The OCT-MAT Project: early diagnosis of ocular edemas

The aim of this project was to develop a practical, user friendly software tool in order to have significant and quantitative information on macular edema from OCT images. The activity has been carried out in collaboration with the Cattedra di oculistica dell’ospedale di Varese (Italy), in 2006-2008. We have developed a novel, dedicated software, called OCT-Measurements Analysis Tool (OCT-MAT), that acquires the avi files from an OCT 3 (Carl Zeiss, Meditec, Dublin, CA, USA) and a OCT/SLO (Ophthalmic Technologies Inc., Toronto, Canada) instruments, and carries out five subsequent elaboration steps. These are (i) the creation of patient’s folder, (ii) the selection of frames from the avi files, (iii) the filtering of the frames, (iv) the extraction of quantative information from the hyporeflective areas and their analysis, and (v) the comparison among frames for patient follow-up.

The OCT-MAT software is able to process and output quantitative information in terms of the number of empty spaces and of their extension in micron2. In addition, it allows us to analyze edema reabsorption during time, by suitable clustering of macular empty spaces (i.e., hyporeflective areas). This new OCT-MAT software has been applied on 30 healthy eyes and on three groups of patients with different macular diseases.The use of the OCT-MAT software allows us to measure the edema in terms of both the number of empty spaces and of their extension directly from the inside retina. Suitable tools are available to customize the standard modalities of operation, in order to optimize the measurements. A dedicated staging system gives a quick interpretation of the results.

The possibility of comparing macula edema measurements belonging to different images processed in subsequent times results in the achievement of numerical information, instead of simple qualitative evaluation, on the evolution of macular edema as well as on edema clearance. The OCT-MAT can be installed on standard, non-dedicated hardware, and the learning curve of an experienced retina specialist is very short.

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Relevant Publications

Sansoni, G.; Tironi, M.; Trebeschi, M.; Tottoli, F.; Azzolini, C.; Donati, S. “Diagnostica oculare mediante sistema di analisi per la misura di aree iporiflettenti intraretiniche“, Atti del XXIV Congresso Nazionale Associazione “Gruppo di Misure Elettriche ed Elettroniche”, pp. 319-320. 2007

Prati, M.; Donati, S.; Tartaglia, V.; Sansoni, G.; Tironi, M.; Chelazzi, P.; Brancato, R.; Azzolini, C. “Correlation Between Visual Acuity and Retinal Sensitivity Before and After Surgery for Macular Diseases“, Investigative Ophthalmology and Visual Sciences, Vol. 49, no. 13. 2008

Donati, S.; Sansoni, G.; Tironi, M.; Chelazzi, P.; Brancato, R.; Azzolini, C. “Evaluation of results of macular surgery: Role of microperimetry-related OCT imaging study“, Abstract and Presentation, 8th. EURETINA congress, Vienna. 2008

The Brotlaibidole project

The project is aimed at studying a very specific typology of archaeological finds, called the ‘Tavolette enigmatiche‘ or ‘Brotlaibidole‘. The activity developed at the Laboratory focused on (i) the optical 3D acquisition of the pieces, (ii) the creation of 3D meshes, and (iii) the study of the occurrences and of the morphological signs impressed on them.

This work is part of a larger activity that involves a number of partners. These are the Regione Lombardia (A.M. Ravagnan), the Provincia di Mantova (T. Grizzi), the Comune di Cavriana (B. Righetti), the Museo Archeologico dell’Alto Mantovano (A. Piccoli), the Università di Verona (S. Marchesini).

The “Brotlaibidole” are small baked-clay objects of prevalently ovoid shape of the 2100-1400 B.C. periods, engraved with symbols and drilled holes whose meaning is still unknown.

Their presence in Italy and in many countries in the northeast Europe represents an “enigma” for the specialists. The reason is that the shape and the orientation of the signs is very similar among the objects, even if they have been found in different geographical sites.

Hence, we have been required to accomplish an extensive measurement campaign in Europe, and to produce and collect the 3D models in a unique database, in view of their future study by the specialists. To carry out the measurement, we used the Vivid 910 sensor (Konica Minolta Inc.). Besides the measurement performances, that well suit to the resolutions required in this application, the system is rugged, portable, and fast in the setup and the acquisition processes. So far, 30 specimens have been acquired, modeled and organized in a database. Their resolution is 120μm.

Following the acquisition and point-cloud elaboration, we carried out a selection of symbols to be compared. The different symbols were extracted from the models and properly oriented in a suitable reference frame.

Symbols from different “pieces” were then superimposed and aligned, in a totally automatic way.

Color coding was used as a user-friendly way to obtain information about the amount of overlapping between the two symbols. All these steps were performed by the self developed “ATEC-3D” software: a user-friendly environment, specifically intended to be used by a non software expert such as an archaeologist.

In the ATEC-3D panel, the signs to be compared are chosen, and they appear as 3D models. Point clouds and their superposition in color coding are presented after suitable automatic registration and distance compensation. An index of similarity (rms value of the differences) is obtained to quantitatively assess the goodness of overlapping.

This process has been tested on a suitable number of self-made signs used as references, printed onto clay surfaces under different angles and with different pressures.

The ATEC-3D software has been delivered to the archaeologists, who have now started the overall comparison of all signs derived from the 30 models, whose 3D acquisition has been made and whose signs are now in the common database.