Ciliary sulcus diameter, white-to-white, and the intrascleral haptic fixation technique

Management of complications of sutureless intrascleral intraocular lens fixation

PURPOSE

The purpose of the study was to report the complications of sutureless intrascleral (SIS) intraocular lens (IOL) fixation and its management.

MATERIALS AND METHODS

A multicenter, retrospective, consecutive interventional case series of patients with intra or postoperative complications after SIS IOL fixation during the technical learning curve of vitreoretinal surgeons from three Taiwanese referral hospitals. The used surgical techniques were the Scharioth technique for intrascleral tunnel fixation, Yamane technique (double-needle scleral fixation), and modified Yamane technique (double-needle flanged haptic scleral fixation). The IOL models and surgical instruments used as well as each patient's ocular characteristics and complication management were recorded.

RESULTS

Of the eight included patients, the complications of 3 (37.5%) and 5 (62.5%) were noted intraoperatively and postoperatively, respectively. Haptic-related complications, including haptic breakage, slippage, and haptic disinsertion, occurred in six eyes. Other complications included uveitis-glaucoma-hyphema syndrome, retinal detachment, and IOL tilt. For the two patients with haptic slippage, repositioning was achieved using a modified cow-hitch technique that resulted in favorable IOL centration and restored visual acuity.

CONCLUSION

Most complications surgeons encountered during their early exposure to SIS IOL fixation were haptic related. Surgeons should be aware of such complications to prevent and manage them during surgery. Our modified cow-hitch technique could be used to reposition IOLs with unilateral haptic slippage.

On the Methods for Estimating the Corneoscleral Limbus

OBJECTIVE

The aim of this study was to develop computational methods for estimating limbus position based on the measurements of three-dimensional (3-D) corneoscleral topography and ascertain whether corneoscleral limbus routinely estimated from the frontal image corresponds to that derived from topographical information.

METHODS

Two new computational methods for estimating the limbus position are proposed: One based on approximating the raw anterior eye height data by series of Zernike polynomials and one that combines the 3-D corneoscleral topography with the frontal grayscale image acquired with the digital camera in-built in the profilometer. The proposed methods are contrasted against a previously described image-only-based procedure and to a technique of manual image annotation.

RESULTS

The estimates of corneoscleral limbus radius were characterized with a high precision. The group average (mean ± standard deviation) of the maximum difference between estimates derived from all considered methods was 0.27 ± 0.14 mm and reached up to 0.55 mm. The four estimating methods lead to statistically significant differences (nonparametric ANOVA (the Analysis of Variance) test, p 0.05).

CONCLUSION

Precise topographical limbus demarcation is possible either from the frontal digital images of the eye or from the 3-D topographical information of corneoscleral region. However, the results demonstrated that the corneoscleral limbus estimated from the anterior eye topography does not always correspond to that obtained through image-only based techniques.

SIGNIFICANCE

The experimental findings have shown that 3-D topography of anterior eye, in the absence of a gold standard, has the potential to become a new computational methodology for estimating the corneoscleral limbus.