Umit Yolcu

Choroidal thickness in systemic arterial hypertension

Purpose To assess choroidal thickness changes in young adults with systemic arterial hypertension. Methods This prospective study comprised 80 hypertensive patients and 80 healthy control subjects. Choroidal thickness was measured with spectral-domain optical coherence tomography (SD-OCT) (RS-3000, Nidek). Choroidal thickness was obtained at the subfovea, 500 µm, 1000 µm, and 1500 µm nasal to the fovea (N500, N1000, N1500) and 500 µm, 1000 µm, and 1500 µm temporal to the fovea (T500, T1000, T1500). Systolic blood pressure (SBP), diastolic blood pressure (DBP), and mean arterial pressure (MAP) were measured with a mercury sphygmomanometer. Only the right eye values were used for statistical comparisons between the groups. Results Mean age was 23.8 ± 2.8 years in hypertensive subjects and 23.5 ± 2.1 years in the control group (p = 0.945). All choroidal thickness measurements (mean choroidal thickness, subfoveal choroidal thickness, all nasal and all temporal choroidal thicknesses) were significantly lower in hypertensive subjects (p<0.001 for subfoveal, N500, T500, T1000, T1500; p = 0.001 for N1000; and p = 0.012 for N1500). The correlations between choroidal thickness measurements and blood pressure (SBP, DBP, MAP) were insignificant (p>0.05 for all correlations). Choroidal thickness measurements were also insignificantly correlated with disease duration (p>0.05 for all correlations). Conclusions The results of this study demonstrated that choroidal thickness decreases in patients with systemic arterial hypertension. This may be caused by arteriolar sclerosis and vascular contraction caused by high intravascular pressure in the choroid.

Transmigrant maxillary canines

OBJECTIVE The objective of this study was to investigate the incidence and pattern of transmigrant maxillary canines. PATIENTS AND METHODS The records of 6000 patients who were presented to our oral and maxillofacial surgery services between January 1998 and January 2007 were reviewed. Observations were made as to the right/left localization and number of transmigrant canines; sex and age of patients; retained deciduous canines; and any other associated pathology. RESULTS A total of 12 patients presented with transmigrated maxillary canines with 6 females (age 15 to 37) and 6 males (age 17 to 57) in 6000 individuals (0.2%). All transmigrant canines were unilateral. The numbers of left and right transmigrant maxillary canines were equal. Ten individuals in 12 patients had not retained deciduous canines. None of these patients had any pathology associated with impacted canines. CONCLUSION The canine transmigration can occur not only in the mandible but also the maxilla. Further studies are necessary to examine this rare phenomenon to allow classification of transmigrant canines in the maxillary arch. Thus, the incidence, demographic factors, and etiology of this phenomenon can be clarified. How transmigrant maxillary canines pass on the contralateral side of the mid palatal suture must be completely clarified.

Micro-computed tomography and histomorphometric analysis of the effects of platelet-rich fibrin on bone regeneration in the rabbit calvarium

OBJECTIVE The present study aimed to investigate the effectiveness of platelet-rich fibrin (PRF) on bone regeneration when used alone or in combination with hydroxyapatite (HA)/beta-tricalcium phosphate (βTCP). DESIGN In this study, 20 New Zealand white rabbits were used and four calvarial defects were prepared in each animal. PRF, Straumann(®) Bone Ceramic (SBC), or PRF+SBC was applied to the defects; one defect was left untreated as a control. Ten rabbits were sacrificed at week 4 (T1) and 10 at week 8 (T2). After micro-computed tomography (micro-CT) scanning, the samples were sent for histological and histomorphometric analysis to evaluate and compare the volume and area of regenerated bone. RESULTS Histomorphometric and micro-CT analysis showed that both PRF and SBC significantly increased bone regeneration at T1 and T2 (P<0.01). When PRF was used in combination with HA/βTCP, a further significant increase in new bone formation was observed at T1 and T2 compared with that when PRF or SBC was used alone (P<0.01). CONCLUSIONS PRF has a positive effect on bone formation when used alone and in combination with HA/βTCP.

Bone regeneration by low-level laser therapy and low-intensity pulsed ultrasound therapy in the rabbit calvarium.

OBJECTIVE We evaluated the efficacy of low-level laser therapy (LLLT) and low-intensity pulsed ultrasound (LIPUS), alone and in combination, in triggering new bone formation. STUDY DESIGN Sixteen New Zealand white rabbits were given two calvarial defects by using a 6-mm trephine bur, then divided into four treatment groups: control, LLLT, LIPUS, and LLLT+LIPUS. The LLLT and LIPUS groups were treated three times a week for two weeks. The LLLT+LIPUS group received each treatment on the same day, 12h apart, three days a week for two weeks. The animals were sacrificed after three weeks. RESULTS LLLT and LIPUS, alone and in combination, enhanced new bone formation in comparison to the untreated controls after three weeks (P<0.05); the combined therapy did not produce an additive effect. CONCLUSIONS Our results demonstrate the efficacy of LLLT or LIPUS in triggering bone regeneration. Therapeutic dose and duration requires further study.

Early Neurodegeneration of the Inner Retinal Layers in Type 1 Diabetes Mellitus.

Purpose: This study explores retinal structural changes in type 1 diabetes without clinically diagnosed diabetic retinopathy (DR). Methods: Peripapillary retinal nerve fiber layer (RNFL) thickness, macular ganglion cell complex (GCC) thickness, and macular thickness (MT) were measured in 90 type 1 diabetic patients by using spectral domain optical coherence tomography. The values were compared with 100 sex- and age-matched healthy controls. The independent t test was used to assess differences in the mean age, mean diabetic and ocular parameters, and the thickness values between the diabetic and control groups. Multiple linear regression analysis was performed to investigate the correlation between the thickness values and diabetic and ocular parameters. Results: Whole-RNFL, the superior and inferior quadrants, and the superior half of the peripapillary RNFL thicknesses were significantly thinner in diabetic patients compared with controls (p < 0.05). GCC thicknesses in the average macular, outer temporal superior and outer temporal inferior sectors were significantly thinner in diabetic patients (p < 0.05). Central and average MTs were similar in both groups (p > 0.05). There were significant negative correlations of the duration of type 1 diabetes with the inner nasal MT, inner temporal superior GCC thickness, inner nasal inferior GCC thickness, and outer nasal superior GCC thickness (p < 0.05). Similarly, there were significant negative correlations of the level of HbA1c with the whole-RNFL thickness, superior-half-RNFL thickness, and superior-quadrant-RNFL thickness (p < 0.05). Conclusions: Type 1 diabetic patients without clinically diagnosed DR had neurodegeneration in the inner retinal layers compared with healthy controls.

Comparison of the Effects of Low-Level Laser Therapy and Ozone Therapy on Bone Healing.

AbstractThis study aims to compare the effect of low-level laser therapy (LLLT) and ozone therapy on the bone healing. Thirty-six adult male Wistar albino rats were used for this study. Monocortical defects were shaped in right femur of all rats. Defects were filled with nano-hydroxyapatite graft. The animals were divided into 3 groups and each group was than divided into 2 subgroups. Then, LLLT with a diode laser was applied to the first group (G1), ozone therapy was applied to the second group (G2), and no treatment was applied to the third group as a control group (G3). Animals were sacrificed after 4th and 8th weeks and the sections were examined to evaluate the density of the inflammation, the formation of connective tissue, the osteogenic potential, and osteocalcin activity. As a result, there were no significant differences among the groups of 4 weeks in terms of new bone formation. In the immunohistochemical assessment, the number of osteocalcin-positive cells was higher in the laser group compared to the other group of 4 weeks; this difference was statistically significant in the LLLT and ozone groups (P < 0.05). Histomorphometric assessment showed that the new bone areas were higher in the LLLT and ozone groups; furthermore, there was a statistically significant difference in the LLLT in comparison with the control group at 8th week (P < 0.05). At the same time immunohistochemical assessment showed that osteocalcin-positive cells were considerably higher in G2 than G1 at 8th week (P < 0.05). The findings of this study may be the result of differences in the number of treatment sessions. Further studies are therefore needed to determine the optimal treatment modality.

Effects of low-level laser therapy on osteoblastic bone formation and relapse in an experimental rapid maxillary expansion model

AIMS AND OBJECTIVES The aim of this study was to investigate the effects of low-level laser therapy (LLLT) on osteoblastic bone formation and relapse during expansion of rat palatal sutures. MATERIALS AND METHODS Thirty-two Wistar rats were randomly allocated into two groups of 16 rats each. In the first group, LLLT was applied 4 days after expansion commenced. Seven days after expansion, retainers were applied for 10 days. The second group was similarly treated, with the exception of laser therapy. All rats were sacrificed on day 7 (n = 1) (the end of the expansion period; laser group (LG) 1 [LLLT 1] and control group (CG) 1 [control 1]) and day 17 (n = 8) (the end of the retention period; LG 2 [LLLT 2] and CG 2 [control 2]) for histological assessment. RESULTS The LLLT 1 group had significantly higher numbers of osteoclasts than did the control 1 group (P = 0.036). No significant between-group difference in osteoblast cell or capillary numbers was evident when day 7 and 17 data were compared. CONCLUSION Histologically, LLLT stimulated bone formation, as revealed by analysis after the retention period. LLLT during expansion may accelerate bone healing.

Retinal structural changes in systemic arterial hypertension: an OCT study

Purpose To assess retinal nerve fiber layer (RNFL), ganglion cell complex (GCC), and macular thickness changes in young adults with systemic arterial hypertension. Methods This study included 80 young patients (age 23.8 ± 2.8 years) with systemic hypertension (sHT) without any known systemic or ocular disease and 80 age-matched (23.5 ± 2.1 years) healthy controls. Retinal nerve fiber layer thickness, macular thickness, and GCC thickness were measured with spectral-domain optical coherence tomography. Results Mean disease duration was 3.45 ± 1.48 years (range 2-10). Differences in intraocular pressure, body mass index, axial length, and spherical equivalent between the groups were insignificant (p>0.05). The differences in RNFL thickness did not differ between the groups. Patients with sHT had significantly lower central macular thickness (p = 0.037), inner superior macular thickness (p = 0.045), and outer temporal superior and outer temporal inferior GCC (p<0.001 for both). The RNFL thickness did not differ significantly in all quadrants between the groups (p>0.05). Systolic and diastolic blood pressure were significantly correlated with inner temporal superior and inner temporal inferior GCC thickness in a negative manner (p<0.05 for all). Conclusions Ganglion cell complex thickness decrease is possibly a better retinal marker for hypertensive changes with respect to RNFL and macular thickness.

Morphological features in eyes with endophthalmitis after cataract surgery–histopathology and optical coherence tomography assessment

To assess the ocular damage that occurs in eyes with postoperative endophthalmitis after cataract surgery (PE) based on optical coherence tomography (OCT) retinal scans of PE eyes and histological specimens of eyes removed due to PE.

Acute effect of cigarette smoking on pupil size and ocular aberrations: a pre- and postsmoking study.

Aim. To evaluate the acute effects of cigarette smoking on photopic and mesopic pupil sizes and wavefront aberrations. Methods. Cigarette smoker volunteers were recruited in the study. Photopic and mesopic pupil sizes and total ocular aberrations were measured before smoking and immediately after smoking. All volunteers were asked to smoke a single cigarette containing 1.0 mg nicotine. Pupil sizes and total ocular aberrations were assessed by optical path difference scanning system (OPD-Scan II ARK-10000, NIDEK). Only the right eyes were considered for statistical analysis. The changes of pupil size and total ocular aberrations after smoking were tested for significance by Wilcoxon signed ranks test. Results. Mean photopic pupil size decreased from 3.52 ± 0.73 mm to 3.29 ± 0.58 mm (P = 0.001) after smoking. Mean mesopic pupil size was also decreased from 6.42 ± 0.75 mm to 6.14 ± 0.75 mm after smoking (P = 0.001). There was a decrease in all the measured components of aberrations (total wavefront aberration, higher-order aberration, total coma, total trefoil, total tetrafoil, total spherical aberration and total higher-order aberration) after smoking; however the differences were insignificant for all (P > 0.05). Conclusion. Our results indicate that pupil constricts after smoking. On the other hand, smoking does not alter ocular aberrations.