EARLY RETINAL MICROVASCULAR ABNORMALITIES IN YOUNG ADULTS WITH TYPE 1 DIABETES MELLITUS WITHOUT CLINICALLY EVIDENT DIABETIC RETINOPATHY.

PURPOSE: To characterize the early retinal microvascular changes in young adults (age: 22.69 ± 3.50 years) with Type 1 diabetes mellitus without clinically detectable diabetic retinopathy using optical coherence tomography angiography and investigate the associated factors. METHODS: A total of 36 participants with Type 1 diabetes mellitus (70 eyes) and 34 healthy controls (57 eyes) were retrospectively reviewed. The analyzed optical coherence tomography angiography indices included capillary vessel density, foveal avascular zone area/perimeter/acircularity index, and foveal vascular density, acquired in the 6 × 6-mm2 area centered on the fovea. The generalized estimation equations model was applied to compare the mean values and to study the associated factors. RESULTS: In subjects with diabetes, statistically significant decreases were observed in parafoveal vessel density in both superficial and deep capillary plexuses, foveal avascular zone area/perimeter, and foveal vascular density when compared with controls (all P < 0.05). Higher glycated hemoglobin level was independently associated with the decrease of parafoveal vessel density as well as the increase of foveal avascular zone area/perimeter (all P < 0.05). Prepubescent onset of diabetes mellitus was also independently associated with the decrease of superficial parafoveal vessel density, foveal avascular zone area/perimeter, and foveal vascular density (P = 0.015, 0.011, 0.015, and 0.001, respectively). CONCLUSION: In young adults with Type 1 diabetes mellitus lacking clinical signs of diabetic retinopathy, optical coherence tomography angiography revealed alterations in retinal microvasculature that were associated with glycated hemoglobin level and onset of diabetes mellitus related to puberty.

Tele-glaucoma versus clinical evaluation: The New Jersey Health Foundation Prospective Clinical Study.

INTRODUCTION: Glaucoma, the second most common cause of blindness, is normally detected in clinic. With technological improvements, tele-glaucoma exams can identify these changes off-site. The quality of tele-glaucoma exams needs to be compared with that of traditional exams. This study's purpose was to validate the tele-glaucoma programme, which allows a physician comprehensive access to patients' data, by comparing results to clinical examinations. METHODS: A prospective study of 107 subjects evaluated in clinic and then tele-glaucoma stations, which consisted of non-mydriatic fundus photography, puff-tonometry, auto-refraction and Optical Coherence Tomography (OCT). The OCT captured central corneal thickness, angle anatomy, cup-to-disc ratio (CDR), retinal nerve fibre layer distribution and posterior-pole ganglion cell complex data. RESULTS: Intraocular pressure (IOP) comparisons between clinical and tele-glaucoma exams had strong positive Pearson correlation coefficients (0.8248 OD, 0.8672 OS). Strong positive correlations were seen for CDR (0.7835 OD, 0.8082 OS) as well as diagnosis (glaucoma, no glaucoma or glaucoma suspect). A moderate positive correlation was seen for return to clinic time (RTC). Tele-glaucoma had an average lower RTC (2.7 vs 3.9 months). Tele-glaucoma was more likely to elicit a non-glaucomatous diagnosis not found in clinic vs a diagnosis found only in clinic (18% vs 5% of subjects). DISCUSSION: Tele-glaucoma allows for detecting glaucoma remotely. These advancements alleviate patient difficulties with obtaining adequate glaucoma screenings and helps ophthalmologists triage patients with more severe pathology. Our study indicates that our tele-glaucoma protocol is comparable to a clinical exam in its ability to detect glaucoma. Further studies will be needed for off-site testing and transferring data separately for analysis.

Are Disposable and Standard Gonioscopy Lenses Comparable?

PURPOSE: Gonioscopy is important in the evaluation and treatment of glaucoma. With increased scrutiny of acceptable sterilization processes for health care instruments, disposable gonioscopy lenses have recently been introduced. Single-time use lenses are theorized to decrease infection risk and eliminate the issue of wear and tear seen on standard, reusable lenses. However, patient care would be compromised if the quality of images produced by the disposable lens were inferior to those produced by the reusable lens. The purpose of this study was to compare the quality of images produced by disposable versus standard gonioscopy lenses. MATERIALS AND METHODS: A disposable single mirror lens (Sensor Medical Technology) and a standard Volk G-1 gonioscopy lens were used to image 21 volunteers who were prospectively recruited for the study. Images of the inferior and temporal angles of each subject's left eye were acquired using a slit-lamp camera through the disposable and standard gonioscopy lens. In total, 74 images were graded using the Spaeth gonioscopic system and for clarity and quality. Clarity was scored as 1 or 2 and defined as either (1) all structures perceived or (2) all structures not perceived. Quality was scored as 1, 2, or 3, and defined as (1) all angle landmarks clear and well focused, (2) some angle landmarks clear, others blurred, or (3) angle landmarks could not be ascertained. The 74 images were divided into images taken with the disposable single mirror lens and images taken with the standard Volk G-1 gonioscopy lens. The clarity and quality scores for each of these 2 image groups were averaged and P-values were calculated. RESULTS: Average quality of images produced with the standard lens was 1.46±0.56 compared with 1.54±0.61 for those produced with the disposable lens (P=0.55). Average clarity of images produced with the standard lens was 1.47±0.51 compared with 1.49±0.51 (P=0.90) with the disposable lens. CONCLUSIONS: We conclude that there is no significant difference in quality of images produced with standard versus disposable gonioscopy lenses. Disposable gonioscopy lenses may be an acceptable alternative to standard reusable lenses, especially in conditions where sterilization is difficult.

Feasibility of retinal screening in a pediatric population with type 1 diabetes mellitus.

PURPOSE: To study the feasibility of using a nonmydriatic camera to screen children with type 1 diabetes mellitus (DM1) as young as 2 years for diabetic retinopathy. METHODS: Prospective pilot imaging study involving children with DM1 aged 2 to 17 years. The screening consisted of: (1) intake form; (2) measurement of blood pressure, pulse, and oximetry; (3) assessment of visual acuity (SIMAV, Padova, Italy); and (4) nonmydriatic color imaging (Canon CX-1 45° 15.1 megapixel camera; Canon Corp., Tokyo, Japan). Images were assessed for signs of diabetic retinopathy and graded for quality on a scale of 1 to 5 by two clinicians. Kappa coefficient was calculated to determine inter-observer agreement. RESULTS: One hundred four of 106 (98%) children underwent imaging (mean age: 11.1 years, 51% male, 88% white). One (1%) child had nonproliferative diabetic retinopathy and 2 (1.9%) had incidental findings. Only 62% of children had an eye examination within the past year, with children with DM1 for more than 5 years significantly more likely to have done so (P = .03). Children who had an eye examination within the past year were significantly older than their counterparts (P = .01). Images of high quality (grades 4 and 5) were acquired in 178 (86%) eyes, and images of some clinical value (grades ≥ 2) were obtained in 207 (99.5%) eyes. Inter-observer agreement for image quality was 0.896. CONCLUSIONS: The feasibility of using a nonmydriatic camera to screen children as young as 2 years for changes related to diabetic eye disease was demonstrated. Nonmydriatic imaging may supplement standard dilated clinical ophthalmology examinations for select patient populations.

Complimentary imaging technologies in blunt ocular trauma.

We describe complimentary imaging technologies in traumatic chorioretinal injury. Color and fundus autofluorescence (FAF) images were obtained with a non-mydriatic retinal camera. Optical coherence tomography (OCT) helped obtain detailed images of retinal structure. Microperimetry was used to evaluate the visual function. A 40-year-old man sustained blunt ocular trauma with a stone. Color fundus image showed a large chorioretinal scar in the macula. Software filters allowed detailed illustration of extensive macular fibrosis. A 58-year-old man presented with blunt force trauma with a tennis ball. Color fundus imaging showed a crescentric area of macular choroidal rupture with fibrosis. FAF imaging delineated an area of hypofluorescence greater on fundus imaging. OCT showed chorioretinal atrophy in the macula. Microperimetry delineated an absolute scotoma with no response to maximal stimuli. Fundus imaging with digital filters and FAF illustrated the full extent of chorioretinal injury, while OCT and microperimetry corroborated the structure and function correlations.

Fundus autofluorescence and colour fundus imaging compared during telemedicine screening in patients with diabetes.

We investigated the use of fundus autofluorescence (FAF) imaging in screening the eyes of patients with diabetes. Images were obtained from 50 patients with type 2 diabetes undergoing telemedicine screening with colour fundus imaging. The colour and FAF images were obtained with a 15.1 megapixel non-mydriatic retinal camera. Colour and FAF images were compared for pathology seen in nonproliferative and proliferative diabetic retinopathy (NPDR and PDR, respectively). A qualitative assessment was made of the ease of detecting early retinopathy changes and the extent of existing retinopathy. The mean age of the patients was 47 years, most were male (82%) and most were African American (68%). Their mean visual acuity was 20/45 and their mean intraocular pressure was 14.3 mm Hg. Thirty-eight eyes (76%) did not show any diabetic retinopathy changes on colour or FAF imaging. Seven patients (14%) met the criteria for NPDR and five (10%) for severe NPDR or PDR. The most common findings were microaneurysms, hard exudates and intra-retinal haemorrhages (IRH) (n = 6 for each). IRH, microaneurysms and chorioretinal scars were more easily visible on FAF images. Hard exudates, pre-retinal haemorrhage and fibrosis, macular oedema and Hollenhorst plaque were easier to identify on colour photographs. The value of FAF imaging as a complementary technique to colour fundus imaging in detecting diabetic retinopathy during ocular screening warrants further investigation.

Software-assisted analysis during ocular health screening.

OBJECTIVE: To describe the use of software-assisted analysis of non-mydriatic 45° color fundus images during comprehensive ocular screening. MATERIALS AND METHODS: Software-driven filters (blue [490 nm; nerve fiber layer], green [550 nm; neural retina], and red [610 nm; pigmented retina/choroid]) and an "emboss" (topographic changes) digital filter were used to enhance image analysis during ocular health screening performed using a Canon (Tokyo, Japan) 8.2-megapixel non-mydriatic retinal camera. Intraocular pressure (model TX-f full auto non-contact tonometer; Canon) and visual acuity (SIMAV, Padova, Italy) were also determined. An on-site medical director analyzed the collected data, provided immediate subject feedback, and made recommendations and referrals for general or specialty ophthalmology clinics. RESULTS: Software-assisted analysis was performed on color images from 128 veterans (mean age, 37.5 years; 66% male; 43% white). Software filters allowed efficient image analysis at a rate of 26 eyes/h. Thirteen (10.2%) persons had a finding consistent with a vision-threatening disease and were referred for a dilated fundus examination. CONCLUSIONS: Software-assisted screening permits thorough and efficient evaluation of ocular health during an ocular screening event.

Effects of prone and reverse trendelenburg positioning on ocular parameters.

BACKGROUND: : In a pilot study of awake volunteers, intraocular pressure (IOP), choroid layer thickness, and optic nerve diameter were shown to increase in the prone position over 5 h with a nonsignificant trend of attenuation using a 4-degree increase of table inclination. These effects have previously not been isolated from anesthetic and fluid administration over a prolonged period, using an adequate sample size. METHODS: : After institutional review board approval, 10 healthy volunteers underwent IOP measurement (Tono-Pen XL, Medtronic Solan, Jacksonville, FL) as well as choroidal thickness and optic nerve diameter assessment (Sonomed B-1000, Sonomed, Inc., Lake Success, NY, or the I System-ABD, Innovative Imaging, Inc., Sacramento, CA) on a Jackson table (Orthopedic Systems, Inc., Union City, CA), during 5 h horizontal prone and 5 h 4-degree reverse Trendelenburg positioning. Measurements were assessed as initial supine, initial prone, and hourly thereafter. Vital signs were recorded at each position and time point. RESULTS: : IOP, choroidal thickness, and optic nerve diameter were observed to increase with time in the prone position. A small degree of reverse Trendelenburg attenuated the increase in choroidal thickness but not IOP or optic nerve diameter. CONCLUSIONS: : Prolonged prone positioning increases IOP, choroid layer thickness, and optic nerve diameter independent of anesthetics and intravenous fluid infusion and 4 degrees of table inclination (15 cm of head to foot vertical disparity) may not attenuate these effects.

Software-assisted optic nerve assessment for glaucoma tele-screening.

Increased optic nerve head (ONH) cup-to-disc ratio (CDR) may indicate glaucoma but evaluation needs to be performed by a trained examiner. This research assessed new software to calculate CDR from ONH images. Digital stereoscopic ONH images from 28 subjects acquired during screening using a nonmydriatic 45-degree camera with 8.2-Megapixel resolution (Canon, Tokyo, Japan) were analyzed by 3 individuals with different levels of ophthalmic training: glaucoma specialist (GS), an optometrist (OD), and trainees. Images were logged and accessed by raters masked to each other's evaluations. Images from two groups were included: normal-appearing ONH (Group 1) and confirmed glaucoma (Group 2). All images were captured in DICOM format. Images were evaluated on a 32-bit, 1,600 x 1,200-pixel resolution monitor. EyeScape software (v. 7.4, Synemed, Inc., Benicia, CA) was used for CDR analysis. Software CDR determination requires an operator to place ONH disc and cup contour lines. Once lines were placed, the software provided CDR calculations (range 0.00-1.00). A total of 84 ONH evaluations were analyzed. Overall CDR mean, standard deviation, standard error of the mean, and mean difference from GS CDR evaluations were determined. Reproducibility was similar for all operators. The trainee had a small, statistically significant greater CDR in group 1 and 2 evaluations. Evaluation of ONH images for CDR can be performed using EyeScape software, by individuals with different levels of ophthalmic training. Accurate determination of CDR is important in tele-screening for vision-threatening diseases, and can aid in identifying subjects with suspicious ONH in need of specialty eye care.

DICOM transmission of simultaneous stereoscopic images of the optic nerve in patients with glaucoma.

We evaluated the Digital Imaging and Communications in Medicine (DICOM) standard for the transmission of stereoscopic images of the optic nerve. Digital optic nerve images were obtained from patients with glaucoma. Fifteen simultaneous stereo images from consecutive patients were analysed independently twice, in random order, by two glaucoma specialists to establish baseline values of vertical and horizontal cup-to-disc (CDV and CDH) ratios and image quality (1 = worst, 5 = best). Images were transmitted to a distant location and returned to the sending site using DICOM standards in both directions. The received images were reassessed again by the two glaucoma specialists. The image file size slightly increased for all received images (mean 2545 kByte) in comparison with the transmitted images (mean 2460 kByte). The mean baseline values for CDV, CDH and quality score were 0.66, 0.59 and 3.9, respectively. The corresponding mean values for the received images were 0.66, 0.62 and 3.73, respectively. The differences between transmitted and received images were not significant. Clinical interpretation of digital stereoscopic images of glaucomatous optic nerves appears to be unaffected by DICOM capture and transmission.