SEE-GRID is based on the SEE++ software for the biomechanical simulation of the human eye. The goal of SEE-GRID is to adapt and to extend SEE++ in several steps and to develop an efficient grid-based tool for ``Evidence Based Medicine'', which supports the surgeons to choose the best/optimal surgery techniques in case of the treatments of different syndromes of strabismus. This paper consists of some speed up curves incase of the calculation of the brainstem pattern wit 45 points. This paper also outlines the further development steps related to the SEE-GRID database. The last section of this paper, will discuss and evaluate the possible designs of grid based Pathology Fitting and Surgery Fitting algorithms.

Over view of SEE++ software system:

 SEE++ means Simulation Expert for Eyes +Diagnoses +Transposition Surgery. SEE++ is software for the biomechanical 3D simulation of the human eye and its muscles. It simulates the common eye muscle surgery techniques in a graphic interactive way that is familiar to an experienced surgeon to deal with the support of diagnosis and treatment of strabismus.

3D View of the human eye Offers a realistic 3D representation of the human eye and the six extra ocular eye muscles Supports camera rotation, zoom-in, zoom-out and gaze rotation User is able to perform interactive surgeries

ARCHITECTURE OF SEE-GRID

The design of SEE-GRID is based on the SEE++ software for the biomechanical simulation of the human eye and its muscles. SEE++ was developed in the frame of the SEE-KID project by Upper Austrian Research and the Upper Austria University of Applied Sciences [SEEKID, Buchberger 2004, and Kaltofen 2002]; it simulates the common eye muscle surgery techniques in a graphic interactive way that is familiar to an experienced surgeon. SEE++ consists of a client component for user interaction and visualization and a server component for running the actual calculations; the message protocol SOAP is used for communication between the two components

SEE++ deals with the support of diagnosis and treatment of strabismus, which is the common name given to usually persistent or regularly occurring misalignment of the eyes. Strabismus is a visual defect in which eyes point in different directions. A person suffering from it may see double images due to misaligned eyes. SEE++ is able to simulate the result of the Hess- Lancaster test, from which the pathological reason of strabismus can be estimated. The outcome of such an examination is two gaze patterns (see Figure 3) of blue points and of red points respectively. The blue points represent the image seen by one eye and the red points the image seen by the simulated other eye, but in a pathological situation there is a deviation between the blue and the red points. The default gaze pattern that is calculated from the patient's eye data by SEE++ contains 9 points. But there exist gaze patterns with 21, 45 or more points (bigger gaze patterns provide more precise results for the decision support in case of some pathology, but their calculations are more time consuming).

In SEE++, a third gaze pattern, a measured one (with green points) of a patient can be given as input. In this case, the goal is to take some default or estimated eye data and to modify a subset of them until the calculated gaze pattern of the simulated eye (red points) matches the measured gaze pattern. This procedure is called pathology fitting. The original algorithm is time consuming and gives only a more or less precise estimation for the pathology of the patient. In the previous phases of the SEE-GRID project [SEE-GRID, 2005/1], the implementation is through” SEE++ to Grid Bridge". It is the initial component of SEE-GRID, via which the normal SEE++ client can get access to the infrastructure of the Austrian Grid (see Figure 1). The SEE++ clients can access this application in the same way as in the original SEE++ system; the usage of grid resources is completely transparent to them.

The ``SEE++ to Grid Bridge'' is able to split gaze pattern calculation requests of clients to independent subtasks and to distribute them among the servers. By this, we demonstrated how normal SEE++ clients are able to access via this bridge (see Figure 1) to the Austrian Grid and how a noticeable speedup can be reached in SEE++ — by applying simple data parallelism — by the exploitation of the huge computational power of the Grid. Then, we also developed a prototype version of the grid-enabled pathology fitting algorithm, whose goal is to determine (approximately) the pathological reason of strabismus in case of a patient.

Surgery Fitting

This method is able to support the doctors to find the best/optimal surgery technique to correct efficiently the vision of the patients. The problem of surgery fitting is similar to pathology fitting, but this case the result of the pathology fitting is taken as input and it is modified until the calculated gaze pattern closely matches the gaze pattern of the healthy eye. Further differences are:

Since only few eye parameters (e.g.: length of the muscles, muscle insertion on the eye globe, etc.) can be changed by surgery, the set of those eye parameters, which the surgery fitting algorithm can modify, is only a subset of the parameters which could be modified by the pathology fitting.

The final goal of the surgery fitting is to correct the (stereo) vision of a patient as much as possible (finding a global minimum). Since the intended optimal state can be uniquely determined by a particular gaze pattern. Here there is no need to apply a sequential heuristic as in the case of pathology fitting.

There is only one possible input data set, this is the fitted pathology (or if the pathology fitter returned more than one solutions, then the doctor has to choose one).