Evaluation of the peripapillary retinal nerve fiber layer and ganglion cell-inner plexiform layer measurements in patients with iron deficiency anemia with optical coherence tomography

Objective: To evaluate the thickness of the peripapillary retinal fiber layer (RNFL) and macula ganglion cell-inner plexiform layer (GCL+) using optical coherence tomography (OCT) in patients with iron deficiency (ID) anemia.

Methods: This study included 73 eyes of 39 patients with ID anemia and 68 eyes of 34 age- and sex-matched healthy subjects. The measurements included the peripapillary RNFL thicknesses as average, 4 quadrant and 12 clock-hour (CH) based and macula GCL+ thicknesses as average and 6 quadrant based. All measurements were completed with Cirrus HD-OCT and the results were compared between the groups.

Results: A total of 73 eyes of 39 patients with ID anemia and 68 eyes of 34 healthy subjects were included to the study. Regarding peripapillary RNFL thicknesses of the study and control patients, the values of average and quadrants revealed no significant differences between the groups. In CH sectors comparison, peripapillary RNFL thicknesses were significantly decreased only in CH4 (68.7?±?14.5?μm in study versus 72.0?±?13.4?μm in control patients, p?=?0.049) and CH5 (93.4?±?20.0μm in study versus 102.2?±?20.1?μm in control patients, p?=?0.01) sectors. All measured quadrants were statistically similar, when macula GCL+ thicknesses were compared between the groups. When the correlations between peripapillary RNFL and macula GCL+ thicknesses and serum hemoglobin and ferritin levels of study and control patients were calculated, the only statistically significant parameter was the correlation of peripapillary RNFL thickness in CH10 sector with serum ferritin level (p?=?0.032, Spearman correlation coefficient: 0.369).

Conclusion: The study revealed that peripapillary RNFL is thinner in nasal-inferior quadrant in patients with ID anemia. The measurements of macula GCL+ thicknesses were similar between the groups. Analyzing the retinal layers using OCT may provide valuable information in neurodegenerative events.     

The effect of voluntary fasting and dehydration on posterior ocular structures

Purpose: Islamic Ramadan is the month of fasting, in which intake of food and drink is restricted from sunrise until sunset. The objective of the present study was to find out the effects of religious fasting on posterior ocular structures.

Materials and methods: In this prospective study, 34 eyes of 34 healthy volunteers with a mean age of 34.09?±?7.20?years were enrolled. Volunteers with any systemic disorder and eyes with pathology or previous surgery were excluded. One week before Ramadan (non-fasting period) and during Ramadan (fasting period) at the same hours (at 08:00 and 16:00?h), choroidal, macular, and retinal nerve fibre layer (RNFL) thicknesses were measured by spectral domain optical coherence tomography. Results were compared using paired sample t-test, and a p value <0.05 was accepted as statistically significant.

Results: The comparison of 16:00-h measurements significantly revealed lower values during fasting period when compared non-fasting period for choroidal thickness (non-fasting and fasting, respectively; subfoveal: 299.26?±?41.3 and 280.03?±?38.75 p?p?p?=?0.001) and paracentral macular thickness (superior: p?=?0.002, inferior: p?=?0.010, temporal: p?=?0.013, and nasal: p?=?0.016). By contrast, no significant differences were found in the central macular thickness between the fasting and non-fasting periods (p?=?0.735). Also, no statistically significant difference was noted for RNFL thickness at the different periods and time points.

Conclusion: Our results reveal that Islamic religious fasting is associated with statistically significant alterations in choroidal and paracentral macular thickness in healthy volunteers. However, more detailed investigations should be designed to evaluate whether fasting has a pivotal influence on pathological conditions.     

The effect of rebreathing and hyperventilation on retinal and choroidal vessels measured by spectral domain optical coherence tomography

Objective: The purpose of this study was to examine the vasoreactivity in retina and choroid of the healthy eyes in response to experimentally altered partial arterial pressure of carbon dioxide (PaCO₂) using a non-invasive technique, spectral domain optical coherence tomography (SD-OCT).

Materials and methods: The study included non-smoking participants between 18 and 35 years of age, having visual acuity of 20/20 and with no systemic and ocular diseases. At baseline, the participants breathed room air (normocapnia). Hypocapnia was created with the help of hyperventilation; for this, the participants were instructed to draw deep and quick breaths, resulting one breathing cycle per 2?s. To create hypercapnia subjects rebreathed from a 5?l bag at least 3?min. Choroidal thickness and retinal artery diameter were measured at baseline, and hyperventilation and rebreathing conditions by SD-OCT.

Results: Twenty eyes of 20 healthy subjects were included in this study. Their mean age was 24.90?±?5.32 years. Hyperventilation caused a significant reduction in choroidal thickness, compared with baseline, at all points; whereas rebreathing caused no significant change at all points. The mean diameters of the arteries were 151.80?±?7.88?μm, with a significant decline to 148.90?±?7.25?μm at hyperventilation condition and a significant increase to 153.50?±?7.88?μm at rebreathing condition (p?=?0.018, p?=?0.043, respectively).

Conclusion: This study demonstrated that, SD-OCT was a useful tool in measuring the ocular vascular response under hypercapnia and hypocapnia conditions. These findings may be helpful for further understanding the physiological nature of ocular blood flow and this preliminary study provides a basis for future studies.     

Spectral domain-optical coherence tomographic findings in patients with ankylosing spondylitis under anti-tumor necrosis factor-alpha therapy

Objective: To evaluate the effect of tumor necrosis factor-alpha (TNF-α) blockade on the thickness of the peripapillary retinal nerve fiber layer (RNFL), the ganglion cell-inner plexiform layers (GCIPL), and the macula in ankylosing spondylitis (AS) patients under anti-TNF-α therapy.

Materials and methods: Twenty-one patients with AS received etanercept, or adalimumab, or infliximab for at least 6 months. Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) levels, and Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) scores were measured before and 6 months after the beginning of the treatment. Peripapillary RNFL, four regional fields (superior, inferior, nasal, and temporal), GCIPL, and macular thicknesses of the patients were analyzed by optical coherence tomography before the treatment, at 3 months and 6 months after the beginning of the treatment.

Results: The mean BASDAI, ESR, and CRP values were 5.2?±?1.5, 31.6?±?21.7, and 15.7?±?13.9, respectively, at the beginning of the treatment and 2.3?±?1.7, 21.3?±?15.1, and 10.1?±?10.3, respectively, 6 months after the beginning of treatment. There were significant differences among the mean BASDAI, ESR, and CRP values at the beginning of treatment and 6 months later (p?p?=?0.007, and p?=?0.009, respectively). There were no significant differences among peripapillary RNFL (p?=?0.24), four regional fields (p?=?0.98, p?=?0.23, p?=?0.09, p?=?0.47), GCIPL (p?=?0.25), or macular (p?=?0.33) thicknesses of the patients during anti-TNF-α treatment. In addition, the mean intraocular pressure levels throughout the follow-up did not show significant variation on repeated-measures ANOVA (p?=?0.77).

Conclusions: TNF-α blockade does not seem to influence RNFL, GCIPL, or macular thickness of patients with AS in the short term.     

Effect of smoking on retina nerve fiber layer and ganglion cell-inner plexiform layer complex

Purpose: The aim of this study is to show the effects of smoking on retina layers, especially retina nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer complex (GCIPL).

Materials and methods: Participants smoking for more than 10 years at least 1 pack of cigarettes a day and a control group, both including participants between ages of 20 and 50 years with no other systemic or ocular diseases were studied. After normality tests, an independent sample t test was used to analyze the differences in age, sex, spherical equivalent (SE), intraocular pressure (IOP), axial length (AL), GCIPL and RNFL values between the groups.

Results: There were 44 participants in each group. There were 32 (62.5%) men and 12(37.5%) women in smokers and 36 (77.88%) men and 8 (22.22%) women in control group. Mean ages were 39.85?±?8.41 and 38.66?±?10.47 years, mean spherical equivalent (SE) values were ?0.15?±?0.4 and 0?±?0.29 dioptries in smokers and control groups, respectively. The IOP, AXL, GCIPL and RNFL values were 17.58?±?3.41?mmHg, 23.69?±?0.56?mm, 84.3?±?5.83?μm and 92.3?±?3.51?μm in the smokers group and 18.5?±?2.91?mmHg, 23.45?±?0.72?mm, 86.11?±?8.02?μm and 97.66?±?8.23?μm in the control group. The inferior, superior, nasal and temporal values of RNFL quadrants were 123.18?±?26.14, 117.05?±?5.51, 64.95?±?8.67 and 63.5?±?6.88?μm in the smokers group and 130.81?±?11.8, 123.55?±?11.03, 72.44?±?9.84 and 58.44?±?7.48?μm in the control group. There were no significant difference of age, sex, SE, IOP, AXL and GCIPL values between the smokers and control groups (p?>?0.05). The mean RNFL was significantly thinner in the smokers group compared to controls (p?=?0.03, independent t test). Inferior and superior quadrants of RNFL decreased in smokers group (p?=?0.01 and p?=?0.03, respectively) but temporal and nasal quadrants did not seem to be changed (p?=?0.96 and p?=?0.07, respectively).

Discussion: Smoking may affect RNFL thickness but not GCIPL.     

The long-term effect of oral isotretinoin therapy on macula ganglion cell complex thickness

Purpose: To evaluate the long-term effect of oral isotretinoin therapy on macula ganglion cell complex (GCC) thickness by spectral domain optical coherence tomography (SD-OCT).

Materials and methods: Newly diagnosed cystic acne patients who received low dose for a long time systemic isotretinoin therapy were included in this study. Thorough ophthalmic evaluation and GCC thickness analysis by using SD-OCT were performed at baseline, and at 1, 3, 6, and 12 months of treatment.

Results: Forty-eight eyes of 24 patients (15 females, 9 males) were included in the study. The mean age of patients was 19.37?±?2.74 years (range 14–25 years). The full ophthalmologic examination was normal in all eyes before treatment. During the treatment there were no change in visual acuity, refractive error, intraocular pressure and tear break-up time. The mean GCC thicknesses were 81.45?±?4.91, 81.45?±?5.12, 81.81?±?4.68, 81.87?±?4.91 and 81.64?±?5.09?μm at pretreatment and at 1, 3, 6, and 12 months of treatment, respectively (p?=?0.803).

Conclusion: One-year systemic use of isotretinoin had no significant effect on the thickness of macula ganglion cell. Macular ganglion cell analysis is useful for determining and following the toxic effects of systemic drugs on the retina. However, it is more rational to consider it as an adjunct to electrophysiological testing rather than used alone.     

Effects of cigarette smoking on choroidal and retinal thickness and ocular pulse amplitude

Background: In our study, we aimed to show the effects of smoking on choroidal thickness and ocular pulse amplitude. It is known that the anatomy and physiologic functions of the choroid is important in ocular diseases like glaucoma and age-related macular degeneration. Choroidal thickness is measured by the spectral domain optical coherence tomography (SD-OCT). The ocular pulse amplitude (OPA) is the difference between the systolic and diastolic intraocular pressure (IOP) and it is an index of choroidal perfusion.

Design: This was a cross-sectional prospective observational study at the Turgut Ozal University Hospital setting.

Participants: The test subjects were divided into two groups: the smokers group which consisted in 24 participants (20 male, 4 female) and the control group with 22 participants (16 male, 6 female).

Methods: The participants underwent full ophthalmological examination including best-corrected visual acuity (BCVA), spherical equivalent (SE) values of refractive errors, intraocular pressure (IOP), ocular pulse amplitude (OPA), central corneal thickness (CCT), axial length (AL) and choroidal thickness. The IOP and the OPA were measured with the dynamic contour tonometer. The CCT and the AL were measured with the Nidek AL-Scan (Nidek Co., Ltd., Gamagori, Japan). The choroidal thickness was measured by the Cirrus high-definition optical coherence tomography (Cirrus Version 6.0; Carl Zeiss Meditec, Dublin, CA).

Results: Gender did not differ significantly between the groups (p?=?0.12). The age, SE, IOP, OPA, CCT and AL did not differ significantly in smokers and control groups (p?=?0.12, p?=?0.37, p?=?0.54, p?=?0.80, p?=?0.56 and p?=?0.82, respectively). The nasal, temporal, central retinal (p?=?021, p?=?021, p?=?0.11) and nasal, temporal, central choroidal thicknesses (p?=?0.80, p?=?0.39, p?=?0.75) did not differ significantly between smokers and control groups.

Conclusions: We could not find a significant difference in OPA, retinal and choroidal thicknesses between smokers and non smokers. Further studies including histopathological changes in larger groups are needed to show the effect of smoking on choroidal thickness especially in patients with ocular diseases like age-related macular degeneration.     

The protective effect of selenium in cisplatin-related retinotoxicity

Purpose: The aim of this study is to evaluate the retinal toxicity of cisplatin and neuroprotective effect of selenium in cisplatin-related retinal toxicity.

Methods: Eighteen adult Wistar-Albino rats were divided into three groups. Group 1 (n?=?6) received intraperitoneal (i.p.) injection of 2.5?ml physiologic saline for three days, group 2 (n?=?6) received i.p. 16?mg/kg cisplatin for three days and group 3 (n?=?6) received i.p. 16?mg/kg cisplatin for three days and 1.5?mg/kg twice daily selenium via gavage five days prior to cisplatin injection and for three days concomitantly with cisplatin injections. The total retinal thickness, outer nuclear layer (ONL), inner nuclear layer (INL) and inner plexiform layer (IPL) thicknesses were measured in hematoxylin/eosin and apoptotic index (AI) of ganglion cell layer (GCL) and INL was evaluated in TdT-mediated dUTP-biotin nick end labeling (TUNEL)-stained retina sections.

Results: Selenium statistically succeeded to reduce total retinal thickness in cisplatin-toxicated retinas: from 210.17?±?23.40 to 173.55?±?20.43, ONL: 49.79?±?5.32 to 41.87?±?6.30, INL: 33.72?±?7.93 to 25.06?±?5.73 and IPL: 53.61?±?8.63 to 45.61?±?6.92?µm in hematoxylin/eosin-stained retina sections. The AI was also reduced in INL (30.10?±?12.02 to 19.48?±?12.99) and in GCL (37.59?±?17.70 to 33.15?±?13.78). However, statistical significance was present in only AI values of INL.

Conclusions: Selenium limited edema due to the toxicity and reduced the retinal thickness and showed neuroprotection in cisplatin-induced retinotoxicity.     

Influence of serous retinal detachment on the outcome of ranibizumab treatment in diabetic macular oedema

Purpose: The purpose of this study was to evaluate the influence of serous retinal detachment (SRD) on the outcome of intravitreal ranibizumab (IVR) therapy in diabetic macular oedema (DME).

Materials and methods: Fifty-one eyes with cystoid macular oedema (CME) and SRD (study group) and 57 eyes with only CME (control group) that received pro re nata (PRN) IVR injections during a 6-month period were retrospectively evaluated. The outcome measures included changes in the central macular thickness (CMT) and best corrected visual acuity (BCVA) and injection numbers.

Results: The mean initial CMT in the study and control groups was 467?±?101 and 440?±?89?µm, respectively. The mean BCVA in the study and control groups was 0.75?±?0.38 and 0.59?±?0.36 logarithm of minimal angle of resolution (LogMAR), respectively (p?=?0.010). The study group received a mean of 2.2?±?0.92 injections, whereas the control group received a mean of 2.54?±?0.9 injections. The decrease in CMT was greater, but not significantly greater, in the study group than in the control group.

Conclusion: The presence of SRD resulted in a less favourable visual acuity (VA) outcome with IVR. Disruption of the ellipsoid zone and abnormality of the foveal avascular zone at the baseline examination were correlated with a lower VA. Both of the pathologies occurred more frequently in the SRD group.     

Efficacy of intravitreal dexamethasone implant for the treatment of macular oedema after pars plana vitrectomy for rhegmatogenous retinal detachment: long-term outcomes

Abstract

Purpose: To investigate the efficacy and safety of intravitreal dexamethasone implant as initial and only treatment for macular oedema after pars plana vitrectomy (PPV) for rhegmatogenous retinal detachment (RRD).

Methods: This study included 14 patients, who were diagnosed with macular oedema after PPV for RRD and who were treated with intravitreal dexamethasone implant. Patients were examined at the time of macular oedema diagnosis (baseline) and 1, 6 and 12?months after treatment, using best corrected visual acuity (BCVA) measurement and optical coherence tomography (OCT).

Results: The mean BCVA at baseline was 0.72?±?0.29 logMAR and improved significantly to 0.37?±?0.21, 0.42?±?0.19 and 0.35?±?0.22 logMAR at month 1, 6 and 12 after treatment with dexamethasone implant. The mean central retinal thickness (CRT) was 623?±?142?μm at baseline and decreased significantly to 339?±?163?μm, 428?±?131?μm and 356?±?147?μm at month 1, 6 and 12 after treatment. Total resolution of macular oedema was observed in 10 out of 14 patients (71.4%) at month 12. Ellipsoid zone was intact in 71.4% of patients at the end of the follow-up, while 71.4% of patients received only one implant until the end of the 12-month follow-up. No adverse events were observed.

Conclusions: Intravitreal dexamethasone implant was found to be effective and safe as initial treatment for macular oedema after PPV for RRD.     

Retinal structural changes in patients receiving tamoxifen therapy by spectral-domain optical coherence tomography

Abstract

Purpose: To evaluate choroidal thickness, ganglion cell complex (GCC) and photoreceptor outer segment (PROS) length were measured in patients with breast cancer undergoing tamoxifen therapy, using spectral-domain optical coherence tomography (SD-OCT); results were compared with those for normal eyes.

Materials and methods: Forty-four patients with breast cancer, undergoing tamoxifen therapy, and 41 healthy controls were included in this prospective, comparative study. All participants underwent a complete ophthalmologic evaluation and SD-OCT. Subfoveal, nasal (nasal distance to fovea 500, 1000, 1500?μm), and temporal (temporal distance to fovea 500, 1000, 1500?μm) choroidal thickness measurements were performed using the enhanced depth imaging mode of SD-OCT. Using an Early Treatment Diagnostic Retinopathy Study (ETDRS) circle at the macular level, the automated retinal segmentation software was applied to determine the thickness of the GCC. PROS length was determined manually, as the distance from the inner surface of the ellipsoid zone to the inner surface of retina pigment epithelium.

Results: The mean choroidal thickness was statistically greater in the tamoxifen group than controls in all quadrants (p?<?0.001 for all quadrants). Of all tamoxifen users (44 eyes of 44 patients), 33 eyes (75%) had uncomplicated pachychoroid (UCP). Pachychoroid pigment epitheliopathy (PPE) was detected in five tamoxifen-group patients (11.3%). Patients with PPE in one eye had UCP in the fellow eye. Central serous chorioretinopathy findings were observed in one patient. Tamoxifen users had statistically lower GCC thickness in all inner rings of the ETDRS inlay and in the nasal outer ring only (p?=?0.027, 0.002, 0.002, 0.001, and 0.030, respectively). No statistically significant difference in mean subfoveal PROS length was found between the groups.

Conclusions: SD-OCT provides valuable information for identifying structural changes and evaluating ocular findings in patients receiving tamoxifen therapy. Increased choroidal thickness, PPE and thinning GCC were detected in tamoxifen users. These OCT findings may be an early indicator of retinal toxicity for patients undergoing tamoxifen therapy in the follow-up period.     

High-resolution optical coherence tomography correlates in ischemic radiation retinopathy

Purpose: To find the abnormalities in various retinal layers caused by radiation retinopathy using spectral domain optical coherence tomography (SD-OCT).

Methods: We report a case of radiation retinopathy that was imaged using SD-OCT Copernicus (Optopol, Zawiercie, Poland). Analysis and synthesis of the OCT image were done using information both at the fovea and 2.5?mm temporal to the fovea.

Results: The layers that were reduced in thickness included the inner plexiform layer (47?μm vs. 74?μm), the inner nuclear layer (17?μm vs. 48?μm), and the outer plexiform layer (25?μm vs. 45?μm), whereas the layers with comparable thickness included the nerve fiber layer (24?μm vs. 25?μm), the outer nuclear layer (42?μm vs. 43?μm), the outer segment–inner segment junction (52?μm vs. 54?μm), and the retinal pigment epithelium (RPE) choriocapillaris layer (30?μm vs. 28?μm).

Conclusion: This report suggests that the radiation-induced damage was confined to the inner layers of the retina. However, secondary outer retinal layer changes may also occur, as suggested by functional derangements.     

Effects of smoking on visual acuity of central serous chorioretinopathy patients

Background: The aim of this study was to evaluate the differences, in terms of visual outcome and treatment needs, between smokers and non-smokers central serous chorioretinopathy (CSCR) patients.

Methods: The files of 252 patients diagnosed with CSCR who had presented to the Retina Unit of the Ophthalmology Clinic at Dicle University Medical School in Turkey were retrospectively evaluated. Eighty-four smokers, with a known history of smoking of at least one pack-year, and 133 non-smokers were included, whereas 35 patients with additional pathologies were excluded from the study.

Results: Of the patients, 192 (88.5%) were male and 25 (11.5%) were female. The mean patient age was 38.8?±?8.1 years (range: 20–68 years). Visual acuity (VA) of the smoker and non-smoker groups was measured as 0.45?±?0.35 and 0.24?±?0.28 logarithm of the minimum angle of resolution (logMar), respectively, at the first visit; 0.19?±?0.29 and 0.06?±?0.14 logMar at the sixth month; and 0.07?±?0.14 and 0.02?±?0.05 logMar at the ninth month. VA measurements at presentation and during all examinations (1th, 6th and 9th month) were significantly different for the two groups. VA was lower in the smoker group. In 27 patients (12.4%), an additional treatment modality was needed. Of the 27 patients, only 8 (6%) were non-smokers, whereas 19 (22.6%) were smokers. There was no difference between groups in the recurrence rate during follow-up (p?=?0.907); 14 (16.7%) smokers and 8 (19.0%) non-smokers experienced a recurrence.

Conclusion: This study has shown that patients selected and who are current smokers have poorer vision and need longer treatment.     

The effects of smoking on corneal endothelial cells: a cross-sectional study on a population from Isfahan,Iran

Purpose: The aim of this study is to compare the effect of smoking in corneal endothelial cell number and morphology by specular microscopy on a non-smoker population.

Methods: Our cross-sectional study was performed on 150 participants from a non-smoker population. Non-contact specular microscopy (Tomey Corporation Inc., Nagoya, Japan) was performed in the center of the cornea of all subjects. The cell density (CD), average cell size (AVG), percent of hexagonality (HEX%) and central corneal thickness (CCT) were calculated and compared in both groups.

Results: Totally, 76 eyes of 76 smokers and 74 eyes of 74 non-smokers were enrolled in the study from 2015 to 2016. The mean age of smokers and non-smokers were 48.61?±?17.04 and 46.39?±?13.02, respectively. The mean number of pack/year among the smokers was 17.36?±?14.68. Also, the mean values of AVG and CD were significantly different for these two groups (p?=?0.011 and p?=?0.039, respectively). Other corneal endothelial variables did not show a significant difference between smokers and non-smokers (p?>?0.05). However, smokers with severe nicotine dependency had significantly greater AVG and lower CD in comparison with the non-smokers (p?=?0.004 and p?=?0.013, respectively).

Conclusion: Our study showed that smoking can cause significant changes in some of the corneal endothelial variables, but not all of them.     

Evaluation of proton beam radiation sensitivity of proliferating choroidal endothelial and retinal ganglion cells with clonogenic assay

Context: Proton beam therapy offers the advantage of precise delivery with limited damage to the healthy tissue and is being tested in the management of exudative age-related macular degeneration (AMD). However, the dosages tested are empirical and not based on preclinical studies.

Objective: In this study we evaluated the effects of varying doses of proton beam radiation on choroidal endothelial cells (CECs) and retinal ganglion cells (RGCs) using clonogenic assay to determine differential sensitivity.

Materials and methods: Each cell type has different efficiency to replicate (plating efficiency (PE)). PE of CEC (RF/6A) and RGC (RGC-5) grown in culture flasks was determined by plating 250 cells each (without any treatment) and counting the number of colonies after 13 days. Radiation induced sensitivity was determined by exposing the semi-confluent RF/6A and RGC-5 cells to proton beam at the doses of 0 (control), 2, 4, 8 and 12 cobalt gray equivalent (CGE). The ability of the cells to repair and replicate to form colonies were analyzed 13 days after radiation with crystal violet stain and the survival ratio was calculated. The significance of survival was analyzed using ANOVA (Graphpad Instat.3).

Results: The PE of CEC and RGC was 12.96?±?0.29% and 40.7?±?1.48%, respectively. A survival ratio of CEC at 2, 4, 8 and 12 CGE proton radiation was 66.0?±?8.6%, 44.3?±?6.5%, 7.6?±?0.3% and 1.14?±?0.06% on exposure to 2, 4, 8 and 12 CGE proton radiation, respectively, p?<?0.01). Survival ratio of RGC was 71.1?±?22.4% (p?=?0.05), 40.2?±?7.9%, 8.89?±?2.6% and 0.78?±?0.31% at 2, 4, 8 and 12 CGE dosages (p?<?0.001).

Discussion: CEC showed dose-dependent decrease in survival rate with values attaining significance at all radiation dosages. In contrast, RGC was comparatively radio resistant and were able to replicate at lower doses and sensitive at higher doses after proton beam radiation.

Conclusion: Since CECs proliferate during neovascularization, this clonogenic assay is a useful assay to assess the sensitivity of CEC to radiation. This study identified that CEC were more sensitive to proton beam radiation than RGC at all doses. This may provide a therapeutic window for administration of proton beam radiation in the management of AMD.     

The effectiveness and reliability of posterior sub-Tenon triamcinolone acetonide injection in branch retinal vein occlusion-related macular edema

Objective: To investigate the effectiveness and reliability of posterior sub-Tenon triamcinolone acetonide (PSTA) application in branch retinal vein occlusion (BRVO)-related macular edema.

Methods: Patients with confirmed BRVO-related macular edema were enrolled in the study. Patients were injected with a single, therapeutic dose of 40?mg PSTA. Detailed ophthalmic examination was performed at baseline and at 1, 3 and 6 months after the treatment. Best corrected visual acuity (BCVA), intraocular pressure (IOP), cataractogenic change (CC) and macular optical coherence tomography (OCT) analysis results were evaluated. The results were compared statistically.

Results: Forty-one eyes of 41 patients with a mean age of 63.49?±?10.99 (55–86) years, 15 (36.6%) females, were included in the study. BCVA in LogMAR values at 1 and 3 months were significantly better than at baseline, while no significant difference from baseline was observed in sixth month values (p?<?0.001, p?<?0.001 and p?=?0.846, respectively). Central macular thickness values obtained using OCT were significantly lower at the first, third and sixth months compared to baseline (p?<?0.001 for all). IOP elevation was determined in only two eyes (4.8%) at the end of the study period, and no CC was detected in any case.

Conclusion: PSTA application is an effective and safe option in BRVO-related macular edema.     

Ocular findings in coal miners diagnosed with pneumoconiosis

Objective: Our study aimed at evaluating ocular findings and structural changes in coal mine workers who were chronically exposed to coal mine dust and diagnosed with pneumoconiosis.

Methods: Ocular findings of 161 eyes of 81 patients diagnosed with pneumoconiosis who had previously worked or are currently working in coal mines were analyzed. Forty-six coal mine workers and sex matched healthy people (n?=?20) participated in the study. Workers who had early changes of pneumoconiosis were included in Group 1 (n?=?17), workers diagnosed with pneumoconiosis were included in Group 2 (n?=?29), and healthy subjects were included in Group 3 (n?=?20). Outcome measures were the difference in peripapillary retinal nerve fiber layer (RNFL) thickness, choroidal thickness (CT), central macular thickness (CMT) and tear function tests between the groups.

Results: RNFL thickness values in Group 1 and 2 were lower than in Group 3, the control group, in all quadrants except the temporal quadrant. However, there was no statistically significant difference in peripapillary RNFL thickness values in any quadrants among the three groups (p?>?0.05). Central subfoveal choroidal thickness and CMT measurements were thinner in Group 1 and 2 than in the control group. However, this difference among groups was not statistically significant (p?>?0.05). Mean schirmer's test result was 8.8?±?1.6?mm in group 1, 7.1?±?1.8?mm in Group 2 and 11.5?±?3.6?mm in the control group. Mean tear break up time (BUT) test result was 7.1?±?1.3?seconds (sec) in Group 1, 6.5?±?1.8?sec in Group 2 and 10.4?±?2.9?s in the control group. The Schirmer's test and BUT test results were both statistically significantly lower in coal mine workers (Group 1 and 2) compared to the control group. Group 1 and Group 2 did not show statistically significant difference in terms of Schirmer's test and BUT test results.

Discussion: The association between pneumoconiosis and coal mine dust contiguity is thought to be due to the effect of coal dust by producing chronic inflammation. In addition, there are several trace elements in coal dust which are toxic to vital tissues. In this study, ocular findings suggest that systemic levels of trace elements and chronic inflammation may not reach to a level that influences ocular structures. Nonetheless, tear functions seem to be affected in coal mine workers.

Conclusion: This study suggests that the systemic effect of coal mine dust in ocular structures is not evident. However, direct contact with coal mine and fume leads to a decrease in tear function tests.     

Swept-source optical coherence tomography analysis in asthmatic children under inhaled corticosteroid therapy

Purpose: To evaluate retinal nerve fiber layer thickness (RNFLT), ganglion cell layer thickness (GCLT), subfoveal choroidal thickness (SFCT), and central retinal thickness (CRT) in asthmatic children who were under inhaled corticosteroid treatment by using Swept-Source Optical Coherence Tomography (SS-OCT).

Material and methods: Fifty-three children were prospectively analyzed in the study. Group 1 included 31 asthmatic children and group 2 included 22 healthy children. Asthmatic children received a dose 250?μg daily of inhaled fluticasone propionate (Flexotide, GlaxoSmithKline, Middlesex, UK). Allergy parameters including, exposure to smoke, eosinophil count, percentage of eosinophils, immunoglobuline (Ig) E levels, number of asthma attacks, number of sensitivity to allergens and follow-up time were recorded. The RNFLT, GCLT, SFCT, and CRT were analyzed with SS-OCT and the data were compared between the groups.

Results: There were 13 girls (41.9%) and 18 boys (58.1%) in group 1 and 13 girls (59.1%) and 9 boys (40.9%) in group 2 (p?=?0.22). The mean age was 9.3?±?2.2 years in group 1 and 9.9?±?1.5 years in group 2 (p?=?0.08). The mean CRT (239.26?±?34.56 µm versus 226.82?±?26.23 µm, p?=?0.22) and mean SFCT (273.97?±?40.95 µm versus 280.41?±?32.78 µm, p?=?0.54) did not significantly differ between the groups. The superior, inferior, and average RNFLT were significantly lower in group 1 than group 2 (p?p?p?Conclusions: The SS-OCT revealed that asthmatic children under inhaled corticosteroid treatment have lower RNFLT than healthy subjects.     

The effects of smoking on dry eye parameters in healthy women

Aim: To investigate the effects of chronic smoking on dry eye parameters.

Methods: Ocular surface disease index (OSDI) and tear function tests such as Schirmer’s test, tear break-up-time (TBUT) test and impression cytology of 63 female chronic smokers and 40 age-matched female non-smokers were analyzed statistically.

Results: The mean OSDI scores, Schirmer test results and TBUT levels were 35.85?±?24.01 point, 14.25?±?5.94?mm and 5.17?±?2.85?s in chronic smokers and 15.20?±?12.93 point, 15.48?±?7.01?mm and 10.03?±?3.44?s in non-smokers, respectively. Differences in OSDI scores, TBUT levels and impression cytology grades among the chronic smokers and non-smokers were statistically significant.

Conclusion: Smoking behavior seems to affect the dry eye parameters negatively.     

Effect of intravitreal injection of dexamethasone implant on corneal endothelium in macular edema due to retinal vein occlusion

Objective: To evaluate the effects of dexamethasone (DEX) implant (Ozurdex®) on corneal endothelium in patients with retinal vein occlusion complicated with macular edema.

Materials and methods: Patients (n?=?31) received 1–3 intravitreal DEX implants in one eye. Measurements were intraocular pressure (IOP) at baseline and 1, 3, and 6 months after the first intravitreal injection and corneal specular microscopy and central corneal thickness (CCT) at baseline and 1 and 6 months. We analyzed endothelial cell density (ECD), coefficient of variation of cell size (CV), and percentage of hexagonality.

Results: Mean follow-up period was 9.7?±?3.3 months. Mean number of injections was 1.5?±?0.8. Mean IOP values were 15.6?±?2.6?mm Hg at baseline, 17.7?±?3.6?mm Hg at one month, 16.4?±?4.1?mm Hg at three months, and 16.0?±?2.7?mm Hg at six months. There was a significant difference in mean IOPs at one month and six months (p?=?0.008). There were no significant differences in mean ECD (p?=?0.375), CV (p?=?0.661), percentage of hexagonality (p?=?0.287), and CCT (p?=?0.331).

Conclusion: Although intravitreal injection of 0.7?mg DEX causes moderate elevation of IOP, it does not seem to have detrimental effects on corneal endothelium at six months.