New Method For Keratoconus Treatment – Disc (Decentered Individualized Sphero-Cylindrical) Protocol And Nova Vision Treatment Planning Software

To present a new method for keratoconus treatment, the Decentered Individualized Sphero-Cylindrical (DISC) Protocol and software for planning and performing the procedure - NOVA Vision treatment planning software. The method and software were designed and developed at the Knezović Eye Institute, Zagreb, Croatia.

The DISC Protocol consists of decentered excimer laser ablation of the patient's partial spherocylindrical refraction from the center of the pupil and the corneal vertex towards the place of greatest corneal curvature (corneal apex) in combination with individual corneal cross-linking.

NOVA Vision treatment planning software integrates data captured from the anterior and posterior surfaces of the cornea using a Scheimpflug tomograph and uses advanced algorithms, vector analysis and differential geometry to calculate the optimal magnitude and location for laser ablation.The new software package enables the user to more easily analyze input data such as mesopic pupillometry, pachymetry, horizontal and vertical pupil-apical distance. In contrast to previous manual input, the data is automatically read from the Scheimpflug tomographic images of the patient's cornea. 

The innovations of the platform are also in the output data, which for each patient individually show the exact location, the optimal horizontal and vertical decentration in micrometers, the optical zone and the depth of the laser ablation.The predictive model has been improved and is generated using a supervised machine learning algorithm based on numerous data on already performed successful surgical interventions.

The novelty is also in the ratio of spherical and cylindrical decentration, depending on the tomographic curvature analyzes and the clinical relevance of the individual component in the patient's manifest refraction.

Prospective postoperative clinical follow-up of results usig this software and the DISC Protocol showed a significant improvement in visual acuity, non-invasiveness, patient satisfaction and improvement in quality of life compared to central ablations of manifest refraction or performing partial topographic or wavefront-guided procedures. Currently, we are in the protocol-making phase for multicenter, randomized porospective clinical study of the use of NOVA Vision software and the DISC Protocol in the treatment of patients with keratoconus.