Face Spectral-domain Optical Coherence Tomography Research Articles

Benign Lobular Inner Nuclear Layer Proliferation associated with Congenital Hypertrophy of the Retinal Pigment Epithelium

Purpose: To report two cases of benign intraretinal tumors of the inner nuclear layer (INL) associated with congenital hypertrophy of the retinal pigment epithelium (CHRPE). Methods: Multimodal imaging of two cases, including fundus color and autofluorescence photography, structural and en face spectral-domain optical coherence tomography (SD-OCT), OCT-angiography, fluorescein and indocyanine green angiography. Results: During a routine examination, intraretinal tumors of the INL associated with several CHRPE lesions were observed in one eye of two male patients, aged 27 and 32 years, respectively. Multimodal imaging showed white multifocal lobulated lesions with arching extensions, located in the INL, which allowed diagnosing benign lobular inner nuclear layer proliferation (BLIP). Conclusion: BLIP is a rare benign tumor located in the INL with a unique pattern and only 4 cases have been reported to date. The present two cases allowed confirming that BLIP is associated with CHRPE, suggesting a concomitant developmental anomaly of the RPE and the inner retina.

32-year-old diabetic patient with progressive vision loss and crystalline retinopathy.

To report the case of severe bilateral retinal vascular occlusion in a patient with hyperoxalosis and chronic renal failure. Observational case report. Medical and imaging records were retrospectively reviewed. The patient was imaged with ultra-widefield (UWF) fundus photography and fluorescein angiography (UWF-FA), cross sectional and en face spectral-domain optical coherence tomography (SD-OCT), and OCT angiography. A 32-year-old diabetic patient receiving peritoneal dialysis was referred because of severe vision loss. UWF color fundus photography showed diffuse sclerotic retinal vessels and diffuse intraretinal crystals in both eyes. UWF-FA illustrated near-complete retinal vascular occlusion and capillary wipe out in both eyes. SD-OCT demonstrated diffuse inner and middle retina thinning in both eyes and multiple intraretinal hyperreflective foci consistent with crystalline deposits in all retina layers of both eyes. OCT angiography revealed severe capillary and large vessel non-perfusion in the superficial and deep retinal capillary plexus of each eye. The serum oxalate levels were increased at 28 µmol/L (reference range < 2 µmol/L) and genetic testing was positive for a heterozygous mutation of the AGXT (Alanine-Glyoxylate Amino Transferase) gene that causes type 1 autosomal recessive primary hyperoxaluria. A diagnosis of hyperoxalosis causing severe retinal vascular occlusion was rendered. Hyperoxalosis was the result of multiple factors including heterozygous AGXT mutation, chronic renal failure insufficiently treated with peritoneal dialysis, and a diet high in oxalate. This case highlights the importance of ruling out retinal oxalosis in patients on peritoneal dialysis in order to initiate prompt hemodialysis and prevent severe retinal vascular occlusion.

Monitoring Lesion Area Progression in Stargardt Disease: A Comparison of En Face Optical Coherence Tomography and Fundus Autofluorescence.

To compare longitudinal changes in en face spectral domain-optical coherence tomography (SD-OCT) measurements of ellipsoid zone (EZ) and retinal pigment epithelium (RPE) loss to changes in the hypoautofluorescent and hyperautofluorescent (AF) areas detected with short-wavelength (SW)-AF in ABCA4-associated retinopathy. SD-OCT volume scans were obtained from 20 patients (20 eyes) over 2.6 ± 1.2 years (range 1-5 years). The EZ, and RPE/Bruch's membrane boundaries were segmented, and en face slab images generated. SubRPE and EZ slab images were used to measure areas of atrophic RPE and EZ loss. These were compared to longitudinal measurements of the hypo- and abnormal AF (hypoAF and surrounding hyperAF) areas. At baseline, the en face area of EZ loss was significantly larger than the subRPE atrophic area, and the abnormal AF area was significantly larger than the hypoAF area. The median rate of EZ loss was significantly greater than the rate of increase in the subRPE atrophic area (1.2 mm2/yr compared to 0.5 mm2/yr). The median rate of increase in the abnormal AF area was significantly greater than the increase in the hypoAF area (1.6 mm2/yr compared to 0.6 mm2/yr). En face SD-OCT can be used to quantify changes in RPE atrophy and photoreceptor integrity. It can be a complementary or alternative technique to SW-AF with the advantage of monitoring EZ loss. The SW-AF results emphasize the importance of measuring changes in the hypo- and abnormal AF areas. The findings are relevant to the selection of outcome measures for monitoring ABCA4-associated retinopathy.

X-linked retinoschisis: OCT-angiography in two brothers from a four-generation family with a p.Arg197Cys pathogenic variant in the RS1 gene.

X-linked juvenile retinoschisis (XLRS) is a rare genetic disease causing retinal splitting. The aim of this work is to describe the optical coherence tomography angiography (OCTA) features in two brothers affected by an hemizygous c.589C>T (p.Arg197Cys) pathogenic variant in exon 6 of the RS1 gene. Each patient underwent a complete ophthalmological examination, including measurement of best corrected visual acuity, slit-lamp biomicroscopy, fundus color photographs, fundus autofluorescence and infrared imaging, fluorescein angiography, spectral-domain optical coherence tomography (SD-OCT) and optical coherence tomography angiography (OCTA). En Face SD-OCT and OCTA revealed the presence of two different pattern of cystic lesions, fusiform and oval, disposed on a petaloid or irregular manner in the perifoveolar area. A widening of the foveal avascular zone with interruption of the vascular arcades was clearly evident. Furthermore, a capillary drop-out was observed in the superficial plexus of the central retina, other than capillary ectasia in the deep capillary plexus. Straight gray lines were visible among the cysts. OCTA data herein described allow a detailed morphological evaluation of XLRS other than a quantitative assessment of retinal capillary flow in this disease. The retinal alterations that we have reported may be helpful to better understand this rare condition with OCTA being a sensitive technique to monitor the evolution of the disease and the response to potential future therapeutic approaches aimed to restore vision.

MACULAR SENSITIVITY IN THE AREA OF INTERNAL LIMITING MEMBRANE PEELING IN EYES AFTER PARS PLANA VITRECTOMY WITH THE TEMPORAL INVERTED INTERNAL LIMITING MEMBRANE FLAP TECHNIQUE FOR A FULL-THICKNESS MACULAR HOLE.

To examine the relationship between retinal sensitivity and the area of internal limiting membrane (ILM) peeling during pars plana vitrectomy for a full-thickness macular hole. Twenty-four eyes a minimum of 6 months after temporal inverted flap pars plana vitrectomy for a full-thickness macular hole were included in the study. En face spectral-domain optical coherence tomography images were used to assess margins of the peeled ILM area. Microperimetry was performed to examine retinal sensitivity within the central 10°. Areas of peeled ILM in en face optical coherence tomography images were correlated with the average sensitivity threshold. Retinal sensitivities at the location of each measurement point were compared with structural abnormalities observed in en face spectral-domain optical coherence tomography images. The mean retinal sensitivity in the area of ILM removal was significantly lower compared with the area of preserved ILM (24.29 ± 3.96 dB vs. 26.19 ± 2.10 dB, P < 0.0001, respectively). The peeled ILM area showed a negative correlation with the average sensitivity threshold (r = -0.56, P < 0.01). A larger area of ILM peeling during temporal inverted flap pars plana vitrectomy for a full-thickness macular hole is related to lower retinal sensitivity in the central macula.

Interpreting Retinal Nerve Fiber Layer Reflectance Defects Based on Presence of Retinal Nerve Fiber Bundles.

SIGNIFICANCEAdaptive-optics scanning-laser-ophthalmoscopy (AOSLO) retinal imaging of the retinal nerve fiber layer (RNFL) helps predict the severity of perimetric damage based on absence of fibers and projection of the defects in en face images of the RNFL from spectral-domain optical coherence tomography (SD-OCT).PURPOSEEn face images of the RNFL reveal reflectance defects in patients with glaucoma and predict locations of perimetric defects. These defects could arise from either loss of retinal nerve fiber bundles or reduced bundle reflectance. This study used AOSLO to assess presence of bundles in areas with RNFL reflectance defects on SD-OCT.METHODSAdaptive-optics scanning laser ophthalmoscopy was used to image a vertical strip of RNFL measuring approximately 30 × 3° between the optic disc and the fovea. Fifteen patients with glaucoma who had SD-OCT reflectance defects that passed through this region were chosen. Four patients had reflectance defects in both superior and inferior hemifields, so presence of bundles on AOSLO was assessed for 19 hemifields. Where bundles were present, the hemifield was scored for whether bundles seemed unusual (low contrast and/or low density). Perimetric defects were considered deep when sensitivity was below 15 dB.RESULTSTen hemifields had a region with no fibers present on AOSLO; all had a corresponding deep perimetric defect. The other nine hemifields had no region in the AOSLO image without fibers: four with normal fibers and five with unusual fibers. The only one of these nine hemifields with a deep perimetric defect was one with low-contrast fibers and overall thin RNFL.CONCLUSIONSRetinal nerve fiber layer reflectance defects, which were associated with deep perimetric defects, usually had a region with absence of fibers on AOSLO images of RNFL. Ability to predict severity of perimetric damage from en face SD-OCT RNFL reflectance images could benefit from quantification that differentiated between absence of fibers and unusual fibers.

Preoperative imaging optimized for epiretinal membrane surgery

BackgroundTo compare imaging modalities for visualizing primary epiretinal membrane (ERM) with each other and with intraoperative digital images (IDI) after blue staining.MethodsThe records of consecutive patients operated for primary ERM over a 12-month period were retrospectively reviewed. Preoperative imaging included color fundus photography (CFP), En Face spectral-domain optical coherence tomography (OCT), 45° infrared- (IR) and blue-reflectance (BR) scanning laser ophthalmoscopy. All images were qualitatively analyzed and scored from 0–4 according to the ability to visualize ERM details (0 = no visible ERM or vessel contraction, 1 = vessel contraction, 2 = retinal folds, 3 = ERM limits, 4 = elevated ERM edge). The preoperative ERM morphology was then compared to that seen on the IDI acquired after 1-min blue dye staining when available.ResultsSeventy eyes were included. The highest score for ERM visualization was obtained on BR and En Face OCT. A score of 3 or 4 was obtained in 68.5%, 62.1%, 17.9% and 13.6% of cases on En Face OCT, BR, CFP and IR images, respectively. IDI were available for 20 eyes, and showed a similar ERM morphology compared to preoperative images in most cases: a negative staining pattern corresponded to a plaque on En face OCT in 91% of eyes. However, IDI failed to show the ERM edges in 37.5% of cases.ConclusionERM morphology was better visualized preoperatively by BR and En Face OCT, in a similar way to the IDI after staining. Future intraoperative visualization systems could integrate both imaging modalities overlaid with the IDI for guiding ERM removal instead of staining.

Long-term follow up of en face optical coherence tomography of the inner retinal surface following internal limiting membrane peeling for idiopathic macular holes.

To evaluate sequential changes in the inner retinal surface using en face spectral domain optical coherence tomography (SD-OCT) following internal limiting membrane (ILM) peeling for idiopathic full thickness macular holes. Retrospective, interventional study on 45 eyes of 42 patients with type 1 macular hole closure after a single procedure and a minimum post-operative follow up of 6months. Best corrected visual acuity (BCVA), fundus photographs, B scan and en face SD-OCT scans were analysed pre-operatively, at 2, 6, 12months post-operatively and then yearly. The presence or absence of concentric macular dark spots (CMDS) on the ILM slab of en face SD-OCT, their distribution pattern and course in terms of number and size of the dark spots was qualitatively assessed at each follow up. CMDS was identified in a total of 26 eyes (57.78%). Of these, it was detected in 21 eyes at 2months and the remaining by 6months. At the time of first detection, the distribution was classified as type 1 in 9 eyes (35%), type 2 in 7 eyes (27%) and type 3 in 10 eyes (38%). There was apparent increase in the number and size of the CMDS in 16 eyes (62%) no later than 12months follow up, while 10 eyes (38%) remained stable. There was no decrease or resolution noted in any patient. The mean post-operative follow up was 19.4months (range 6-69months). Inner retinal defects in the form of CMDS can be picked up on en face SD-OCT between 2-6months post-operatively. They remain stable or become more prominent upto 12months follow up, but do not regress once present. En face SD-OCT is recommended in all cases where ILM is peeled to assess CMDS.

Optical Coherence Tomography Neuro-Toolbox for the Diagnosis and Management of Papilledema, Optic Disc Edema, and Pseudopapilledema.

Distinguishing optic disc edema from pseudopapilledema is a common, sometimes challenging clinical problem. Advances in spectral-domain optical coherence tomography (SD-OCT) of the optic nerve head (ONH) has proven to be a cost effective, noninvasive, outpatient procedure that may help. At its core are tools that quantify the thickness of the retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GC-IPL). The SD-OCT also provides a set of tools that may be qualitatively interpreted in the same way that we read an MRI. They include the transverse axial, en face, and circular tomogram. Our goal is to describe a practical office-based set of tools using SD-OCT in the diagnosis and monitoring of papilledema, optic disc edema, and pseudopapilledema. Searches on PubMed were performed using combinations of the following key words: OCT, papilledema, pseudopapilledema, optic disc drusen, retinal folds (RF), and choroidal folds (CF). The principal elements of SD-OCT analysis of the ONH are the RNFL and GC-IPL thickness; however, these metrics have limitations when swelling is severe. Qualitative interpretation of the transverse axial SD-OCT aids in assessing peripapillary shape that may help distinguish papilledema from pseudopapilledema, evaluate atypical optic neuropathies, diagnose shunt failures, and identify outer RF and CF. There is a consensus that the SD-OCT is the most sensitive way of identifying buried optic disc drusen. En face SD-OCT is especially effective at detecting peripapillary wrinkles and outer retinal creases, both of which are common and distinctive signs of optic disc edema that rule out pseudopapilledema. Mechanically stressing the ONH in the adducted eye position, in patients with papilledema, may expose folds and peripapillary deformations that may not be evident in primary position. We also discuss how to optimize the acquisition and registration of SD-OCT images. The SD-OCT is not a substitute for a complete history and a careful examination. It is, however, a convenient ancillary test that aids in the diagnosis and management of papilledema, optic disc edema, and pseudopapilledema. It is particularly helpful in monitoring changes over the course of time and distinguishing low-grade papilledema from buried drusen. The application of the SD-OCT toolbox depends on optimizing the acquisition of images, understanding its limitations, recognizing common artifacts, and accurately interpreting images in the context of both history and clinical findings.

Optical Coherence Tomography Characteristics of Quiescent Type 1 Neovascularization in Eyes with Nonexudative Age-related Macular Degeneration

Objectives:To describe the lesion characteristics of nonexudative, quiescent, asymptomatic type 1 neovascularization (NV) on B-scan and en face spectral domain optical coherence tomography (SD-OCT) in eyes with nonexudative age-related macular degeneration (AMD).Materials and Methods:In this retrospective, observational, consecutive case series, 27 patients who were already being followed and treated for exudative AMD in one eye were included in the study for their fellow eyes, which were initially nonexudative but developed exudative findings during follow-up. Initial B-scan and en face SD-OCT, fluorescein angiography (FA), and indocyanine green angiography (ICGA) images of these 27 eyes were examined retrospectively. The characteristic B-scan SD-OCT features of type 1 NV in this silent and asymptomatic stage were described.Results:The 27 eyes of 27 patients (13 males and 14 females; mean age 69.5±8.2 years) with nonexudative AMD had a mean best corrected visual acuity (BCVA) of 0.6±0.3 Snellen. Initial B-scan OCT images of all eyes (100%) showed retinal pigment epithelium (RPE) elevations and irregularities caused by a moderately reflective material in the sub-RPE space without fluid accumulation in the intraretinal/subretinal or sub-RPE space. Twenty-four eyes (88.8%) showed sub-RPE hyperreflective lesions consistent with type 1 NV on en face OCT images. While none of the eyes showed signs of type 1 NV in FA, macular plaque was observed in 8 eyes (29.6%) in ICGA. The mean time to onset of exudative findings was 8.3±4.03 months.Conclusion:In eyes with nonexudative AMD, there may be quiescent and asymptomatic type 1 NV lesions which do not yet show exudative changes. This NV has characteristic features on B-scan SD-OCT and can also be detected with en face OCT. Detection and close monitoring of these quiescent and inactive type 1 NV lesions during the asymptomatic, pre-exudative period are important for early treatment.

Evaluating inner retinal dimples after inner limiting membrane removal using multimodal imaging of optical coherence tomography

BackgroundTo evaluate inner retinal dimples after peeling of the inner limiting membrane (ILM) for macular holes (lamellar macular hole [LMH] and full-thickness macular hole [FTMH]) via multiple imaging modes of spectral-domain optical coherence tomography (OCT) and to assess their relationship with preoperative vitreoretinal interface conditions.MethodsThe data of 38 eyes in 35 patients who underwent surgery for LMH, and FTMH were retrospectively studied. The presence of postoperative inner retinal dimples was judged by a combination of en face OCT layer images and cross-sectional images. The demographic and clinical characteristics of eyes with and without inner retinal defects were compared to identify factors involved in the formation of the defects.ResultsInner retinal defects were found in 26 eyes (68%) after surgery. They appeared on the en face OCT ILM layer images as multiple dark spots limited to the ILM peeling area, and corresponded to dimples or pitting of inner retinal layers on cross-sectional OCT images. In 5 cases (19%), apparent progression of inner retinal defects was observed on the en face OCT images as increasing numbers and sizes of the dark spots, which seemed to follow an eccentric growth pattern starting from the central macula. In addition, highly myopic eyes were found to be associated with the formation of more severe inner retinal defects.ConclusionsMultiple imaging modes of en face spectral-domain OCT provide comprehensive information about the appearance of inner retinal dimples. High myopic eyes seem to develop more severe inner retinal defects after ILM peeling.

En Face Optical Coherence Tomography Angiography Imaging Versus Fundus Photography in the Measurement of Choroidal Nevi.

Choroidal nevi are common benign intraocular tumors with a small risk of malignant transformation. This retrospective study investigates the use of en face spectral-domain optical coherence tomography angiography (SD-OCTA) in determining the clinical features and measurement of choroidal nevi. Patients with choroidal nevi were imaged with both OCTA and a fundus photography device. Greatest longitudinal dimension (GLD), perpendicular dimension (PD), and the GLD/PD ratio were assessed on each device. Inter-device variation and intra- and inter-rater reliability analyses were performed. Fourteen patients with choroidal nevi were included. No significant difference between the GLD/PD ratio as measured by all three devices was found (Chi-square = 2.8, 2 df, P = .247). Intraclass correlation coefficients were greater than 0.7 for repeated measures on all devices, suggesting good repeatability and reproducibility. This study demonstrated inter-device consistency and high intra- and inter-rater reliability when measuring choroidal nevi. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:741-747.].

EXPLORING PHOTORECEPTOR REFLECTIVITY THROUGH MULTIMODAL IMAGING OF OUTER RETINAL TUBULATION IN ADVANCED AGE-RELATED MACULAR DEGENERATION.

To investigate the microscopic structure of outer retinal tubulation (ORT) and optical properties of cone photoreceptors in vivo, we studied ORT appearance by multimodal imaging, including spectral domain optical coherence tomography (SD-OCT) and adaptive optics scanning laser ophthalmoscopy. Four eyes of four subjects with advanced age-related macular degeneration underwent color fundus photography, infrared reflectance imaging, SD-OCT, and adaptive optics scanning laser ophthalmoscopy with a high-resolution research instrument. Outer retinal tubulation was identified in closely spaced (11 μm) SD-OCT volume scans. Outer retinal tubulation in cross-sectional and en face SD-OCT was a hyporeflective area representing a lumen surrounded by a hyperreflective border consisting of cone photoreceptor mitochondria and external limiting membrane, per previous histology. In contrast, ORT by adaptive optics scanning laser ophthalmoscopy was a hyporeflective structure of the same shape as in en face SD-OCT but lacking visualizable cone photoreceptors. Lack of ORT cone reflectivity by adaptive optics scanning laser ophthalmoscopy indicates that cones have lost their normal directionality and waveguiding property due to loss of outer segments and subsequent retinal remodeling. Reflective ORT cones by SD-OCT, in contrast, may depend partly on mitochondria as light scatterers within inner segments of these degenerating cells, a phenomenon enhanced by coherent imaging. Multimodal imaging of ORT provides insight into cone degeneration and reflectivity sources in optical coherence tomography.

Quantitative Analysis of En Face Spectral-Domain Optical Coherence Tomography Imaging in Polypoidal Choroidal Vasculopathy.

Spectral-domain optical coherence tomography (SD-OCT) imaging can be used to visualize polypoidal choroidal vasculopathy (PCV) lesions in the en face plane. Here, the authors describe a novel lesion quantification technique and compare PCV lesion area measurements and morphology before and after anti-vascular endothelial growth factor (VEGF) treatment. Volumetric SD-OCT scans in eyes with PCV before and after induction anti-VEGF therapy were retrospectively analyzed. En face SD-OCT images were generated and a pixel intensity thresholding process was used to quantify total lesion area. Thirteen eyes with PCV were analyzed. En face SD-OCT PCV lesion area quantification showed good intergrader reliability (intraclass correlation coefficient = 0.944). Total PCV lesion area was significantly reduced after anti-VEGF therapy (2.22 mm2 vs. 2.73 mm2; P = .02). The overall geographic pattern of the branching vascular network was typically preserved. PCV lesion area analysis using en face SD-OCT is a reproducible tool that can quantify treatment related changes. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:126-133.].

HYPERREFLECTIVE RETINAL SPOTS IN NORMAL AND DIABETIC EYES: B-Scan and En Face Spectral Domain Optical Coherence Tomography Evaluation.

To evaluate hyperreflective retinal spots (HRS), in normal subjects and diabetic patients without and with macular edema (diabetic macular edema, DME), on linear B-scans and corresponding en face image of spectral-domain optical coherence tomography. Retrospective evaluation of images of 54 eyes/subjects (16 normal subjects, 19 diabetic patients without DME, and 19 with DME). On horizontal B-scan spectral-domain optical coherence tomography, passing through the center of the fovea, the following characteristics of HRS were evaluated: location (inner retina or outer retina), size (≤30 or >30 μm), reflectivity (similar to nerve fiber layer or to retinal pigment epithelium-Bruch complex), and presence or absence of back shadowing. On en face spectral-domain optical coherence tomography, the following patterns were evaluated: 1) isolated HRS (not corresponding to any visible lesion); 2) HRS corresponding to a segment of retinal capillary or microaneurysm wall; and 3) HRS corresponding to hard exudate. All gradings were performed twice by two graders in a masked fashion. Size ≤30 μm, reflectivity similar to nerve fiber layer, and absence of back shadowing were associated with absence of vessels or any other lesion on en face image (P = 0.0001 for all). Size >30 μm, reflectivity similar to retinal pigment epithelium-Bruch complex, presence of back shadowing, and location in the outer retina were all associated with presence of hard exudate on en face imaging (P < 0.0001 for all). Multiple logistic regression analysis showed that HRS present in the inner retina (P < 0.0001), size >30 μm (P = 0.0029), and presence of back shadowing (P < 0.0001) are directly associated with presence of microaneurysms on en face image. Intragrader and intergrader repeatability were excellent for all evaluations. Hyperreflective retinal spots ≤30 μm, reflectivity similar to nerve fiber layer, and absence of back shadowing may represent activated microglial cells; HRS >30 μm, reflectivity similar to retinal pigment epithelium-Bruch complex, presence of back shadowing, and location in the outer retina may represent hard exudate; HRS >30 μm, presence of back shadowing, and location in the inner retina may represent microaneurysms. These hypotheses may be tested in further studies.

En Face Spectral-Domain Optical Coherence Tomography for the Diagnosis and Evaluation of Polypoidal Choroidal Vasculopathy.

To evaluate the diagnostic capability of en face spectral-domain optical coherence tomography (SD-OCT) in patients with polypoidal choroidal vasculopathy (PCV) diagnosed by indocyanine green angiography (ICGA). A retrospective, consecutive case series of 100 eyes diagnosed with PCV by ICGA were imaged with en face SD-OCT. Evaluation of the PCV complex on en face SD-OCT was performed on the ability to diagnose PCV by the characteristic configuration of the PCV complex and the extent and size of the PCV lesion. The PCV complex was better visualized on ICGA in 45 eyes, on en face SD-OCT in 44 eyes, and equally well in 11 eyes. The extent of the PCV complex was larger on en face SD-OCT in 65 eyes, larger on ICGA in 23 eyes, and equal in size in 12 eyes. En face SD-OCT images the characteristic findings of PCV and provides a noninvasive way to diagnose and treat PCV when ICGA is not available. [Ophthalmic Surg Lasers Imaging Retina. 2016;47:737-744.].

En Face Spectral-Domain Optical Coherence Tomography for the Monitoring of Lesion Area Progression in Stargardt Disease.

PurposeWe investigated the progression of Stargardt disease (STGD1) over a multiyear follow-up by evaluating the macular lesion area as computed by an automatic algorithm from spectral-domain optical coherence tomography (SD-OCT).MethodsWe reviewed medical records of STGD1 patients, with a clinical and molecular diagnosis of STGD1 at a single institution, who underwent best-corrected visual acuity (BCVA), fundus photography, SD-OCT, full-field electroretinography, and, when available, fundus autofluorescence (FAF). Regression models were fitted on the selected clinical parameters; in particular, on the macular lesion area computed by SD-OCT, to evaluate the disease progression over a multiyear follow-up.ResultsThe comparison between SD-OCT and FAF, available for 22 patients, showed that macular lesion area, assessed by SD-OCT, significantly correlated with the area of absent FAF (P < 0.001). Moreover, the longitudinal analysis, performed in 98 patients, showed a significant enlargement of macular lesion area at an estimated exponential rate of 4.6% per year (P = 0.046), together with a significant worsening of BCVA (0.06 logMAR per year; P < 0.001) and a significant decrease of macular thickness (1.6% per year; P = 0.005) over the follow-up.ConclusionsThe current study describes, for the first time in literature, a longitudinal analysis of the macular lesion area assessed by SD-OCT in STGD1 disease, showing a significant progression over the follow-up. Our findings suggest that the evaluation of macular lesion area by en face SD-OCT, together with FAF, could drive the choice of the most amenable candidates and the most suitable area to be treated in gene therapy clinical trials.

Quantitative Analysis of Outer Retinal Tubulation in Age-Related Macular Degeneration From Spectral-Domain Optical Coherence Tomography and Histology.

PurposeTo assess outer retinal tubulation (ORT) morphology from spectral-domain optical coherence tomography (SD-OCT) volumes and donor eye histology, analyze ORT reflectivity, and estimate the number of cones surviving in ORT.MethodsIn SD-OCT volumes from nine patients with advanced AMD, ORT was analyzed en face and in B-scans. The hyperreflective ORT border in cross-section was delineated and surface area calculated. Reflectivity was compared between ORT types (Closed, Open, Forming, and Branching). A flatmount retina from a donor with neovascular AMD was labeled to visualize the external limiting membrane that delimits ORT and allow measurements of cross-sectional cone area, center-to-center cone spacing, and cone density. The number of cones surviving in ORT was estimated.ResultsBy en face SD-OCT, ORT varies in complexity and shape. Outer retinal tubulation networks almost always contain Closed cross-sections. Spectral-domain OCT volumes containing almost exclusively Closed ORTs showed no significant direction-dependent differences in hyperreflective ORT border intensity. The surface areas of partial ORT assessed by SD-OCT volumes ranged from 0.16 to 1.76 mm2. From the flatmount retina, the average cross-sectional area of cone inner segments was 49.1 ± 7.9 μm2. The average cone spacing was 7.5 ± 0.6 μm. Outer retinal tubulation cone density was 20,351 cones/mm2. The estimated number of cones in ORT in a macula ranged from 26,399 to 186,833 cones, which is 6% to 44% of the cones present in a healthy macula.ConclusionsThese first estimates for cone density and number of cones surviving in ORT suggest that ORT formation considerably distorts the photoreceptor mosaic. Results provide additional insight into the reflectivity characteristics and number of ORT cones observable in living patients by SD-OCT, as cones persist and disease progresses.

Monitoring neovascularization in aggressive posterior retinopathy of prematurity using optical coherence tomography angiography

We describe the use of optical coherence tomography angiography (OCTA) in detecting and monitoring regression of the neovascular complex (NVC) in a case of aggressive posterior retinopathy of prematurity (AP-ROP). A premature Asian Indian girl with AP-ROP underwent laser photoablation at 26 days of life. Persistent NVC at the posterior border of the lasered retinal bed was detected clinically. On en face spectral domain optical coherence tomography (SD-OCT) and OCTA, the NVC appeared as an arborizing vascular net in the superficial capillary plexus. The deep capillary plexus and outer retinal layers showed corresponding flow outlines that suggested deeper extensions of the lesion. Supplemental laser treatment of the NVC was performed. Ten days later repeat en face SD-OCT and OCTA of the identical retinal location revealed that the vascular tortuosity and dilatation had reduced and that the flow lesions in the deeper layers were undetectable. Our findings in this case suggest that the NVC in AP-ROP extends beyond the superficial retina.

En Face Spectral-Domain Optical Coherence Tomography Imaging of Outer Retinal Hard Exudates in Diabetic Macular Edema Based on Optical Coherence Tomography Patterns.

To evaluate en face spectral-domain optical coherence tomography (SD-OCT) findings of the outer retinal hard exudates in diabetic macular edema (DME). Exploratory analyses of prospective and consecutive case series. Fifty-five eyes treated with intravitreal ranibizumab (IVR) (Lucentis; Genentech, South San Francisco, CA) for 12 months were classified according to OCT features of DME: diffuse retinal thickening (DRT), cystoid macular edema (CME), and serous retinal detachment (SRD). Area fraction of outer nuclear layer (ONL) hard exudates (HEs) was assessed from en face OCT images. Area fraction of ONL HEs increased from 1.45% ± 1.22% to 2.24% ± 1.31% in DRT and from 2.24% ± 1.85% to 3.25% ± 1.52% in CME. HE gain was greatest during first 3 months (DRT = 0.83%; CME = 1.25%). SRD showed no difference in HEs (P = .462). ONL HEs increased in DRT and CME at month 12 following IVR. Rapid gain of HEs was found during the initial loading phase of IVR.