Richard F. Spaide

Enhanced Depth Imaging Spectral-Domain Optical Coherence Tomography

PURPOSE To describe a method to obtain images of the choroid using conventional spectral-domain (SD) optical coherence tomography (OCT) and to evaluate choroidal thickness measurements using these images. DESIGN Observational case series. METHODS The images were obtained by positioning the SD OCT device close enough to the eye to obtain an inverted representation of the fundus in healthy volunteers who did not have pupillary dilation. Seven sections, each comprised of 100 averaged scans, were obtained within a 5- x 15-degree rectangle centered on the fovea. The choroidal thickness under the fovea in each image was measured by independent observers. RESULTS The choroidal thickness could be evaluated in every subjects choroidal image. The mean choroidal thickness under the fovea was 318 microm in the right eye and 335 microm in the left eye. The choroidal thickness showed a high correlation in both eyes (r = 0.82; P < .001). The correlation between the measurements performed by the independent observers was highly significant (right eye, r = 0.93; left eye, r = 0.97; P < .001 for both). CONCLUSIONS This method provides detailed, measurable images from the choroid, a structure that heretofore has been difficult to image in clinical practice.

A pilot study of enhanced depth imaging optical coherence tomography of the choroid in normal eyes.

PURPOSE To measure macular choroidal thickness in normal eyes at different points using enhanced depth imaging (EDI) optical coherence tomography (OCT) and to evaluate the association of choroidal thickness and age. DESIGN Retrospective, observational case series. METHODS EDI OCT images were obtained in patients without significant retinal or choroidal pathologic features. The images were obtained by positioning a spectral-domain OCT device close enough to the eye to acquire an inverted image. Seven sections were obtained within a 5 x 30-degree area centered at the fovea, with 100 scans averaged for each section. The choroid was measured from the outer border of the retinal pigment epithelium to the inner scleral border at 500-microm intervals of a horizontal section from 3 mm temporal to the fovea to 3 mm nasal to the fovea. Statistical analysis was performed to evaluate variations of choroidal thickness at each location and to correlate choroidal thickness and patient age. RESULTS The mean age of the 30 patients (54 eyes) was 50.4 years (range, 19 to 85 years), and 14 patients (46.7%) were female. The choroid was thickest underneath the fovea (mean, 287 microm; standard deviation, +/- 76 microm). Choroidal thickness decreased rapidly in the nasal direction and averaged 145 microm (+/- 57 microm) at 3 mm nasal to the fovea. Increasing age was correlated significantly with decreasing choroidal thickness at all points measured. Regression analysis suggested that the subfoveal choroidal thickness decreased by 15.6 microm for each decade of life. CONCLUSIONS Choroidal thickness seems to vary topographically within the posterior pole. The thickness of the choroid showed a negative correlation with age. The decrease in the thickness of the choroid may play a role in the pathophysiologic features of various age-related ocular conditions.

Intravitreal bevacizumab treatment of choroidal neovascularization secondary to age-related macular degeneration.

Purpose: To describe the short-term anatomical and visual acuity responses after intravitreal injection of bevacizumab (Avastin, Genentech) in patients with choroidal neovascularization (CNV) secondary to age-related macular degeneration (AMD). Methods: We conducted a retrospective study of patients with CNV secondary to AMD who were treated with intravitreal injection of bevacizumab (1.25 mg) during a 3-month period. Patients underwent best-corrected Snellen visual acuity testing, optical coherence tomography, and ophthalmoscopic examination at baseline and follow-up visits. Results: There were 266 consecutive eyes of 266 patients who received injections, and follow-up information was available for 251 (94.4%). The mean age of the patients was 80.3 years, the mean baseline visual acuity was 20/184, and 175 (69.7%) had inadequate response to alternate methods of treatment. At the 1-month follow-up (data available for 244 patients), the mean visual acuity was 20/137 (P < 0.001 as compared with baseline), and 74 (30.3%) of patients had improvement in visual acuity as defined by a halving of the visual angle. At the 2-month follow-up (data available for 222 patients), the mean visual acuity was 20/122 (P < 0.001), and 78 (31.1%) of patients had visual improvement. At the 3-month follow-up (data available for 141 patients), the mean visual acuity was 20/109 (P < 0.001), and 54 (38.3%) of patients had visual acuity improvement. The mean central macular thickness at baseline was 340 &mgr;m and decreased to a mean of 247 &mgr;m at month 1 (P < 0.001) and 213 &mgr;m at month 3 (P < 0.001). At 1 month, two patients had mild vitritis, as did one patient at 2 months, who had a history of recurrent uveitis. No endophthalmitis, increased intraocular pressure, retinal tear, or retinal detachment occurred. The risk for thromboembolic disorders did not seem to be different than reported previously in studies concerning macular degeneration. Conclusion: There were no apparent short-term safety concerns for intravitreal bevacizumab injection for CNV. Treated eyes had a significant decrease in macular thickness and improvement in visual acuity. The follow-up was too short to make any specific treatment recommendations, but the favorable short-term results suggest further study is needed.

Idiopathic polypoidal choroidal vasculopathy (IPCV).

Eleven patients, 40 to 71 years old, had a choroidal vasculopathy that led to hemorrhagic and exudative macular degeneration. The patients had peculiar polypoidal, subretinal, vascular lesions associated with serous and hemorrhagic detachments of the retinal pigment epithelium. This macular disorder, which we have named idiopathic polypoidal choroidal vasculopathy (IPCV), appears to represent a distinct entity that differs clinically and demographically from age-related macular degeneration (AMD) and other macular diseases associated with subretinal neovascularization. Recognition of this condition is important because it may have specific risk factors, natural course, and management considerations that differ from those of age-related macular degeneration.

Enhanced Depth Imaging Optical Coherence Tomography Of The Choroid In Central Serous Chorioretinopathy

Purpose: The purpose of the study was to evaluate the choroidal thickness in patients with central serous chorioretinopathy, a disease attributed to increased choroidal vascular hyperpermeability. Methods: Patients with central serous chorioretinopathy underwent enhanced depth imaging spectral-domain optical coherence tomography, which was obtained by positioning a spectral-domain optical coherence tomography device close enough to the eye to acquire an inverted image. Seven sections, each comprising 100 averaged scans, were obtained within a 5° × 30° rectangle to encompass the macula. The subfoveal choroidal thickness was measured from the outer border of the retinal pigment epithelium to the inner scleral border. Results: The mean age of subjects undergoing enhanced depth imaging spectral-domain optical coherence tomography was 59.3 years (standard deviation, 15.8 years). Seventeen of 19 patients (89.5%) were men, and 12 (63.2%) patients had bilateral clinical disease. The choroidal thickness measured in 28 eligible eyes of the 19 patients was 505 &mgr;m (standard deviation, 124 &mgr;m), which was significantly greater than the choroidal thickness in normal eyes (P ≤ 0.001). Conclusion: Enhanced depth imaging spectral-domain optical coherence tomography demonstrated a very thick choroid in patients with central serous chorioretinopathy. This finding provides additional evidence that central serous chorioretinopathy may be caused by increased hydrostatic pressure in the choroid.

Enhanced depth imaging optical coherence tomography of the choroid in highly myopic eyes.

PURPOSE To measure macular choroidal thickness (CT) in highly myopic eyes using enhanced depth imaging optical coherence tomography (OCT). DESIGN Retrospective, observational case series. METHODS Enhanced depth imaging OCT images were obtained in highly myopic eyes (> or =6 diopters [D]). Images of CT were obtained by positioning a spectral-domain OCT device close enough to the eye to acquire an inverted image. CT was measured from the outer border of the retinal pigment epithelium to the inner scleral border at 1000-mum intervals of a horizontal section from 3 mm temporal to the fovea to 3 mm nasal to the fovea. Statistical analysis was performed to evaluate CT at each location and to correlate CT with age and refractive error. RESULTS The mean age of the 31 patients (55 eyes) was 59.7 years (+/- 17.6 years; range, 24 to 90 years), and the mean refractive error was -11.9 D (+/- 3.7 D). The mean subfoveal CT was 93.2 microm (+/- 62.5 microm) and was correlated negatively with age (P = .006), refractive error (P < .001), and history of choroidal neovascularization (P = .013). Regression analysis suggested that subfoveal CT decreased by 12.7 mum for each decade of life and by 8.7 microm for each D of myopia. CONCLUSIONS The choroid in highly myopic eyes is very thin and undergoes further thinning with increasing age and degree of myopia. Abnormalities of the choroid may play a role in the pathogenesis of myopic degeneration.

Retinal Vascular Layers Imaged by Fluorescein Angiography and Optical Coherence Tomography Angiography

IMPORTANCE The retinal vasculature is involved in many ocular diseases that cause visual loss. Although fluorescein angiography is the criterion standard for evaluating the retina vasculature, it has risks of adverse effects and known defects in imaging all the layers of the retinal vasculature. Optical coherence tomography (OCT) angiography can image vessels based on flow characteristics and may provide improved information. OBJECTIVE To investigate the ability of OCT angiography to image the vascular layers within the retina compared with conventional fluorescein angiography. DESIGN, SETTING, AND PARTICIPANTS In this study, performed from March 14, 2014, through June 24, 2014, a total of 5 consecutive, overlapping B-scan OCT angiography images composed of 216 A-scans were obtained at 216 discrete positions within a region of interest, typically a 2 × 2-mm area of the retina. The flow imaging was based on split-spectrum amplitude decorrelation angiography (SSADA), which can dissect layers of vessels in the retina. These distinct layers were compared with the fluorescein angiograms in 12 healthy eyes from patients at a private practice retina clinic to evaluate the ability to visualize the radial peripapillary capillary network. The proportion of the inner vs outer retinal vascular layers was estimated by 3 masked readers and compared with conventional fluorescein angiograms of the same eyes. MAIN OUTCOMES AND MEASURES Outcome measures were visualization of the radial peripapillary capillary network in the fluorescein and SSADA scans and the proportion of the inner retinal vascular plexus vs the outer retinal capillary plexus as seen in SSADA scans that would match the fluorescein angiogram. RESULTS In none of the 12 eyes could the radial peripapillary capillary network be visualized completely around the nerve head by fluorescein angiography, whereas the network was readily visualized in the SSADA scans. The fluorescein angiograms were matched, with a mean proportion of the inner vascular plexus being 95.3% (95% CI, 92.2%-97.8%) vs 4.7% (95% CI, 2.6%-5.7%) for the outer capillary plexus from the SSADA scans. CONCLUSIONS AND RELEVANCE Fluorescein angiography does not image the radial peripapillary or the deep capillary networks well. However, OCT angiography can image all layers of the retinal vasculature without dye injection. Therefore, OCT angiography, and the findings generated, have the potential to affect clinical evaluation of the retina in healthy patients and patients with disease.

Intravitreal bevacizumab (Avastin) treatment of macular edema in central retinal vein occlusion: a short-term study.

Purpose: To report the short term anatomic and visual acuity response after intravitreal injection of bevacizumab (Avastin, Genentech) in patients with macular edema due to central retinal vein occlusion (CRVO). Methods: The authors conducted a retrospective study of patients with macular edema due to CRVO who were treated with at least one intravitreal injection of bevacizumab 1.25 mg in 0.05 mL. Patients underwent Snellen visual acuity testing, optical coherence tomography (OCT) imaging, and ophthalmoscopic examination at baseline and follow-up visits. Results: There were 16 eyes of 15 consecutive patients with a mean age of 76.1 years (SD 9.8 years). Intravitreal triamcinolone had been previously administered to 9 patients, but all of these patients either had no improvement or had excessive intraocular pressure caused by the triamcinolone. The patients received a mean of 2.8 injections of bevacizumab per eye. No adverse events were observed, including endophthalmitis, clinically evident inflammation, increased intraocular pressure, retinal tears, retinal detachment, or thromboembolic events in any patient. The mean central macular thickness at baseline was 887 &mgr;m and decreased to a mean of 372 &mgr;m at month 1 (P < 0.001). The mean baseline acuity was 20/600 (logMAR = 1.48) and the mean acuity at month 1 was 20/200 (logMAR = 1.05), a difference that was highly significant (P = 0.001). At last follow-up, a mean of 3 months after the first injection, the mean visual acuity was 20/138 (logMAR = 0.84), which was significantly better than baseline (P < 0.001). Visual acuity improvement, defined as a halving of the visual angle, was seen in 14 of the 16 eyes. Conclusion: Initial treatment results of patients with macular edema secondary to CRVO did not reveal any short-term safety concerns. Intravitreal bevacizumab resulted in a significant decrease in macular edema and improvement in visual acuity. The number of patients in this pilot study was limited and the follow-up is too short to make any specific treatment recommendations, but the favorable short-term results suggest further study is needed.

Indocyanine green videoangiography of idiopathic polypoidal choroidal vasculopathy

Purpose: To identify the precise choroidal abnormalities associated with idiopathic polypoidal choroidal vasculopathy (IPCV), patients with IPCV were examined with indocyanine green (ICG) videoangiography. Methods: Twelve patients with IPCV were examined using standard clinical, fluorescein, and ICG videoangiographic techniques. Results: Indocyanine green videoangiography showed two basic choroidal vascular changes: a branching network of vessels in the inner choroid, and vascular dilations at the border of the network of vessels. The vascular dilations appeared to be associated with the exudative and hemorrhagic manifestations of IPCV. Conclusion: The choroidal vasculopathy seen in IPCV is distinct from the changes seen in other choroidal abnormalities. Recognition of these changes aids in diagnosis and patient management, since the clinical implications of IPCV differ from those of other similar entities.

Intravitreal bevacizumab (Avastin) treatment of proliferative diabetic retinopathy complicated by vitreous hemorrhage.

Purpose: To report the short-term anatomic and visual acuity response after intravitreal injection of bevacizumab (Avastin, Genentech) in patients with proliferative diabetic retinopathy complicated by vitreous hemorrhage. Methods: Two patients with vitreous hemorrhage due to proliferative diabetic retinopathy were treated with at least one intravitreal injection of bevacizumab 1.25 mg in 0.05 mL. The patients underwent Snellen visual acuity testing, ophthalmoscopic examination, and fluorescein angiography at baseline and follow-up visits. Results: Both patients had proliferative diabetic retinopathy with vitreous hemorrhage extensive enough to preclude panretinal photocoagulation. Following intravitreal injection of bevacizumab both patients experienced improvement in visual acuity starting within the first week. At 1 month of follow-up one patient had 2 lines of improvement in visual acuity and the other 5 lines. Each patient had regression of retinal neovascularization at 1 month of follow-up. Repeat injection was given to one patient at the 1-month follow-up because of slight leakage from neovascularization on the nerve, and to the other patient at 3 months because the retinal neovascularization showed early signs of reperfusion. The vitreous hemorrhage in each patient showed partial resolution at 1 week and nearly complete regression at 1 month. No adverse events were observed in either patient. Conclusions: Initial treatment results of patients with vitreous hemorrhage and proliferative diabetic retinopathy did not reveal any short-term safety concerns. Intravitreal bevacizumab resulted in marked regression of neovascularization and rapid resolution of vitreous hemorrhage. The favorable short-term results suggest further study is needed in a larger group of patients.