Adem Türk

Evaluation of the Nerve Fiber Layer and Macula in the Eyes of Healthy Children Using Spectral-Domain Optical Coherence Tomography

PURPOSE To determine the normative values of the peripapillary retinal nerve fiber layer (RNFL), macular thickness, and macular volume in healthy children using spectral-domain optical coherence tomography (SD-OCT) and analyze the correlation of such values with age, refraction error, and biometric measurements. DESIGN Observational case series. METHODS This institutional study involved 107 eyes from 107 healthy pediatric patients (54 female, 53 male) with ages between 6 and 16 years. After the biometric measurements and refractive error values (in spherical equivalent) of the cases were obtained, the peripapillary RNFL, macular thickness, and macular volume values were calculated using the Spectralis OCT device. RESULTS Among the study group, with an average age of 10.46 ± 2.94 years, the average axial length (AL) was 23.33 ± 0.89 mm; the average spherical equivalent (SE) value was -0.27 ± 0.99 diopter. The average peripapillary RNFL thickness was 106.45 ± 9.41 μm; the average macular thickness was 326.44 ± 14.17 μm; and the average macular volume was 0.257 ± 0.011 mm(3). The aforementioned OCT measurements were not significantly correlated with age, SE, or AL values (P > .05 for all). CONCLUSIONS This study reports SD-OCT findings among healthy pediatric cases. SD-OCT can be reliably used for pediatric patients because of its short exposure time and high degree of image resolution.

The relationship between diabetic retinopathy and serum levels of ischemia-modified albumin and malondialdehyde.

Purpose: To establish the correlation between ischemia-modified albumin (IMA) and malondialdehyde (MDA) and the development of diabetic retinopathy (DRP) in patients with diabetes mellitus. Methods: Seventy Type 2 diabetic patients, 35 with DRP, and 36 healthy controls were enrolled in this study. Serum IMA and MDA levels were compared statistically. Receiver operating characteristic curve analysis was also performed to calculate the value of IMA and MDA in distinguishing DRP. Results: Mean serum IMA levels were 0.658 ± 0.128 absorbance units in the non-DRP group, compared with 0.767 ± 0.074 absorbance units in the DRP group and 0.619 ± 0.044 absorbance units in the control group. Mean serum MDA levels were 0.325 ± 0.172 nmol/mL, 0.244 ± 0.152 nmol/mL, and 0.178 ± 0.131 nmol/mL, respectively. The differences in IMA and MDA levels were statistically significant for all groups (P < 0.05 for all). The areas under the receiver operating characteristic curves for the determination of DRP in diabetic patients were 0.789 (95% confidence interval, 0.682-0.896) for IMA and 0.3 (95% confidence interval, 0.175-0.426) for MDA. Conclusion: Both serum IMA and serum MDA levels were higher in the diabetic patients compared with the control group. In particular, the high sensitivity of IMA toward DRP showed that it reflected retinal vascular complication better than MDA. Ischemia-modified albumin may be a useful marker in monitoring the risk of DRP development.

Evaluation of Choroidal Thickness in Ankylosing Spondylitis Using Optical Coherence Tomography

Abstract Purpose: To investigate posterior segment (PS) findings in the eye in patients with ankylosing spondylitis (AS). Methods: Eighty-four patients with AS and 63 healthy controls were enrolled. PS evaluations were performed using optical coherence tomography (OCT). Foveal thickness, peripapillary retinal nerve fiber layer thickness, macular volume, ganglion cell complex, and choroidal thickness (CT) values were compared between the groups. Results: Mean CT was higher in patients with AS (326.5 ± 71.5 µm) than in the healthy controls (286.2 ± 59.5 µm) (p = 0.001). There was no significant difference between patients with AS and the healthy control group in terms of other OCT parameters. There was also no significant correlation between CT, AS activity index, and disease duration. Conclusions: This is the first study to evaluate effects of AS on CT. CT was high in patients with AS compared to healthy controls.

The results of intravitreal bevacizumab injections for persistent neovascularizations in proliferative diabetic retinopathy after photocoagulation therapy.

Purpose: The purpose of this study was to evaluate the effectiveness of intravitreal bevacizumab on persistent retinal neovascularizations in proliferative diabetic retinopathy. Methods: Thirty-three eyes of 24 patients (mean age, 52.75 ± 8.2 years) with proliferative diabetic retinopathy showing recurrences or no regressions in neovascularizations were evaluated in this study. After the intravitreal injection of 1.25 mg/0.05 mL of bevacizumab, the first examination was performed within 3 days and repeated at 1 week, 1 month, 3 months, and 6 months. In these examinations, localization and dimensions of neovascularizations were evaluated with red-free photographs and/or fluorescein angiography. Results: All patients had type II diabetes for a period of 12 ± 4.4 years (range, 2–20 years). After a single dose of bevacizumab, complete resolution rate of neovascularizations was 78.8% at 1 month, 63.6% at 3 months, and 45.4% at 6 months. When evaluated together with 9 eyes that had a second injection at 3 months, the complete resolution rate was 60.6% at 6 months. Mean best-corrected visual acuity and macular volume were 1.06 logarithm of the minimum angle of resolution (20/225 in Snellen) and 11.65 mm3 before treatment. Six months after treatment, these were 0.73 logarithm of the minimum angle of resolution (20/108 in Snellen) and 8.92 mm3 (P = 0.048 and 0.003, respectively). Conclusion: Bevacizumab can be used safely and successfully in patients with proliferative diabetic retinopathy who do not experience any resolution or experience recurrences after panretinal photocoagulation.

Flow Cytometrical Analysis of Adhesion Molecules, T-Lymphocyte Subpopulations and Inflammatory Markers in Pterygium

Background/Aim: Pterygium is a relatively frequent ocular surface disease with an unexplained etiopathogenesis. Our study was carried out with the aim to identify the presence of inflammatory cells and mediators such as T-lymphocyte subgroups (CD4 and CD8), intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1) and human leukocyte antigen-DR (HLA-DR) in pterygium tissue. Methods: Pterygium tissue, obtained from 24 patients, and normal conjunctival tissue, from the nasal bulbar conjunctiva obtained from 14 patients operated for ocular perforations or vitrectomy, were separated into epithelial and stromal components under the microscope and suspended with phosphate-buffered saline solution to form a suspension. Cell suspensions were treated with specific antibodies for ICAM-1, VCAM-1, and HLA-DR and T-lymphocyte subgroups and evaluated with flow cytometry. The obtained data were compared statistically. Results: When compared to the control tissue samples, higher rates of ICAM-1-positive cells, VCAM-1-positive cells and HLA-DR-positive cells were recorded in pterygium tissue samples. CD4 and CD8 lymphocytes were also found to be at higher levels when compared to the control group. There was a statistically significant difference between the two groups. Conclusion: When compared with normal conjunctival tissue, pterygium tissue had increased levels of T-lymphocyte infiltration and inflammatory markers demonstrating the possible contribution of cellular immunity to the pathogenesis.

Comparison of Oculus Pentacam and Stratus optical coherence tomography for measurement of central corneal thickness.

Purpose: Measurement of central corneal thickness (CCT) plays an essential role in the diagnosis and treatment of many ocular diseases. In this study, we aimed to compare the CCT measurements obtained using the Scheimpflug system (Pentacam; Oculus, Inc) with a retinal optical coherence tomography device (Stratus OCT; Carl Zeiss Meditec, Inc) to examine healthy corneas. Methods: CCT measurements of 80 eyes belonging to 40 male patients (mean age: 24.48 ± 6.01 years) were evaluated with the Pentacam and the Stratus OCT. The relationship between the CCT values obtained with these 2 devices was examined with a Pearson correlation analysis, a paired t test, and a Bland-Altman analysis. Results: The average CCT value obtained with Pentacam was 546.11 ± 34.15 μm and that obtained with Stratus OCT was 567.76 ± 35.02 μm. Although the average difference between the devices was 21.65 ± 8.59 μm (P < 0.0001), the measurements obtained with both devices were significantly correlated (r = 0.969, P < 0.0001). In Bland-Altman analysis, there was a high consistency between measurements obtained with either Pentacam or Stratus OCT devices. Conclusions: Corneal thickness measurements differ depending on the device used. Corneal thicknesses that have been calculated with Pentacam were lower than the values obtained with Stratus OCT. Both devices used for CCT measurement are easily applied, noninvasive, and effective. However, the devices are not interchangeable. Stratus OCT is not optimal for CCT measurement because of the important limitations of using manual measurements, but it can be used if other measurement devices designed for the purpose are not available.

Evaluation of the Repeatability and the Reproducibility of AL-Scan Measurements Obtained by Residents

Purpose. To assess the repeatability and reproducibility of ocular biometry and intraocular lens (IOL) power measurements obtained by ophthalmology residents using an AL-Scan device, a novel optical biometer. Methods. Two ophthalmology residents were instructed regarding the AL-Scan device. Both performed ocular biometry and IOL power measurements using AL-Scan, three times on each of 128 eyes, independently of one another. Corneal keratometry readings, horizontal iris width, central corneal thickness, anterior chamber depth, pupil size, and axial length values measured by both residents were recorded together with IOL power values calculated on the basis of four different IOL calculation formulas (SRK/T, Holladay, and HofferQ). Repeatability and reproducibility of the measurements obtained were analyzed using the intraclass correlation coefficient (ICC). Results. Repeatability (ICC, 0.872-0.999 for resident 1 versus 0.905-0.999 for resident 2) and reproducibility (ICC, 0.916-0.999) were high for all biometric measurements. Repeatability (ICC, 0.981-0.983 for resident 1 versus 0.995-0.996 for resident 2) and reproducibility were also high for all IOL power measurements (ICC, 0.996 for all). Conclusions. The AL-Scan device exhibits good repeatability and reproducibility in all biometric measurements and IOL power calculations, independent of the operator concerned.

Optical coherence tomography findings in a child with posterior scleritis

PURPOSE To present the findings of optical coherence tomography (OCT) in a child with posterior scleritis. METHODS A 13-year-old boy was admitted to our clinic with symptoms of low degree of vision and ocular pain. Ophthalmologic examination, ocular ultrasonography, magnetic resonance imaging, fundus fluorescein angiography (FFA), and OCT investigations were carried out and the results were evaluated. RESULTS Visual acuity was 10/10 in the right eye, and finger counting at 1 meter in the left eye. Anterior segments and vitreous were normal in both eyes. Fundus examination revealed the edema on the macula and the normal disc margins on the left eye, while the right eye was normal. The FFA revealed the leakage on the macula. Posterior scleral thickening, choroidal effusion, and serous retinal detachment were determined in ocular ultrasonography, suggesting posterior scleritis. There were interesting cystic forms underneath the retina and serous macular detachment (SMD) in the first OCT examination. The patient was treated with oral prednisolone for 10 days and then with oral indomethacin for 20 days. Following the systemic treatment the visual acuity of the left eye improved, subjective signs disappeared, and the OCT manifestations returned to normal. CONCLUSIONS In this case report, OCT provided new information about the retinochoroidal structure in posterior scleritis. These findings may be helpful for the diagnosis of this rare condition, but further studies are needed.

Consecutive exotropia: risk factor analysis and management outcomes.

Purpose: To report the frequency of risk factors and outcomes of consecutive exotropia (XT) following bimedial rectus recession (BMR) for the treatment of childhood esotropia (ET). Methods: Ninety-eight patients with ET, who underwent only BMR between 1996 and 2007, were included in this study. Predictors of the development of consecutive XT and treatment outcomes were compared between groups (group 1, cases with consecutive XT; group 2, cases without consecutive XT). Results: Mean follow-up time after BMR surgery was 7.23 ± 3.62 years. There was no significant difference between the groups in terms of age, preoperative angle of near deviation, follow-up time, or refraction for both eyes (p>0.05 for all). The differences regarding preoperative angle of distance deviation (p = 0.009), presence of inferior oblique overaction (p = 0.023), amount of BMR (p = 0.028), and postoperative adduction limitation (p<0.0001) between the groups were statistically significant. However, only preoperative angle of distance deviation and presence of postoperative adduction limitation were independent risk factors for the development of consecutive XT (p = 0.043, p = 0.007, respectively). Conclusions: Postoperative adduction limitation should alert physicians to the increased risk of developing consecutive XT in the long-term follow-up after BMR for the treatment of childhood ET.

Serum Anti-carbonic Anhydrase Antibodies and Oxidant–Antioxidant Balance in Patients with Acute Anterior Uveitis

Abstract Purpose: To study the existence of anti-carbonic anhydrase antibodies (anti-CA-I&II) in acute anterior uveitis (AAU) patients and to analyze the relationship between the levels of these antibodies and the total antioxidant capacity (TAC), total oxidant capacity (TOC), oxidative stress index (OSI), and malondialdehyde (MDA) level. Methods: Forty-five AAU cases and 43 healthy controls were enrolled in this prospective study. Results: The average anti-CA I and II antibody levels were 0.433 ± 0.306 and 0.358 ± 0.261 IU/mL, respectively, in the AAU group and 0.275 ± 0.147 and 0.268 ± 0.108 IU/mL, respectively, in the control group (p = 0.004 and p = 0.036, respectively). In addition, it was found that the TOC, OSI, and MDA levels in the AAU subjects were statistically significantly higher than those of the control subjects. Conclusions: These results suggest that autoimmune responses against CA I and CA II and an altered serum oxidant-antioxidant balance may be involved in the pathogenesis of AAU.