N. Nigam

The Role of Abnormal Vitreomacular Adhesion in Age-related Macular Degeneration: Spectral Optical Coherence Tomography and Surgical Results

PURPOSE To assess the incidence of vitreomacular adhesion and traction in age-related macular degeneration (AMD), and to evaluate surgical treatment in a subset of patients with choroidal neovascularization (CNV) nonresponsive to anti-neovascular growth factor (anti-VEGF) treatment. DESIGN Retrospective observational case-control and interventional case series. METHODS Spectral optical coherence tomography, combined with simultaneous scanning laser ophthalmoscope (Spectral OCT/SLO), was performed in 170 eyes of 94 elderly patients, 61 with exudative AMD, 59 with nonexudative AMD, and 50 control eyes. The presence of hyaloid adhesion to the posterior pole, and vitreomacular traction (VMT) were determined. Five patients with VMT underwent surgical hyaloid removal. Best-corrected visual acuity (BCVA) and retinal thickness were evaluated as outcomes. RESULTS Hyaloid adhesion was present in 17 eyes with exudative AMD (27.8%), 15 eyes with nonexudative AMD (25.4%), and eight control eyes (16%). Significant difference was found among the groups (P = .002). Among the eyes with hyaloid adhesion, VMT was shown in 10 eyes (59%) with exudative AMD, two eyes (13%) with nonexudative AMD, and one control eye (12%). VMT was associated with the severity of AMD (P = .0082). The area of hyaloid adhesion was significantly smaller than and concentric to the area of CNV complex in eyes with exudative AMD. Eyes with VMT that underwent surgery experienced a modest improvement of BCVA and decrease of retinal thickness. CONCLUSIONS Hyaloid adhesion to the macula is associated with AMD, and frequently causes VMT in eyes with CNV. Tractional forces may antagonize the effect of anti-VEGF treatment, and cause pharmacological resistance in a subpopulation of patients. Future studies are needed to define the role of vitreoretinal surgery in such cases. Spectral OCT/SLO allows careful diagnosis and follow-up.

Correlation between Spectral-Domain Optical Coherence Tomography and Fundus Autofluorescence at the Margins of Geographic Atrophy

PURPOSE To study the appearance of margins of geographic atrophy in high-resolution optical coherence tomography (OCT) images and to correlate those changes with fundus autofluorescence (FAF) imaging. DESIGN Retrospective, observational case study. METHODS Patients with geographic atrophy secondary to dry age-related macular degeneration were assessed by means of spectral-domain OCT (Spectralis Heidelberg Retinal Angiograph/OCT; Heidelberg Engineering, Heidelberg, Germany; or OTI Inc, Toronto, Canada) as well as autofluorescence imaging (Heidelberg Retinal Angiograph or Spectralis; Heidelberg Engineering). The outer retinal layer alterations were analyzed in the junctional zone between normal retina and atrophic retina and were correlated with corresponding FAF. RESULTS Twenty-three eyes of 16 patients between 62 and 96 years of age were examined. There was a significant association between OCT findings and the FAF findings (r = 0.67; P < .0001). Severe alterations of the outer retinal layers at margins on spectral-domain OCT correspond significantly to increased autofluorescence; smooth margins on OCT correspond significantly to normal FAF (kappa, 0.7348; P < .0001). CONCLUSIONS Spectral-domain OCT provides in vivo insight into the pathogenesis of geographic atrophy and its progression. Visualization of reactive changes in the retinal pigment epithelial cells at the junctional zone and correlation with increased FAF; secondary to increased lipofuscin, together these methods may serve as determinants of progression of geographic atrophy.

Optical coherence tomography-raster scanning and manual segmentation in determining drusen volume in age-related macular degeneration.

Purpose: Drusen are the hallmark of age-related macular degeneration (AMD), and substantial evidence exists that the amount of drusen and their effect on retinal pigment epithelium is a strong predictor of progression of AMD and vision loss. Until recently, it was not possible to quantitate the volume of the drusen. However, the use of image-stabilized scanning laser ophthalmoscope or spectral domain-optical coherence tomography (OCT) has enabled determination of drusen volume of this abnormal material. The purpose of this study was to assess the correlation of drusen volume with Age-Related Eye Disease Study (AREDS) grade and drusen area in dry AMD. Methods: Thirty-six eyes from 18 patients with nonexudative AMD with visual acuity between 20/16 and 20/160 were studied. Spectral domain-OCT or simultaneous OCT scans were taken as color fundus photographs (35°) of each eye. Early Treatment Diabetic Retinopathy Study visions were also recorded. The full AREDS score excluding late-stage AMD was determined by agreement between two trained observers. Drusen volume was determined by examination of a series of 96 spectral domain-OCT scans taken from arcade to arcade for a length of 6 mm. The volume was determined by calculating the drusen area in each scan and determining the drusen volume by calculating the effective volume of each cut using National Institutes of Health Image J. Drusen were identified and outlined manually, not using an automated algorithm. Results: There was a strong and significant correlation between drusen volume and AREDS-determined drusen area (P < 0.0001, r = 0.78). In addition, there was a correlation between AREDS classification and drusen volume (P = 0.023, r = 0.43) as determined by pairwise correlation. Conclusion: Drusen volume as determined by spectral domain-OCT correlates with AREDS-determined drusen area and AREDS grade in nonexudative AMD. The correlation is not perfect, however, because drusen area and volume average 40% and 82% of the variation, respectively. Drusen volume can provide additional information in grading the severity of eyes with dry AMD.

Spectral domain optical coherence tomography for imaging ERM, retinal edema, and vitreomacular interface.

Purpose: To evaluate images taken with OTI-OPKO Spectral domain optical coherence tomography (OCT; OTI-OPKO Health Inc, Miami, FL)/scanning laser ophthalmoscope (resolution of 5–8 &mgr;m) and compare them with conventional StratusOCT (Carl Zeiss Meditec Inc, Dublin, CA) in eyes with epiretinal membranes (ERMs), macular edema, and vitreoretinal interface abnormalities. Methods: We evaluated 79 consecutive eyes with retinal pathologies using Spectral OCT/scanning laser ophthalmoscope and StratusOCT at the Jacobs Retina Center, University of California San Diego, CA. Pathologies included ERM, macular edema, and vitreomacular traction. Two masked reviewers graded the pathologic findings on the basis of visibility (scale 0–III). A quantitative continuous scale grading system was also used. Results: Statistical analysis showed significant differences in ERM visibility between the spectral OCT/scanning laser ophthalmoscope and StratusOCT (P < 0.0001; signed-rank test). Furthermore, posterior hyaloid visibility was significantly different (P < 0.0001) as was the macular edema grading (P < 0.0001). The Gaussian noise grading system was performed for a smaller subset of 40 eyes and it gave the same results. Spectral OCT was particularly useful in the diagnosis of subtle ERM, minimal diffuse macular edema, and morphology of macular cystic spaces, posterior vitreous detachment, and attachments of the posterior hyaloid. Conclusion: The Spectral OTI-OPKO instrument allows significantly better visualization of vitreoretinal surface diseases like ERM, posterior hyaloid, and retinal edema than StratusOCT. High-speed Spectral OCT/scanning laser ophthalmoscope allows rapid image acquisition, higher number of cuts, and better sampling yielding superior imaging of retinal pathology.

Prognosti implications of pigment epithelial detachment in bevacizumab (avastin)-treated eyes with age-related macular degeneration and choroidal neovascularization.

Purpose: To evaluate the response to primary bevacizumab treatment of eyes with age-related macular degeneration (AMD) and choroidal neovascularization (CNV) with a large pigment epithelial detachment (PED) component and to compare the increase in visual acuity and reabsorption of retinal fluid in PED eyes with eyes with CNV in AMD with a minimal to no PED component. Methods: We reviewed 43 consecutive eyes with CNV and AMD on primary bevacizumab therapy. There were 13 eyes with a large PED component in AMD with CNV and 30 eyes with a minimal to no PED in CNV. Only patients with no previous treatment for AMD and those started on purely intravitreal bevacizumab treatment were taken in the study. Pigment epithelial detachment size, time to PED collapse, and retinal or subretinal fluid resolution were determined as was Early Treatment Diabetic Retinopathy Study vision. Time to resolution of intraretinal and subretinal fluid was compared between the PED group and the non-PED group using survival analysis. Results: In AMD with CNV eyes having a large PED component, sub- and intraretinal fluid initially resolved faster than the sub-PED fluid (P = 0.03). The subretinal pigment epithelial fluid itself was highly resistant. Visual acuity improvement was similar in both groups. Conclusion: Despite monthly intravitreal bevacizumab injections for neovascular AMD patients with a large component PED, the majority had minimal to no response of the PED. Sub- and intraretinal fluid response was faster in neovascular AMD without large PEDs, but after 7 months, vision change and reabsorption of intra- and subretinal fluid were similar in the two groups. Sub- and intraretinal fluid response did not appear to be related to PED size. Bevacizumab was very effective in reducing more of the sub- and intraretinal fluid than the PED fluid in AMD with CNV.

The use of intraoperative indocyanine green dye to assist in epiretinal membrane removal: a novel application of indocyanine green surgical use.

PURPOSE To review cases of endoscopic orbital apex surgery using posterior nasal septectomy and describe the technique and benefits. METHODS A retrospective chart review of all cases of endoscopic orbital apex surgery with the use of intraoperative posterior nasal septectomy over a 3-year period. Three cases are described, and the technique and limitations and advantages of this approach are detailed. RESULTS Endoscopic orbital apex surgery cases over a 3-year period were reviewed. Three of these cases involved the use of posterior nasal septectomy. All 3 cases involved large lesions at the orbital apex and periorbital skull base. Two of the lesions also involved the cavernous sinus and one extended in the optic canal. The alternative for all patients would have involved a transcranial approach. During the mean follow-up of 9 months, no complications were noted. CONCLUSION The use of posterior nasal septectomy in endoscopic surgery has been used for access of the skull base. This is the first description of this technique for access of orbital apical lesions. This technique improves visualization and surgical access to the orbital apex and periorbital skull base, sparing the patient larger craniofacial surgeries. No complications were noted in this preliminary patient cohort.PURPOSE To review cases of endoscopic orbital apex surgery using posterior nasal septectomy and describe the technique and benefits. METHODS A retrospective chart review of all cases of endoscopic orbital apex surgery with the use of intraoperative posterior nasal septectomy over a 3-year period. Three cases are described, and the technique and limitations and advantages of this approach are detailed. RESULTS Endoscopic orbital apex surgery cases over a 3-year period were reviewed. Three of these cases involved the use of posterior nasal septectomy. All 3 cases involved large lesions at the orbital apex and periorbital skull base. Two of the lesions also involved the cavernous sinus and one extended in the optic canal. The alternative for all patients would have involved a transcranial approach. During the mean follow-up of 9 months, no complications were noted. CONCLUSION The use of posterior nasal septectomy in endoscopic surgery has been used for access of the skull base. This is the first description of this technique for access of orbital apical lesions. This technique improves visualization and surgical access to the orbital apex and periorbital skull base, sparing the patient larger craniofacial surgeries. No complications were noted in this preliminary patient cohort.

Colour versus grey-scale display of images on high-resolution spectral OCT

Aim: To determine whether colour or grey-scale images from high-resolution spectral optical coherence tomography (OCT) are superior in visualising clinically important details of retinal structures. Methods: Patients with macular pathologies were imaged using spectral OCT (OTI, Toronto, Canada). Two reviewers independently analysed the retinal structures and pathologies and graded them on a four-point scale on the basis of the visibility. A third reviewer masked to the results then reviewed images where there was a different score for colour versus grey scale. Results: Statistical analysis showed the grey-scale image to be significantly better in visualising the details of epiretinal membrane, photoreceptor and retinal pigment epithelium layer morphology than the colour scale image (p = 0.00088–0.0006). In 16.17% of eyes, the colour image led to the false impression of photoreceptor disruption. Conclusion: Grey-scale images are qualitatively superior to the colour-scale images on high-resolution spectral OCT. Colour images can be misleading, as the displayed colours are false colours, and the observer may see a dramatic change in colour and interpret that as a large change in the OCT reflectivity.

Interferon induced sarcoid uveitis with papillitis and macular edema.

PURPOSE To describe the ocular manifestations of interferon induced sarcoidosis. METHODS Observational case report. RESULTS A 42-year-old woman with hepatitis C developed papillitis and macular edema together with cutaneous lesions 3 months after starting interferon and ribavirin therapy. The therapy was stopped. After 17 months of observation, visual acuity remained stable and papillitis and macular edema persisted. The patient was finally treated with sub-tenons repository methyl prednisolone in the left eye which significantly resolved both macular edema and papillitis and also improved vision. CONCLUSION Interferon induced sarcoidosis is a new entity and can have ocular manifestations such as uveitis and papillitis as one of the presenting features, which is not common.