Eyyup Karahan

The Effect of ND:YAG Laser Posterior Capsulotomy Size on Refraction, Intraocular Pressure, and Macular Thickness.

Purpose. The aim of this study is to examine the influence of capsulotomy size on, spherical equivalent (SE), intraocular pressure (IOP), and macular thickness. Materials and Methods. Sixty-eight patients were examined preoperatively and 1, 4, and 12 weeks after Nd:YAG capsulotomy. Patients were divided into two groups based on the postoperative capsulotomy size. Changes in SE, IOP, and macular thickness were compared between two groups. Results. We found a higher hyperopic shift in large capsulotomy group. In both groups 1 and 2, IOP increased 1 week postoperatively. Intraocular pressure rise in group 2 was higher than in group 1. Both groups had increased macular thickness at 1 week postoperatively. The degree of macular thickening was similar in group 1 and group 2. Comment. Patients who underwent a larger capsulotomy have a higher hyperopic shift and IOP elevation. Rise in macular thickness was similar in large and small capsulotomy groups.

Anterior migration of dexamethasone implant in a pseudophakic patient with intact posterior capsule

Intravitreal application of Ozurdex® (Allergan, Inc., Irvine, CA, USA) which is a biodegradable, sustained-release dexamethasone implant has been reported to be effective in the treatment of macular edema. Migration of such implant into the anterior chamber has been recently described in cases without perfect zonular or the posterior capsular integrity. Herein, we report the first case with anterior migration of Ozurdex® implant that mislocated just behind the intraocular lens (IOL) in an intact capsular bag. It is thought that such implant migrated anteriorly towards into the posterior chamber through weak zonules as the present case had a medical history of uneventful phacoemulsification surgery with the implantation of posterior chamber IOL. However, the migrated implant was well tolerated since there was no sign of the corneal complication, rise in intraocular pressure, and anterior chamber reaction. Close follow-up was scheduled to find out any signs of anterior segment pathology. Meanwhile dexamethasone implant completely degraded at the 4th month of postoperative follow-up.

Retinal nerve fiber layer thickness changes in obstructive sleep apnea syndrome: one year follow-up results.

AIM To investigate the retinal nerve fiber layer (RNFL) thickness changes in patients with obstructive sleep apnea syndrome (OSAS) for one year follow-up. To discuss the possibility of detecting tendency of glaucoma in this population by using spectral domain optical coherence tomography (3D-OCT-2000 Spectral domain). METHODS After polysomnographic study, all subjects (64 OSAS patients and 40 controls) underwent detailed ophthalmological examination. After these examinations, patients with glaucoma and patients who had ophthalmological and/or systemic disease were excluded from the study. Totally, 20 patients in OSAS group and five patients in controls were excluded from the study in the first examination and follow-up period. The RNFL thickness was assessed with OCT. Forty-four OSAS patients and 35 control subjects were followed up 12mo. RNFL thickness change and OSAS patients were evaluated for severity of disease by Apnea-Hypopnea Index (AHI). RESULTS Forty-four OSAS patients and 35 controls were enrolled in the study. Statistically significance was found between OSAS patients and controls at the 12(th) mo. Average RNFL thickness was found to be significantly lower in last measurements in OSAS patients when compared with first measurements and control subjects (P<0.001, 0.002, respectively). There was a statistically significant correlation among AHI, and RNFL thickness (P<0.05). CONCLUSION The results suggest that the patients with OSAS were related with a proportional decrease in the RNFL thickness. These patients should be followed up regularly for glaucomatous changes. Detecting more RNFL thinning in severe OSAS was important.

Correlation of intraocular pressure with central corneal thickness in premature and full-term newborns

Purpose To evaluate the relation of central corneal thickness (CCT) and intraocular pressure (IOP) in preterm and full-term newborns. Methods The study included preterm infants who were admitted to the neonatal intensive care unit. A group of consecutive full-term newborns served as control group. Linear and multiple regression analysis were carried out to assess the association of IOP with sex, gestational/postconceptional age, birthweight, mean oxygenation time, stages of retinopathy of prematurity (ROP), and CCT. Linear and multiple regression analysis were also carried out to assess the association of CCT with sex, gestational/postconceptional age, birthweight, mean oxygenation time, and stages of ROP. Results Mean IOP was 17.5 ± 2.1 mm Hg in premature newborns and 16.3 ± 1.9 mm Hg in full-term newborns (p = 0.001). Mean CCT was 576.5 ± 16.8 µm in premature newborns and 562.7 ± 18.5 mm in full-term newborns (p = 0.000). Intraocular pressure was not correlated with CCT in preterm infants. Intraocular pressure was moderately correlated with CCT in full-term infants. Sex, postconceptional age at birth and at measurement, age after birth at measurement, birthweight, mean oxygenation time, and stage of ROP were not related to IOP. Central corneal thickness was not correlated with any parameter. Conclusions Our results showed that the CCT does not affect IOP significantly in preterm infants. More prospective studies are needed for determining the effect of CCT and other ocular and systemic factors on IOP in preterm infants.

Comparison of the Retinomax hand-held autorefractor versus table-top autorefractor and retinoscopy.

AIM To compare noncycloplegic and cycloplegic results of Retinomax measurements with findings achieved after cycloplegia using table-top autorefractor and retinoscopy. METHODS The study included 127 patients (mean age 96.7mo, range 21 to 221). Retinomax (Rmax) (Nikon Inc., Japan) was used to obtain noncycloplegic refraction. Under cycloplegia, refraction was measured with Rmax, table-top autorefractor (TTR) (Nikon NRK 8000, Inc., Japan) and retinoscopy. The values of sphere, spherical equivalent, cylinder and axis of cylinder were recorded for Rmax, TTR and retinoscopy in each eye. All results were analyzed statistically. RESULTS THE MEAN SPHERIC VALUES (SV), SPHERICAL EQUIVALENT VALUES (SEV) AND CYLINDRICAL VALUES (CV) OF THE NONCYCLOPLEGIC RMAX (SV: 0.64 D, SEV: 0.65 D and CV: 0.03 D, respectively) were found to be significantly lower than cycloplegic TTR (1.43 D, 1.38 D and 0.3 D; P=0.012, P=0.011 and P=0.04, respectively) and retinoscopy (1.34 D, 1.45 D and 0.23 D; P=0.04, P=0.002 and P=0.045, respectively). Mean cycloplegic SV, SEV, CV were not significantly different between Rmax and TTR, Rmax and retinoscopy, TTR and retinoscopy. Cycloplegic or noncycloplegic axis values were not different between any method. CONCLUSION Rmax may be used successfully as a screening tool but may not be accurate enough for actual spectacle prescription. Cycloplegic Rmax measurements may be able to identify refractive error in children because of approximate results to retinoscopy.

The effect of caffeine on choroidal thickness in young healthy subjects

Abstract Background: To investigate the effect of oral caffeine intake on choroidal thickness using optical coherence tomography (OCT). Methods: Eighteen otherwise healthy caffeine users and 18 controls were enrolled. All participants underwent OCT scanning with high-speed and resolution spectral-domain OCT device (3D OCT 2000, Topcon, Japan) at baseline, and 1 and 3 h following 200-mg oral caffeine intake in the study and after oral placebo in the control group. The measurements were taken in the morning (10–12 am) to avoid diurnal fluctuation. Results: The median choroidal thickness at the fovea prior to oral caffeine intake was 337.00 (IQR 83.75) μm, which decreased to 311.00 (IQR 79.25) μm at 1 h and 311.00 (IQR 75.00) μm at 3 h following oral caffeine intake (p = 0.001, 0.002, respectively). The median choroidal thickness was also significantly decreased following oral caffeine intake at other five extrafoveal points (p < 0.05 for all). The difference in choroidal thickness was not statistically significant between 1 and 3 h of caffeine intake at all six points. In the control group, the median baseline choroidal thickness at the fovea was 330.00 (IQR 88.75) μm, which was 330.50 (IQR 80.75) μm at 1 h and 330.50 (IQR 90.75) μm at 3 h (p = 0.552, 0.704, respectively). Conclusions: Caffeine causes a significant decrease in choroidal thickness following oral intake. This decrease might be a result of reduced ocular blood flow due to its vasoconstrictive effect.

The Evaluation of Choroidal Vascular Changes Associated with Vascular Dysregulation in Patients with Multiple Sclerosis Using Enhanced Depth Imaging Optical Coherence Tomography

Purpose: To evaluate the choroidal thickness (CT) in patients with Multiple Sclerosis (MS) using enhanced depth imaging optical coherence tomography (EDI-OCT) and comparing it with healthy subjects. Material/Methods: Sixty-four eyes of 32 patients with MS (22 women, 10 men, mean age: 37.5 ± 8.21 years) were enrolled in this study. Their choroidal thickness was measured using EDI-OCT, and compared with healthy subjects. CT was measured at fovea and at four extrafoveal points. Results: The mean subfoveal choroidal thickness was 327.01 ± 64.60 μm in MS patients and 365.3 ± 99.14 μm in controls ( p=0.019 ). Significant differences were found at points temporal 500 μm, temporal 1000 μm and nasal 500 μm to the fovea between patients and control group ( p=0.018, 0.003 and 0.03, respectively). Conclusions: Patients with MS had thinner choroids when compared to normal subjects. The decrease in mean choroidal thickness in MS patients compared to controls may be related to vascular dysregulation or inflammatory pathology of MS. Further prospective studies are needed to evaluate the choroidal thickness in MS patients.

The Effect of Age, Gender, Refractive Status and Axial Length on the Measurements of Hertel Exophthalmometry

Purpose : To evaluate the normal distribution of exophthalmometric values in Turkish adult population and the effect of age, gender, refractive status and axial length on globe position. Methods : One hundred and twenty-two males and 114 healthy females with age ranging from 18 to 87 years were included in the study. The study population was recruited from patients presenting to our institution for routine refractive examination. Hertel exophthalmometer was used to measure the degree of ocular protrusion. Effect of age, refractive error, interpupillary distance, and axial length on globe position was detected with linear regression analyses. Results : The mean Hertel exophthalmometric size was 15.7+2.6 mm (range; 11 to 21 mm). The mean value for males was 16.1±2.6 mm (range; 11 to 21 mm), and for females 15.5±2.6 mm (range; 11 to 20 mm). The mean distance between the lateral rims of the orbit was 102 + 5.1 mm (range; 88 to 111mm). The mean exophthalmometric values were not statistically different in males and females. Age and mean spherical equivalents were negatively correlated with exophthalmometric measurements. Axial length was positively correlated with exophthalmometric measurements. Conclusion : The exophthalmometric measurement of the eye is affected by the age, spherical equivalent and the axial length. Standard normative values of the Hertel exophthalmometric measurements should be reevaluated with larger samples.

Spontaneous resolution of macular edema after silicone oil removal.

AIM To investigate the macular changes in eyes filled with silicone oil (SO) and course of these changes after SO removal. METHODS A retrospective optical coherence tomography scan review was conducted for twenty-four patients who underwent uncomplicated pars plana vitrectomy with SO tamponade for complex retinal detachments were detected with optical coherence tomography before, and one week, one month and three months after SO removal. RESULTS Mean duration of SO tamponade was 3.6±1.0mo (range: 3-7mo). Cystoid macular edema (CME) was detected in 3 eyes before SO removal. Submacular fluid was represented in 1 eye before silicone SO removal. Resolution of CME and submacular fluid was achieved 1mo after SO removal in all eyes. Mean best corrected visual acuity (BCVA) was 1.15±0.65 (range, hand movement to 0.2) before SO removal in the eyes without macular changes. After SO removal, the mean BCVA values at 1wk and 1 and 3mo, and 0.82±0.23, 0.76±0.21, and 0.70±0.19, all of which were significantly better than baseline (P=0.030, 0.017, 0.006 respectively). In the eyes with macular CME and subretinal fluid the mean BCVA was significantly improved at 3mo after SO removal compared with baseline (P=0.037). CONCLUSION Decreased visual acuity in eyes filled with SO could be caused by macular complications due to SO. CME and subretinal fluid may resolve without any additional macular surgery after SO removal.

Correlation of choroidal thickness with outer and inner retinal layers.

BACKGROUND AND OBJECTIVE To investigate the correlation of choroidal thickness with the outer and inner retinal layers. PATIENTS AND METHODS A retrospective OCT scan review was conducted for healthy patients. Choroidal, outer retinal layer, and inner retinal layer thicknesses were measured at the fovea and 500 μm, 1,000 μm, and 1,500 μm temporal and nasal to the fovea. Retinal thickness was also measured at the foveal center. Choroidal thickness (CT) was compared at different locations, and correlation of CT with the outer and inner retinal layers was examined. RESULTS Mean CT was thinnest nasally, thicker in the subfoveal region, and then thinner again temporally. Correlations found between CT and outer retinal layer thicknesses at temporal points to the fovea were slightly higher than correlations between CT and inner layer thicknesses. CONCLUSION The correlation between choroidal thickness and the outer retinal layer was very weak. Similar prospective trials are needed to assess the correlation of CT with retinal layers.