Dubravka Biuk

Analysis of biomechanical properties of patellar ligament graft and quadruple hamstring tendon graft

INTRODUCTION Two types of transplant are commonly used in the surgical management of anterior cruciate ligament lesions: the central part of the patellar ligament and quadruple tendons of the gracilis muscle and semitendinosus muscle. AIMS The aim of this study was to determine the biomechanical characteristics of patellar ligament transplants and transplants of the quadruple tendons of the hamstring muscles under tensile force in the laboratory, and to compare the results in each group of samples. MATERIALS AND METHODS The study comprised 160 specimens: 40 specimens of gracilis muscle tendons, 40 of semitendinosus muscle tendons, 40 of quadruple tendons and 40 of the patellar ligament, approximately equally distributed according to sex, age (50-70 years) and the side of the body from which the specimen had been taken. RESULTS The working curve analysis of the specimens under tensile load of a maximum force of 30N showed the least elongation (0.31%) in the quadruple tendon, followed by the gracilis muscle tendon (1.48%) and patellar ligament tendon (3.91%). CONCLUSIONS The quadruple tendon specimen showed greater strength and higher elasticity compared with the patellar ligament specimen, which proved the starting hypothesis.

Histological analysis of cross-sectional area of quadruple hamstring tendons and patellar ligament samples in relation to age and gender

AIMS The middle of the patellar ligament and the quadruple hamstring tendons (gracilis and semitendinosus) are two types of graft predominantly used in anterior cruciate ligament (ACL) reconstruction. The aim of this study was to determine the morphometric characteristics of patellar ligament grafts and hamstring tendon grafts and to compare the results according to subject age and gender. MATERIALS AND METHODS The study was conducted on a total of 120 samples: 40 of gracilis tendon, 40 of semitendinosus tendon and 40 of patellar ligament, distributed equally according to gender, age (50-75 years) and the side of the body from which the sample was harvested. RESULTS Morphometric and histological analyses showed that patellar ligament samples had less cross-sectional area than quadruple tendon samples (49.29 mm(2) compared with 51.46 mm(2), respectively). Sexual dimorphism was noticed in distal cross-sections of gracilis tendons (p=0.09), cross-sections of quadruple tendons (p=0.07) and patellar ligament samples (p=0.01) because of different muscular build. CONCLUSIONS All samples obtained from male subjects had larger cross-sectional areas compared with the samples taken from females. Furthermore, samples obtained from subjects aged 60 years or under had larger cross-sectional areas than samples obtained from subjects aged at least 61 years for all types of graft.

Protective Effect of Blepharospasm on the Anterior Segment of the Eye

SUMMARY – The aim of the study was to determine the role of blepharospasm as a protective factor for the anterior segment of the eye by comparing the degree of blepharospasm and changes of the anterior segment structures. The study included sixty female patients older than forty years with the clinical diagnosis of blepharospasm. They were divided into two groups; the first group consisted of patients with stage I and II of blepharospasm with dominant dry eye symptoms, and the second group consisted of patients with stage III and IV of blepharospasm who required interventional therapy (all patients in this study were treated with botulinum toxin type A). Staining of ocular surface with vital dyes such as fluorescein was used to determine ocular surface defects. Fluorescein stains the corneal epithelial defects, which were statistically less pronounced in the interventional group. In conclusion, comparison of the results between the two groups of patients may implicate that advanced blepharospasm has a protective effect on ocular surface.

Prevalence of Open Angle Glaucoma in Risk Groups in Slavonia and Baranya Region

The aim of this prospective study was to detect primary open angle glaucoma (POAG) in its early stage in patients at a higher risk of its development, and to identify the risk group with the highest prevalence of POAG. The study was conducted at Department of Ophthalmology, Osijek University Hospital Centre, and included 250 patients divided into five groups, as follows: group 1, patients with diabetes type 1 and type 2; group 2, patients with arterial hypertension (blood pressure >140/90 mm Hg); group 3, patients with positive family history of POAG; group 4, patients with myopia between -3.0 and -8.0 diopters; and group 5, control group including patients aged 40 with no risk factors for POAG development. Study results showed that distribution of glaucoma patients was not equal across the groups. The prevalence of POAG in all patients was 5.6%, whereas in patients with positive family history of POAG it was 14%, which was statistically significantly higher than in patients with diabetes and myopia (4% both), as well as in control group. The difference was greatest in comparison to control group. There was no statistically significant difference in glaucoma incidence between the group of patients with positive family history (14%) and patients with systemic hypertension (6%). The results obtained suggest that of all risk factors analyzed, positive family history of POAG is the most important risk factor for glaucoma development in all risk groups.

Sensitivity of Diagnostic Tests for Dry Eye in Patients with Blepharospasm

The aim of the study was to evaluate diagnostic tests for keratoconjunctivitis sicca (Schirmer test, tear break-up time (TBUT) test, and corneal staining with fluorescein and lissamine green dye) in patients with blepharospasm. This prospective study included 60 female patients older than 40 with blepharospasm, divided into two groups according to clinical symptoms. For fluorescein test, the surface under the ROC curve was 1.0 with standard error (SE) 0 and 95% confidence interval (95% CI) 0.940-1.0; for Schirmer test, the surface under the ROC curve was 0.817 with SE 0.0555 and 95% CI 0.696-0.905; for lissamine green test, the surface under the ROC curve was 0.813 with SE 0.056 and 95% CI 0.691-0.902; and for TBUT test, the surface under the ROC curve was 0.772 with SE 0.061 and 95% CI 0.645-0.870. According to the results of ROC curve, which determines the sensitivity and specificity of normal values, comparison of diagnostic tests for keratoconjunctivitis sicca used in this study showed that fluorescein test had the best sensitivity and specificity. Schirmer test should be avoided in patients with blepharospasm because its results are influenced by frequent blinking and are not appropriate for study interpretation. Despite the pathologic values of TBUT test (numerically), this test is still acceptable for patients with blepharospasm because its interval takes more time than the interval between two blinks.

Retinal Nerve Fiber Layer Thickness in Glaucoma Patients Treated with Multiple Intravitreal Anti-Vegf (Bevacizumab) Injections

Over the past decade, intravitreal injections of anti-VEGF agents have been widely used and intensively developed as a treatment option for many ophthalmological indications. Due to its availability and low cost, the most frequently used anti-VEGF agent is bevacizumab. This type of therapy is often indicated in patients with exudative age-related macular degeneration (ARMD) and diabetic macular edema (DME). If, in addition to these two conditions, patients have a diagnosis of primary open angle glaucoma (POAG), they also present with optic nerve head (ONH) retinal nerve fiber layer (RNFL) thinning. The aim of this prospective study was to establish whether administering bevacizumab to patients with POAG leads to additional reduction of RNFL thickness. The study included 60 patients divided into two groups. First group comprised the eyes of patients with exudative ARMD and POAG, whereas second group comprised the eyes of patients with DME and POAG, all treated with bevacizumab. Control group comprised the fellow eye of each involved patient, which was not treated with bevacizumab. In a period of one year, all patients underwent optical coherence tomography (OCT) measurements of ONH RNFL thickness. The results of all patients were compared between the two study groups and then with control group results. Study results showed a decrease of RNFL in both groups of patients. Comparison of these two groups of patients after one year revealed a statistically more significant decrease in RNFL thickness in the second group (DME + POAG).