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.     

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 topiramate on choroidal thickness and anterior chamber parameters in the treatment of patients with migraine

Objective: To investigate the effects of topiramate on choroidal thickness and anterior chamber parameters using optical coherence tomography in the treatment of patients with migraine.

Methods: A total of 22 eyes of 22 adults (12 females, 10 males) diagnosed with migraine and scheduled to topiramate treatment for pain control were recruited in this prospective study. Choroidal thickness (CT), anterior chamber depth (ACD), anterior chamber angle (ACA), spherical refractive equivalent (SphEq) and intraocular pressure (IOP) measurements were recorded at baseline (prior the topiramate therapy), first and second month visits for the statistical analysis. One-way ANOVA with repeated measures test was used for the statistical evaluation.

Results: Mean age of the patients was 40.2?±?6.5?years. Mean CT at central fovea was 324?±?47?μm initially, 341?±?45?μm in the first month and 344?±?46?μm in the second month, thus first and second month measures were significantly higher than base values (p?p?=?0.001). Baseline ACD (3.66?±?0.22?mm) measures significantly decreased at the first month (3.63?±?0.22?mm) and second month (3.62?±?0.22?mm, p?=?0.009). Also, a significant reduction was detected in the first (36.2?±?4.9°) and second month (35.9?±?5.1°) ACA measures comparing with baseline (39.1?±?5.1°, p?=?0.05). A significant myopic shift was determined in the first and second month SphEq values (?0.08?±?0.6, ?0.10?±?0.6, respectively, p?=?0.05).

Conclusions: The study revealed increased CT and altered anterior chamber parameters and IOP due to topiramate therapy. Therefore, the patients using topiramate should be carefully monitored by an ophthalmologist considering the possible side effects.     

The effect of cigarette smoking on retinal nerve fiber layer thickness in patients with migraine

Context: Migraine is a frequent and disabling chronic neurological condition with complex pathophysiology. Both cigarette smoking and migraine may cause damage to the optic nerve. Objective: The primary objective of this study was to investigate the effect of cigarette smoking on retinal nerve fiber layer (RNFL) thickness in patients with migraine.

Materials and methods: Eighty-four consecutive patients diagnosed with migraine (34 smokers and 50 nonsmokers) and 66 age- and gender-matched healthy non-smoker controls were enrolled for this observational cross-sectional study. RNFL thickness was measured using spectral-domain optical coherence tomography (OCT) and then RNFL thickness in patients with migraine who smoke was compared to nonsmoking patients with migraine and healthy subjects.

Results: The average, superior, nasal and inferior RNFL thicknesses were significantly thinner in patients with migraine compared to the control group (p?<?0.001, p?=?0.02, p?<?0.001 and p?=?0.04, respectively). The average and inferior RNFL thicknesses were significantly reduced in smoker patients with migraine compared to the nonsmokers (p?=?0.011, p?=?0.045, respectively). Nonsmoker patients with migraine had significantly thinner average and nasal RNFL thicknesses than the control group (p?=?0.001, p?=?0.001, respectively).

Conclusion: Cigarette smoking may cause significant RNFL thinning in patients with migraine. OCT may be a feasible technique for determination of smoking-induced ocular damage in patients with migraine.     

Peripapillary choroidal thickness in patients with chronic obstructive pulmonary disease

Objective: To evaluate the peripapillary choroidal thickness of patients with chronic obstructive pulmonary disease (COPD) via enhanced depth imaging optical coherence tomography (EDI-OCT).

Materials and methods: A total of 80 patients with COPD (80 eyes) and 50 control subjects (50 eyes) were enrolled. Choroidal scans and the retinal nerve fiber layer (RNFL) thickness were obtained for all eyes using OCT.

Results: The average peripapillary choroidal thickness measurements of the COPD group (147.58?±?53.53?μm) were lower than the control group (160.84?±?44.73?μm) (p?=?0.068). Inferior segment thicknesses were significantly thinner than the other segments (p?<?0.05). Subfoveal choroidal thickness and RNFL thickness measurements of the COPD group were also lower than those of the control group (p?=?0.111).

Conclusion: Hypoxia in COPD seems to affect the choroidal thickness. Thinning of the choroid may be attributed to increased vascular resistance and reduced blood flow in patients with COPD. The possible effects of the disease to the eye may be clarified through the role of the choroidal vasculature in the blood supply of the anterior optic nerve head.     

Optical coherence tomography findings in patients with alcohol use disorder and their relationship with clinical parameters

Abstract

Purpose: In our study, we aimed to investigate the ganglion cell-inner plexiform layer thickness (GCIPL), retinal nerve fibre layer thickness (RNFL), mean macular volume (MMV), central macular thickness (CMT), mean macular thickness (MMT), and choroidal thickness (CT) values with optical coherence tomography (OCT) in patients who are diagnosed with alcohol use disorder (AUD).

Materials and methods: The study included 43 patients who were diagnosed with AUD, and 43 healthy controls. Detailed biomicroscopic examinations of all the participants, visual acuity, intraocular pressure, anterior and posterior segment examinations, and then, OCT measurements were carried out.

Results: Although the measured values for RNFL in the superior and temporal quadrant are within normal limits, they were slightly higher compared to those in the control group (p values 0.127 and 0.191 for superior quadrant and temporal quadrant, respectively). The CT measurements in all quadrants were higher than the control group; however, these measurements were not statistically significant (p?>?0.05). When the relation between clinical features and OCT findings of the patients were examined, it was determined that the ages of the patients were statistically significantly and inversely correlated with the temporal CT and also the nasal and temporal quadrants of RNFL.

Conclusions: Our study is the first study that examines the retinal GCIPL and CT with OCT in patients who are diagnosed with AUD. In our results, it was determined that there were no statistically significant differences between the participants in terms of OCT parameters. Further studies with larger sampling groups evaluating neurotransmission findings may provide wider results.     

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.     

Histopathological changes of the nasal mucosa induced by smoking

Changes in the histopathology of the respiratory epithelium in response to cigarette smoking have been studied in depth in the lungs, but data on the nasal lining are lacking. The aim of the present retrospective study was to investigate the histological changes that occur in the nasal mucosa of smokers compared with non-smokers. The study group included 47 patients who underwent partial resection of the inferior turbinates. Archival nasal tissue samples were collected and examined by light microscopy: the number of goblet cells was counted, and the degree of inflammation, congestion, and edema was graded as mild, moderate, or severe. Epithelial thickness was measured as well. Findings were compared between smokers (n?=?21) and non-smokers (n?=?26). On statistical analysis, significant differences were found between the smokers and non-smokers in mean number of goblet cells in the nasal epithelium, 43.43?±?16.80 vs. 16.23?±?5.65 respectively (p?<?0.0001), mean edema grade, 2.43?±?0.75 vs. 1.12?±?0.33 respectively (p?<?0.0001), and mean epithelial thickness, 111.9?±?25.8 μm vs. 60.4?±?18.4 μm respectively (p?<?0.0001). The corresponding mean values of congestion were 2?±?0.71 and 1.27?±?0.67 (p < 0.001), and of inflammation, 1.81?±?0.60 and 1.81?±?0.85 (NS). In conclusion, the histopathological findings in the nasal mucosa of smokers resemble reported findings in the bronchial respiratory epithelium. The main differences from non-smokers are greater goblet cell hyperplasia and thicker epithelium.     

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.     

Evaluation of the effects on choroidal thickness of bimatoprost 0.03% versus a brinzolamide 1.0%/timolol maleate 0.5% fixed combination

Objective: To investigate the effects of two different medical treatment options on choroidal thickness (CT) in cases of open-angle glaucoma (OAG).

Methods: Sixty-seven eyes newly diagnosed with OAG and 52 healthy eyes constituting the control group were included in the study. Glaucomatous eyes were randomly divided into two subgroups; Group I was started on bimatoprost 0.03% and Group II on a brinzolamide 1.0%/timolol maleate 0.5% fixed combination (BTFC). Intraocular pressure (IOP), ocular pulse amplitude (OPA) and subfoveal CT measurements were performed in all eyes in the study before treatment and on weeks 2, 4 and 8 after treatment.

Results: Mean initial IOP values in groups I and II and the control group were 25.5?±?4.7, 25.1?±?5.2 and 16.1?±?2.9?mmHg, mean OPA values were 3.7?±?1, 3.6?±?1.4 and 2.4?±?0.6?mmHg and mean CT values were 269.4?±?83, 264.5?±?84.4 and 320.1?±?56.6?μm, respectively. Eight weeks after treatment, mean IOP values in Groups I and II and the control group were 18.3?±?2.6, 18.1?±?3.4 and 15.7?±?2.9?mmHg, mean OPA values were 2.9?±?1.2, 2.8?±?1.5 and 2.3?±?0.8?mmHg and mean CT values were 290.2?±?87.3, 271.8?±?82.5 and 319.3?±?56.8?μm, respectively. No significant difference was determined in terms of the decrease in IOP and OPA obtained after treatment in Group I and Group II. However, a significant difference was observed between the two groups in terms of choroidal thickening after treatment.

Conclusion: The use of topical ocular hypotensive medication in eyes with OAG results in an increase in CT. This increase is relatively greater with bimatoprost 0.03% therapy compared to BTFC.     

Accelerated corneal collagen cross-linking for progressive keratoconus

Purpose: To evaluate the efficacy of accelerated corneal cross-linking (CXL) procedure for progressive keratoconus.

Materials and methods: Twenty-three eyes of 23 patients undergone accelerated CXL procedure were evaluated preoperatively and postoperatively at 1st, 3rd and 6th month for uncorrected distant visual acuity (UDVA), best corrected distant visual acuity (CDVA), spherical error, cylindrical error, spherical equivalent (SE), keratometric values and thinnest corneal thickness (TCT) values with corneal topography by Scheimpflug camera and endothelial cell density (ECD).

Results: The mean UDVA was improved from 0.97?±?0.41 logarithm of minimal angle of resolution (logMAR) to 0.76?±?0.45 logMAR at the 6th month after CXL (p?=?0.332). The mean CDVA was improved from 0.49?±?0.30 logMAR to 0.34?±?0.22 logMAR at the 6th month after CXL (p?=?0.026). The mean sphere was decreased from ?4.47?±?4.1 diopter (D) to ?3.79?±?3.86?D and the mean cylinder was decreased from ?5.60?±?2.2?D to ?4.55?±?1.98?D and the mean SE was decreased from ?7.22?±?4.48?D to ?6.36?±?4.34?D at the 6th month after CXL (p?=?0.128, p?=?0.002 and p?=?0.045, respectively). Flat keratometry, steep keratometry, mean keratometry and maximum keratometry were significantly reduced at the 6th month after CXL (p?=?0.025, p?p?=?0.004 and p?=?0.03, respectively). TCT and ECD were not changed significantly the 6th month after CXL (p?=?0.135 and p?=?0.082, respectively).

Conclusion: Accelerated CXL procedure was effective to stabilize progression of keratoconus with significant reduction in topographic keratometric values and significant increase in CDVA in 6 months.     

Evaluation of retinal nerve fiber layer thickness in vernal keratoconjunctivitis patients under long-term topical corticosteroid therapy

Purpose: The aim of this study was to evaluate the retinal nerve fiber layer (RNFL) thickness in vernal keratoconjunctivitis (VKC) patients who were under long-term topical corticosteroid therapy.

Methods: Thirty-six eyes of 36 VKC patients with clear cornea and normal videokeratography and 40 eyes of 40 age- and gender-matched normal children were included in the study. Clinical and demographic characteristics of the patients were noted and detailed ophthalmological examination was performed. Visual acuity (VA), spherical equivalent (SE), axial length (AL) and RNFL thickness measurements were compared between the groups. To correct ocular magnification effect on RNFL, we used Littmann’s formula.

Results: All VKC patients had history of topical corticosteroid use and the mean duration of the topical corticosteroid use was 23.8?±?9.09 months. There was no significant difference between the groups in terms of intraocular pressure (IOP). VKC group had significantly worse VA, greater SE and AL and thinner mean global, superior and inferior RNFL thickness. There were significant negative correlations between the duration of topical corticosteroid use and the mean global, superior and temporal RNFL thickness in VKC group. After correction of magnification effect, VKC group still had thinner mean global, superior and inferior RNFL thickness, and significant difference between the groups in inferior RNFL thickness did not disappear.

Conclusion: Significant RNFL thickness difference between the groups suggests a possible effect of long-term corticosteroid use in VKC patients. Because visual field (VF) analysis in pediatric patients is difficult to perform and IOP may be illusive, RNFL thickness measurements in addition to routine examinations in VKC patients may help clinicians in their practice.     

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.     

Assessment of ocular neurotoxicity in patients treated with systemic cancer chemotherapeutics

Purpose: Cisplatin and Paclitaxel are two chemotherapeutic agents known to produce neurotoxicity when used for cumulative dose regimens. In this study we aim to assess their toxicity in the optic nerve, and to evaluate the retinal nerve fibre layer (RNFL) thickness and visual field changes in lung cancer patients treated with Cisplatin and Paclitaxel.

Methods: Fifteen patients who were treated intravenously with 75?mg/m² cisplatin and 175?mg/m² paclitaxel every 3 weeks, up to a maximum of six courses, were enrolled in this prospective clinical trial. All patients underwent complete ophthalmological assessments before their treatments began, as well as three months after the completion of their treatments. The RNFL thickness measurements were performed using optical coherence tomography (OCT). Functional testing included the use of frequency-doubling technology (FDT) perimetry and the Humphrey visual field analyser (HFA). The main outcome measurements included the average RNFL thicknesses and visual field indices (mean deviation [MD] and pattern standard deviation [PSD]).

Results: The median age of the 15 patients (nine male and six female) was 63.49 years old (range: 53–77). The average RNFL thickness measurement during the baseline examination was 103.73?μm (range: 97–111). Three months after the cessation of treatment the RNFL thickness declined to 97.4?μm (range: 91–102). Statistical analysis showed a significant thinning between the two measurements (p?=?0.032). The MD and PSD values recorded by the HFA demonstrated no statistically significant changes 3 months after the cessation of treatment (p?>?0.207 and p?>?0.186, respectively). There were statistically significant decreases in both the MD (0.48 to ?1.13?dB) and PSD (2.13 to 0.65?dB) indices measured by the FDT perimetry (p?=?0.041 and p?=?0.025, respectively).

Conclusions: In our study, the systemic administration of Cisplatin and Paclitaxel affected the peripapillary RNFL thicknesses and visual field indices as revealed by FDT perimetry. OCT and FDT perimetry may be adjunctive tools for the screening of ocular toxicity in patients treated with these agents.     

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 long-term anatomical and visual effect of intravitreal triamcinolone injection during vitrectomy for the treatment of idiopathic macular epiretinal membrane

Purpose: To compare the long-term anatomical and visual outcomes of patients with idiopathic epiretinal membrane (ERM) removed by vitrectomy and membrane peeling with or without the use of intravitreal injection of triamcinolone acetonide (IVTA).

Methods: A retrospective chart review was performed. Subjects who underwent vitrectomy and who were followed over 12 months were included. The study included two groups of patients. In group 1 (71 eyes), the patients underwent vitrectomy and membrane peeling without the use of IVTA. In group 2 (27 eyes), 2?mg of IVTA was given at the end of the surgery. The main outcome measures were best-corrected visual acuity (BCVA), central foveal thickness (CFT) determined by optical coherence tomography (OCT), the number of cataract surgeries, and the use of anti-glaucomatous drugs during the follow-up period.

Results: This study included 98 eyes with ERM from 98 patients. There was no significant difference between the two groups with respect to age, gender, pre- and postoperative lens status, BCVA, CFT, or length of the follow-up period. The mean age for all of the patients was 62.45?±?10.01 (mean ± SD) years, and the mean follow-up length was 20.58?±?9.64 (mean ± SD) months. In all cases, the mean best-corrected logarithm of minimum angle of resolution (logMAR) acuity improved from a preoperative value of 0.91?±?0.32 [Snellen equivalent (SE), 0.16?±?0.14] to a postoperative value of 0.46?±?0.36 (SE, 0.46?±?0.29) (P?<?0.0001). The CFT was reduced from a preoperative value of 473.46?±?96.91 μm to a postoperative value of 302.44?±?69.80 μm (P?<?0.0001). Six patients (22.2%) in group 2 required anti-glaucomatous drugs to control intraocular pressure (IOP) during the follow-up period, and three patients (4.2%) in group 1 required drugs to control IOP (P?=?0.012).

Conclusions: The postoperative visual outcomes for patients with idiopathic ERM were favorable, but CFT did not return to a normal level, even in eyes in which 2?mg IVTA was used. The IVTA use after ERM removal produced no significant benefits during long-term follow-up, but IVTA did increase the risk of increased IOP.     

Effect of chronic smoking on lens nucleus as assessed by Pentacam HR lens densitometry in young adults

Objective: To evaluate the effects of chronic tobacco smoking on lens nucleus by Pentacam HR lens densitometry (LD) in young adults.

Design: Prospective cross-sectional case series.

Methods: Thirty subjects (23?M, 7 F) who were chronic cigarette smokers (≥10 cigarettes/day for at least 2 years) (group 1) and another 30 subjects (23?M, 7 F) who did not smoke (group 2), were included in this study. The patients were matched for age and sex between the groups. The exclusion criteria were any history of ocular surgery, any systemic disorders and any ocular diseases except for mild refractive disorders. Lens densitometry measurements were done with the Pentacam HR (Oculus, Wetzlar, Germany). The Schirmer test and pachymetry measurements were also performed.

Results: Mean age of the patients for both groups was 28.90?±?8.20 years (range: 18–40 years). Mean lens densitometry (LD) measurements of Group 1 (chronic cigarette smoking group) were higher than those of Group 2 (control group) in all LD techniques; however only mean “peak” LD measurements showed a statistically significant difference between these two groups (Group 1: 8.67?±?0.61, Group 2: 8.44?±?0.70, p?=?0.04). The mean Schirmer test value was 12.43?±?5.60?mm in Group 1 and 13.00?±?4.26?mm in Group 2 (p?=?0.55). The mean central corneal thickness (CCT) value was 564.23?±?34.61?µm in Group 1 and 550.47?±?32.94?µm in Group 2 (p?=?0.03).

Discussion: The Pentacam HR LD seems to be an important option for the evaluation of lens nucleus in young adults, because it gives objective and quantitative data.

Conclusion: Although chronic smoking increases lens nucleus density in young adults, the effect is not statistically significant when compared with the control group.     

Plasma and tissue disposition of florfenicol in Escherichia coli lipopolysaccharide-induced endotoxaemic sheep

1.?The purpose of this study was to understand the effects of the acute inflammatory response (AIR) induced by Escherichia coli lipopolysaccharide (LPS) on florfenicol (FFC) and FFC-amine (FFC-a) plasma and tissue concentrations.

2.?Ten Suffolk Down sheep, 60.5?±?4.7?kg, were distributed into two experimental groups: group 1 (LPS) treated with three intravenous doses of 1?μg/kg bw of LPS at 24, 16, and 0.75?h (45?min) before FFC treatment; group 2 (Control) was treated with saline solution (SS) in parallel to group 1. An IM dose of 20?mg FFC/kg was administered at 0.75?h after the last injection of LPS or SS. Blood and tissue samples were taken after FFC administration.

3.?The plasma AUC_0–4?h values of FFC were higher (p?=?0.0313) in sheep treated with LPS (21.8?±?2.0?μg·min/mL) compared with the control group (12.8?±?2.3?μg·min/mL). Lipopolysaccharide injections increased FFC concentrations in kidneys, spleen, and brain. Low levels of plasma FFC-a were observed in control sheep (C_max?=?0.14?±?0.01?μg/mL) with a metabolite ratio (MR) of 4.0?±?0.87%. While in the LPS group, C_max increased slightly (0.25?±?0.01?μg/mL), and MR decreased to 2.8?±?0.17%.

4.?The changes observed in the plasma and tissue concentrations of FFC were attributed to the pathophysiological effects of LPS on renal hemodynamics that modified tissue distribution and reduced elimination of the drug.     

Research on the comparison of the demethylvancomycin’s diffusion–deposition characteristics in the ocular solid tissues of sustained subtenon drug delivery with subconjunctival injection

Purpose: To compare the demethylvancomycin’s diffusion–deposition characteristics in the ocular solid tissues of sustained subtenon drug delivery with subconjunctival injection.

Method: Sixty adult white rabbits were randomly assigned to the subtenon drug delivery group and the subconjunctival injection group. The subtenon drug delivery group was continuously infused demethylvancomycin to the subtenon of rabbits. The subconjunctival injection group was injected demethylvancomycin to the subconjunctival of rabbits. Cornea, iris and sclera were collected for high-performance liquid chromatography analyses to determine drug concentrations at one hour, three hours, six hours, 12?h and 24?h of drug administration. WinNonlin 6.3 was used to calculate the parameters of cumulative area under the curve (AUC_cum) of demethylvancomycin.

Results: The peak levels of demethylvancomycin concentration of the subtenon drug delivery group and the subconjunctival injection group were 92.406?±?21.555 and 51.778?±?14.001?μg/g in cornea, 28.451?±?10.229?μg/g and 42.271?±?27.291?μg/g in iris, 153.166?±?51.738?μg/g and 57.423?±?18.480?μg/g in sclera. The differences of concentrations between the two groups in cornea and sclera were statistically significant (F?=?487.775, p?F?=?132.748, p?F?=?4.848, p?=?0.064). The maximum of AUC_cum of the subtenon drug delivery group and the subconjunctival injection group was 1808.23?h?*?μg/g and 273.73?h?*?μg/g in cornea, 489.12?h?*?μg/g and 216.16?h?*?μg/g in iris and 2166.34?h?*?μg/g and 392.57?h?*?μg/g in sclera at 24?h of drug administration.

Conclusion: The sustained subtenon drug delivery had a better drug permeability and accumulation in the intraocular solid tissue compared to subconjunctival injection, which demonstrated it was probably a promising and effective approach for treating posterior segment diseases and endophthalmitis.     

Comparison of morning versus evening dosing and 24-h post-dose efficacy of travoprost compared with latanoprost in patients with open-angle glaucoma

ABSTRACT

Objective: To compare the IOP-lowering efficacy of a.m.-dosed travoprost and latanoprost at 24-h post-dose.

Research design and methods: Open-angle glaucoma patients not naïve to prostaglandin therapy and currently controlled on p.m.-dosed (2100) latanoprost (n?=?21) or travoprost (n?=?30) had baseline IOPs measured at 0900. In a randomized, single-masked, crossover design, patients received travoprost (Travatan) or latanoprost (Xalatan) at 0900 for 4?weeks, then were crossed over to receive the second prostaglandin for another 4?weeks. Treatment IOP was measured at 0900 prior to morning dose at both 4 and 8?week visits. Patient dosing preference (a.m./p.m.) was surveyed on exit.

Main outcome measure: Intraocular pressure (IOP).

Results: The mean IOP in the first period when all patients were dosed in the evening was assessed 12?h after dosing at 09:00 and it was similar in the two treatment groups (mean?±?standard deviation: 17.9?±?2.7?mmHg for travoprost versus 17.7?±?2.5?mmHg for latanoprost, p?=?0.812). In the a.m.-dosing crossover comparison, the 24-h post-dose IOP was significantly lower (?p?<?0.001) on travoprost (16.9?±?3.1?mmHg) compared to latanoprost (18.6?±?3.3?mmHg). In the exit survey, 51% of patients preferred a.m.-dosing.

Conclusions: a.m.-dosed travoprost is superior to a.m.-dosed latanoprost by 1.7?mmHg at 24-h post-dose.