The pathological association between the anterior eye segment and the retina in a murine model of neovascular glaucoma.

Neovascular glaucoma (NVG) is caused by the formation of new blood vessels in the angle, iris, and cornea in retinal ischemic disease, such as proliferative diabetic retinopathy (PDR) and retinal vein occlusion (RVO), which can reduce the visual acuity. However, the pathophysiological symptoms of NVG are still not well understood because there is no model for the formation of NVG in the angle, iris, and cornea. The aim of this study was to investigate the involvement of NVG during ischemic disease, in a murine model of retinal ischemia. We evaluated the changes of the intraocular pressure (IOP) and pathological symptoms in the anterior eye segment and retina in this model, and the changes in the RNA or protein expression of vascular endothelial growth factor (VEGF) and fibrosis-related factors were analyzed in the retina and cornea by quantitative real-time polymerase chain reaction or western blot, respectively. Furthermore, we examined the changes in IOP after intravitreal injection of an anti-VEGF antibody. First, NVG formed in the retinal ischemic murine model, and the IOP was elevated in mice with NVG formation. Interestingly, VEGF expression was decreased in the retina but increased in the cornea in the murine model of NVG. On the other hand, fibrosis-related factors were increased in the retina and also significantly increased in the cornea in NVG. Moreover, the administration of anti-VEGF antibody immediately after vessel occlusion suppressed the increase in IOP, but administration at 7 days after vessel occlusion accelerated the increase in IOP. These findings suggest that the formation of NVG may be correlated with the pathological symptoms of retinal ischemic disease, via changes in VEGF and fibrosis-related factor expression.

Factors Associated with Worsening Proliferative Diabetic Retinopathy in Eyes Treated with Panretinal Photocoagulation or Ranibizumab.

PURPOSE: To compare rates and identify predictive factors for events that represent worsening of proliferative diabetic retinopathy (PDR) in eyes treated with panretinal photocoagulation (PRP) or ranibizumab. DESIGN: Randomized clinical trial (55 United States sites). PARTICIPANTS: Three hundred ninety-four study eyes from 305 adults with PDR, visual acuity (VA) 20/320 or better, and no history of PRP. INTERVENTION: Panretinal photocoagulation or intravitreous ranibizumab injections (0.5 mg/0.05 ml). MAIN OUTCOME MEASURES: Time from randomization to a composite PDR-worsening outcome defined as the first occurrence of vitreous hemorrhage, retinal detachment, anterior segment neovascularization, or neovascular glaucoma. RESULTS: Through 2 years, the cumulative probability of worsening PDR was 42% (PRP) versus 34% (ranibizumab; hazard ratio [HR], 1.33; 99% confidence interval [CI], 0.90 to 1.98; P = 0.063). Worse baseline levels of diabetic retinopathy severity (Early Treatment Diabetic Retinopathy Study scale) were associated with increased risk of worsening PDR, regardless of treatment group (64% [high-risk PDR or worse] vs. 23% [moderate PDR or better]; HR, 3.97; 99% CI, 2.48 to 6.36; P < 0.001). In the PRP group, eyes receiving pattern scan versus conventional single-spot PRP also were at higher risk for worsening PDR (60% vs. 39%; HR, 2.04; 99% CI, 1.02 to 4.08; P = 0.008), regardless of the number of spots placed or the number of sittings to complete the initial PRP. Eyes in both groups with vision-impairing (VA 20/32 or worse) center-involved diabetic macular edema (DME) at baseline were required to receive ranibizumab for center-involved DME. Therefore the composite outcome was compared by treatment in the subgroup of eyes that did not have vision-impairing center-involved DME at baseline. For these eyes, the rate of PDR-worsening was greater with PRP than ranibizumab (45% vs. 31%; HR, 1.62; 99% CI, 1.01 to 2.60; P = 0.008). CONCLUSIONS: In eyes with PDR, ranibizumab resulted in less PDR worsening compared with PRP, especially in eyes not required to receive ranibizumab for center-involved DME. Although anti-vascular endothelial growth factor therapy requires a more frequent visit schedule than PRP, these findings provide additional evidence supporting the use of ranibizumab as an alternative therapy to PRP for PDR, at least through 2 years.

Wholemount imaging reveals abnormalities of the aqueous outflow pathway and corneal vascularity in Foxc1 and Bmp4 heterozygous mice.

Mutations in the FOXC1/Foxc1 gene in humans and mice and Bmp4 in mice are associated with congenital anterior segment dysgenesis (ASD) and the development of the aqueous outflow structures throughout the limbus. The aim of this study was to advance our understanding of anterior segment abnormalities in mouse models of ASD using a 3-D imaging approach. Holistic imaging information combined with quantitative measurements were carried out on PECAM-1 stained individual components of the aqueous outflow vessels and corneal vasculature of Foxc1(+/-) on the C57BL/6Jx129 and ICR backgrounds, Bmp4(+/-) ICR mice, and wildtype mice from each background. In both wildtype and heterozygotes, singular, bifurcated and plexus forms of Schlemm's canal were noted. Of note, missing portions of the canal were seen in the heterozygous groups but not in wildtype animals. In general, we found the number of collector channels to be reduced in both heterozygotes. Lastly, we found a significant increase in the complexity of the corneal arcades and their penetration into the cornea in heterozygotes as compared with wild types. In conclusion, our 3-D imaging studies have revealed a more complex arrangement of both the aqueous vessels and corneal arcades in Foxc1(+/-) and Bmp4(+/-) heterozygotes, and further advance our understanding of how such abnormalities could impact on IOP and the aetiology of glaucoma.

Optical coherence tomography angiography in dural carotid-cavernous sinus fistula.

BACKGROUND: Recently, applications of optical coherence tomography angiography (OCTA) have been limited to the retina and posterior segment. Although early studies have described its use for other clinical applications, its role in anterior segment vasculature and optic disc imaging has been limited thus far. CASE PRESENTATION: We describe a novel clinical application of OCTA in a patient with dural carotid-cavernous sinus fistula (CCF), which was complicated by increased intra-ocular pressure (IOP). In this case report, we used the OCTA to delineate increased epsicleral venous flow in the affected eye with secondary raised IOP. Current measurements of episcleral venous pressure are either invasive or provide highly variable results, thus the OCTA may have the potential to provide a more reliable approach to assess episcleral vasculature. We also describe the use of OCTA to detect early glaucomatous nerve damage, associated with focal reductions in peripapillary retinal perfusion. CONCLUSIONS: We present an early report of using OCTA of the anterior segment to allow rapid, non-invasive delineation of abnormal episcleral venous plexus secondary to dural CCF. The OCTA was also useful for detecting early reduction in peripapillary retinal perfusion, which suggests early glaucomatous optic neuropathy. This suggests that OCTA may have a role for determining risk of glaucoma in patients with CCF in future.

Optical Coherence Tomography Angiography for Anterior Segment Vasculature Imaging.

PURPOSE: To evaluate the application of an optical coherence tomography angiography (OCTA) system adapted for the assessment of anterior segment vasculature. DESIGN: Cross-sectional, observational study. PARTICIPANTS: Consecutive subjects with normal eyes on slit-lamp clinical examination and patients with abnormal corneal neovascularization. METHODS: All scans were performed using a commercially available AngioVue OCTA system (Optovue, Inc., Fremont, CA) using an anterior segment lens adapter and the split-spectrum amplitude decorrelation angiography algorithm. Each subject underwent scans from 4 quadrants (superior, inferior, nasal, and temporal) in each eye by 2 trained, independent operators. MAIN OUTCOME MEASURES: Analysis of signal strength, image quality, and reproducibility of corneal vascular measurements was performed. RESULTS: In our study of 20 normal subjects (10 men, 10 women; mean age, 25.3±7.8 years), we found good repeatability (κ coefficient, 0.76) for image quality score and good interobserver agreement for vasculature measurements (intraclass coefficient, 0.94). After optimization of the angiography scan protocol, vascular measurements within the regions of interest were compared in the superior versus inferior quadrants (mean vascular loops, 3.34±1.16 vs. 3.12 ± 0.90 [P = 0.768]; segment-to-loop ratio, 4.18±0.71 vs. 4.32±0.87 [P = 0.129]; fractal dimension [Df] value, 1.78±0.06 vs. 1.78±0.06 [P = 0.94]; vascular loop area, 25.9±14.5 vs. 25.9±10.7 × 10(-3) mm(2) [P = 0.21]) and nasal versus temporal quadrant (mean vascular loops, 2.89±0.98 vs. 3.57±0.99 [P < 0.001]; segment-to-loop ratio, 3.94±0.69 vs. 4.55±0.78 [P = 0.897]; Df value, 1.78±0.06 vs. 1.77±0.06 [P = 0.14]; vascular loop area, 29.7±15.7 vs. 22.1±7.1 × 10(-3) mm(2) [P = 0.38]. We then used the established OCTA scanning protocol to visualize abnormal vasculature successfully in 5 patients with various corneal pathologic features, including graft-associated neovascularization, postherpetic keratitis scarring, lipid keratopathy, and limbal stem cell deficiency. CONCLUSIONS: This preliminary study describes a method for acquiring OCTA images of the cornea and limbal vasculature with substantial consistency. This technique may be useful for the objective evaluation of corneal neovascularization in the future.

Anterior segment ischemia following diode laser photocoagulation for aggressive posterior retinopathy of prematurity.

PURPOSE: To describe the clinical and demographical characteristics and treatment outcomes of the premature infants who were presented with the signs of anterior segment ischemia (ASI) following transpupillary diode laser photocoagulation for aggressive posterior retinopathy of prematurity (APROP). METHODS: The records of the premature infants who developed ASI following bilateral laser photocoagulation between November 2010 and December 2013 in a single institution for the treatment of APROP were retrospectively reviewed. The clinical and demographical characteristics, laser parameters, anterior segment complications, and structural outcomes were evaluated. RESULTS: Nine eyes of five infants (three males, two females) were recruited for the study. Mean gestational age (GA), birth weight (BW), and postmenstrual age (PMA) at the time of laser ablation were 28.2 ± 2.5 weeks, 1,287.0 ± 483.4 g and 34.8 ± 2.2 weeks, respectively. All eyes were treated with a near-confluent pattern of laser ablation. Several anterior segment complications were observed including corneal edema (nine eyes), posterior synechia (nine eyes), pupillary membranes (five eyes), shallow anterior chamber (three eyes), hyphema (three eyes), and focal lens opacities (two eyes), of all resolved completely. Permanent dense cataracts observed in two eyes of two infants who were scheduled for lensectomy and anterior vitrectomy. None of the eyes progressed to phthisis bulbi. CONCLUSIONS: Anterior segment ischemia after laser treatment of APROP is a rarely encountered clinical entity. Mild and transient cases may resolve without any long-term sequelae but severe ones may progress to permanent cataract requiring further surgery.

The three-dimensional organisation of the post-trabecular aqueous outflow pathway and limbal vasculature in the mouse.

The mouse eye has been used as a model for studies on the microanatomy of the outflow pathways but most of what is known comes from histological sections. These studies have focused mainly on the morphological features of the trabecular meshwork, Schlemm's canal and aqueous channels that link to the superficial episcleral vasculature. However, the anatomical architecture of the aqueous outflow vessels and their relationship to each other and to the general vascular circulation is not well understood. The aim of this study was to provide a detailed description of the microarchitecture of the aqueous outflow vessels and their relationship to the superficial limbal/episcleral vasculature throughout the entire limbus. The aqueous outflow vessels and blood and lymphatic vessels were imaged in PECAM-1 and LYVE-1 immunostained whole anterior segments of adult mice and three-dimensional (3-D) reconstructions of the optical sections were generated to reveal the aqueous, blood and lymphatic architecture. The arterial supply, venous drainage, organisation of perilimbal vasculature, collector channels/aqueous veins and the morphology of Schlemm's canal were revealed in their entirety and the relationships between these structures is described. Schlemm's canal was PECAM-1 positive but there was no affinity for the lymphatic marker LYVE-1. We show that Schlemm's canal is a continuous circular structure and more often seen as a single, broad, varicose vessel with short regions appearing as a plexus. Aqueous veins link Schlemm's canal to the superficial vasculature and there were no direct links seen between the canal and the lymphatic vessels.

[Application fluorescein angiography: a new method for assessment of anterior eye segment hemomicrocirculation].

PURPOSE: To develop a noninvasive fluorescein angiography (FAG) method for the anterior eye segment (AES) assessment which would imply using the most-ordered site of bulbar conjunctival capillary bed as the object of dye administration. MATERIAL AND METHODS: The study enrolled 30 individuals (41 eyes) with no evident ocular pathology and significant systemic diseases aged from 18 to 70 years and 19 patients with uveitis, of whom 10 patients (10 eyes) aged 43-57 had anterior uveitis and 9 patients (10 eyes) aged 17-29 had pars planitis. Assessment of conjunctival microcirculation was done by the proposed method of fluorescein angiography in which the dye is applied to the bulbar conjunctival capillary bed. RESULTS: In all cases after a microdose of fluorescein was administered to the intermediate zone capillaries it distributed into two venous systems of the AES: peripheral and prelimbal venules. Circulation time and vascular permeability (depending on the presence or absence of extravasal hyperfluorescence) were described. Angiographic patterns in healthy individuals and patients with either clinical form of uveitis appeared to differ considerably. CONCLUSIONS: Findings of the proposed noninvasive application FAG reflect the state of capillary and venular components of bulbar conjunctival microcirculatory system. Sings of increased hemoperfusion of the AES and vascular permeability were seen in patients with acute anterior uveitis, whereas in pars planitis patients vascular hyperpermeability was associated with decreased hemoperfusion of the AES. The proposed method can be used for monitoring of the inflammatory process in anterior and peripheral uveitis.

[Application fluorescein angiography for assessment of anterior eye segment hemomicrocirculation in patients with cataract and pseudoexfoliation syndrome].

OBJECTIVE: to study the state of anterior eye segment (AES) hemomicrocirculation by means of application fluorescein angiography (FAG) in patients with cataract of different maturity solely or in combination with pseudoexfoliation syndrome (PES). MATERIAL AND METHODS: A total of 58 patients (98 eyes) with cataract or cataract and PES aged from 45 to 82 years (68.4 +/- 5.2 years on average) were assessed (study group). These patients were divided into 2 subgroups: I--patients with cataract and no PES, II--patients with both cataract and PES. The control group included 15 individuals (21 eyes) without ophthalmic pathology aged from 47 to 72 years (57.7 +/- 4.7 years on average). Conjunctival microcirculation was assessed by the proposed FAG method, in which the dye is introduced directly to the bulbar conjunctival capillary bed through application. RESULTS: The following parameters of application FAG that characterize hemomicrocirculation of the AES were analyzed: venular appearance time, venous phase duration, beginning of extravasal hyperfluorescence, microvessels functionality regarding their number and caliber. All patients demonstrated hypoperfusion, the intensity of which correlated with cataract maturation and the presence of PES. CONCLUSION: Application FAG adequately reflects the state of hemomicrocirculation of the AES in cataracts and PES.

Retcam fluorescein gonioangiography: a new modality for early detection of angle neovascularization in diabetic retinopathy.

PURPOSE: To evaluate the role of Retcam fluorescein gonioangiography in detecting neovascularization of the angle and correlate the same with gonioscopy in diabetic retinopathy. METHODS: One hundred and fifty eyes of 150 patients (25 each of mild, moderate, severe, very severe nonproliferative diabetic retinopathy (NPDR) proliferative diabetic retinopathy (PDR); and PDR with high-risk characteristics) were recruited. They underwent complete ocular examination including applanation tonometry, gonioscopy, Retcam fluorescein gonioangiography, and fundus fluorescein angiography. RESULTS: Using Retcam fluorescein gonioangiography, of 150 eyes neovascularization of the angle was detected in 37 eyes (24.66%) compared with 22 eyes (14.66%) on gonioscopy (P = 0.04). Small newly formed vessels were evident only with Retcam fluorescein gonioangiography. In 10 of 50 patients (20%) with severe/very severe NPDR, angle neovascularization was appreciable on Retcam fluorescein angiography compared with 5 patients (10%) on gonioscopy. Similarly, 25 of 50 patients (50%) with PDR/PDR with high-risk characteristics had neovascularization of the angle on Retcam gonioangiography compared with 17 (34%) on gonioscopy. CONCLUSION: Retcam fluorescein gonioangiography is a novel technique for early detection of angle neovascularization in diabetic retinopathy and hence preventing progression to neovascular glaucoma. The objective nature of this test helps in precise decision making compared with gonioscopy for early intervention especially in cases of pre-PDR.

Anterior segment fluorescein angiography of the normal canine eye using a dSLR camera adaptor.

PURPOSE: To describe anterior segment fluorescein angiography (ASFA) of the normal canine eye using two different sedation/anesthetic protocols and a digital single lens-reflex (dSLR) camera adaptor. METHODS: Dogs free of ocular and systemic disease were used for this study. Dogs received maropitant citrate (1.0 mg/kg SQ) and diphenhydramine (2.0mg/kg SQ) 20min prior to butorphanol [n = 6] (0.2 mg/kg IV) or propofol [n=6] (4 mg/kg IV bolus, 0.2 mg/kg/min CRI). Standard color and red-free images were obtained prior to administration of 10% sodium fluorescein (20 mg/kg IV). Image acquisition was performed using a dSLR camera (Canon 7D), dSLR camera adaptor, camera lens (Canon EF-S 60 mm f/2.8 macro), and an accessory flash (Canon 580EXII). Imaging occurred at a rate of 1/s immediately following bolus for a total of 30 s, then at 1, 2, 3, 4, 5, and 10 min. RESULTS: Twelve dogs with a combined mean age of 5.1 years and various iris colors were imaged. Arterial, capillary, and venous phases were identified and time sequences recorded. Visibility of the vascular pattern was inversely related to iris pigmentation. Complete masking of blood flow was noted with heavily pigmented irises. Vessel leakage was noted in some eyes. Proper patient positioning and restricted ocular movements were critical in acquiring quality images. No adverse events were noted. CONCLUSION: This study demonstrated that quality high resolution ASFA images were obtainable using a novel dSLR camera adaptor. ASFA of the normal canine eye is limited to irises, which are moderately to poorly pigmented. Use of general anesthesia produced higher quality images and is recommended for ASFA in the dog.

Anterior segment uses of bevacizumab.

PURPOSE OF REVIEW: A significant recent advancement in the treatment of neovascularization of the anterior segment of the eye is the development of antivascular endothelial growth factor (anti-VEGF) therapeutic agents.We present a review of the current knowledge on anti-VEGF therapy with bevacizumab for anterior segment neovascularization. RECENT FINDINGS: A review of the recent peer-reviewed literature reveals an increasing number of experimental and clinical studies on the use of Avastin in both human and animal eye models. Although the numbers are still relatively small, the evidence suggests that bevacizumab may be effective in the treatment of corneal and iris neovascularization. Its effect on primary and recurrent pterygium is more controversial. In general, achievement of vessels regression is usually partial, and recurrence may occur after cessation of treatment. Response to treatment is affected by the chronicity of vessels, their extent, the cause for blood vessels formation, and the route of administration. SUMMARY: Effective short-term response together with high patient tolerance to local bevacizumab therapy offer encouraging results for the management of anterior segment neovascular disorders. Although statistically significant regression of vessels has been documented in many studies, the clinical significance of this finding is still a subject of debate.

Adverse events associated with intraocular injections of bevacizumab in eyes with neovascular glaucoma.

BACKGROUND: Bevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor (VEGF), has been reported to cause rapid regression of anterior segment neovascularization in eyes with neovascular glaucoma when administered intraocularly. Several studies have reported the safety profile of intravitreal injections of bevacizumab in patients with various retinal pathologies. We investigated the occurrence of adverse events associated with intraocular bevacizumab injections in patients with neovascular glaucoma. METHODS: We retrospectively reviewed the charts of 84 eyes of 70 patients with neovascular glaucoma that received intraocular bevacizumab injections to treat anterior segment neovascularization for the first time at Kanazawa University Hospital. RESULTS: The mean age of the patients was 63.5 ± 13.3 years (± standard deviation; range, 31-85 years). The underlying retinal diseases were proliferative diabetic retinopathy in 58 eyes (69%), central retinal vein occlusion in 17 eyes (20%), ocular ischemic syndrome in four eyes (5%), central retinal artery occlusion in three eyes (4%), branch retinal vein occlusion in one eye (1%), and radiation retinopathy in one eye (1%). The total number of intraocular injections of bevacizumab was 116 (1.4 ± 0.8 injections/eye, range, one to five injections/eye). Most were intravitreal injections (1.25 mg/0.05 ml; 115 injections, 99%). No cases had marked inflammation, lens injuries, marked vitreous hemorrhage, retinal detachment, or endophthalmitis. However, two eyes (2%) of two cases (3%) developed central retinal artery occlusion 3 or 4 days after bevacizumab injection. Both were among four eyes (i.e., 50%) with ocular ischemic syndrome. One of them had received an intracameral injection of bevacizumab (0.75 mg/0.03 ml) before the adverse event. No cases experienced systemic side-effects including myocardial infarction and cerebrovascular accidents within 3 months after bevacizumab injection. CONCLUSIONS: Central retinal artery occlusion may be a relatively common complication following intraocular injection of anti-VEGF agents in patients with neovascular glaucoma, particularly when it was associated with ocular ischemic syndrome. Since visual prognosis of central retinal artery occlusions is usually poor, intraocular injection of anti-VEGF agents should be performed with thoughtful consideration of the risks and benefits of the treatment, and with a strict follow-up examination, especially in high-risk patients.

Ocular neovascularization associated with central and hemicentral retinal vein occlusion.

PURPOSE: To investigate the incidence of ocular neovascularization (NV) in central and hemicentral retinal vein occlusion. METHODS: The study comprised consecutive 912 (673 nonischemic and 239 ischemic) central retinal vein occlusion and 190 (147 nonischemic, 43 ischemic) hemicentral retinal vein occlusion eyes. Ophthalmic evaluation at initial and follow-up visits included recording visual acuity, visual fields, and detailed anterior segment and fundus examinations and fluorescein fundus angiography. RESULTS: In ischemic central retinal vein occlusion, within 6 months from time of onset, the cumulative probability of development of iris NV was 49%, angle NV 37%, NV glaucoma 29%, retinal NV 9%, and disk NV 6%. More severe peripheral retinal hemorrhages were significantly associated with iris NV (P = 0.005), angle NV (P = 0.0004), and NV glaucoma (P = 0.012). Eyes that developed disk NV had more cotton wool spots (P = 0.058) than those without. In ischemic hemicentral retinal vein occlusion, within 12 months of onset, the cumulative probability of development of retinal NV was 29%, disk NV 12%, and iris NV 12%; within 6 months of onset, angle NV was found in 10% and NV glaucoma in 5%. Anterior chamber flare was associated with anterior segment NV and may precede the development of NV. Patients who developed NV were significantly younger, and there was a greater prevalence of NV glaucoma in patients with primary open angle glaucoma. CONCLUSION: In ischemic central retinal vein occlusion, anterior segment NV is much more common than posterior segment NV, and the cumulative chance of developing anterior segment NV is maximum during the first 6 months. In ischemic hemicentral retinal vein occlusion, posterior segment NV is much more common than anterior segment NV.

Anterior segment angiography in strabismus surgery.

BACKGROUND: Anterior ciliary arteries travelling along recti muscles provide anterior segment vascularization, which can be compromised by surgery involving more than 2 muscles. PATIENTS AND METHODS: We studied retrospectively the files of 10 patients in whom a fluorescein angiography of the iris had been performed as a pre-operative assessment prior to a second or third oculomotor surgery. RESULTS: The median age of the patients was 47.5 years (range 15 to 73 years). Relative iris ischemia was present in 4 patients following multiple surgeries, none of them presenting any general cardiovascular risk. The initial surgical protocol was modified according to angiographic results in these 4 patients. CONCLUSION: When further surgery has to be performed on previously multi-operated patients, anterior segment angiography can be useful in the planning of surgery in order to minimize the risks of anterior segment ischemia.

Anterior segment ischemia with rubeosis iridis after a circular buckling operation treated successfully with an intravitreal bevacizumab injection: a case report and review of the literature.

PURPOSE: To report a case of anterior segment ischemia (ASI) with rubeosis iridis after circular buckling surgery in a highly-myopic patient which was successfully treated with a second intravitreal bevacizumab injection. METHODS: Case report and review of the literature. DISCUSSION: ASI is a rare but potentially serious complication of posterior segment surgery. Finally it leads to neovascular glaucoma as a result of rubeosis iridis. An encircling band can compromise anterior segment circulation in different ways: by manipulation or disinsertion of the recti muscles, by occlusion of the vortex veins through compression or by changes in the blood supply of iris and ciliary body. This patient developed rubeosis iridis secondary to ASI. There was a remarkable regression of rubeosis iridis one month after a second intravitreal bevacizumab injection. Other case reports of bevacizumab use in neovascular glaucoma have shown clinical improvements of these patients, with intraocular pressure control and reduction of the neovascularization process. CONCLUSION: We describe a highly-myopic patient who developed ASI with rubeosis iridis after a circular buckling operation. Slit-lamp examination and gonioscopy can show very little rubeosis iridis and can be misleading. Iris fluorescein angiography is the most sensitive technique for evaluation of iris vessel abnormalities and is of considerable value in the early detection of rubeosis iridis. This report demonstrates the rapid resolution of rubeosis iridis on iris fluorescein angiography after a second intravitreal injection of bevacizumab. How long this regression will persist is unknown and repeated injections of bevacizumab may be necessary if rubeosis reappears.

High speed, long range, deep penetration swept source OCT for structural and angiographic imaging of the anterior eye.

This study reports the development of prototype swept-source optical coherence tomography (SS-OCT) technology for imaging the anterior eye. Advances in vertical-cavity surface-emitting laser (VCSEL) light sources, signal processing, optics and mechanical designs, enable a unique combination of high speed, long range, and deep penetration that addresses the challenges of anterior eye imaging. We demonstrate SS-OCT with a 325 kHz A-scan rate, 12.2 µm axial resolution (in air), and 15.5 mm depth range (in air) at 1310 nm wavelength. The ultrahigh 325 kHz A-scan rate not only facilitates biometry measurements by minimizing acquisition time and thus reducing motion, but also enables volumetric OCT for comprehensive structural analysis and OCT angiography (OCTA) for visualizing vasculature. The 15.5 mm (~ 11.6 mm in tissue) depth range spans all optical surfaces from the anterior cornea to the posterior lens capsule. The 1310 nm wavelength range enables structural OCT and OCTA deep in the sclera and through the iris. Achieving high speed and long range requires linearizing the VCSEL wavenumber sweep to efficiently utilize analog-to-digital conversion bandwidth. Dual channel recording of the OCT and calibration interferometer fringe signals, as well as sweep to sweep wavenumber compensation, is used to achieve invariant 12.2 µm (~ 9.1 µm in tissue) axial resolution and optimum point spread function throughout the depth range. Dynamic focusing using a tunable liquid lens extends the effective depth of field while preserving the lateral resolution. Improved optical and mechanical design, including parallax "split view" iris cameras and stable, ergonomic patient interface, facilitates accurate instrument positioning, reduces patient motion, and leads to improved imaging data yield and measurement accuracy. We present structural and angiographic OCT images of the anterior eye, demonstrating the unique imaging capabilities using representative scanning protocols which may be relevant to future research and clinical applications.

Changes of the vasculature and innervation in the anterior segment of the RCS rat eye.

Investigating the anterior eye segment vasculature and innervation of dystrophic RCS rats, two major unique findings were observed: in the iris, young adult animals with retinal dystrophy showed an increase in substance P nerve fibres and a dilation of arterioles and capillaries. This finding continued during ageing. In the pars plana region, the surface covered by venules decreased continuously with age. In older animals, this decrease was parallelled by a local decrease of sympathetic TH-positive nerve fibres supplying these venules. For both conditions, no comparable data exists so far in the literature. They might point to a unique situation in the anterior eye segment of the dystrophic RCS rat.