GIANT INTRAOPERATIVE CORNEAL BULLA MANAGED WITH BANDAGE LENS TECHNIQUE DURING VITRECTOMY SURGERY

PURPOSE

To report a case of giant intraoperative corneal bulla formation in a patient with a history of recent phacoemulsification with clear corneal incision that was managed with a bandage contact lens intraoperatively.

METHODS

Retrospective case report with anterior segment optical coherence tomography.

RESULTS

A 77-year-old woman with a history of recent complicated cataract surgery with retained lens fragments underwent pars plana vitrectomy and scleral-fixated intraocular lens placement. During pars plana vitrectomy, a large corneal bulla formed at the site of the main corneal incision, confirmed with anterior segment optical coherence tomography. A bandage contact lens with viscoelastic was used to overcome visualization challenges and safely proceed with the surgery.

CONCLUSION

This is the first report of corneal bullae formation during pars plana vitrectomy that is confirmed by anterior segment optical coherence tomography and successfully managed with a bandage contact lens intraoperatively.

Prevalence, Progression, and Modifiable Risk Factors for Diabetic Retinopathy in Youth and Young Adults With Youth-Onset Type 1 and Type 2 Diabetes: The SEARCH for Diabetes in Youth Study

OBJECTIVE

To determine the prevalence, progression, and modifiable risk factors associated with the development of diabetic retinopathy (DR) in a population-based cohort of youth-onset diabetes.

RESEARCH DESIGN AND METHODS

We conducted a multicenter, population-based prospective cohort study (2002-2019) of youth and young adults with youth-onset type 1 diabetes (n = 2,519) and type 2 diabetes (n = 447). Modifiable factors included baseline and change from baseline to follow-up in BMI z score, waist/height ratio, systolic and diastolic blood pressure z score, and A1C. DR included evidence of mild or moderate nonproliferative DR or proliferative retinopathy. Prevalence estimates were standardized to estimate the burden of DR, and inverse probability weighting for censoring was applied for estimating risk factors for DR at two points of follow-up.

RESULTS

DR in youth-onset type 1 and type 2 diabetes is highly prevalent, with 52% of those with type 1 diabetes and 56% of those with type 2 diabetes demonstrating retinal changes at follow-up (mean [SD] 12.5 [2.2] years from diagnosis). Higher baseline A1C, increase in A1C across follow-up, and increase in diastolic and systolic blood pressure were associated with the observation of DR at follow-up for both diabetes types. Increase in A1C across follow-up was associated with retinopathy progression. BMI z score and waist/height ratio were inconsistently associated, with both positive and inverse associations noted.

CONCLUSIONS

Extrapolated to all youth-onset diabetes in the U.S., we estimate 110,051 cases of DR developing within ∼12 years postdiagnosis. Tight glucose and blood pressure management may offer the opportunity to mitigate development and progression of DR in youth-onset diabetes.

Long-term outcomes of modified glued versus flanged intrascleral haptic fixation techniques for secondary intraocular lenses

PURPOSE

To report the long-term refractive outcomes and complications of two scleral fixation techniques for secondary intraocular lenses (IOL).

METHODS

Consecutive patients who underwent secondary IOL insertion at a tertiary care academic hospital using either modified glued ("glued") or flanged intrascleral haptic fixation (FISHF) techniques with over 12 months of follow-up were retrospectively reviewed. Pre- and postoperative corrected distance visual acuity (CDVA), postoperative complications, and refractive surprises were reported.

RESULTS

Thirty-eight patients underwent "glued" fixation and 22 underwent FISHF, with mean follow-up times of 3.1 ± 0.5 and 2.0 ± 1.2 years, respectively. Aphakia secondary to trauma was the main surgical indication. MA50BM or MA60AC IOLs (Alcon Laboratories Inc., Fort Worth, TX) were implanted in 92% of "glued" patients, while CT Lucia 602 IOLs (Carl Zeiss Meditec Inc., Dublin, CA) were used in 96% of FISHF patients. Postoperative spherical equivalent significantly improved compared to preoperative values (p < 0.001). No significant difference in CDVA was seen between the two techniques. FISHF resulted in mean hyperopic surprises of + 0.81D and + 0.69D using the Holladay 2 and Barrett Universal II formulae, respectively, which was significantly greater than the "glued" patients. A higher rate of IOL dislocation was seen in the "glued" cohort (13%) compared to FISHF (0%).

CONCLUSIONS

Retrospective long-term outcomes of patients with complex ocular comorbidities undergoing a modified "glued" technique demonstrated a higher rate of IOL dislocation but more predictable refractive outcomes compared to the FISHF technique. The FISHF technique resulted in a significant hyperopic shift using fourth-generation IOL calculators.

Quantitative Handheld Swept-Source Optical Coherence Tomography Angiography in Awake Preterm and Full-Term Infants

Purpose

To compare retinal vascular parameters acquired by handheld swept-source optical coherence tomography angiography (SS-OCTA) between nonsedated preterm and full-term infants.

Methods

Preterm and full-term infants at the University of Washington Medical Center were enrolled. Retinal angiograms (nominal size ∼7 × 7 mm²) were obtained at each routine retinopathy of prematurity (ROP) screening session for preterms and once during the first 72 hours of life for full-terms. Macular vessel area density and nonperfusion area were evaluated on the binarized vasculature map in both small (1.5 × 1.5 mm) and large (3 × 3 mm) quadrants. Average vessel diameter and tortuosity values were obtained from each large vessel branch (length >200 µm). All vascular analyses used previously published algorithms.

Results

Handheld SS-OCTA captured 31 of 55 (56%) high-quality volumes on 8 awake preterm infants (gestational age 28 ± 4 weeks, birth weight 891 ± 314 g, postmenstrual age at first imaging session 37 ± 2 weeks) and 48 of 54 (89%) volumes on 12 awake full-term infants (gestational age 39 ± 1 weeks, birth weight 3405 ± 329 g). Signal-to-noise ratio was 5.08 ± 1.52 dB in preterm and 4.90 ± 1.12 dB in full-term infants. Preterm infants had higher mean large vessel tortuosity compared to full-term infants (P = 0.004). The large nasal quadrant vessel area density of infants with stage 3 and/or pre-plus or worse ROP was higher than other preterm infants (P = 0.007).

Conclusions

Although inadequate image quality limited usable imaging sessions, handheld SS-OCTA achieved adequate signal-to-noise ratio in nonsedated infants for quantitative retinal vascular parameter analysis.

Translational Relevance

Large- and small-vessel parameters were associated with prematurity and ROP severity, respectively.

Quantitative assessment of choriocapillaris flow deficits in diabetic retinopathy: A swept-source optical coherence tomography angiography study

Purpose

To quantitatively assess choriocapillaris (CC) flow deficits in eyes with diabetic retinopathy (DR) using swept-source optical coherence tomography angiography (SS-OCTA).

Methods

Diabetic subjects with different stages of DR and age-matched healthy subjects were recruited and imaged with SS-OCTA. The en face CC blood flow images were generated using previously published and validated algorithms. The percentage of CC flow deficits (FD%) and the mean CC flow deficit size were calculated in a 5-mm-diameter circle centered on the fovea from the 6×6-mm scans.

Results

Forty-five diabetic subjects and 27 control subjects were included in the study. The CC FD% in diabetic eyes was on average 1.4-fold greater than in control eyes (12.34±4.14% vs 8.82±2.61%, P < 0.001). The mean CC FD size in diabetic eyes was on average 1.4-fold larger than in control eyes (2151.3± 650.8μm² vs 1574.4±255.0 μm², P < 0.001). No significant difference in CC FD% or mean CC FD size was observed between eyes with nonproliferative DR and eyes with proliferative DR (P = 1.000 and P = 1.000, respectively).

Conclusions

CC perfusion in DR can be objectively and quantitatively assessed with FD% and FD size. In the macular region, both CC FD% and CC FD size are increased in eyes with DR. SS-OCTA provides new insights for the investigations of CC perfusion status in diabetes in vivo.

Outcomes of sutureless secondary intraocular lens fixation with haptic flanging in a cohort of surgically complex eyes

PURPOSE

To describe clinical outcomes of secondary intraocular lens (IOL) implantation using sutureless trans-scleral techniques in surgically complex eyes.

METHODS

Retrospective surgical case series of 45 eyes that underwent secondary IOL implantation using a sutureless haptic flange technique. Demographic data of age, sex, primary diagnosis, best-corrected visual acuity (BCVA), refractive error, intraocular pressure, full ophthalmic exam findings, surgical approach, and any intraoperative complications were noted.

RESULTS

The most common indication for secondary IOL implantation was aphakia, most commonly after ocular trauma. The primary outcome measures were pre-operative and post-operative BCVA, which revealed recovery of pre-operative vision levels by post-operative week 1 and improved vision by post-operative month 1 (p = 0.03). Secondary outcome measures of target refraction pre-operatively and post-operatively revealed significant reduction in post-operative spherical equivalent to achieve BCVA (p < 0.001). Targeting of the secondary IOLs using Barrett Universal II, Holladay 1, Holladay 2, and SRK/T all exhibited a hyperopic shift post-operatively in post-traumatic aphakic eyes and a myopic shift in the post complicated cataract extraction eyes. No intraoperative adverse events were noted. The most common post-operative complication was transient IOP elevation, with most patients completing 6 months of follow-up.

CONCLUSION

There is rapid visual rehabilitation and reduction of spherical equivalent correction to attain BCVA in eyes with a history of ocular trauma that undergo secondary IOL implantation using a trans-scleral flange technique. Moreover, this study highlights that a specific IOL power formula can be more predictive of the desired refractive outcome depending on the indication for secondary IOL implantation.

Prognostic Utility of Whole-Genome Sequencing and Polymerase Chain Reaction Tests of Ocular Fluids in Postprocedural Endophthalmitis

PURPOSE

To associate detection of potential pathogen DNA in endophthalmitis with clinical outcomes.

DESIGN

Prospective cohort study.

METHODS

Patients in whom endophthalmitis was diagnosed following an intraocular procedure were recruited. Clinical outcome data from baseline, week-1, month-1, and month-3 visits were collected. Intraocular biopsy samples were cultured by standard methods. Quantitative polymerase chain reaction (qPCR) was performed for specific pathogens and whole-genome sequencing (WGS).

RESULTS

A total of 50 patients (mean age 72 years old; 52% male) were enrolled. Twenty-four cases were culture-positive and 26 were culture-negative. WGS identified the cultured organism in 76% of culture-positive cases and identified potential pathogens in 33% of culture-negative cases. Month-1 and -3 visual acuities did not vary by pathogen-positive versus pathogen-negative cases as detected by either culture or WGS. Visual outcomes of Staphylococcus epidermidis endophthalmitis were no different than those of pathogen-negative cases, whereas the patients infected with other pathogens showed worse outcome. Higher baseline bacterial DNA loads of bacteria other than those of S epidermidis detected by WGS were associated with worse month-1 and -3 visual acuity, whereas the S epidermidis loads did not appear to influence outcomes. Torque teno virus (TTV) and Merkel cell polyomavirus (MCV) were detected by qPCR in 49% and 19% of cases, respectively. Presence of TTV at presentation was associated with a higher rate of secondary pars plana vitrectomy (P = .009) and retinal detachment (P = .022).

CONCLUSIONS

The presence and higher load of bacteria other than S epidermidis detected by WGS or DNA from TTV by qPCR in ocular fluids is associated with worse outcomes in post-procedure endophthalmitis.

Microvascular Changes in the Choriocapillaris of Diabetic Patients Without Retinopathy Investigated by Swept-Source OCT Angiography

Purpose

To investigate the microvascular changes in macular retina and choriocapillaris (CC) in diabetic eyes without retinopathy using swept-source optical coherence tomography angiography (SS-OCTA).

Methods

A commercial SS-OCTA system was used to collect 6 × 6-mm macular scans from patients. Three depth-resolved retinal slabs and a CC slab were segmented by a validated semiautomated algorithm. Retinal vessel area density, vessel skeleton density, and nonperfusion area were calculated on segmented retinal slabs. Foveal avascular zone was automatically measured based on en face image of the whole retinal layer. For CC quantification, the percentage of flow deficits (FD%) and the flow deficit (FD) sizes were measured. 

Results

Sixteen eyes from 16 diabetic patients without clinically detectable retinopathy and 16 eyes from 16 age-matched nondiabetic controls were included. There was no significant difference between the two groups in all retinal vessel quantitative parameters (all P > 0.05). However, the mean FD% and mean FD sizes were significantly increased in CC in the central 1.0-mm disk (P = 0.011 and P = 0.017, respectively), the central 1.5-mm rim (P = 0.003 and P = 0.009, respectively), the central 2.5-mm rim (P = 0.018 and P = 0.020, respectively), and the entire 5.0-mm disk (P = 0.009 and P = 0.008, respectively) in diabetic eyes compared with controls.

Conclusions

CC perfusion in the macula is decreased in diabetic patients without retinopathy as compared to age-matched normal controls. Decreased CC perfusion in the macula may be an early indicator of otherwise clinically undetectable diabetic vasculopathy.

Laser Peripheral Iridotomy Curriculum: Lecture and Simulation Practical

INTRODUCTION

Approximately 20 million people worldwide are affected by primary angle closure glaucoma, which is often treated with a laser peripheral iridotomy (LPI). In the United States, at least 60,000 to 80,000 LPIs are performed annually. However, complications can arise from improperly performed LPIs. While the Accreditation Council for Graduate Medical Education requires that all ophthalmology residents perform at least four primary LPIs prior to graduating, formal training is often lacking. In an effort to standardize LPI teaching, an LPI lecture curriculum and skills practice session were introduced.

METHODS

A lecture and wet-lab curriculum was developed at the University of Washington to formally teach first-year ophthalmology residents the indications and techniques for LPI. Pre- and postcurriculum knowledge was tested, and LPI performance was assessed by comparing pre- and postcurriculum total number of shots and time needed to successfully complete an LPI on a commercially available model eye.

RESULTS

The course was highly rated by 10 residents (all PGY 2), with an increase in pre- versus posttest scores, an improvement in LPI performance metrics, and an increase in pre- versus postcurriculum scores for the three survey questions regarding curriculum objectives.

DISCUSSION

This course improved learner knowledge and confidence in performing LPI. Test scores improved following the course, as did self-assessed confidence levels of the residents. Residents made a number of positive comments about the course. We plan to continue holding this training session every year at our institution.

Profound Presentation of Retinopathy in a Patient with Sickle Cell Trait and Diabetes Mellitus

This is a Photo Essay and does not have an abstract.

Ultra-Widefield Protocol Enhances Automated Classification of Diabetic Retinopathy Severity with OCT Angiography

PURPOSE

To assess the diagnostic usefulness of retinal nonperfusion to classify eyes based on diabetic retinopathy (DR) severity on OCT angiography (OCTA) and determine whether wider field of view (FOV) OCTA protocols enhance the diagnostic usefulness of retinal nonperfusion in the classification of DR severity.

DESIGN

Retrospective cross-sectional study.

PARTICIPANTS

Diabetic patients undergoing ultra-widefield (UWF) OCTA imaging at 1 academic retina practice.

METHODS

Ultra-widefield OCTA images with 100° FOV were obtained from 60 eyes. Eyes were grouped as those with diabetes without retinopathy (DWR), those with nonproliferative diabetic retinopathy (NPDR), or those with proliferative diabetic retinopathy (PDR). The ratio of nonperfusion (RNP) was expressed as the percent area of capillary nonperfusion within the FOV. The RNP was obtained in the FOV 100° image and concentric sectors encompassing 10°, 10° to 30°, 30° to 50°, and 50° to 100°.

MAIN OUTCOME MEASURES

Mean RNP among DR groups, mean RNP measured among FOV sectors, and area under the curve (AUC) of the receiver operating characteristics when using RNP as a cutoff value to distinguish between DR groups.

RESULTS

Mean RNP from the FOV 50° to 100° sector was different among all groups: DWR, 14.6±5.1%; NPDR, 27.5±7.5%; and PDR, 41.5±19.1% (P < 0.01). Within each DR group, field of view from 50° to 100° measured higher RNP than all other sectors (P < 0.01). Field of view from 50° to 100° showed the highest optimal sensitivity and specificity to distinguish NPDR from DWR with an RNP cutoff value of 21.2% (89.5% and 88.2%; AUC, 0.944) and PDR from NPDR with an RNP cutoff value of 31.6% (79.2% and 78.9%; AUC, 0.752).

CONCLUSIONS

Ratio of nonperfusion on average is higher in more severe DR. The most peripheral sector of the widefield OCTA (FOV 50°-100°) showed on average higher RNP and showed more diagnostic usefulness in determining DR severity compared with more central sectors and the FOV 100 image as a whole.

Handheld swept-source optical coherence tomography with angiography in awake premature neonates

Background

Retinopathy of prematurity (ROP) can lead to retinal detachment and severe vision loss and is a common cause of childhood blindness. Optical coherence tomography angiography (OCTA) is a non-invasive imaging modality that can be used to detect potential abnormalities in the microvasculature in this population. The objective of this study is to assess the feasibility of a newly developed handheld swept source OCT (SS-OCT) device to successfully acquire structural vitreoretinal and retinal microvascular images in awake premature infants.

Methods

OCT and OCTA images were acquired at the time of routine ROP examinations from awake, unsedated preterm infants in the Neonatal Intensive Care Unit using a clinical research prototype handheld probe integrated with an SS-OCT system working at 1,060 nm wavelength and an imaging speed of 200,000 A-scans per second (200 kHz), enabling volume OCT and OCTA scans. Each volume was acquired with approximately 36˚ field of view (~6.3×6.3 mm in infants) in 4.8 s. Quality of acquired OCT and OCTA volume images, microvascular information, and vitreoretinal features were determined by 3-masked grader consensus.

Results

Twelve infants (5 females, mean gestational age 28.3 weeks, median birth weight 901 g, stages 0 to 3 ROP) underwent a total of 73 individual eye imaging sessions. High-quality OCT images of the fovea and the optic nerve were present in 69/73 (94.5%) and 56/73 (76.7%) scans, respectively. Vitreous bands were observed in 10/73 (13.7%); punctate hyperreflective vitreous opacities in 47/73 (64.4%); epiretinal membrane (ERM) in 6/73 (8.2%); and cystoid macular edema (CME) in 12/73 (16.4%) scans. Mild vessel elevation was noted in 3/73 (4.1%) images, and severe vessel elevation in 4/73 (5.5%) scans. OCTA images obtained in 8 awake infants revealed good quality images of the foveal microvasculature in 11/19 (58%) eye imaging sessions for 6/8 (75%) infants; and peripapillary microvasculature in 14/19 (74%) eye imaging sessions for 5/8 (63%) infants.

Conclusions

The SS-OCTA handheld device can capture important vitreoretinal characteristics such as peripapillary and foveal microvasculature, as well as hyperreflective punctate vitreous opacities and tractional vitreous bands, which may predict ROP severity. These images were captured in awake, premature infants without the use of direct ocular contact, an eyelid speculum, or sedation.

Ultra-wide optical coherence tomography angiography in diabetic retinopathy

Background

To implement an ultra-wide optical coherence tomography angiography imaging (UW-OCTA) modality in eyes with diabetic retinopathy (DR) with the aim of quantifying the burden of microvascular disease at baseline and subsequent clinic visits.

Methods

UW-OCTA was implemented on a 1,060 nm swept source (SS) OCTA engine running at 100 kHz A-line rate with a motion tracking mechanism. A montage scanning protocol was used to capture a 100-degree field of view (FOV) using a 4×4 grid of sixteen total individual 6×6 mm² scans. Typical OCTA images with a FOV of 3×3, 6×6 and 12×12 mm² were obtained for comparison. DR patients were scanned at baseline and follow-up. They were treated at the clinician's discretion. Vessel density and non-perfusion area maps were calculated based on the UW-OCTA images.

Results

Three proliferative DR patients were included in the study. UW-OCTA images provided more detailed visualization of vascular networks compared to 50-degree fluorescein angiography (FA) and showed higher burden of pathology in the retinal periphery that was not captured by typical OCTA. Neovascularization complexes were clearly detected in the two patients with active PDR. Vessel density and non-perfusion maps were used to measure progressive capillary non-perfusion and regression of neovascularization between visits.

Conclusions

UW-OCTA provides approximately 100-degree OCTA images of the fundus comparable to that of wide-angle fundus photography, and may be more applicable in conditions such as DR which affect the peripheral retina in contrast to standard OCTA.

Optical Coherence Tomography Microangiography Imaging of Circumscribed Choroidal Hemangioma

Optical coherence tomography angiography (OCTA) is a new imaging technology capable of providing three-dimensional (3-D) retinal and choroidal microvascular maps without a need for exogenous dye. In this study, the authors evaluate the retinal and choroidal microvascular architecture of the macula in a patient with choroidal hemangioma using OCTA. Widefield OCTA with tracking capability and segmentation was performed to provide images with a field of view at 9 × 9 mm². The en face maximum projection was used to generate 2-D angiograms of different layers with color-coded images. Variable levels of perfusion within the lesion were identified, which correlate well with the known vascular abnormalities of choroidal hemangiomas. OCTA demonstrated an accurate modality to measure the 3-D borders of this lesion. This is the novel utilization of OCTA imaging on choroidal hemangioma. OCTA may provide detailed vascular findings in circumscribed choroidal hemangiomas, which may aid in the diagnosis and evaluation of the treatment response. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:134-137.].

Projection artifact removal improves visualization and quantitation of macular neovascularization imaged by optical coherence tomography angiography

PURPOSE

To visualize and quantify the size and vessel density of macular neovascularization (MNV) using optical coherence tomography angiography (OCTA) with a projection artifact removal algorithm.

DESIGN

Multicenter, observational study.

PARTICIPANTS

Subjects with MNV in at least one eye.

METHODS

Patients were imaged using either a swept-source OCT angiography (SS-OCTA) prototype system or a spectral-domain OCT angiography (SD-OCTA) prototype system. The optical microangiography (OMAG) algorithm was used to generate the OCTA images. Projection artifacts from the overlying retinal circulation were removed from the OMAG OCTA images using a novel algorithm. Following removal of the projection artifacts from the OCTA images, we assessed the size and vascularity of the MNV. Concurrent fluorescein angiography (FA) and indocyanine green angiography (ICGA) images were used to validate the artifact-free OMAG images whenever available.

MAIN OUTCOME MEASURES

Size and vascularity of MNV imaged with OCTA before and after the use of a projection-artifact removal algorithm.

RESULTS

A total of 30 subjects (40 eyes) diagnosed with MNV were imaged. Five patients were imaged before and after intravitreal injections of vascular endothelial growth factor (VEGF) inhibitors. Following the use of the projection artifact removal algorithm, we found improved visualization of the MNV. Lesion sizes and vascular densities were more easily measured on all the artifact-free OMAG images. In eyes treated with vascular endothelial growth factor inhibitors, vascular density was reduced in all five eyes after treatment, and in four eyes, the size of the MNV decreased. One of five patients showed a slight increase in lesion size, but a decrease in vascular density.

CONCLUSIONS

OCTA imaging of MNV using the OMAG algorithm combined with removal of projection artifacts resulted in improved visualization and measurements of the neovascular lesions. OMAG with projection artifact removal should be useful for assessing the response of MNV to treatment using OCTA imaging.

Intravitreal Injection Technique

INTRODUCTION

Intravitreal injection of therapeutic medications has become one of the most commonly performed procedures in ophthalmology. Over the past decade, a number of guidelines have been published that recommend proper techniques to increase the safety of intravitreal injections. In this course, we teach and practice the skills necessary to perform safe intravitreal injections.

METHODS

The course was developed for first-year ophthalmology residents and was designed to be delivered in one 2-hour session. Associated materials include guidelines for faculty facilitators and residents to prepare them for safe intravitreal injection of therapeutic medications. Also included are a slide presentation, wet-lab practice guidelines, and an evaluation form.

RESULTS

Learner response has been universally very positive. Residents (N = 15) have reported that structured lectures with practice in the wet lab improved their skill for intravitreal injection of therapeutic medication.

DISCUSSION

Overall, we found that our curriculum improved learner knowledge about safe intravitreal injections and learners' self-assessed confidence in the three objectives of the curriculum.

Association between OCT-based microangiography perfusion indices and diabetic retinopathy severity

AIM

To evaluate the association between retinal capillary non-perfusion and diabetic retinopathy (DR) severity using optical coherence tomography-based microangiography (OMAG).

METHODS

33 patients (51 eyes) with a history of diabetes underwent imaging with a 68 kHz Cirrus-5000 spectral domain OMAG prototype. Demographic and clinical characteristics were collected. The perfusion index (PI) was defined as per cent coverage of area by retinal vessels with flow, measured within a minimum of 6.8×6.8 mm² OMAG scan. The PI in each ETDRS zone was analysed using an automated algorithm. Univariate and multivariate analyses were used to determine the degree of association between PI and DR severity.

RESULTS

51 eyes with different DR severities were imaged. More severe DR was significantly associated with lower PI after adjusting for logarithm of the minimum angle of resolution best-corrected visual acuity, hyperlipidaemia, diabetes type and ETDRS ring in a multivariate mixed linear model. Compared with the none-mild non-proliferative diabetic retinopathy (NPDR) group, the moderate-severe NPDR group had 2.7 lower PI (p=0.03) and proliferative DR group had 4.3 lower PI (p=0.003). All ETDRS zones except for the foveal centre showed inverse associations between PI and DR severity (p values<0.001 to 0.862).

CONCLUSIONS

A statistically significant inverse association exists between PI and DR severity. Our study suggests that PI may become a useful biomarker in evaluating and following the progression of DR.

Optical coherence tomography based microangiography as a non-invasive imaging modality for early detection of choroido-neovascular membrane in choroidal rupture

Introduction

To evaluate and identify early microvascular changes in patient with choroidal rupture using optical coherence tomography (OCT) based microangiography (OMAG).

Case description

One patient (one eye) with confirmed diagnosis of choroidal rupture after sustained ocular blunt trauma underwent OMAG imaging. OMAG was performed by Zeiss spectral domain OCT-angiography prototype using a “6.5 mm × 6.5 mm” field of view around macular region. The resulting images were presented into bilayers: the retinal layer and the choroidal layer.

Discussion and evaluation

Choroidal rupture sites were easily shown on OMAG images with clear evidence of multiple breaks in Bruch’s membrane involving macula and the region superior to nerve. OMAG provided detailed vascular network patterns in the areas of choroidal rupture, showing a concern for choroidal neovascularization (CNV). The OMAG demonstrated cross sectional area to visualize CNV location relative to the other layers of the retina, identifying functional blood vessels through the lesion. The patient’s progress was followed using OMAG.

Conclusion

The images provided by OMAG give detailed microvascular findings about the macula and adjacent retinal region along with the underlying choroidal alternations. In our case, details of the architecture and vascular flow of CNVM in choroidal rupture was delivered by OMAG, which were used to follow the progression of the disease progression. Further studies are needed to assess the role of quantitative and qualitative OCT microangiography in the evaluation and treatment of choroidal rupture.

PNEUMATIC DISPLACEMENT AS A TREATMENT OF TRAUMATIC MACULAR HOLE WITH SUBMACULAR HEMORRHAGE

PURPOSE

To report the potential benefit of pneumatic displacement with perfluoropropane in the acute treatment of traumatic macular hole and submacular hemorrhage.

METHODS

This article is a descriptive case report. Intravitreal injection of 0.3 mL of undiluted C3F8 was performed in an outpatient clinic setting, with strict face-down positioning for 7 days thereafter.

PATIENT

An otherwise healthy 22-year-old white man with no past ocular history.

RESULTS AND DISCUSSION

Initial examination and optical coherence tomography documented significant displacement of the submacular hemorrhage, and stabilization of the macular hole 24 hours after pneumatic retinopexy was performed. Best-corrected visual acuity on presentation was counting fingers in the affected eye, which improved to 20/50 with a closed macular hole 6 weeks after his initial injury.

Increased prostaglandin E2 (PGE2) levels in proliferative diabetic retinopathy, and correlation with VEGF and inflammatory cytokines

PURPOSE

We determined vitreous levels of prostaglandin E2 (PGE(2)), VEGF, and 15 other cytokines in diabetic and nondiabetic patients undergoing vitrectomy.

METHODS

Of 26 eyes of 26 patients enrolled consecutively, 13 eyes underwent vitrectomy for complications related to proliferative diabetic retinopathy, and the other 13 for epiretinal membrane, macular hole, vitreous opacities, or dislocated intraocular lens. Undiluted vitreous samples were taken at the time of surgery and frozen immediately at -80°C, and later analyzed for PGE(2), VEGF, and 15 other cytokines.

RESULTS

PGE(2) levels were 53% higher in diabetic eyes. Mean ± standard deviation PGE(2) levels were 25.11 ± 11 pg/mL and 16.40 ± 7 pg/mL in diabetic and nondiabetic eyes, respectively (P < 0.03). Mean ± standard deviation VEGF levels were 2225 ± 3798 pg/mL and 66 ± 185 pg/mL in diabetic and nondiabetic eyes, respectively (P < 0.001). Other cytokines, including eotaxin-1, growth related oncogene (GRO), interleukin (IL)-6, IL-8, interferon-γ-inducible protein of 10 kDa (IP-10), monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor alpha (TNF-α), and platelet-derived growth factor-AA, also were elevated significantly in diabetic eyes. A significant correlation was seen between PGE(2) levels and IP-10 and VEGF (P = 0.04).

CONCLUSIONS

PGE(2) levels are significantly higher in the vitreous of patients with complications from proliferative diabetic retinopathy, and correlate with IP-10 and VEGF. The results of our study suggest that PGE(2) may have a pathogenic role in diabetic retinopathy and implicates a potential therapeutic role for nonsteroidal anti-inflammatory drugs. (ClinicalTrials.gov number, NCT01609881.).

The short-term effects of antioxidant and zinc supplements on oxidative stress biomarker levels in plasma: a pilot investigation

PURPOSE

To determine if short-term Age-Related Eye Disease Study (AREDS) antioxidant and zinc supplementation affects biomarkers of oxidative stress, possibly serving as a predictor of their efficacy.

DESIGN

Prospective interventional case series.

METHODS

Nineteen subjects, 12 with intermediate or advanced age-related macular degeneration (AMD) (AREDS categories 3 or 4) and 7 non-AMD controls, were admitted to the Vanderbilt General Clinical Research Center and placed on a controlled diet for 7 days. Antioxidant and zinc supplements were stopped 2 weeks prior to study enrollment. Dietary supplementation with 500 mg vitamin C, 400 IU vitamin E, 15 mg β-carotene, 80 mg zinc oxide, and 2 mg cupric oxide per day was instituted on study day 2. Blood was drawn on study days 2 and 7, and plasma concentrations of cysteine (Cys), cystine (CySS), glutathione (GSH), isoprostane (IsoP), and isofuran (IsoF) were determined.

RESULTS

Short-term AREDS supplementation significantly lowered mean plasma levels of CySS in participants on a regulated diet (P = .034). No significant differences were observed for Cys, GSH, IsoP, or IsoF. There were no significant differences between AMD patients and controls.

CONCLUSIONS

This pilot interventional study shows that a 5-day course of antioxidant and zinc supplements can modify plasma levels of CySS, suggesting that this oxidative stress biomarker could help predict how likely an individual is to benefit from AREDS supplementation. Further, CySS may be useful for the evaluation of new AMD therapies, particularly those hypothesized to affect redox status.

Plasma biomarkers of oxidative stress and genetic variants in age-related macular degeneration

PURPOSE

To compare plasma levels of oxidative stress biomarkers in patients with age-related macular degeneration (AMD) and controls and to evaluate a potential relationship between biochemical markers of oxidative stress and AMD susceptibility genotypes.

DESIGN

Prospective case-control study.

METHODS

Plasma levels of oxidative stress biomarkers were determined in 77 AMD patients and 75 controls recruited from a clinical practice. Cysteine, cystine (CySS), glutathione, isoprostane, and isofuran were measured, and participants were genotyped for polymorphisms in the complement factor H (CFH) and age-related maculopathy susceptibility 2 (ARMS2) genes.

RESULTS

CySS was elevated in cases compared with controls (P = .013). After adjustment for age, sex, and smoking, this association was not significant. In all participants, CySS levels were associated with the CFH polymorphism rs3753394 (P = .028) as well as an 8-allele CFH haplotype (P = .029) after correction for age, gender, and smoking. None of the other plasma markers was related to AMD status in our cohort.

CONCLUSIONS

Our investigation of the gene-environment interaction involved in AMD revealed a relationship between a plasma biomarker of oxidative stress, CySS, and CFH genotype. These data suggest a potential association between inflammatory regulators and redox status in AMD pathogenesis.

Reduced choroidal neovascular membrane formation in cyclooxygenase-2 null mice

PURPOSE

To assess the degree of laser-induced choroidal neovascular membrane formation in wild-type (WT) and COX-2 null mice and to measure vascular endothelial growth factor (VEGF), interleukin (IL)-1β, and tumor necrosis factor (TNF)-α levels in the retina and choroid.

METHODS

Four laser burns were placed in each eye of WT and COX-2 null mice to induce choroidal neovascularization. Fluorescein angiography (FA) was performed at 14 days, and retinal pigment epithelium-choroid-sclera (choroidal) flat mounts were prepared. The retina and choroid were isolated from WT and COX-2 null mice at 24, 72, and 168 hours after laser photocoagulation and from unlasered eyes and were tested for VEGF, IL-1β, and TNF-α.

RESULTS

COX-2 null mice demonstrated 58% (P = 0.001) and 48% (P = 0.001) reductions in CNV formation on FA and choroidal flat mounts, respectively, compared with WT mice. For unlasered mice, mean VEGF concentrations in the retina and choroid were 1.2 ± 0.42 pg/mg protein for WT but only 0.42 ± 0.2 pg/mg protein for COX-2 null mice (P < 0.05). After laser photocoagulation, WT mice showed significantly greater VEGF and IL-β expression in the retina and choroid by 168 hours (P < 0.05) and 72 hours (P < 0.05), respectively, compared with COX-2 null mice.

CONCLUSIONS

COX-2 null mice exhibited significantly less choroidal neovascular membrane formation associated with reduced expression of VEGF. The results of this study suggest that COX-2 modulates VEGF expression in CNV and implicates a potential therapeutic role for nonsteroidal anti-inflammatory drugs.

Multiplex cytokine analysis reveals elevated concentration of interleukin-8 in glaucomatous aqueous humor

PURPOSE

To test the hypothesis that immune activation occurs in glaucoma by comparing concentrations of multiple cytokines in aqueous humor (AH) from patients with primary open angle glaucoma (POAG) and from cataract patients without glaucoma as controls.

METHODS

Cytokine concentrations in AH obtained during surgery were measured using microparticle-based immunoassays. Localized expression of IL-8 protein was investigated by immunohistochemistry of human eyes.

RESULTS

Eight cytokines (IL-1β, IL-2, IL-4, IL-5, IL-10, IL-12, IFN-γ, and TNF-α) were below the limits of detection, and two cytokines (IL-18 and IL-15) were detected at low levels or in only a few patients. Although IL-6 was detected in 26 of 30 control patients (median, 2.7 pg/mL) and in 23 of 29 POAG patients (median, 1.6 pg/mL), the difference was not statistically significant. IL-8 was detected in 28 of 30 control patients (median, 1.8 pg/mL) and in all 29 POAG patients (median, 4.9 pg/mL). The higher IL-8 concentration in the AH of POAG patients was statistically significant (P < 0.001). In pairs of eyes from patients with asymmetric glaucomatous optic nerve damage, IL-8 concentration was higher in the AH of the more severely affected eye (P < 0.05). Patients with severe visual field defects had higher IL-8 concentrations in the AH than did patients with mild visual field defects. IL-8 protein expression was found in human retina and optic nerve.

CONCLUSIONS

Concentration of the inflammatory cytokine IL-8 is significantly elevated in the AH of POAG patients, supporting the hypothesis that immune activation occurs in glaucoma.

Modulation of Nrf2-dependent antioxidant functions in the RPE by Zip2, a zinc transporter protein

PURPOSE

To characterize the involvement of Zip2, a zinc transporter protein, in the antioxidant functions of cultured human retinal pigment epithelial (RPE) cells.

METHODS

The expression of zinc transporter proteins was determined by RT-PCR. Intracellular zinc concentration was assessed by staining with a zinc-sensitive dye followed by flow cytometry. Stable overexpression of the transporter protein Zip2 was achieved by transducing ARPE-19 cells with a retroviral vector containing the open reading frame of the human Zip2 gene. Activity of nuclear factor erythroid 2-related factor 2 (Nrf2) was measured using a dual luciferase assay after transient transfection of reporter plasmids containing the antioxidant response element (ARE). Glutamate-cysteine ligase (GCL) expression was measured by quantitative real-time RT-PCR.

RESULTS

Cultured RPE cells could transport zinc with Zip2 as an influx transporter expressed in ARPE-19 cells and human RPE cells isolated from postmortem donor eyes. The mRNA level of Zip2 was influenced by intracellular and extracellular zinc concentrations. Overexpression of Zip2 resulted in increased Nrf2 activity, higher GCL expression, and increased glutathione synthesis.

CONCLUSIONS

RPE cells can actively uptake zinc through the transporter Zip2, and the increased intracellular zinc upregulates the Nrf2-dependent antioxidant function.

AcrySof Natural filter decreases blue light-induced apoptosis in human retinal pigment epithelium

PURPOSE

The effect of AcrySof filter (UV light-filtering chromophore; Alcon) and AcrySof Natural filter (UV- and blue light-filtering chromophores) on blue light-induced apoptosis in human retinal pigment epithelial (RPE) cells was evaluated.

DESIGN

Laboratory investigation

CLINICAL RELEVANCE

Acrysof Natural filter reduces the blue-light toxicity in RPE cells and may have a positive impact on age-related macular degeneration (AMD).

METHODS

RPE cells were exposed to blue light (430-450 nm) in the presence of either the AcrySof (UV only) filter or Acrysof Natural (UV and blue light) filter for 10 days. The rate of apoptosis was analyzed.

RESULTS

Blue light induced significant apoptosis in RPE cells. AcrySof Natural filter significantly reduced the blue light-induced apoptosis when compared to AcrySof filter. The amount of blue-light energy reaching the cells with the AcrySof filter was 4.25 mW/cm(2) and with the AcrySof Natural filter was 2.5 mW/cm(2).

CONCLUSIONS

AcrySof Natural filter significantly reduced blue light-induced apoptosis. This was most likely due to its filtering effect on blue wavelength light, which reduces the energy that reaches the cells. In patients with cataract who are at a high risk for AMD, the implantation of a blue light-filtering intraocular lens may be considered.

Time-Resolved Detection of Melanin Free Radicals Quenching Reactive Oxygen Species

Melanin, a ubiquitous, heterogeneous biological polymer composed of many different monomers, contains a population of stationary, intrinsic semiquinone-like radicals. Additional extrinsic semiquinone-like radicals are reversibly photogenerated with visible or UV irradiation. The free radical chemistry of melanin is complex and not well characterized, especially the photochemistry of melanin in the presence of oxygen. To determine directly how melanin reacts in the presence of oxygen, time-resolved electron paramagnetic resonance (TREPR) spectroscopy was used to examine melanin free radical chemistry in human retinal pigment epithelium (RPE) cells under aerobic and anaerobic conditions. A TREPR difference spectrum was used to explore the nature of melanin chemistry in the presence of oxygen. The position and symmetrical line shape of the TREPR three-dimensional difference spectrum shows that when reactive oxygen species (ROS) are scavenged, only one of the two or more chemically different melanin free radical species participates in ROS scavenging. This protective melanin radical species exists in both the extrinsic and intrinsic populations of melanin free radicals, allowing melanin to protect the RPE from toxic species in both the light and dark.

Melanin photoprotection in the human retinal pigment epithelium and its correlation with light-induced cell apoptosis

Time-resolved electron paramagnetic resonance (TREPR) spectroscopy was used to study melanin free radicals in human retinal pigment epithelium (RPE) cells and tyrosine-derived synthetic melanin. TREPR signal traces from RPE cells reveal in vivo light-induced melanin free radical photochemistry in more detail than previously known. Electron spin polarization reflecting a non-Boltzmann population within the energy levels of the spin system is observed in RPE cells as the result of the triplet state photoproduction and subsequent disappearance of free radicals in the melanin polymer. In a set of RPE cells cultured from individual sources, differences in optical absorption, continuous wave EPR spectra, and TREPR signals were correlated with apoptosis assays performed by flow cytometry. Continuous wave EPR spectra of RPE cells and TREPR of acidified synthetic melanin suggest that increased melanin aggregation provides an increase in photoprotection in the RPE cells that are relatively less susceptible to blue light-induced apoptosis.