Strabismus - new surgical and examination techniques

Project: Research

Project Details


Strabismus (misalignment of the eye, or squint) can cause double vision and impaired vision, as well as being a social handicap. The surgical procedure for the correction of strabismus involves adjusting the eye muscles to pull the eye into the correct position. The aim of this project is to solve some of the clinical problems encountered in the surgical correction of strabismus through experimental and clinical research.
A serious problem in strabismus surgery is the lack of tissue required to move the optical muscles so as to correct the defect. In 1994 we were the first in the world to use donor sclera (from the Tissue Bank of Skåne University Hospital, Sweden) to extend optical muscles. This technique has been described in the literature. We now intend to evaluate the clinical benefits and the benefits to the patient of this technique through the retrospective analysis of the outcomes of this procedure, so that the method can be employed at other clinics in Sweden and in other countries. If this technique can be more widely applied, the benefits to the patient will be considerable.

Another problem encountered in strabismus surgery is the risk of reduced blood flow to the anterior part of the eye as the arteries passing through the optical muscles are severed during surgery. It is important to maintain the blood flow in the eye to avoid visual impairment. There is, however, no established technique for monitoring the blood flow in the eye during surgery. We intend to study the importance of blood flow on the outcome of strabismus surgery, and establish how many muscles can be severed and moved during one surgical procedure. No measurements of this kind have been performed previously, but it is anticipated that new imaging techniques such as diffuse reflectance spectroscopy and laser speckle contrast imaging will make this possible. We are developing these techniques in collaboration with Dr. Nina Reistad at the Department of Physics at the Faculty of Engineering, Lund University. Measurements of blood flow, oxygenation, metabolism and tissue viability will be made on patients undergoing normal strabismus surgery using laser Doppler flowmetry, laser speckle contrast imaging, thermography, retCam and diffuse reflectance spectroscopy. Measurements will be made before severing the optical muscles (medial rectus, lateral rectus, superior rectus, inferior rectus). It is planned to include 20 patients for each optical muscle in the study. Biopsies will be analyzed using cytological and molecular biology techniques to determine tissue viability.

A third problem encountered in strabismus surgery is knowing the exact amount by which the optical muscles should be moved to position the eye correctly. We have a large amount of comprehensive data on strabismus surgery including detailed documentation of muscle adjustments and the change in strabismus angle. We are in the process of investigating the relation between these parameters with the aim of creating an algorithm for muscle adjustment, based on mathematical analysis.
Effective start/end date2016/01/01 → …

UKÄ subject classification

  • Ophthalmology