Funda Dikkaya

Corneal Endothelial Cell Density and Morphology in Healthy Turkish Eyes

Purpose. To describe the normative values of corneal endothelial cell density, morphology, and central corneal thickness in healthy Turkish eyes. Methods. Specular microscopy was performed in 252 eyes of 126 healthy volunteers (M : F, 42 : 84). Parameters studied included mean endothelial cell density (MCD), mean cell area (MCA), coefficient of variation (CV) in cell size, percentage of hexagonal cells, and central corneal thickness (CCT). Results. The mean age of volunteers was 44.3 ± 13.5 (range, 20 to 70) years. There was a statistically significant decrease in MCD (P < 0.001; correlation, −0.388) and percentage of hexagonal cells, (P < 0.001; correlation, −0.199) with age. There was also a statistically significant increase in MCA (P < 0.001; correlation, 0.363) with increasing age. There was no statistically significant difference in MCD, MCA, CV in cell size, percentage of hexagonal cells, and CCT between genders and there was also no significant difference in these parameters between fellow eyes of subjects. Conclusions. Normotive data for the endothelium in the Turkish population are reported. Endothelial cell density in the Turkish eyes is less than that described in the Japanese, American, Chinese, and Filipino eyes and higher than that described in Indian, Thai, and Iranian eyes.

Effect of Fasting on Corneal Biomechanical and Structural Parameters.

ABSTRACT Purpose: To evaluate the effects of hunger and thirst on corneal biomechanical and structural parameters during Ramadan fasting. Materials and Methods: Corneal biomechanical properties and intraocular pressures of 29 eyes of 29 healthy subjects were evaluated by Reichert ocular response analyzer; and structural and anatomical properties of cornea and anterior eye chamber of same eyes were scanned with Oculus Pentacam anterior segment analyzer. Each eye has been evaluated at 8 am and 4 pm both during and 1 month after Ramadan. Changes of subjects’ weight were calculated and their relationship with corneal biomechanical and structural parameters was assessed. Results: Intraday changes in horizontal corneal astigmatism (p = 0.02), anterior chamber volume (p = 0.01), intraocular pressure associated with the Goldmann IOPg (p = 0.02) and corneal resistance factor (CRF) (p = 0.04) were significantly different when measured during the fasting period in Ramadan and 1 month thereafter. Moreover, when we compared 8 am measurements taken during and after Ramadan, we observed significant differences for anterior chamber volume (p = 0.04) and anterior chamber angle values (p = 0.03). Similarly, for 4 pm measurements, there were significant differences for IOPg (p = 0.01) and CRF values (p = 0.00). Conclusions: Fasting lasting for more than 12 h during Ramadan creates an important window of opportunity to investigate the response of anterior chamber of eye to hunger and thirst. The current study contributes to the existing literature on the effects of dietary habits and water intake on corneal and anterior chamber properties.

Corneal endothelial cell density and morphology in patients with acromegaly

OBJECTIVE Acromegaly has various impacts on many organs. The ophthalmologic effects of acromegaly have not yet been investigated in detail. The aim of the current study was to evaluate qualitative and quantitative changes in corneal endothelial cells and central corneal thickness (CCT) of the patients with acromegaly. DESIGN In this prospective, cross-sectional study, 128 eyes of 64 patients with acromegaly (female/male=40/24) and 208 eyes of 104 age and gender-matched healthy volunteers (female/male=69/35) were included. Endothelial cell density (ECD), cellular area (CA), coefficient of variation (CV) in cell size, percentage of hexagonal cells, and CCT were measured in patients with acromegaly and in healthy volunteers using the noncontact specular microscopy (SP-3000P: Topcon Corporation, Tokyo, Japan). RESULTS ECD and CA were lower in cases with acromegaly than in controls (ECD in acromegaly: 2615.65 cell/mm(2) and in controls: 2700.35 cell/mm(2); p=0.002. CA in acromegaly: 382.30μm(2) and in controls: 400.30μm(2); p=0.02). In the entire group with acromegaly, the time elapsed since diagnosis was positively correlated with CA and was negatively correlated with ECD (r=+0.39, p=0.001 and r=-0.42, p=0.001). CONCLUSIONS The endothelial layer of the cornea may be under risk of impairment with prolonged disease duration in acromegaly. Consistency of the corneal endothelium should be also sought during long-term follow-up of the cases with acromegaly.

Comparison of Central Corneal Thickness with Ultrasound Pachymetry, Noncontact Specular Microscopy and Spectral Domain Optical Coherence Tomography

ABSTRACT Background: To determine the agreement of central corneal thickness (CCT) measurements taken with ultrasonic pachymetry (USP), spectral domain optical coherence tomography (SD-OCT) and noncontact specular microscopy (NSM). Methods: A prospective, observational, cross-sectional study was performed in the outpatient ophthalmology clinic. CCT was measured in a total of 147 eyes of 147 consecutive healthy patients with USP, NSM, and SD-OCT. Same examiner performed all examinations. Bland–Altman plots were used to evaluate the agreement between instruments. Results: The average CCT values obtained by USP, NSM, and SD-OCT were 555 ± 37 µm, 554 ± 34 µm, and 546 ± 34 µm, respectively. There was a strong correlation between instruments: USP with SD-OCT (r = 0.937, p < 0.01), USP with NSM (r = 0.943, p < 0.01) SD-OCT with NSM (r = 0.975, p < 0.01) for CCT. The mean differences (lower/upper limit of agreement) for CCT measurements were −10 ± 12.9 µm (15.28/−35.28) between SD-OCT and USP, −8.1 ± 7.7 µm (7/−23.2) between SD-OCT and NSM, and 1.8 ± 12.3 µm (25.9/−22.3) between USP and NSM. Conclusions: USP and NSM were found to have comparable CCT measurements and these two methods can be used correspondingly. However, CCT measurements by SD-OCT were lower when compared to other methods.

Corneal Viscoelastic Properties in Patients with Angioid Streaks

Abstract Purpose: The aim of this study is to investigate the possible corneal biomechanical changes in patients with angioid streaks and to understand if the calcified and thickened Bruchs membrane associated with angioid streaks influences elasticity of the eye and intraocular pressure. Materials and Methods: Twelve eyes of 12 patients with angioid streaks (six males and six females) and 12 eyes of 12 age- and sex-matched healthy volunteers were enrolled in the study. Corneal hysteresis (CH), corneal resistance factor (CRF), corneal compensated intraocular pressure (IOPcc) and Goldmann-correlated intraocular pressure (IOPg) were measured with an Ocular Response Analyzer (ORA). Central corneal thickness (CCT) was measured with an ultrasound pachymeter. Results: Mean CRF and IOPg values in eyes with angioid streaks (12.10 ± 1.27 and 17.76 ± 2.73, respectively) were significantly higher than those in matched control eyes (10.70 ± 1.28 and 14.67 ± 2.72, respectively; p = 0.01 for CRF, p = 0.007 for IOPg). There was no statistically significant difference between eyes with angioid streaks and matched control eyes in measured CH, IOPcc and CCT values (p = 0.29, p = 0.09 and p = 0.86, respectively). Conclusions: This study revealed that angioid streaks can affect corneal biomechanical properties by increasing CRF, as compared to the healthy eyes. Increased CRF means increased resistance for effect of IOP on eye so it can be speculated that these patients tend to be more protected for glaucoma.

Anizohipermetropik ambliyopisi olan yetişkinlerin ön segment parametrelerinin Sirius topografi ile değerlendirilmesi

Amac: Anizohipermetropik ambliyopisi olan yetiskinlerde on segment parametrelerini Sirius topografi ile degerlendirmek. Gerec ve Yontem: Anizohipermetropik ambliyopisi olan 48 hasta ve 45 saglikli yetiskin calisma kapsaminda prospektif olarak degerlendirildi. Tum hastalarin sikloplejik damla oncesi ve sonrasinda Sirius topografi cihazi ile muayeneleri gerceklestirildi. On ve arka ortalama keratometri degerleri, santral kornea kalinliklari (SKK), on kamara derinlikleri (OKD), kornea volumu (KV) ve on kamara volumleri (OKV) gruplar arasinda karsilastirildi. Bulgular: On ve arka ortalama keratometri degerleri, SKK, OKD, KV ve OKV arasinda ambliyopisi olan hastanin ambliyopik gozu, diger goz ve kontrol hastasinin gozleri arasinda sikloplejik damla oncesi ve sonrasi olcumlerde fark saptanmadi (p>0.05). Sonuc: Ambliyopisi olan yetiskinlerde ambliyopik goz, diger goz ve kontrol gozler arasinda sikloplejik damla oncesi ve sonrasinda Sirius topografi ile yapilan degerlendirmede on segment parametreleri arasinda anlamli fark saptanmamistir.

Effect of Hemifacial Spasm on Intraocular Pressure Measurement

Purpose To evaluate the effect of hemifacial spasm (HFS) on intraocular pressure (IOP) measurement. Methods Twenty-four consecutive patients with HFS and 25 age- and gender-matched randomly selected eyes of healthy volunteers underwent corneal pachymetry and IOP measurements using Goldmann applanation tonometer (GAT) and noncontact tonometer (NCT). IOP measurements were performed before (during HFS) and 2 weeks after Botox injections in HFS patients and in healthy volunteers without Botox injections. Results There was no statistical difference between involved eye side and uninvolved eye side of HFS patients in measured central corneal thickness. Similarly, no difference was found between involved eye side of HFS patients and controls. There were no statistically significant differences comparing IOP values before treatment and levels measured at 2 weeks of Botox injections, either with GAT (p = 0.33, 0.11) or NCT (p = 0.80, 0.43) devices in the involved eyes and uninvolved eyes of patients with HFS, respectively. There were also no significant differences in these parameters (GAT (p = 0.63) and NCT (p = 0.54)) in controls. Conclusions Contractions in facial muscles may not lead to significant increase in IOP in HFS patients. This result may help clinical decision making in the treatment of glaucoma patients with HFS. This trial is registered with NCT03390803.

Posterior Polar Central Choroidal Dystrophy: A Case Report

A 52-year-old male presented with a 25-year history of decreasing vision. Best corrected visual acuity was 0.3 in his right and 0.2 in his left eye. Fundoscopic examination showed bilateral symmetric atrophy of the retinal pigment epithelium and choriocapillaris in the posterior polar areas between vascular arcades and surrounding the optic disc. On fluorescein angiography, the large choroidal vessels beneath these affected regions were easily seen. Fundus autofluorescence imaging showed clearly defined hypoautofluorescent areas that corresponded to the aforementioned lesions. Atrophy of the choriocapillaris and outer retinal layer were detected in optical coherence tomography. Photopic and scotopic responses were subnormal in flash electroretinogram (ERG), and responses were also minimal in pattern ERG and multifocal ERG. The patient was diagnosed with posterior polar central choroidal dystrophy. We aimed to present the results of fluorescein angiography, fundus autofluorescence imaging, optical coherence tomography, and electrophysiological tests in this rare case of posterior polar central choroidal dystrophy.