Muhip Özkan

Corneal thickness measurements in normal and keratoconic eyes: Pentacam comprehensive eye scanner versus noncontact specular microscopy and ultrasound pachymetry

PURPOSE: To compare central corneal thickness (CCT) measurements taken with the Pentacam comprehensive eye scanner (CES), noncontact specular microscopy (SM), and ultrasound pachymetry (UP) in normal and keratoconic corneas. SETTING: Department of Ophthalmology, Ankara University School of Medicine, Ankara, Turkey. METHODS: In a prospective study, 3 CCT measurements were taken with the Pentacam CES, SM, and UP in that sequence from 1 eye of 45 consecutive patients with myopia (group A) and 62 consecutive patients with keratoconus (group B). Eyes with keratoconus were further divided into 3 subgroups, mild, moderate, and severe, according to the mean keratometry readings. RESULTS: Pentacam CES (r = 0.994) and UP (r = 0.993) demonstrated very high and comparable reproducibility in group A. In group B, Pentacam CES displayed better reproducibility (r = 0.988) than UP (r = 0.969) and SM (r = 0.901). The mean CCT measurements of Pentacam CES and UP were not significantly different in group A (P = .37) and in eyes with mild keratoconus (P = .29), whereas significant differences between all instrument pairs were evident in group B and in moderate and severely keratoconic eyes (P<.05). Noncontact SM measurements were significantly smaller than those of Pentacam CES and UP in all groups (P<.05) when a measurement could be obtained. There were significant linear correlations between CCT measurements of Pentacam CES, UP, and noncontact SM in groups A, B, and mildly keratoconic eyes (P<.001). CONCLUSIONS: Results suggest that whereas Pentacam CES and UP may be used interchangeably in normal eyes in the clinical setting for the measurement of CCT, one should be cautious interpreting corneal thickness data from Pentacam CES, UP, and particularly SM in eyes with keratoconus. Whereas, in normal and mildly keratoconic eyes, Pentacam CES and UP demonstrated very high and comparable reproducibility, in moderately keratoconic eyes, Pentacam CES readings showed better reproducibility than UP.

Evaluation of Scheimpflug imaging parameters in subclinical keratoconus, keratoconus, and normal eyes.

PURPOSE: To determine the efficacy of different Scheimpflug‐imaging parameters in discriminating between subclinical keratoconus, keratoconus eyes, and normal eyes. SETTING: Department of Ophthalmology, Ankara University Faculty of Medicine, Ankara, Turkey. DESIGN: Comparative case series. METHODS: Pentacam Scheimpflug measurements were taken in eyes with mild to moderate keratoconus, subclinical keratoconus, or with myopic astigmatism (normal eyes). Several parameters provided by the software or derived from the elevation maps were evaluated and compared between the groups. The Mann‐Whitney test, receiver‐operating‐characteristic (ROC) curves, and logistic regression analysis were used to compare the mean measurements and to evaluate the sensitivity and specificity of the parameters or constructed models. RESULTS: The corneal power and elevation measurements were statistically significantly higher and the cornea was significantly thinner in eyes with subclinical or clinical keratoconus than in normal eyes (P<.05). The ROC curve analysis showed high overall predictive accuracy of various elevation and thickness indices in discriminating ectatic corneas from normal corneas. Logistic regression analysis showed that the goodness of fit of a model using a combination of corneal power, thickness, and anterior elevation parameters was best in discriminating keratoconus eyes from normal eyes, whereas that of a model using a combination of corneal power, thickness, and posterior elevation was best in discriminating subclinical keratoconus eyes from normal eyes. CONCLUSION: Combined analysis of anterior and posterior corneal power, elevation, and thickness data provided by the Scheimpflug device effectively discriminated between ectatic corneas and normal corneas. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

NOD2/CARD15, NOD1/CARD4, and ICAM-1 gene polymorphisms in Turkish patients with inflammatory bowel disease

PurposeThe genetic susceptibility of people with certain NOD2/CARD15, NOD1/CARD4, and ICAM-1 gene variants to inflammatory bowel disease is still under investigation. The aim of this study was to investigate polymorphisms in the NOD2/CARD15 (R702W, G908R, and 3020insC), NOD1/CARD4 (E266K, D372N), and ICAM-1 (G241R, K469E) genes, which are known to be associated with inflammation, in Turkish patients with inflammatory bowel disease and healthy control groups.MethodsThe genotypes of 70 patients with endoscopically and histopathologically diagnosed Crohns disease (38 men, 32 women; mean age, 38.8 ± 1.3), 120 patients with ulcerative colitis (67 men, 53 women; mean age, 41.7 ± 1.3) and 106 healthy control subjects (37 men, 69 women; mean age, 35.7 ± 1.4), who stated that they had never had any prior bowel disease history, were compared. A polymerase chain reaction-restriction fragment length polymorphism analysis was performed for two variants of the ICAM-1 gene, the three main variants of the NOD2/CARD15 gene, and the E266K variant of the NOD1/CARD4 gene, and DNA sequencing was used for the D372N polymorphism of the NOD1/CARD4 gene.ResultsIn this study, the three previously described Crohns disease-predisposing variants of the NOD2/CARD15 gene and the polymorphisms examined in the NOD1/CARD4 and ICAM-1 genes were not found to be associated with ulcerative colitis or Crohns disease.ConclusionsThese findings suggest that the polymorphisms observed in the NOD2/CARD15, NOD1/CARD4, and ICAM-1 genes are not genetic susceptibility factors for Crohns disease or ulcerative colitis in Turkey.

Peritumoral brain edema in intracranial meningiomas

OBJECTIVE The goal of this study was to determine the relationship between patient age and gender and meningioma location, histological subtype, size, lobulation and peritumoral brain edema (PTBE). PATIENTS AND METHODS In a series of 55 patients with intracranial meningiomas, factors possibly related to the development of PTBE were analyzed. We used an EI (edema index) as the indicator of PTBE. EI was calculated by dividing the area of PTBE by that of the tumor. Thus if EI = 1, there is no PTBE. Univariate analysis was used to evaluate the relationship between EI and related factors. The MEI (mean edema index) difference between age groups was calculated using the Duncan Test. RESULTS We found that none of the factors analyzed influenced PTBE except patient age 61-70 years, which correlated with PTBE (p = 0.022). The difference between MEI in the 41-50 years and 61-70 years age groups was significant, with that in the 61-70 years age group being significantly higher. CONCLUSION We conclude that these findings in the 61-70 years age group may constitute an increased risk of perioperative mortality and morbidity.

Cytokine gene polymorphisms in Turkish patients with inflammatory bowel disease

Objective. Crohns disease (CD) and ulcerative colitis (UC) are chronic inflammatory diseases of the bowel, the causes of which are not fully known. Ethnic differences in disease prevalence, familial aggregation of the disease and studies of twins provide the most important evidence to suggest that genetic factors play a role in the pathogenesis of inflammatory bowel disease (IBD). The aim of this study was to examine the allelic polymorphisms that can determine the immune response levels in tumor necrosis factor alpha (TNFα), interleukin-1β (IL-1B), interleukin-1 receptor antagonist ( IL-1RN) and interleukin-10 (IL-10) genes and to investigate their roles in the inflammatory pathway in IBD. Material and methods. The study included 120 patients with UC and 70 patients with CD who were diagnosed either endoscopically or histopathologically. The control group comprised 105 healthy individuals who stated that they had never had any bowel disease during their life span. The polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method for polymorphisms in the TNFα gene at positions −308 and −238, the IL-10 gene at positions −1082 and −627, the IL-1B gene at −511 regions and the variable number of tandem repeat (VNTR) method for polymorphism in the intron 2 of the IL-1RN gene were performed. The results were analyzed on agarose gel electrophoresis. Results. No significant differences were found in the allele and genotype frequencies of the polymorphisms in the IL-1B, IL10, TNFα and IL-1RN genes between the patients with UC and CD and controls. Conclusions. The results suggest that these polymorphisms were not important risk factors in the susceptibility to IBD in Turkish patients.

Antiepileptic activity of melatonin in guinea pigs with pentylenetetrazol-induced seizures

Abstract Background: Antiepileptic and neuroprotective effects of melatonin (N-acetyl-5-methoxytryptamine) have been shown at higher doses (50–160 mg/kg). We aimed to investigate the antiepileptic effects of low-dose melatonin (10 mg/kg) on pentylenetetrazol (PTZ)-induced experimental epilepsy model. Materials and Methods: Twelve male albino guinea pigs weighing 500–800 g were used in our work. Initially, latent period, seizure intensity and mortality parameters were evaluated during the epileptic seizure induced by PTZ. After a recovery period of 7 days, effects of the neuroprotective agent, melatonin (which is dissolved in 2.5% ethanol–saline solution), on epileptic seizures induced by PTZ were evaluated. Effects of 2.5% ethanol, which is an anticonvulsant agent when administered acutely in high concentrations, on PTZ-induced seizures were also evaluated. Results: Data obtained from the study groups (PTZ, PTZ + melatonin and PTZ + ethanol) were evaluated by paired t-test, and p<0.005 was considered statistically significant. The differences of latent periods between the PTZ and PTZ + melatonin groups were found to be statistically significant (p<0.001). Conclusion: Although melatonin does not have a primary anticonvulsant effect at low doses (10 mg/kg), it lowers the mortality rates and attenuates seizure severity while increasing the latent period.

Anterior chamber parameters measured by the Pentacam CES after uneventful phacoemulsification in normotensive eyes

Purpose:  We set out to quantify changes in the anterior chamber volume (ACV), anterior chamber depth (ACD) and anterior chamber angle (ACA) measurements obtained by the Pentacam rotating Scheimpflug camera following uneventful phacoemulsification surgery in normotensive eyes with open iridocorneal angles.

Corneal elevation and thickness in relation to the refractive status measured with the Pentacam Scheimpflug system

PURPOSE: To prospectively evaluate the elevation and thickness data in patients with different types of refractive errors. SETTING: Department of Ophthalmology, Ankara University Faculty of Medicine, Ankara, Turkey. METHODS: After the refractive errors in 215 consecutive patients were determined, corneal topography measurements with the Pentacam Scheimpflug system were taken in the right eye of all patients and the right eye of 31 healthy emmetropic volunteers. The eyes with refractive errors were assigned to 1 of the following 4 groups: myopia, myopic astigmatism, high myopia, and hyperopia. The means of the parameters of 3 Pentacam measurements were evaluated and compared. RESULTS: Eyes with high myopia had significantly lower mean corneal thickness and volume measurements and higher mean anterior chamber depth (ACD) and anterior chamber volume (ACV) measurements than eyes in the other groups. The mean ACD, ACV, and anterior chamber angle were significantly lower in hyperopic eyes than in the other groups. The mean keratometry readings were statistically significantly flatter in the hyperopia group than in the other 4 groups. CONCLUSIONS: Eyes with high myopia had thinner corneas and deeper anterior chambers than emmetropic eyes and eyes in the other ametropic groups. Excluding eyes with hyperopia, which had significantly flat anterior and posterior elevation measurements, the elevation measurements in eyes with myopic refractive errors did not differ from each other or from those in emmetropic eyes. These findings may help clinicians and refractive surgeons using the Pentacam to better define normal from abnormal in the clinical setting.

Efficacy of Lodoxamide 0.1 % versus N-Acetyl Aspartyl Glutamic Acid 6% Ophthalmic Solutions in Patients with Vernal Keratoconjunctivitis

In a double-masked, randomized and controlled clinical trial, the effectiveness and safety of lodoxamide 0.1% eye drops were compared with N-acetyl aspartyl glutamic acid 6% (NAAGA) drops in the treatment of 120 patients with vernal keratoconjunctivitis. There were 60 patients in each of the two study groups. The drugs were instilled 4 times daily for 60 days. Follow-up examinations were made on days 7, 30 and 60. Of the 120 patients, 98 (50 in lodoxamide and 48 in NAAGA groups) were still available for follow-up on day 7, 89 (45 in lodoxamide and 44 in NAAGA groups) on day 30 and 75 (38 in lodoxamide and 37 in NAAGA groups) on day 60. Lodoxamide was clinically more effective than NAAGA. Statistically significant trends toward improvement were noted in the lodoxamide group in resolving papillae on day 30, decreasing corneal staining on days 30 and 60, relieving photophobia on day 60, tearing on days 7, 30 and 60 and itching on days 30 and 60. Lodoxamide 0.1% was more effective in lowering the mean scores for corneal staining on days 30 and 60 (p < 0.05). The composite scores for clinical signs and symptoms calculated by averaging the mean scores for signs and symptoms showed clinically significant differences in favor of the lodoxamide group. More frequent follow-up visits might have resulted in better statistical correlations. Treatment-related adverse events were reported in both groups with similar frequency but none were permanent or serious.

Tumour necrosis factor-alpha, interleukin-10, interferon-gamma and vitamin D receptor gene polymorphisms in patients with chronic hepatitis delta.

No data exist to assess certain polymorphisms that have a potential effect on the immune response in patients with chronic hepatitis delta (CHD). The aim of this study was to investigate polymorphisms in 6 polymorphic sites: IL‐10 ‐1082 (rs1800896), IL‐10 ‐627 (rs1800872), IFN‐γ +874 (rs62559044), TNF‐α ‐308 (rs1800629), vitamin D receptor (VDR) FokI (rs2228570) and VDR TaqI (rs731236). The genotypes of 67 patients with CHD and 119 patients with chronic hepatitis B (CHB) were compared. In addition, 56 individuals with resolved hepatitis B virus (HBV) infection were used as a control group for patients with CHB. Polymorphisms in TNF‐α, IL‐10, and VDR genes were analysed using polymerase chain reaction/restriction fragment length polymorphism methods. The IFN‐γ gene polymorphism was detected by allele‐specific polymerase chain reaction (PCR). Patients with CDH were more likely to have advanced liver disease compared with patients with CHB (P < 0.0001). IL‐10 ‐1082 and VDR TaqI polymorphisms showed significant differences between patients with CHD and CHB. The high secretory IL‐10 ‐1082 genotype GG was less frequent in CHD compared with patients with CHB and resolved HBV (17.7%, 37.4% and 47.1%, respectively (P < 0.05 for CHD vs CHB and resolved HBV). The frequency of the high secretory VDR TaqI TT genotype was 86.6% in patients with CHD, 62.7% in patients with CHB and 62.5% in resolved HBV individuals (CHD vs CHB: P < 0.05). None of the polymorphisms analysed had an effect on HBV persistence. IL‐10 ‐1082 and VDR TaqI polymorphisms may contribute to the more severe liver disease associated with CHD compared with CHB.