Juraj Timkovič

Optical Nerve Disc Segmentation Using Circual Integro Differencial Operator

The paper deals with design of suitable methodology for the detection of the optic nerve disc from ophthalmological images. This issue was frequently solved in the past based on the Hough transform. The problem is that some the clinical images lack of sufficient contrast and so it is difficult to identify individual objects in the images. In our analysis, we process the image data, which are poorly distinguishable. Another significant drawback is the lower resolution of the analyzed data, which leads to poor identification of the optic nerve disc. For the detection of the optic nerve disc is used integro differential operator, which is looking for objects in the image that have a circular shape. The advantage of this proposed solution is sufficient sensitivity even in the weaker contrast environment.

Evaluation of the WinROP system for identifying retinopathy of prematurity in Czech preterm infants.

AIMS Retinopathy of Prematurity (ROP) is a potentially serious condition that can afflict preterm infants. Timely and correct identification of individuals at risk of developing a serious form of ROP is therefore of paramount importance. WinROP is an online system for predicting ROP based on birth weight and weight increments. However, the results vary significantly for various populations. It has not been evaluated in the Czech population. This study evaluates the test characteristics (specificity, sensitivity, positive and negative predictive values) of the WinROP system in Czech preterm infants. METHODS Data on 445 prematurely born infants included in the ROP screening program at the University Hospital Ostrava, Czech Republic, were retrospectively entered into the WinROP system and the outcomes of the WinROP and regular screening were compared. RESULTS All 24 infants who developed high-risk (Type 1 or Type 2) ROP were correctly identified by the system. The sensitivity and negative predictive values for this group were 100%. However, the specificity and positive predictive values were substantially lower, resulting in a large number of false positives. Extending the analysis to low risk ROP, the system did not provide such reliable results. CONCLUSIONS The system is a valuable tool for identifying infants who are not likely to develop high-risk ROP and this could help to substantially reduce the number of preterm infants in need of regular ROP screening. It is not suitable for predicting the development of less serious forms of ROP which is however in accordance with the declared aims of the WinROP system.

Congentinal Central Toxoplasma Chorioretinitis - Case Study

Congenital toxoplasmosis is a globally spread infectious disease caused by transplacental transmission of an intracellular parasitic protozoan Toxoplasma gondii. The infection can cause serious multi-organ complications, and in the case of vertical transmission, can lead up to fetal death - depending on the stage of pregnancy at the time of infection and the overall condition of the mothers immune system. Chorioretinitis, hydrocephalus and intracranial calcifications are a typical triad of symptoms associated with the disease. Toxoplasmic chorioretinitis in particular is the most common ocular manifestation. If the central retina is affected, it can cause a severe impairment of central visual acuity or lead up to blindness in the child. Prenatal screening of this disease is presently voluntary in the Czech Republic. This article reports on a case study of a toxoplasmic chorioretinitis in a newborn child observed from the active stage and the development of the affected retina over time. Further is also reported on the diagnostics and the treatment of multi-organ complications which occurred in this patient. Ophthalmologic examination was performed after diagnosis of hydrocephalus, which revealed severe changes of retina. Hydrocephalus was then properly treated. An overview of the diagnostic and therapeutic methods and the screening options available in the Czech Republic compare with other countries is also presented in the report. Key words: congenital toxoplasmosis, chorioretinitis, multi-organ complications, screening, hydrocephalus.

A rare form of ankyloblepharon filiforme adnatum associated with the Hay–Wells syndrome and a c.1709T>C mutation on the TP63 gene

ABSTRACT Introduction: Ankyloblepharon filiforme adnatum associated with Hay–Wells syndrome is a rare congenital disease caused by mutations in TP63 gene on the 3q27 chromosome. Here, we report a case of a new-born suffering from this syndrome in whom we detected a mutation c.1709T>C not previously included in the Ensemble database. Case description: A girl delivered in the 34th week of gestation from a physiological pregnancy was born with extensive burn-like skin defects, ankyloblepharon filiforme adnatum, palate cleft, onychodystrophy of all limbs and syndactyly of toes. Hay–Wells syndrome was suspected and confirmed by genetic examination. A heterozygous missense change c.1709T>C was found in the TP63 gene. This variant leads to a 570th codon exchange of leucine for proline (p.Leu570Pro) on the protein level. The eyelid separation was performed surgically, burns were treated locally and cosmetic surgeries correcting other defects are planned for the near future. The girl is still monitored by a multidisciplinary team. Conclusions: The mutation was not previously described in the literature or databases and should be included into these as probably pathogenic. A multidisciplinary approach is necessary to care for a patient with Hay–Wells syndrome, such care however can provide good results.

Extraction of Optical Disc Geometrical Parameters with Using of Active Snake Model with Gradient Directional Information

An analysis of the optical disc is challenging task in the field of clinical ophthalmology. Optical disc (OD) is frequently utilized as reference parameter for time evolution of retinal changes therefore, their analysis is significantly important. In the clinical practice, there are especially problem with lower quality of retinal records acquired by retinal probe of RetCam 3, and worse observation of OD area. Therefore, many algorithms are unable to precisely approximate of OD area. We propose a method based on the active snake model carrying out automatic extraction of retinal disc area even in the spots where an OD is not clearly observable, or image edges completely missing. Furthermore, the proposed solution calculates OD centroid, and respective area for further comparison of OD with retinal lesions.

A new modified technique for the treatment of high-risk prethreshold ROP under the direct visual control of RetCam 3

PURPOSE To describe a new modified technique in the treatment of ROP (retinopathy of prematurity) using the RetCam 3 digital imaging system - Camera-Assisted Laser photocoagulation and Cryotherapy of the Retina (CALCR). METHODS From Nov 2011 to Oct 2013, 113 infants were diagnosed with ROP. The average post-conceptual age (PCA) at the time of diagnosis was the 35(th) week of PCA; the average birth weight was 1,041 g. According to the ETROP study, the avascular part of the retina of infants with high-risk prethreshold ROP was treated with a trans-scleral diode laser or with cryotherapy within 48-72 h after the diagnosis. The intervention was performed under general anaesthesia under the direct visual control of the RetCam 3. RESULTS The CALCR technique was used in all 23 infants (46 eyes) diagnosed with high-risk prethreshold ROP. The average age of these infants at the time of the intervention was the 38(th) week of PCA. None of the infants had any serious complications during the CALCR procedure. In contrast to the traditional technique, CALCR offers many benefits: the image of the retina is real, magnified and not inverted, it shows details of the retina in a high resolution, photo and video documentation is available. Therefore the preoperative, intraoperative and postoperative condition of the retina can be precisely evaluated and compared on a fully standardized basis. CONCLUSIONS The CALCR procedure represents a new technique providing greater accuracy when targeting the avascular part of the retina, enables better visualisation and more precise treatment, and reduces the risk of unintended damage to healthy retinal tissue.