Ahmet Özkök

Corneal biomechanical properties of patients with acromegaly

Purpose Growth hormone (GH) and insulin-like growth factor-1 (IGF-1) excess in acromegaly have various effects on many organs. The ophthalmologic effects of GH and IGF-1 excess have not yet been investigated in detail. The aim of the current study is to compare the corneal biomechanical properties of patients with acromegaly and those of healthy subjects. Methods 45 patients with acromegaly (F/M=27/18) and 42 age-matched and gender-matched healthy individuals (F/M=24/18) were enrolled in this cross-sectional study. Central corneal thickness (CCT), corneal resistance factor (CRF), corneal hysteresis (CH), corneal compensated intraocular pressure (IOPcc) and Goldmann correlated IOPG were measured in patients with acromegaly and in healthy individuals using the Ocular Response Analyser (ORA). GH and IGF1 values were also determined in the study group. Results The mean CH and CRF values were higher in acromegalic patients (12.1±2.2 and 12.3±2.4, respectively) than in healthy subjects (11.0±1.6 and 10.8±1.5, respectively; for CH, p=0.014; for CRF, p=0.001). Mean IOPG measurement was higher in the acromegaly group than in the control group (p=0.017). There was no statistically significant difference in measured CCT (p=0.117) and IOPcc (p=0.594) values between acromegalic patients and healthy subjects. Conclusions These findings indicate that acromegaly has target organ effects on the eye. Consequently, it can change corneal biomechanical properties such as corneal hysteresis and the CRF. Corneal biomechanical properties are known to affect the accuracy of IOP measurements. These findings should be taken into account when measuring IOP values in acromegaly patients, as IOP readings may be overestimated.

Corneal Viscoelastic Differences Between Pseudoexfoliative Glaucoma and Primary Open-angle Glaucoma

Purpose:The aims of this study were to assess the biomechanical properties of corneas with pseudoexfoliative glaucoma (PEXG) and to compare them with those of patients with primary open-angle glaucoma (POAG). Methods:This prospective, comparative case series consisted of 73 eyes of 73 patients, 35 eyes with PEXG (PEXG group) and 38 eyes with POAG (POAG group). Corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated intraocular pressure (IOPCC), and Goldmann-correlated intraocular pressure (IOPG) were determined by using ocular response analyzer (ORA). IOP using Goldmann applanation tonometer (GAT) and ultrasonic central corneal thickness (CCT) were also measured for each eye. Exclusion criteria included refractive error/astigmatism of >3.00 D, history of intraocular surgery, corneal disease, angle-closure glaucoma, and secondary glaucoma other than PEXG. In cases where both eyes were eligible, the right eye was preferred for analysis. The main outcome measures were CH, CRF, IOPCC, IOPG, and GAT. The results were statistically analyzed by using t test, general linear model, and the Pearson correlation test. Results:The mean CH was found to be significantly lower in patients with PEXG (8.8±1.4 mm Hg) than those with primary open-angle glaucoma (9.9±1.2 mm Hg; P=0.0007). The mean CRF was found to be significantly lower in patients with PEXG (9.5±1.8 mm Hg) than those with POAG (11.1±1.3 mm Hg; P<0.0001). IOPCC was not significantly different between the groups (PEXG, 16.7 ±2.5 mm Hg; POAG, 16.9±2.4 mm Hg; P=0.72). IOPG was significantly lower in PEXG group (14.7±2.7 mm Hg) compared with the POAG group (16.5±2.5 mm Hg; P=0.004). GAT was significantly lower in the PEXG group (14.6±2.7 mm Hg) compared with the POAG group (16.4±2.8 mm Hg; P=0.007). There was no significant difference between the groups regarding mean CCT (PEXG, 546.1±34.9 &mgr;; POAG, 549.1±25 &mgr;; P=0.66) and mean age (PEXG, 70.3±8.2; POAG, 67.6±8.8; P=0.17). The difference between the IOPCC and the GAT was 2.1 and 0.5 mm Hg in both PEXG and POAG groups, respectively. Conclusions:Patients with PEXG had lower CH and CRF values than those with POAG. These findings require further investigation to assess the role of differing corneal biomechanical properties between the 2 groups and its association with poor prognosis among patients with PEXG.

Comparability of Icare Pro Rebound Tonometer with Goldmann Applanation and Noncontact Tonometer in a Wide Range of Intraocular Pressure and Central Corneal Thickness

Purpose: To evaluate the agreement between the reading values of the Goldmann applanation tonometer (GAT), Icare Pro rebound tonometer (IRT) and noncontact tonometer (NCT) in glaucoma patients. Methods: This cross-sectional study comprised 292 eyes of 292 patients selected from a glaucoma outpatient clinic. The intraocular pressure (IOP) was measured sequentially, at a 10-min interval each, in the following order: NCT, IRT and GAT. The central corneal thickness (CCT) was measured using Pentacam HR before the IOP measurements. Results: The mean IOPs measured by the GAT, NCT and IRT were 20.17 ± 6.73 mm Hg (range: 4-48), 19.77 ± 6.88 mm Hg (range: 3-46) and 19.30 ± 5.15 mm Hg (range: 7.30-44.5), respectively. The correlation coefficients of the GAT and IRT, NCT and IRT, and GAT and NCT measurements were r2 = 0.673, r2 = 0.663 and r2 = 0.938 (all p < 0.001), respectively. The IRT tends to overestimate in the low GAT-measured IOPs, whereas it underestimates in high GAT-measured IOPs. The measurements of all 3 devices were also correlated with the CCT at a statistically significant level (GAT: r2 = 0.063, NCT: r2 = 0.063, IRT: r2 = 0.058). Conclusion: The agreement between the IRT and GAT measurements is higher in the IOP range of 9-22 mm Hg, whereas significant discrepancies occur as the IOP deviates from normal values. The variability of the IRT and GAT measurements over a wide range of CCT is minimal.

Demographic features of subjects with congenital glaucoma.

Context: Congenital glaucoma is a potentially blinding ocular disease of the childhood. Identification of the possible associated risk factors and may be helpful for prevention or early detection of this public health problem. Aims: To demonstrate the demographic features of congenital glaucoma subjects. Setting and Design: The charts of congenital glaucoma patients referred to Tamcelik Glaucoma Center were retrospectively reviewed through the dates of 2000 and 2013. Materials and Methods: Analyzed data included diagnosis, age at first presentation, symptoms at first presentation, laterality of the disease, sex, presence of consanguinity, family history of congenital glaucoma, maturity of the fetus at delivery, and maternal age at conception. Statistical Analysis Used: Statistical Package for Social Sciences (SPSS) version 19.0 by IBM (SPSS Inc, Chicago, Illinois, USA) was used to compare the mean of continuous variables with Students t-test and analysis of variance (ANOVA) and χ2 test was used to test differences in proportions of categorical variables. Results: The data of 600 eyes of 311 patients were analyzed. The distribution of primary and secondary congenital glaucoma among the patients were 63.3% (n = 197) and 36.7% (n = 114), respectively. Of the 311 patients, 57.2% (n = 178) were male and 42.8% (n = 133) were female. The overall frequency of bilateral disease was 92.3% (n = 287). Overall rate of consanguinity and positive family history was 45.3% (n = 141) and 21.2% (n = 66), respectively. Conclusions: Bilateral disease in this study was more common than previously reported studies. Positive family history was more frequent in primary congenital glaucoma although not statistically significant.

Comparison of the effects of first and second generation silicone hydrogel contact lens wear on tear film osmolarity.

AIM To compare the effects of first and second generation silicone hydrogel (SiH) contact lens wear on tear film osmolarity. METHODS The healthy subjects who have never used contact lenses before were enrolled in the study. Tear film osmolarity values of 16 eyes (group 1) who wore first generation SiH contact lenses were compared with those of 18 eyes (group 2) who wore second generation SiH contact lenses after three months follow-up. RESULTS Before contact lens wear, tear film osmolarity of groups 1 and 2 were 305.02±49.08 milliosmole (mOsm) and 284.66±30.18mOsm, respectively. After three months of contact lens wear, osmolarity values were found 317.74±60.23mOsm in group 1 and 298.40±37.77mOsm in group 2. Although osmolarity values for both groups of SiH contact lens wear after three months periods were slightly higher than before the contact lens wear, the difference was not statistically significant. CONCLUSION Contact lens wear may cause evaporation from the tear film and can increase tear film osmolarity leading to symptoms of dry eye disease. In the current study, there is a tendency to increase tear film osmolarity for both groups of SiH contact lens wear, but the difference is not statistically significant.

Comparison of retinal nerve fiber layer and macular thickness measurements with Stratus OCT and OPKO/OTI OCT devices in healthy subjects

AIM To compare retinal nerve fiber layer (RNFL) and macular thickness measurements obtained with the Stratus optical coherence tomography (OCT) and OPKO/OTI OCT devices. METHODS Included in the study were 59 eyes of 30 participants. All measurements for each eye were done on the same day with both devices. Students paired t-tests were used to compare the central macular thickness and RNFL measurements of the Stratus OCT and OPKO/OTI OCT. Pearson correlation was used to assess the relationship between the devices. Coefficient of variation (COV) was calculated to assess intersession repeatability. RESULTS Using both the Stratus OCT and OPKO/OTI OCT, respectively, the measured mean average RNFL thicknesses were 98.9±11.1 µm and 115.1±9.6 µm (P=0.001), and the measured mean central retinal thicknesses (CRT) were 196.2±18.8 µm and 204.5±21.1 µm (P<0.001). Measured by the two devices, the RNFL thickness values were correlated in all quadrants, as were the retinal thickness values except the inferior outer sector. COV for average RNFL and CRT thickness were 2.9% and 4.6% for Stratus OCT, and 2.1% and 4.2% for OPKO/OTI OCT, respectively. CONCLUSION We found good reproducibility of RNFL and retina thickness measurements for both Stratus OCT and OPKO/OTI OCT devices. However, even though the two OCT systems provided statistically correlated results, the values for both RNFL and macular thickness were statistically different. RNFL and macular thickness measurements with the OPKO/OTI OCT were higher than that of the Stratus OCT; therefore, the two OCT systems cannot be used interchangeably for the measurements of RNFL and macular thickness.

Corneal Decompensation after Selective Laser Trabeculoplasty

A 64-year-old Caucasian man referred for decreased vision after selective laser trabeculoplasty (SLT). Slit lamp examination revealed diffuse corneal edema. Despite intensive topical treatment including steroids, corneal edema did not resolve; on the contrary, it advanced to bullous keratopathy. Corneal edema after SLT is an exceptionally rare complication and in all of the previous reports edema resolved with medical treatment. To the best of our knowledge, this is the first report presenting persistent corneal edema after SLT.

In Vivo Evaluation of the Biomechanical Properties of Optic Nerve and Peripapillary Structures by Ultrasonic Shear Wave Elastography in Glaucoma.

Background Primary open-angle glaucoma is a multifactorial serious disease characterized by progressive retinal ganglion cell death and loss of visual field. Objectives The purposes of this study were to investigate shear wave elastography (SWE) use in the evaluation of the optic nerve (ON) and peripapillary structures, and to compare the findings between glaucomatous and control eyes. Patients and Methods A case-controlled study, including 21 patients with primary open-angle glaucoma and 21 age-matched control subjects, was carried out. All of the participants had comprehensive ophthalmological exams that included corneal biomechanical measurements with ocular response analyzer. In vivo evaluation of the biomechanical properties of the ON and peripapillary structures were performed with SWE in all participants. The Kolmogorov–Smirnov test was used to analyze the normal distribution of data. Differences of parameters in ophthalmologic data and stiffness values of patients with and without glaucoma were evaluated using the Mann-Whitney U test. Results There were no statistically significant differences between the glaucoma and control groups in terms of age (P > 0.05) and gender (P > 0.05). Corneal hysteresis was lower in the glaucoma group (P < 0.05). Corneal compensated intraocular pressure and Goldmann correlated intraocular pressure were higher in the glaucoma group (P < 0.0001 for both). The mean stiffness of the ON and peripapillary structures were significantly higher in glaucoma patients for each measured region (P < 0.05). Conclusion The study evaluated the biomechanical properties of the ON and peripapillary structures in vivo with SWE in glaucoma. We observed stiffer ON and peripapillary tissue in glaucomatous eyes, indicating that SWE claims new perspectives in the evaluation of ON and peripapillary structures in glaucoma disease.

Congenital Bilateral Upper Eyelid Eversion: Report of a Case

Abstract Congenital bilateral upper eyelid eversion is a rare condition and the definite cause is not known. It is often seen in Black babies or babies with Down’s syndrome. With early diagnosis and appropriate treatment, the condition can be managed without surgery. We report a case of congenital upper eyelid eversion in an otherwise healthy Caucasian neonate, born by normal vaginal delivery. The case responded well to conservative treatment, including eyelid repositioning, lubricants, antibiotic ointment, and eyelid patching.

An Exceptional Case of Full-thickness Macular Hole Closure in a Patient with Behçet Disease

Abstract Purpose: To present a case of a full-thickness macular hole closure in a patient with Behcet uveitis Design: A 23-year-old-male patient with Behcet Disease had clinically inactive uveitis with topical steroids, oral azathiopurine and cyclosporine until he developed a retinal infiltrate in the left eye which evolved into a full-thickness macular hole during the follow-up. Methods: Strict control of inflammation and subsequent vitrectomy was planned. Meanwhile another attack of panuveitis developed in the left eye and subcutaneous Interferon alfa-2b interferon treatment was initiated. Results: After 2 months, the patient was clinically inactive with complete closure of the macular hole. Conclusions: Strict control of inflammation may result in closure of the macular hole and avoid the need for vitrectomy.