantation of a posterior chamber pIOL is important because the lens is placed in the sulcus. The devices 14 or Artemis 2, 23,24 can be useful for this purpose. Refractive surgery with implantation of pIOLs requires an exhaustive analysis of the anterior segment configuration to avoid postoperative complications in the medium-and long-term postoperative period.…”

“…Few studies have assessed the correlation between the external measurements and intraocular dimensions. 13,14 The objective of this study was to study the equivalence of the traditional corneal or WTW diameter measured by a digital caliper provided by the CSO topographer (Costruzione Strumenti Oftalmici) and the ATA diameter measured by optical coherence tomography (OCT) (Visante, Carl Zeiss Meditec AG).…”