Hasan Altinkaynak

Biomechanical evaluation of cornea in topographically normal relatives of patients with keratoconus.

Purpose: To compare the biomechanical properties of the cornea between topographically normal relatives of patients with keratoconus and age-matched controls. Methods: Thirty healthy individuals (control group) and 30 topographically normal relatives of patients with keratoconus (study group) were enrolled in this prospective, cross-sectional comparative study. Topographical measurements including pachymetric values, keratometry values, irregularity, and inferior–superior dioptric asymmetry difference values in the right eye of each participant were obtained using Orbscan II (Bausch & Lomb Laboratories, Inc, Rochester, NY). Corneal hysteresis (CH), corneal resistance factor (CRF), corneal compensated intraocular pressure, and Goldmann-related intraocular pressure were also measured using the Reichert Ocular Response Analyzer (ORA). Results: Topographic parameters were not significantly different between both groups (P > 0.05). Mean CH was 9.9 ± 1.6 mm Hg in the study group and 11.3 ± 1.0 mm Hg in the control group (P = 0.001); mean CRF was 9.8 ± 1.6 mm Hg and 11.2 ± 2.1 mm Hg in the study and control groups, respectively (P = 0.013). Mean Goldmann-related intraocular pressure was 15.0 ± 4.3 mm Hg in the study group and 15.8 ± 6.7 mm Hg in the control group (P = 0.603); mean corneal compensated intraocular pressure was 16.2 ± 4.7 mm Hg in the study group and 15.4 ± 5.8 mm Hg in the control group (P = 0.595). Conclusions: The CH and CRF values were significantly lower in the relatives of patients with keratoconus than in the controls. Future studies including monitoring of these participants with topographical and biomechanical measurements may indicate the role of this study in detection of early corneal changes in relatives of patients with keratoconus.

Effects of chronic smoking on central corneal thickness, endothelial cell, and dry eye parameters

Abstract Objective: To evaluate the effect of chronic cigarette smoking on dry eye parameters, endothelial cells, and corneal thickness. Design: Prospective cross-sectional case series. Methods: In this cross-sectional study, 49 eyes of 49 chronic smokers (smoker group) and 53 eyes of 53 age-matched, healthy non-smokers (non-smoker group) were enrolled. All participants underwent measurements of tear breakup time (TBUT), central corneal thickness (CCT) measurements with contact pachymeter and the Schirmer test with anesthesia. Corneal endothelial cells were evaluated by non-contact specular microscopy and photographed for analysis of cell density and hexagonality and the coefficient of variation in cell size. Results: The mean Schirmer score and TBUT value were significantly lower in the smoker group compared to the non-smoker group (p = 0.015) and p < 0.001, respectively). No statistically significant difference was found in the mean CCT, mean endothelial cell density, endothelial cell size, SD of size, and CV of size between smokers and non-smokers (p > 0.05). However, a lower percentage of endothelial hexagonal cells were observed in smokers than non-smokers (p < 0.001). Discussion and conclusion: Our results suggest that cigarette smoking seems to affect the Schirmer score, TBUT value, and hexagonal cells of the corneal endothelium.

Thinning of Choroidal Thickness in Patients with Rheumatoid Arthritis Unrelated to Disease Activity

Abstract Purpose: To investigate subfoveal and perifoveal choroidal thickness (CT) in patients with rheumatoid arthritis (RA). Methods: A study group of 117 patients with RA and a control group of 46 age-matched healthy individuals were enrolled in the study. Subfoveal and perifoveal CTs were measured using enhanced depth imaging optical coherence tomography (EDI-OCT). Perifoveal CT was measured 1,500 µm nasally and 1,500 µm temporally apart from the foveal center. Relationship between the disease activity score 28 (DAS-28) and subfoveal CT was also evaluated. Results: The mean subfoveal CT values in the study and control groups were 226.90 ± 43.61 μm and 299.74 ± 48.06 μm, respectively, which made for a statistically significant difference (p < 0.001). Likewise, perifoveal CT values were significantly thinner in the study group when compared with control group. DAS-28 wasn’t correlated with subfoveal CT in the study group. Conclusions: CT was significantly thinner in patients with RA when compared with healthy controls.

Choroidal Thickness in Patients with Systemic Lupus Erythematosus Analyzed by Spectral-domain Optical Coherence Tomography

Abstract Purpose: The aim of this study is to investigate the effect of systemic lupus erythematosus (SLE) on choroidal thickness (CT) in the subfoveal and perifoveal area as measured by enhanced depth imaging optical coherence tomography (EDI-OCT) in patients with SLE. Materials and methods: Fifty-eight patients with SLE (study group) and 58 healthy individuals (control group) were enrolled in the study. The subfoveal and perifoveal CT were measured by EDI-OCT. Results: The mean CT (μm) subfoveal, nasal, and temporal was 231.2 ± 57.6, 190.56 ± 30.64, and 222.65 ± 37.45 in the study group and 297.5 ± 45.1, 248.34 ± 39.67, and 286.54 ± 49.65 in the control group, respectively (p < 0.001, for all). Conclusion: The mean subfoveal, nasal, and temporal CT values were statistically significantly lower in patients with SLE when compared with healthy controls.

Subfoveal Choroidal Thickness in Patients with Chronic Heart Failure Analyzed by Spectral-Domain Optical Coherence Tomography

Abstract Purpose: To evaluate the subfoveal choroidal thickness (SFCT) measured by enhanced depth imaging optical coherence tomography (EDI-OCT) in eyes of chronic heart failure (CHF) patients. Methods: Fifty-six patients with CHF and 56 age- and gender-matched healthy individuals were enrolled. The SFCT was measured by EDI-OCT. The ejection fraction of left ventricle (EFLV), age, intraocular pressure (IOP), axial length (AL), systolic and diastolic blood pressure, and ocular perfusion pressure (OPP) were also measured. Results: Mean SFCT was 181.2 ± 80.23 μm in the study group and 283.6 ± 52.4 μm in the control group (p = 0.000). There was a statistically significant correlation between the SFCT and each of EFLV and age. SFCT value was not statistically significantly associated with AL, IOP and OPP. Conclusıon: Our results suggest that SFCT is lower in eyes of CHF patients compared to age- and gender-matched healthy individuals.

Measurement of choroidal thickness and macular thickness during and after pregnancy

AIM To investigate the effect of pregnancy on subfoveal choroidal thickness (SFCT) and macular thickness in both pregnant and not pregnant healthy women. METHODS Twenty-nine healthy pregnant women in their third trimester and 36 age-matched healthy women were enrolled in a prospective, cross-sectional study. Foveal and parafoveal thickness in the four quadrants and SFCT were measured by optical coherence tomography (OCT) in the healthy pregnant women (i.e. study group) and healthy women (i.e. control group). OCT measurements were again measured 3mo after delivery in the study group. RESULTS Mean SFCT measurements in the control group, pregnant women of the study group, and after delivery of the study group were 320.86±59.18 µm, 387.97±59.91 µm, and 332.40±26.03 µm, respectively. There was a statistically significant difference in the mean SFCT values between pregnant women of the study group and the control group (P=0.000). Foveal and parafoveal thickness values were not statistically significant in either the study or control group. CONCLUSION SFCT increases during pregnancy and returns to normal range in the three months after delivery. Macular thickness does not show any change during pregnancy.

Occupational Exposure to Lead Decreases Macular, Choroidal, and Retinal Nerve Fiber Layer Thickness in Industrial Battery Workers

Abstract Purpose: To evaluate the toxic effects of chronic lead (Pb) exposure on retinal nerve fiber layer thickness (RNFLT), macular thickness (MT) and choroidal thickness (CT) in battery industry workers. Materials and Methods: Male factory workers (n = 50) and healthy non-employees (n = 20) participated in the study. Group 1 (n = 22) comprised lead workers; Group 2 (n = 16), box makers; Group 3 (n = 12), assistant personnel; and Group 4 (n = 20), healthy non-employees. All participants were given Best-Corrected Visual Acuity (BCVA) tests, full ophthalmologic examinations, and Spectral Domain Optical Coherence Tomography (SD-OCT) of the optic nerve head, RNFL, macula, and choroid. Blood lead levels (BLL) in venous blood samples were determined. The duration of exposure to lead varied, and is expressed in months. Results: Average (mean ± SD) ages of participants were 27.55 ± 4.00, 28.69 ± 3.48, 32.00 ± 3.38, and 29.85 ± 5.48 yrs (Groups 1–4, respectively). BLL were 46.2 ± 2.32, 29.31 ± 3.30, 16.9 ± 1.9, and 2.85 ± 0.98 µg/dL (Groups 1–4, respectively). Durations of exposure to lead were 43.86 ± 10.81, 42.81 ± 4.86, and 49.42 ± 6.14 mo (Groups 1–3, respectively). OCT averages for RNFL were 101.68 ± 5.32, 119.50 ± 13.47, 127.67 ± 8.92, and 130.9 ± 6.63 μm (Groups 1–4, respectively). Although RNFLTs of Group 1 were significantly less than those of for Groups 2–4, and, RNFLTs of Groups 2 and 3 were significantly less than that of Group 4, there were no significant differences between Group 2 and 3. MTs were 94.50 ± 6.78, 105.63 ± 5.43, 111.50 ± 6.74 and 147.95 ± 6.67 μm, (Groups 1–4, respectively). CTs were 176.41 ± 15.39, 222.19 ± 17.79, 239.17 ± 15.64, and 251.50 ± 10.98 μm (Groups 1–4, respectively). Both MTs and CTs displayed significant differences among the four groups. Conclusions: Ocular changes in individuals who are chronically exposed to lead include decrease in RNFT, MT, and CT, and thus these parameters should be evaluated during ophthalmologic examination of individuals working in lead-based industries.

Evaluation of anterior segment parameters during and after pregnancy.

PURPOSE To compare the anterior segment parameters during pregnancy and post-pregnancy. MATERIALS AND METHODS Fifty-four healthy pregnant women in their third trimester with ages ranging from 18 to 38 years were included in the study. All of the patients underwent comprehensive ophthalmologic examinations, including refraction, anterior segment, and fundus examinations, intraocular pressure, and axial length measurements. In addition, anterior chamber angle, anterior chamber depth, anterior chamber volume, corneal volume, central corneal thickness, and keratometry values were measured by Pentacam Scheimpflug camera. All measurements were measured again 3 months after delivery. RESULTS The mean intraocular pressure, anterior chamber angle, anterior chamber depth, anterior chamber volume, corneal volume, central corneal thickness, and keratometry measurements were significantly different during pregnancy and post-pregnancy (p<0.05 for all); however, the mean spherical refraction, cylindrical refraction, and axial length were not statistically significantly different during pregnancy and post-pregnancy (p>0.05 for all). CONCLUSIONS We found that there is an increase in the anterior chamber parameters, corneal volume, corneal thickness, and corneal curvature and a decrease in intraocular pressure in the third trimester.

Choroidal thickness changes after dynamic exercise as measured by spectral-domain optical coherence tomography

Purpose: To measure the choroidal thickness (CT) after dynamic exercise by using enhanced depth imaging optical coherence tomography (EDI-OCT). Materials and Methods: A total of 19 healthy participants performed 10 min of low-impact, moderate-intensity exercise (i.e., riding a bicycle ergometer) and were examined with EDI-OCT. Each participant was scanned before exercise and afterward at 5 min and 15 min. CT measurement was taken at the fovea and 1000 μ away from the fovea in the nasal, temporal, superior, and inferior regions. Retinal thickness, intraocular pressure, ocular perfusion pressure (OPP), heart rate, and mean blood pressure (mBP) were also measured. Results: A significant increase occurred in OPP and mBP at 5 min and 15 min following exercise (P ˂ 0.05). The mean subfoveal CT at baseline was 344.00 ± 64.71 μm compared to 370.63 ± 66.87 μm at 5 min and 345.31 ± 63.58 μm at 15 min after exercise. CT measurements at all locations significantly increased at 5 min following exercise compared to the baseline (P ˂ 0.001), while measurements at 15 min following exercise did not significant differ compared to the baseline (P ˃ 0.05). There was no significant difference in retinal thickness at any location before and at 5 min and 15 min following exercise (P ˃ 0.05). Conclusion: Findings revealed that dynamic exercise causes a significant increase in CT for at least 5 min following exercise.

Measurement of Choroidal Thickness Following Caffeine Intake in Healthy Subjects

Abstract Purpose: The aim of this study is to investigate the effect of 200 mg caffeine on subfoveal choroidal thickness (CT) in the macular area as measured by enhanced depth imaging optical coherence tomography (EDI-OCT) in healthy subjects. Materials and methods: Fifty healthy individuals (study group) and 50 healthy individuals (control group) were enrolled in study. In the study group, participants received a 200 mg caffeine capsule and the control group consisted of subjects who received plasebo capsule. The subfoveal CT was measured by EDI-OCT before the caffeine intake and at 30 min, 1 h, 2 h, 3 h, 4 h and 6 h following caffeine intake. Results: SFCT after caffeine intake was significantly decreased at 30 min, 1 h, 2 h, 3 h and 4 h compared to the baseline measurement, while the difference between baseline and 6 h was not statistically significant in the study group. There were no significant differences between the baseline and the other measurement times in the control group (p > 0.05). Conclusion: The thinning of CT begins about 30 min after the oral ingestion of 200 mg of caffeine and lasts for about four hours.