Devrim Toslak

Macular Findings Obtained by Spectral Domain Optical Coherence Tomography in Retinopathy of Prematurity

Purpose. To examine the macular findings obtained with spectral domain optical coherence tomography (SD OCT) in infants with retinopathy of prematurity (ROP). Materials and Methods. The macular SD OCT images of 190 premature infants were analyzed. Data regarding central foveal thickness (CFT), cystoid macular edema (CME), and cyst grading were compared. The relationships of CFT with gestational age and birth weight were investigated. Results. The results were obtained from 358 eyes of 179 infants (81 females and 98 males) of a mean gestational age of 30.9 ± 2.7 weeks and a mean birth weight of 1609 ± 477u2009g. ROP was diagnosed in 126 eyes and CME in 139 eyes. A significantly greater percentage of eyes with ROP were found to have CME (54%) compared to eyes without ROP (31%; P = 0.001). The incidence of CME was 46.3% for stage 1 ROP, 57.1% for stage 2, and 87.5% for stage 3. There was a weakly inverse correlation between CFT, gestational age, and birth weight (P = 0.025, r = −0.227; P = 0.002, r = −0.182, resp., Spearman correlation test). Conclusions. High-quality SD OCT images can be obtained from premature infants using the iVue system. Severity and frequency of CME in premature infants increase as stage of ROP increases.

Choroidal Thickness in Patients with Mild Cognitive Impairment and Alzheimer’s Type Dementia

Aim. To asses both choroidal thickness differences among Alzheimers type dementia (ATD) patients, mild cognitive impairment (MCI) patients, and healthy control (C) subjects and choroidal thickness relationships with cognitive performance. Methods. A total of 246 eyes of 123 people (41 ATD, 38 MCI, and 44 healthy C subjects) were included in this study. Complete ophthalmological and neurological examination was performed in all subjects. Choroidal thicknesses (CT) were measured at seven locations: the fovea, 500-1500-3000u2009μm temporal and 500-1500-3000u2009μm nasal to the fovea by enhanced depth imaging optical coherence tomography (EDI-OCT). Detailed neurological examination including mini mental state examination (MMSE) test which evaluates the cognitive function was applied to all participants. Results. The ages and genders of all participants were similar in all groups. Compared with healthy C subjects, the CT measurements at all regions were significantly thinner both in patients with ATD and in patients with MCI than in healthy C subjects (p < 0.05). The MMSE scores were significantly different among ATD patients, MCI patients, and healthy C subjects. They were 19.3 ± 1.8, 24.8 ± 0.9, and 27.6 ± 1.2 in ATD, MCI, and healthy controls, respectively (p < 0.001). There were also significant correlation between MMSE score and choroidal thickness at each location (p < 0.05). Conclusions. CT was reduced in ATD patients and MCI patients. Since vascular structures were affected in ATD patients and MCI patients, they had thin CT. Besides CT was correlated with degree of cognitive impairment. Therefore CT may be a new biomarker in diagnosis and follow-up of MCI and ATD patients.

Response to: Comment on “Choroidal Thickness in Patients with Mild Cognitive Impairment and Alzheimer’s Type Dementia”

We would like to thank Ilhan et al. [1] for their comments regarding our article. In our study, we found out that choroidal thickness (CT) decreased in the eyes of patients with both Alzheimers type dementia (ATD) and mild cognitive impairment (MCI) compared to the healthy control group. Therefore, we suggested that CT value could be used as a new biomarker in early diagnosis of ATD and MCI patients and follow-up of their progression [2].

Evaluation of nailfold videocapillaroscopy in central serous chorioretinopathy

BackgroundNailfold videocapillaroscopy (NVC) is a diagnostic tool to evaluate micro-vasculature. The presence of choroidal vasculopathy is apparent in central serous chorioretinopathy (CSCR).ObjectivesThis study was aimed at assessing capillaroscopic nailfold findings in patients with CSCR. To the best of our knowledge, there is no study assessing NVC findings in CSCR in the literature.MethodSixty-one patients with CSCR who met the inclusion criteria, and 82 age- and sex-matched healthy controls were included to the study. A videocapillaroscopy device with 200× magnification was used for capillaroscopic assessment.ResultsThe mean age was 48.79u2009±u200911.15xa0years in the patient group (13 female, 48 male) and 49.38u2009±u20099.02xa0years in the control group (17 female, 65 male). The age and gender were comparable in the patient and control groups (pu2009=u20090.727 and pu2009=u20090.933, respectively). The capillary count was found to be decreased in the patient group compared to control group. No significant correlation was found between capillary count and choroidal thickness (pu2009=u20090.551; ru2009=u2009−0.081). In the patient group, the frequencies of major capillaroscopic findings including capillary ectasia, aneurysm, micro-hemorrhage, avascular area, tortuosity, neo-formation, bizarre capillary, bushy capillary, meander capillary and extravasation were found to be increased in the patient group. However, no significant correlation was detected between capillaroscopic findings and disease type and presence of attacks.ConclusionsThis is first study in which nailfold capillary assessment was performed in patients with CSCR, and we detected major capillaroscopic changes. These findings suggest that CSCR can be a systemic microvasculopathy. Further studies are needed to clarify the diagnostic and prognostic value of capillaroscopy in CSCR.

Trans-palpebral illumination: an approach for wide-angle fundus photography without the need for pupil dilation.

It is technically difficult to construct wide-angle fundus imaging devices due to the complexity of conventional transpupillary illumination and imaging mechanisms. We report here a new method, i.e., trans-palpebral illumination, for wide-angle fundus photography without the need for pupil dilation. By constructing a smartphone-based prototype imaging device, we demonstrated a 152° view in a single-shot image. The unique combination of low-cost smartphone design and automatic illumination optimization promises an affordable solution to conduct telemedicine assessment of eye diseases, which will improve access to eye care for patients in rural and underserved areas.

Cognitive performance of primary open-angle glaucoma and normal-tension glaucoma patients.

PURPOSEnTo assess cognitive performance differences among primary open-angle glaucoma (POAG) patients, normal-tension glaucoma (NTG) patients, and healthy control (C) subjects.nnnMETHODSnA total of 60 participants (20 POAG, 20 NTG, and 20 C subjects) were included in this study. A detailed ophthalmologic examination was performed on all participants. A spectral domain-optical coherence tomography (SD-OCT) system was used to measure the ganglion cell-inner plexiform layer (GC-IPL) and retinal nerve fiber layer (RNFL) thicknesses. To assess the cognitive performance of all participants, detailed neurological examinations, including the mini-mental state examination (MMSE), were performed by the same neurologist.nnnRESULTSnThere were no significant differences among the groups in terms of age (p =0.348) or gender (p =0.935). The mean RNFL thicknesses were significantly different among the groups (85.2 ± 14.7, 76.8 ± 10.3, and 91.4 ± 7.7 µm in the POAG, NTG, and C subjects, respectively; p <0.001). The mean GC-IPL thicknesses were 77.5 ± 9.7 µm in the POAG group, 73.4 ± 7.8 µm in the NTG group, and 78.8 ± 3.8 µm in the C group. Differences among the groups were not statistically significant (p =0.085). MMSE scores were 26.1 ± 1.4, 25.7 ± 2.3, and 28.8 ± 0.9 in the POAG, NTG, and C groups, respectively. There were significant differences among the three groups (p <0.001). Specifically, there were significant differences between the NTG and C groups (p <0.001), and between the POAG and C groups (p =0.001). There was no significant difference between the POAG and NTG groups (p =0.595).nnnCONCLUSIONSnThere appear to be similar risk factors in glaucoma and neurodegenerative disorders that cause deterioration in cognitive performance. Comparing the low MMSE scores of the POAG and NTG patients with the scores of healthy C participants supports our hypothesis. Consequently, it is recommended that a neurologist should also examine glaucoma patients.

A New Objective Parameter in Hydroxychloroquine-Induced Retinal Toxicity Screening Test: Macular Retinal Ganglion Cell-Inner Plexiform Layer Thickness

ObjectivesnThis study aims to detect hydroxychloroquine (HCQ)-induced retinal toxicity at an earlier stage through the use of spectral-domain optical coherence tomography device, especially by measuring macular retinal ganglion cell-inner plexiform layer (RGC-IPL) thickness.nnnPatients and methodsnIn this study, 92 eyes of 46 Caucasian female patients (mean age 53.6±8.1 years; range 32 to 69 years) who were taking HCQ were assigned to group 1, while 80 eyes of 40 age-matched Caucasian female control subjects (mean age 56.1±10.7 years; range 34 to 71 years) were assigned to group 2. RGC-IPL thickness and retinal nerve fiber layer thickness were measured in all subjects by Cirrus high-definition optical coherence tomography model 5000 device using macular cube 512¥128 and optic disc cube 200¥200 protocols. We performed an evaluation to see if there was any difference between the measured values of the groups. The correlation between average RGC-IPL thickness measures and cumulative dose of HCQ and duration of use was analyzed.nnnResultsnRetinal ganglion cell-inner plexiform layer of group 1 was found to be statistically thinner than that of group 2 both on average and in all segments (superior, superonasal, inferonasal, inferotemporal and superotemporal) except inferior segment when segmented (p<0.05). Additionally, a statistically significant negative correlation was found between the average RGC-IPL thickness and cumulative dose of HCQ (r= -0.371, p=0.001) as well as the duration of use (r= -0.308, p=0.006).nnnConclusionnPatients taking HCQ were found to have decreased RGC-IPL thickness at an early stage due to retinal toxicity induced by the drug. We think that measuring the RGC-IPL thickness may become an important objective in HCQ screening tests.

Smartphone-based imaging of the corneal endothelium at sub-cellular resolution

Abstract This aim of this study was to test the feasibility of smartphone-based specular microscopy of the corneal endothelium at a sub-cellular resolution. Quantitative examination of endothelial cells is essential for evaluating corneal disease such as determining a diagnosis, monitoring progression and assessing treatment. Smartphone-based technology promises a new opportunity to develop affordable devices to foster quantitative examination of endothelial cells in rural and underserved areas. In our study, we incorporated an iPhone 6 and a slit lamp to demonstrate the feasibility of smartphone-based microscopy of the corneal endothelium at a sub-cellular resolution. The sub-cellular resolution images allowed quantitative calculation of the endothelial cell density. Comparative measurements revealed a normal endothelial cell density of 2978 cells/mm2 in the healthy cornea, and a significantly reduced cell density of 1466 cells/mm2 in the diseased cornea with Fuchs’ dystrophy. Our ultimate goal is to develop a smartphone-based telemedicine device for low-cost examination of the corneal endothelium, which can benefit patients in rural areas and underdeveloped countries to reduce health care disparities.

Is the unaffected eye really unaffected? Color Doppler ultrasound findings in unilaterally active central serous chorioretinopathy

PurposeTo evaluate ocular hemodynamic changes using color Doppler ultrasonography imaging (CDI) with an emphasis on unaffected eyes of patients with central serous chorioretinopathy (CSC).MethodsTwenty-seven patients with active CSC and 25 controls were analyzed using spectral domain-optical coherence tomography (SD-OCT) and CDI for choroidal imaging and evaluation of retrobulbar vessels, respectively.ResultsResistive index (RI), pulsatility index (PI), and peak systolic velocity (PSV) of the ophthalmic artery (OA) and PSV, end-diastolic velocity (EDV), and mean velocity (Vmean) of the central retinal artery (CRA) in the patient group were less than those in the control group. RI and PI of the CRA were greater in the patient group compared to the control group. RI, PI, PSV, and Vmean of the OA and PSV, EDV, and Vmean of the CRA in the patients’ unaffected eyes were less than those in the control group. OCT measurements of central choroidal thickness (CCT) of the affected eyes in the patient group were significantly greater than those of the unaffected eyes in the patient and control groups; that of the unaffected eyes was greater than that in the control group.ConclusionsHemodynamic changes in OA reflect choroidal hyperperfusion. Hemodynamic and OCT changes in the unaffected eyes of the patient group suggest CSC as a bilateral disorder and the systemic nature of the disease. Further investigations may aid in the evaluation of treatment response and the follow-up of disease, providing a new insight into management strategies.

Combining ODR and Blood Vessel Tracking for Artery–Vein Classification and Analysis in Color Fundus Images

Purpose This study aims to develop a fully automated algorithm for artery–vein (A-V) and arteriole-venule classification and to quantify the effect of hypertension on A-V caliber and tortuosity ratios of nonproliferative diabetic retinopathy (NPDR) patients. Methods We combine an optical density ratio (ODR) analysis and blood vessel tracking (BVT) algorithm to classify arteries and veins and arterioles and venules. An enhanced blood vessel map and ODR analysis are used to determine the blood vessel source nodes. The whole vessel map is then tracked beginning from the source nodes and classified as vein (venule) or artery (arteriole) using vessel curvature and angle information. Fifty color fundus images from NPDR patients are used to test the algorithm. Sensitivity, specificity, and accuracy metrics are measured to validate the classification method compared to ground truths. Results The combined ODR-BVT method demonstrates 97.06% accuracy in identifying blood vessels as vein or artery. Sensitivity and specificity of A-V identification are 97.58%, 97.81%, and 95.89%, 96.68%, respectively. Comparative analysis revealed that the average A-V caliber and tortuosity ratios of NPDR patients with hypertension have 48% and 15.5% decreases, respectively, compared to that of NPDR patients without hypertension. Conclusions Automated A-V classification has been achieved by combined ODR-BVT analysis. Quantitative analysis of color fundus images verified robust performance of the A-V classification. Comparative quantification of A-V caliber and tortuosity ratios provided objective biomarkers to differentiate NPDR groups with and without hypertension. Translational Relevance Automated A-V classification can facilitate quantitative analysis of retinal vascular distortions due to diabetic retinopathy and other eye conditions and provide increased sensitivity for early detection of eye diseases.