Three-dimensional spectral domain optical coherence tomography and light microscopy of an intravitreal parasite.

BACKGROUND: Various imaging modalities play a role in diagnosing parasitic infections of the eye. We describe the spectral domain optical coherence tomography (SD-OCT) findings of an intravitreal parasite with subsequent evaluation by light microscopy. FINDINGS: This is a case report of a 37-year-old Ecuadorian man who presented with uveitic glaucoma and a new floater in his left eye for 1 week's duration. Full ophthalmic examination revealed an intravitreal parasite. Color fundus photography, fluorescein angiography (FA), ocular ultrasonography (US), and SD-OCT were performed. The parasite was removed via 23-gauge pars plana vitrectomy and sent to pathology for evaluation. Color fundus photography and ocular ultrasonography demonstrated an elongated foreign body within the vitreous above the retina. FA demonstrated minimal vascular changes in the vicinity of the parasite. SD-OCT was utilized to visualize the parasite and to create a three-dimensional (3D) image. The parasite was determined to be most consistent with Gnathostoma spp. by morphologic analysis. CONCLUSIONS: This is the first reported case of SD-OCT of an intravitreal parasite with corresponding evaluation by pathology. SD-OCT allows non-invasive, high-resolution visualization and 3D reconstruction of parasitic anatomy which may help establish tomographic criteria for species identification.

Incidence of cystoid macular edema with iris-fixated posterior chamber intraocular lenses in patients presenting with lens dislocation.

The aim of this study is to determine the incidence of cystoid macular edema (CME) following repositioning and McCannel iris-suturing of dislocated intraocular lenses. This study is conducted in an urban private practice. A retrospective chart review was performed on consecutive patients who presented with posteriorly dislocated IOLs and underwent iris-sutured posterior chamber (PC) intraocular lens (IOL) placement using the McCannel suture technique by a single surgeon for IOL repositioning from December 2008 to August 2012. All charts were reviewed for etiology of dislocation, time elapsed from cataract surgery, best-corrected visual acuity (BCVA), slit-lamp examination, tonometry, and dilated fundus examination. Presence of CME was determined by spectral domain optical coherence tomography (Cirrus HD OCT; Carl Zeiss Meditec, Dublin, California, USA). Of the 58 cases reviewed, lens dislocation resulted from trauma in 21 %, zonular incompetence in 17 %, recent intraocular surgery in 12 %, and unknown in 50 %. Mean best-corrected logMAR visual acuity improved from 1.07 preoperatively to 0.52 postoperatively (P < 0.001). The mean follow-up time was 7.8 months. Two cases (3.4 %) of CME occurred postoperatively at a mean follow-up time of 4.5 months. Of these two patients, one had concurrent fragmetome lensectomy at the time of initial surgery. Iris-sutured PC IOL placement in this case series resulted in an improvement in BCVA with a low incidence of CME.

Delayed macular hole formation after demarcation laser photocoagulation for subclinical retinal detachment.

The purpose of this paper is to report a series of macular holes that developed after demarcation laser photocoagulation for subclinical retinal detachments. This observational case series consists of three eyes from three patients seen between 2005 and 2012. Delayed idiopathic macular hole formation occurred following demarcation laser photocoagulation for subclinical retinal detachment. Demarcation laser photocoagulation of subclinical retinal detachments may predispose to macular hole formation.

Evaluation of vascular disease progression in retinopathy of prematurity using static and dynamic retinal images.

PURPOSE: To measure accuracy and speed for detection of vascular progression in retinopathy of prematurity (ROP) from serial images. Two strategies are compared: static side-by-side presentation and dynamic flickering of superimposed image pairs. DESIGN: Prospective comparative study. METHODS: Fifteen de-identified, wide-angle retinal image pairs were taken from infants who eventually developed plus disease. Image pairs representing vascular disease progression were taken ≥1 week apart, and control images without progression were taken on the same day. Dynamic flickering pairs were created by digital image registration. Ten experts independently reviewed each image pair on a secure website using both strategies, and were asked to identify progression or state that images were identical. Accuracy and speed were measured, using examination date and ophthalmoscopic findings as a reference standard. RESULTS: Using static images, experts were accurate in a mean (%) ± standard deviation (SD) of 11.4 of 15 (76%) ± 1.7 image pairs. Using dynamic flickering images, experts were accurate in a mean (%) ± SD of 11.3 of 15 (75%) ± 1.7 image pairs. There was no significant difference in accuracy between these strategies (P = .420). Diagnostic speed was faster using dynamic flickering (24.7 ± 8.3 seconds) vs static side-by-side images (40.3 ± 18.3 seconds) (P = .002). Experts reported higher confidence when interpreting dynamic flickering images (P = .001). CONCLUSIONS: Retinal imaging provides objective documentation of vascular appearance, with potentially improved ability to recognize ROP progression compared to standard ophthalmoscopy. Speed of identifying vascular progression was faster by review of dynamic flickering image pairs than by static side-by-side images, although there was no difference in accuracy.

Accuracy of retinopathy of prematurity image-based diagnosis by pediatric ophthalmology fellows: implications for training.

PURPOSE: To measure the accuracy of image-based retinopathy of prematurity (ROP) diagnosis by pediatric ophthalmology fellows. METHODS: This was a comparative case series of expert versus nonexpert clinicians in image-based ROP diagnosis. An atlas of 804 retinal images was captured from 248 eyes of 67 premature infants with a wide-angle camera (RetCam-II, Clarity Medical Systems, Pleasanton, CA). Images were uploaded to a study website from which an expert pediatric retinal specialist and five pediatric ophthalmology fellows independently provided a diagnosis (no ROP, mild ROP, type 2 ROP, or treatment-requiring ROP) for each eye. Two different retinal specialists experienced in ROP examination served as additional controls. Primary outcome measures were sensitivity and specificity of image-based ROP diagnosis by fellows compared to a reference standard of image-based interpretation by the expert pediatric retinal specialist. Secondary outcome measure was intraphysician reliability. RESULTS: For detection of mild or worse ROP, the mean (range) sensitivity among the five fellows was 0.850 (0.670-0.962) and specificity was 0.919 (0.832-0.964). For detection of type 2 or worse ROP by fellows, mean (range) sensitivity was 0.527 (0.356-0.709) and specificity was 0.938 (0.777-1.000). For detection of treatment-requiring ROP, mean (range) sensitivity was 0.515 (0.267-0.765) and specificity was 0.949 (0.805-1.00). CONCLUSIONS: Pediatric ophthalmology fellows in this study demonstrated high diagnostic specificity in image-based ROP diagnosis; however, sensitivity was lower, particularly for clinically significant disease.

Volumetric three-dimensional reconstruction and segmentation of spectral-domain OCT.

Despite advances in optical coherence tomography (OCT), three-dimensional (3D) renderings of OCT images remain limited to scanning consecutive two-dimensional (2D) OCT slices. The authors describe a method of reconstructing 2D OCT data for 3D retinal analysis and visualization in a Computer Assisted Virtual Environment (CAVE). Using customized signal processing software, raw data from 2D slice-based spectral-domain OCT images were rendered into high-resolution 3D images for segmentation and quantification analysis. Reconstructed OCT images were projected onto a four-walled space and viewed through stereoscopic glasses, resulting in a virtual reality perception of the retina. These 3D retinal renderings offer a novel method for segmentation and isolation of volumetric images. The ability to manipulate the images in a virtual reality environment allows visualization of complex spatial relationships that may aid our understanding of retinal pathology. More importantly, these 3D retinal renderings can be viewed, manipulated, and analyzed on traditional 2D monitors independent of the CAVE.

Trends in primary retinal detachment surgery: results of a Bicenter study.

PURPOSE: To assess trends and outcomes in retinal detachment (RD) surgery based on a retrospective, interventional, bicenter study. METHODS: Baseline demographic data, surgical procedures, and outcomes from 230 patients with a diagnosis of primary rhegmatogenous RD, who underwent surgery between January 2007 and December 2008 at the Rudolf Foundation Clinic, Vienna (Center 1) and the Weill Cornell Medical College, New York, (Center 2) were analyzed using a regression model. RESULTS: Besides the baseline parameters, lens status (P = 0.01), refraction (P = 0.01), retinal tears (P < 0.02), proliferative vitreoretinopathy (P = 0.02), and previous treatment (P < 0.02), the primary RD procedure (P < 0.0001) was significantly different between the 2 centers. In Center 1, scleral buckling was the most common primary RD procedure (66.19%) compared with vitrectomy (82.42%) in Center 2. Primary retinal reattachment (88.49% Center 1 vs. 84.62% Center 2, P = 0.43) and best-corrected visual acuity at the final follow-up (best-corrected visual acuity ≥ 0.3 logarithm of minimum angle of resolution 48.92% Center 1 vs. 47.25% Center 2, P = 0.78) were not significantly different between the 2 centers. CONCLUSION: Although there is a trend toward primary vitrectomy, scleral buckling was preferred in the center in Vienna and primary vitrectomy in the center in New York. Despite the different primary RD procedures, anatomical and visual outcomes were comparable.

Treatment of noninfectious posterior uveitis with dexamethasone intravitreal implant.

PURPOSE: To report our experience with dexamethasone 0.7 mg sustained-release intravitreal implant (Ozurdex(®); Allergan, Inc, Irvine, CA) in noninfectious posterior uveitis. METHODS: A retrospective chart review of patients with noninfectious uveitis treated with sustained-release dexamethasone 0.7 mg intravitreal implant was performed. Complete ophthalmic examination including signs of inflammatory activity, visual acuity, fundus photography, fluorescein angiography, optical coherence tomography, and tolerability of the implant were assessed. RESULTS: Six eyes of 4 consecutive patients treated with a total of 8 dexamethasone 0.7 mg sustained-release intravitreal implants for posterior noninfectious uveitis were included. Two patients presented with unilateral idiopathic posterior uveitis; 2 patients had bilateral posterior uveitis, one secondary to sarcoidosis and the other to Vogt-Koyanagi-Harada syndrome. All eyes showed clinical and angiographic evidence of decreased inflammation following implant placement. Mean follow-up time post-injection was 5.25 months. Four eyes received 1 and 2 eyes received 2 Ozurdex implants during the follow-up period. The duration of effect of the implant was 3 to 4 months. No serious ocular or systemic adverse events were noted during the follow-up period. CONCLUSIONS: In patients with noninfectious posterior uveitis, sustained-release dexamethasone 0.7 mg intravitreal implant may be an effective treatment option for controlling intraocular inflammation.

Detection of retinal changes in Parkinson's disease with spectral-domain optical coherence tomography.

PURPOSE: This pilot study investigated whether high-resolution spectral-domain optical coherence tomography (SD-OCT) could detect differences in inner retinal layer (IRL), peripapillary retinal nerve fiber layer (RNFL), and macular thickness between patients with Parkinson's disease (PD) and controls. METHODS: Both eyes of patients with PD and age-matched controls were imaged with the Heidelberg Spectralis(®) HRA + OCT. RNFL, IRL, and macular thickness were measured for each eye using Heidelberg software. These measurements were compared with validated, published normal values for macular and RNFL thickness, and compared with matched controls for IRL thickness. RESULTS: Eighteen eyes from nine subjects with PD and 19 eyes of 16 control subjects were evaluated using SD-OCT. The average age of PD patients was 64 years with a range of 52-75 years. The average age of controls was 67 years with a range of 50-81 years. No significant reduction in IRL thickness was detected between PD patients and age-matched controls at 13 points along a 6 mm horizontal section through the fovea. No significant difference in RNFL thickness was detected between PD patients and published normal values. Overall average RNFL thickness was 97 µm for PD patients, which exactly matched the normative database value. However, significant differences in macular thickness were detected in three of nine subfields between PD subjects and published normal values. In PD subjects, the outer superior subfield was 2.8% thinner (P = 0.026), while the outer nasal and inner inferior subfields were 2.8% (P = 0.016) and 2.7% (P = 0.001) thicker compared to published normal values. CONCLUSION: In this pilot study, significant differences in macular thickness were detected in three of nine subfields by SD-OCT. However, SD-OCT did not detect significant reductions in peripapillary RNFL and IRL thickness between PD patients and controls. This suggests that macular thickness measurements by SD-OCT may potentially be used as an objective, noninvasive, and easily quantifiable in vivo biomarker in PD. Larger, longitudinal studies are needed to explore these relationships further.

Long-term outcomes of intravitreal antivascular endothelial growth factor therapy for the management of choroidal neovascularization in pseudoxanthoma elasticum.

PURPOSE: The purpose of this study was to report long-term results of intravitreal antivascular endothelial growth factor therapy in the management of choroidal neovascularization in patients with angioid streaks associated with pseudoxanthoma elasticum. METHODS: A consecutive series of patients with pseudoxanthoma elasticum and choroidal neovascularization were managed with intravitreal antivascular endothelial growth factor injections (bevacizumab 1.25 mg/0.05 mL or ranibizumab 0.5 mg/0.05 mL). The main outcome measures were visual acuity and greatest lesion height as measured by optical coherence tomography. RESULTS: Nine eyes of nine consecutive patients received intravitreal antivascular endothelial growth factor therapy. During the mean follow-up period of 28.6 months, eyes received an average of 8.4 injections. At baseline, the mean visual acuity was 20/368 (median, 20/60) and improved to 20/281 (median, 20/40) at the last visit (P = 0.14). Visual acuity either improved or stabilized in all 9 eyes (100%). Serial optical coherence tomography measurements showed a mean of 353 mum at baseline and decreased to 146 mum at the last visit (P = 0.005). No complications were noted. CONCLUSION: These long-term results support the use of intravitreal antivascular endothelial growth factor therapy for the management of choroidal neovascularization in patients with pseudoxanthoma elasticum. Continued experience with intravitreal bevacizumab or ranibizumab in this population will help establish long-term efficacy and better define optimal dosing strategies.