Maria Cristina Savastano

IN VIVO CHARACTERIZATION OF RETINAL VASCULARIZATION MORPHOLOGY USING OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY.

Purpose: To evaluate retinal vessel morphology using split-spectrum amplitude-decorrelation angiography with optical coherence tomography in healthy eyes. Methods: Fifty-two eyes of 26 healthy volunteers (age range from 35 to 48 years; mean age 41.94 years; SD: ±4.13) were evaluated by optical coherence tomography angiography in the macular region. The protocol acquisition consisted of a 216 × 216 A-scan that was repeated 5 times in the same position, in 3 × 3 mm centered into the fovea. Results: All 52 eyes showed 2 separate vascular networks in the inner retina: the superficial network, located in the nerve fiber layer and in the ganglion cell layer, and the deep network, detected in the outer plexiform layer. The superficial and deep networks showed interconnections of vertical vessels. The reference planes to observe the 2 networks were defined at 60 &mgr;m, with an inner limiting membrane reference (6 &mgr;m offset), and 30 &mgr;m, with an inner plexiform layer reference (60 &mgr;m offset), respectively. Conclusion: Optical coherence tomography angiography can separately detect the superficial vascular and the deep vascular networks. These networks are overlaid and seem to be fused when seen with standard angiographies. Furthermore, optical coherence tomography angiography technology allows for the visualization of abnormal blood column and vessel wall details.

Longitudinal Optical Coherence Tomography–angiography Study Of Type 2 Naive Choroidal Neovascularization Early Response After Treatment

Purpose: To assess the longitudinal development of choroidal neovascularization (CNV) Type 2 after intravitreal anti–vascular endothelial growth factor by optical coherence tomography–angiography (OCT-A). Methods: Five eyes of five patients with naive CNV Type 2 were assessed by OCT-A in this observational longitudinal study. To perform, the OCT-A used an 840-nm wavelength OCT device (XR-Avanti, Freemont; Optovue) based on split-spectrum amplitude-decorrelation angiography algorithm. The timing of analysis was after 24 hours, between 7 days and 10 days, between 12 days and 18 days, and 30 days after the intravitreal anti–vascular endothelial growth factor injections. The protocol of analysis was 3-mm  × 3-mm OCT angiograms centered at the macula. The day after the injection, OCT-A showed the decrease of neovascularization, with apparent vessel fragmentation. The CNV area was reduced with pruning of thinner anastomoses and loss of smaller vessels. Decrease of dimensions of CNV area, microvascular rarefaction, and vessels narrowing was observed between 7 days and 10 days, between 12 days and 18 days because of the further loss of smaller capillaries. Residual flow was always visible to the afferent trunk over the time. Results: The mean age of patients was 72.6 (SD ±16.22) years. All were women, naive cases, and followed from 5 months to 14 months. Over that time, they had a mean number of 5.5 intravitreal injections (from 3 to 8) and a mean number of 11 OCT-A examinations each (from 8 to 26). The most salient result emerging from this study is the consistency in the patterns of cyclic CNV variations after treatment in different patients. This CNV cycle was approximately 62 days long. Conclusion: This study suggests that OCT-A is able to detect the Type 2 CNV developments. This new method allows noninvasive analysis of CNV networks remodeling during anti–vascular endothelial growth factor follow-up. In conclusion, OCT-A provides a useful approach for monitoring the CNV Type 2 over the time.

Capillary Network Anomalies In Branch Retinal Vein Occlusion On Optical Coherence Tomography Angiography

Purpose: To analyze the foveal microvasculature features in eyes with branch retinal vein occlusion (BRVO) using optical coherence tomography angiography based on split spectrum amplitude decorrelation angiography technology. Methods: A total of 10 BRVO eyes (mean age 64.2 ± 8.02 range between 52 years and 76 years) were evaluated by optical coherence tomography angiography (XR-Avanti; Optovue). The macular angiography scan protocol covered a 3 mm × 3 mm area. The focus of angiography analysis were two retinal layers: superficial vascular network and deep vascular network. The following vascular morphological congestion parameters were assessed in the vein occlusion area in both the superficial and deep networks: foveal avascular zone enlargement, capillary non-perfusion occurrence, microvascular abnormalities appearance, and vascular congestion signs. Image analyses were performed by 2 masked observers and interobserver agreement of image analyses was 0.90 (&kgr; = 0.225, P < 0.01). Results: In both superficial and deep network of BRVO, a decrease in capillary density with foveal avascular zone enlargement, capillary non-perfusion occurrence, and microvascular abnormalities appearance was observed (P < 0.01). The deep network showed the main vascular congestion at the boundary between healthy and nonperfused retina. Conclusion: Optical coherence tomography angiography in BRVO allows to detect foveal avascular zone enlargement, capillary nonperfusion, microvascular abnormalities, and vascular congestion signs both in the superficial and deep capillary network in all eyes. Optical coherence tomography angiography technology is a potential clinical tool for BRVO diagnosis and follow-up, providing stratigraphic vascular details that have not been previously observed by standard fluorescein angiography. The normal retinal vascular nets and areas of nonperfusion and congestion can be identified at various retinal levels. Optical coherence tomography angiography provides noninvasive images of the retinal capillaries and vascular networks.

A Longitudinal Follow-Up Study of Saffron Supplementation in Early Age-Related Macular Degeneration: Sustained Benefits to Central Retinal Function

Objectives. In a previous randomized clinical trial (Falsini et al. (2010)), it was shown that short-term Saffron supplementation improves retinal flicker sensitivity in early age-related macular degeneration (AMD). The aim of this study was to evaluate whether the observed functional benefits from Saffron supplementation may extend over a longer follow-up duration. Design. Longitudinal, interventional open-label study. Setting. Outpatient ophthalmology setting. Participants. Twenty-nine early AMD patients (age range: 55–85 years) with a baseline visual acuity >0.3. Intervention. Saffron oral supplementation (20 mg/day) over an average period of treatment of 14 (±2) months. Measurements. Clinical examination and focal-electroretinogram-(fERG-) derived macular (18°) flicker sensitivity estimate (Falsini et al. (2010)) every three months over a followup of 14 (±2) months. Retinal sensitivity, the reciprocal value of the estimated fERG amplitude threshold, was the main outcome measure. Results. After three months of supplementation, mean fERG sensitivity improved by 0.3 log units compared to baseline values (P < 0.01), and mean visual acuity improved by two Snellen lines compared to baseline values (0.75 to 0.9, P < 0.01). These changes remained stable over the follow-up period. Conclusion. These results indicate that in early AMD Saffron supplementation induces macular function improvements from baseline that are extended over a long-term followup.

Choroid Thickness Measurement with RTVue Optical Coherence Tomography in Emmetropic Eyes, Mildly Myopic Eyes, and Highly Myopic Eyes:

Purpose. To evaluate choroid thickness (CT) with RTVue spectral domain optical coherence tomography (SD-OCT) and the effect of age and myopia in eyes without posterior complications. Methods. In this multicenter cross-sectional study, all enrolled patients were over age 18 and divided them in 3 groups based on refraction: emmetropia (+1 D to −1 D), mild myopia (–1 D to −6 D), and high myopia (–6 D to −20 D) groups. Horizontal scans through the fovea were acquired with RTVue OCT (Optovue Inc., Fremont, California, USA). Choroid thickness was measured at 500 µm intervals up to 1,500 µm temporal and nasal to the fovea by 2 graders. Mean CT was calculated based on the average of the 7 locations. Statistical analysis was performed to evaluate CT at each location, the effects of age and myopia, and grader agreement. Results. A total 85 eyes of 85 subjects (30 emmetropic, 24 myopic, and 31 high myopic) were enrolled. Excellent grader agreement was observed with an intraclass correlation coefficient (ICC) >0.97. The mean CT was 248.2±78.5 (µm) for emmetropia (age = 58±18), 247.0±85.4 (µm) for myopia (age = 45±20), and 131.5±70.9 (µm) for high myopia (age = 54±13). The mean CT was not significantly different between emmetropia and myopia groups, which were significantly thicker than high myopia group. The overall slope of age-related change for the mean CT was −1.95 µm/y and the effect of age differed among the groups. Conclusions. Choroid thickness can be measured from RTVue OCT images with good reproducibility. Age and high myopia appear to negatively affect CT. The age effect may vary with refraction groups.

Differential vulnerability of retinal layers to early age-related macular degeneration: Evidence by SD-OCT segmentation analysis

PURPOSE We evaluated layer-by-layer retinal thickness in spectral-domain optical coherence tomography (SD-OCT), determined by automated segmentation analysis (ASA) software in healthy and early age-related maculopathy (ARM) eyes. METHODS There were 57 eyes (specifically, 19 healthy eyes under 60 years old, 19 healthy eyes over 60, and 19 ARM eyes) recruited into this cross-sectional study. The mean ages were 36.78 (SD, ±13.82), 69.89 (SD, ±6.14), and 66.10 (SD, ±8.67) years, respectively, in the three study groups. The SD-OCT scans were transferred into a dedicated software program that performed automated segmentation of different retinal layers. RESULTS Automated layer segmentation showed clear boundaries between the following layers: retinal nerve fiber layer (RNFL), ganglion cell layer plus inner plexiform layer (GCL+IPL), inner nuclear layer plus outer plexiform layer (INL+OPL), outer nuclear layer (ONL), and RPE complex. The thickness of the RNFL, ONL, and RPE layers did not show a statistically significant change across the three groups by ANOVA (P = 0.10, P = 0.09, P = 0.15, respectively). The thickness of GCL+IPL and INL+OPL was significantly different across the groups (P < 0.01), being reduced in the ARM eyes compared to healthy eyes, under and over 60 years old. CONCLUSIONS The early morphologic involvement of the GCL+IPL and INL+OPL layers in ARM eyes, as revealed by the ASA, could be related to early anatomic changes described in the inner retina of ARM eyes. This finding may represent a morphologic correlation to the deficits in postreceptoral retinal function in ARM eyes.

A morpho-functional study of amblyopic eyes with the use of optical coherence tomography and microperimetry.

PURPOSE To determine whether retinal nerve fiber layer thickness (RNFLT), macular thickness, foveal volume, macular sensitivity, and fixation in patients with amblyopia differ between the amblyopic eye and the fellow eye. METHODS Optical coherence tomography (OCT) and microperimetry (MP-1) were used to evaluate patients with unilateral amblyopia. Patients were divided into 2 groups, those with strabismic amblyopia and those with refractive amblyopia. OCT maps were used to calculate foveal volume, macular thickness, and RNFLT; MP-1 was used to determine macular sensitivity and fixation. RESULTS A total of 30 patients were included (13 males; mean age 19.7 years [range, 10-38 years]), 15 in each group. Mean best-corrected visual acuity was 20/35 (range, 20/50 to 20/32) in the amblyopic eye and 20/21 (range, 20/20 to 20/25) in the fellow eye. In both groups, mean foveal volume and RNFLT did not differ significantly between eyes. Only macular thickness in the strabismic group differed significantly between the amblyopic and fellow eyes (P = 0.03). Macular sensitivity was significantly greater in the fellow eye in both groups (strabismic group, P = 0.002; refractive group, P = 0.013), whereas fixation did not change significantly between the amblyopic and fellow eye. RNFLT and macular sensitivity was found to be significantly correlated (strabismic group, r = 0.84, P = 0.002; refractive group, r = 0.66, P = 0.02). CONCLUSIONS Our data suggest that although RNFLT does not vary between eyes, macular sensitivity is reduced in patients with amblyopia.

Measurement of retinal nerve fiber layer thickness, macular thickness, and foveal volume in amblyopic eyes using spectral-domain optical coherence tomography

Although the changes in the anatomy of the visual cortex and lateral geniculate nucleus as the result of amblyopia have been well documented, retinal involvement is still controversial. Time-domain optical coherence tomography with an axial resolution of 10 μm has been used to evaluate retinal and peripapillary tissues in amblyopic eyes with contradictory results. Spectral domain optical coherence tomography has a greater resolution (5-10 μm) and can determine retinal layers more precisely. Our purpose was assess by means of spectral domain optical coherence tomography whether the retinal nerve fiber layer thickness, macular thickness, and foveal volume of the amblyopic and the fellow eyes differ in patients with unilateral amblyopia. Intereye differences in these parameters were found to be insignificant.

Morphologic differences, according to etiology, in pigment epithelial detachments by means of en face optical coherence tomography.

Purpose: To assess morphologic differences in pigment epithelial detachment (PED) with en face optical coherence tomography in central serous chorioretinopathy (CSC) and age-related macular degeneration (AMD). Methods: We recruited 30 eyes of 22 patients with PED. Nine eyes had a clinical diagnosis of CSC and 21 had AMD. All patients were assessed with en face optical coherence tomography. Morphologic PED aspects were estimated on C-scans and classified according to shape, inner silhouette, content, wall aspects, wall thickness, and size. Results: Pigment epithelial detachment shape was predominantly circular (88.8%) in CSC and irregular or with multilobular features in AMD (76.2%). The PED inner silhouette had a smooth aspect (88.9%) in CSC and a slightly granular aspect or granular profile in AMD (100%). Clear PED content was the most characteristic feature of CSC (88.9%) but not of AMD. In CSC, PED morphologic wall aspect was uniform or slightly irregular (100%), while in AMD, it was slightly irregular (52.4%) or irregular (47.6%). Pigment epithelial detachment wall thickness and dimensions were larger in AMD than in CSC. Statistically significant differences were observed between CSC and AMD concerning PED inner silhouette, contents, wall aspects, and wall thickness measurements. Conclusion: En face optical coherence tomography scanning is a valuable tool for showing important morphologic differences between CSC and AMD.

Macular functional changes evaluated with MP-1 microperimetry after intravitreal bevacizumab for subfoveal myopic choroidal neovascularization: one-year results.

Purpose: The purpose of this study was to evaluate 1-year functional and structural effects of intravitreal bevacizumab for subfoveal choroidal neovascularization secondary to pathologic myopia (myopic choroidal neovascularization). Methods: Fifteen eyes with myopic choroidal neovascularization participated in this prospective interventional, noncomparative case series. All patients were treated with one intravitreal injection of 1.25 mg bevacizumab. Retreatments were performed in case of persistent or recurrent leakage on fluorescein angiography and/or intraretinal fluid on optical coherence tomography. Evaluation of best-corrected visual acuity using Early Treatment of Diabetic Retinopathy Study criteria, MP-1 microperimetry, optical coherence tomography, and fluorescein angiography were performed before treatment and 1 month, 3 months, 6 months, and 1 year after treatment. Results: After a follow-up of 12 months, best-corrected visual acuity improved on average of 0.23 logarithm of the minimum angle of resolution. Mean macular sensitivity within the central 8° increased on average of 2.62 dB at 12-month postinjection. The mean number of measurement points within the central absolute scotoma reduced significantly from 12.47 before treatment to 6.27 at 1-year follow-up. An improvement of fixation stability from baseline was observed in 9 patients (60%). No treatment adverse events were evidenced. Conclusion: Improvement of macular sensitivity and fixation stability 1 year after intravitreal bevacizumab for myopic choroidal neovascularization suggest a stable and progressive macular function recovery. The mean treatment session was 1.53, with 53.3% of patients needing only a single intravitreal bevacizumab injection, supporting a potential long-lasting efficacy of intravitreal bevacizumab treatment.