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.     

Reduced central corneal thickness in patients with isotretinoin treatment

Context: It is well known that oral isotretinoin treatment causes numerous ocular side-effects.

Objective: To investigate the effect of systemic isotretinoin treatment on central corneal thickness (CCT) values due to meibomian gland disease (MGD).

Participants: In this prospective study, 47 patients (27 men, 20 women) with nodulocystic acne vulgaris treated with oral isotretinoin (0.8?mg/kg daily) were included.

Methods: All patients were analyzed with the Pentacam Scheimpflug topography at baseline, on the 3rd and 6th month of treatment. Main outcome measures were MGD scores and CCT.

Results: The mean age of patients was 25.1?±?4.4 years. The mean MGD scores were significantly higher at 3rd month (1.3?±?0.9) and 6th month (1.5?±?1.0) of treatment compared with baseline (1.1?±?0.9) (p?p?p?=?0.038, r?=??0.221).

Conclusion: Isotretinoin treatment causes higher MGD scores. A statistically significant decrease in CCT due to MGD was detected at 6th month of treatment.     

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 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.     

The effect of oral isotretinoin on visual contrast sensitivity and amount of lacrimation in patients with acne vulgaris

Context: Acne vulgaris is a puberty-onset chronic inflammatory disease of the pilosebaceous unit. Isotretinoin is a derivative of vitamin A commonly used for severe and nodulocystic acne. While isotretinoin has many side effects related to the eye, visual system and lacrimation, there is no information regarding isotretinoin’s influence on contrast sensitivity.

Aim: To investigate the effect of isotretinoin on visual contrast sensitivity and the amount of lacrimation.

Materials and methods: The study included 25 patients (16 females and 9 males) who underwent isotretinoin treatment. The treatment duration ranged from 4 to 7 months. Patients were examined both before the start and at the end of treatment using the Schirmer test in each eye. The contrast sensitivity measurement was performed both individually for each eye and in a binocular fashion using the Pelli–Robson Sensitivity Chart.

Results: The results of the Schirmer test before treatment were 19.74?±?3.63?mm for the right eye and 19.66?±?3.63?mm for the left eye. Post-treatment measurement results were 17.24?±?3.5?mm for the right eye and 16.68?±?3.73?mm for the left eye. There was a statistically significant difference between the before and after treatment measurements (p?<?0.000). Before treatment, contrast sensitivity was 1.45?±?0.19 for the right eye and 1.42?±?0.2 for the left eye. The binocular measurement was 1.54?±?0.14. After treatment, the right eye was 1.47?±?0.19, the left eye was 1.46?±?0.18, and the binocular measurement was 1.54?±?0.18. There were no statistically significant differences between before and after treatment (p?>?0.05).

Discussion: There are contradicting reports on the results of the Schirmer test. The only similar study that has evaluated contrast sensitivity used the drug acitretin, the results of which are consistent with those the present study.

Conclusion: Our study is significant in that it is the first to investigate the effects of isotretinoin on visual contrast sensitivity that is closely associated with real-world performance. Our results need to be supported by future studies.     

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.     

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.     

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 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.     

Effect of smoking on the thickness of retinal layers in healthy smokers

Purpose: To compare the thicknesses of the retinal layers in smokers with those of nonsmoking healthy subjects using spectral-domain optical coherence tomography (SD-OCT).

Methods: One hundred and eight subjects were included in the study. Two groups were separated as smokers and nonsmokers. Both groups were chosen to be similar in terms of age and gender. SD-OCT images were generated with Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany). An automated algorithm was developed to segment the macular retina into eight layers and quantitate the thickness of each layer for the fovea, parafovea and perifovea.

Results: The mean smoking history was 18.33?±?8.45?years (range: 10–40). The mean number of pack-years was 22.22?±?15.51 (range: 10–80). No significant difference was observed regarding retinal layer measurements between the smoker and nonsmoker groups. Also, no significant difference was observed for central macular thicknesses at 1000, 3000, and 6000?μm between two groups.

Conclusion: The thickness of retinal layers in healthy smokers was similar to those of healthy individuals.     

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.     

Effects of selective serotonin reuptake inhibitors on intraocular pressure and anterior segment parameters in open angle eyes

Purpose: To evaluate the short- and long-term effects of selective serotonin reuptake inhibitors (SSRIs) on intraocular pressure (IOP) and anterior segment parameters in open angle eyes.

Materials and methods: This cross-sectional study included 325 eyes of 166 subjects. Subjects were divided into three groups: Group 1 included 116 eyes of 58 patients receiving SSRIs for 1?week–6?months, Group 2 included 102 eyes of 53 patients receiving SSRIs for longer than 6?months and Group 3 included 107 eyes of 55 healthy subjects not receiving any drugs. All of the patients receiving SSRIs were diagnosed as major depressive disorder. All groups were chosen to be similar in terms of age and gender. All patients underwent a detailed ophthalmologic examination including IOP measurement by Goldmann applanation tonometer and gonioscopy. Anterior segment parameters including pupil diameter (PD), central corneal thickness (CCT), anterior chamber depth (ACD), anterior chamber volume (ACV), and anterior chamber angle (ACA) were assessed by a Scheimpflug system.

Results: Pupil diameter was significantly larger in patients receiving SSRIs for <6?months and ≥6?months than the control subjects (3.53?±?0.71?mm, 3.48?±?0.60?mm versus 3.11?±?0.72?mm, p?p?Conclusions: Selective serotonin reuptake inhibitors cause mydriasis which is persistent during the treatment. In depression patients with open angle eyes, short- and long-term use of SSRIs leads to decrease in IOP.     

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.     

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.     

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.     

The acute respiratory exposure by intratracheal instillation of Sprague–Dawley rats with diesel particulate matter induces retinal thickening

Context: Adverse health effects of ambient particulate matter (PM) have been demonstrated in humans, mostly in terms of respiratory and cardiovascular events. However, whether ambient particle could affect the eyes had not been fully revealed.

Objective: This study investigated the effect of acute respiratory exposure to PM on eyes.

Methods: Diesel exhaust product (DEP) of 200?mg/l was given endotracheally in Sprague–Dawley rats for 1?h (n?=?12) and compared to normal control (n?=?4). We enucleated eyes and histologically evaluated. Immunohistochemical stains for CD34 (Dako, Glostrup, Denmark, 1:50) and Ki-67 (DakoCytomation, Glostrup, Denmark, 1:150) were performed to evaluate new vessel formation and proliferation activity.

Results: After endotracheal DEP exposure, the thickness of retina was significantly increased to 258?±?96?μm in DEP group, while that of control was 113?±?9?μm (p?=?0.025). Among the retinal structure, inner plexiform, inner and outer nuclear and rod/cone cell layers were significantly thickened (p?=?0.00, 0.017, 0.004, 0.001, respectively). The outer plexiform layer of DEP group showed a tendency of thickening, but statistically insignificant. The afferent fiber and ganglion cell layer showed no thickness difference between two groups, but prominent capillaries with congestion were noted in DEP group. Neither neovascularization nor increased proliferation was demonstrated on CD34 and Ki-67 immunohistochemical staining in DEP group.

Conclusion: This study shows that the acute respiratory exposure of ambient PM increased retinal thickness, especially inner plexiform, inner and outer nuclear and rod/cone cell layers. We thought that increase of retinal thickness in DEP group resulted in hypoxia-induced edema.     

Effectiveness of a new tobramycin (0.3 % ) and dexamethasone (0.05 % ) formulation in the treatment of experimental Pseudomonas keratitis

ABSTRACT

Objective: To quantitatively determine, in a Pseudomonas keratitis model, the anti-inflammatory and bactericidal properties of a new formulation of tobramycin (0.3?%?) and dexamethasone (0.05?%?) that utilizes a xanthan gum vehicle.

Research methods: In a randomized and masked fashion, rabbit corneas (n?≥?16 eyes per group) were intrastromally injected with 10³ colony-forming units (CFU) of P. aeruginosa. Eyes were untreated or were administered a single drop every 15?min between 16 and 17?h postinfection (PI) and then a single drop every 30?min between 17 and 22?h PI, a total of 15 drops of either 0.1?%?dexamethasone and 0.3?%?tobramycin (TobraDex; Tdex) or a new formulation 0.3?%?tobramycin and 0.05?%?dexamethasone with xanthan gum (TobraDex ST; ST). Slit lamp examination scores (SLE?±?SEM) were derived from grading seven parameters at 22?h PI. Rabbits were sacrificed at 23?h PI and the log CFU?±?SEM per cornea was determined.

Results: Untreated eyes had SLE scores of 11.11?±?0.43 and had log CFU of 7.27?±?0.06. Eyes treated with Tdex, as compared to the untreated eyes, had significantly lower SLE scores (7.39?±?0.21, p?<?0.0001) and significantly fewer bacteria (6.32?±?0.29 log CFU, p?=?0.0213). Eyes treated with ST had a SLE score (6.56?±?0.19) that was significantly lower than both the untreated eyes (p?<?0.0001) and the eyes treated with Tdex (p?=?0.0124). Furthermore, eyes treated with ST had significantly fewer log CFU (5.78?±?0.30) than untreated eyes (p?=?0.0001) or eyes treated with Tdex (p?=?0.0434).

Conclusions: The ST formulation with xanthan gum demonstrated statistically superior anti-inflammatory and bactericidal properties as compared to Tdex.

Limitations: Variations in inoculation procedures produced limited eye-to-eye differences in the infection.     

Effect of isotretinoin treatment on the inflammatory markers in patients with acne vulgaris: can monocyte/HDL be a new indicator for inflammatory activity of isotretinoin treatment?

Abstract

Background: Oral isotretinoin (ISO) can effect markers of inflammation in patients with acne vulgaris. To our knowledge, there are no data on the relationship between ISO and monocyte to HDL cholesterol ratio (MHR). In this study, it is aimed to examine the effect of the ISO treatment on the MHR and other inflammatory markers in patients with acne vulgaris.

Materials and methods: In this study, 89 out of 120 patients with severe/very severe acne vulgaris according to the Global Acne Grading Scale who received at least 3 months of ISO treatment were evaluated. The complete blood counts including mean levels of mean platelet volume, plateletcrit (PTC), neutrophil to lymphocyte ratio (NLR), platelet to lymphocyte ratio (PLR), MHR, and serum biochemistry panel were evaluated before and after ISO treatment.

Results: The mean platelet value, NLR, and PLR levels underwent a statistically significant decrease after ISO treatment (p?<?0.05) while MHR increased significantly 3 months after ISO treatment (p?=?0.017). The mean platelet value, NLR, and PLR levels were 9.56?±?1.05, 2.15?±?0.81, and 142.45?±?48.33 before treatment while were 9.32?±?1.45, 1.90?±?0.99, and 127.94?±?41.38 after treatment, respectively. On the other hand, MHR was 9.76?±?4.27 and 10.86?±?4.12 before and after treatment, respectively.

Conclusions: In this study, we found that ISO may have both inflammatory and anti-inflammatory effects by using MPV, PTC, NLR, PLR, and MHR. The inflammatory effects of ISO may be associated with possible inflammatory diseases. MHR can be used as a novel marker to investigate the inflammatory effect of the ISO.     

Diode laser photocoagulation posterior to the ridge in severe stage 3+ threshold retinopathy of prematurity

Purpose: To evaluate the results of diode laser photocoagulation (DLP) of the retina posterior to the ridge in eyes with severe Zone II, Stage 3+ threshold retinopathy of prematurity (ROP).

Method: DLP was applied posterior to the fibrovascular ridge for advanced Zone II, Stage 3+ threshold ROP patients, either as the primary treatment combined with DLP of the avascular retina (group 1), or as a secondary treatment in eyes that had previously undergone DLP of the avascular retina (group 2). Statistical analysis was performed using SPSS software trail version 16.0. Values are presented as mean?±?SD.

Results: A total of 50 eyes of 29 premature infants were treated (14 [48%] male, 15 [52%] female). The mean gestational age was 29.5?±?2.2 weeks (range: 26–34 weeks). The mean birth weight was 1259 0.72?±?409.15?g (range: 500–2050?g). The mean gestational age for DLP of the avascular region anterior to the ridge and DLP posterior to the ridge was 37?±?3 weeks and 38?±?3 weeks, respectively. The mean follow-up was 26?±?5 weeks (18–38 weeks). In 48 eyes, the tractional fibrovascular ridge had regressed. Transient retinal hemorrhage was the most common complication. Three eyes exhibited optic-disc dragging; two eyes progressed to Stage 4a ROP; two eyes presented with macular traction, without any detachment; and one eye developed a vitreous hemorrhage, which resolved spontaneously. There were no statistically significant differences between complicated and uncomplicated eyes regarding gestational age, birth weight and applied laser spot numbers (p?>?0.05 for all, Mann–Whitney U test).

Conclusion: DLP, posterior to the ridge as an additive treatment in the management of severe Zone II, Stage 3+ threshold ROP patients, is safe and effective; this approach could be used as either the primary treatment, or as the follow-up to failed laser treatment of the avascular retina to halt the progression of the disease.