Idiopathic Macular Holes Atypical Macular Holes Vitreomacular Traction Syndrome
Lesions that ophthalmoscopically resemble various stages of macular hole development include lamellar holes, macular cysts, foveal detachments of the neurosensory retina or pigment epithelium, and epiretinal membranes with macular pseudoholes [1,2], OCT can effectively distinguish these pathologies in cross-section . Full-thickness macular holes show a clear loss of retinal tissue in the fovea extending to the pigment epithelium on OCT. In contrast, lamellar holes and pseudoholes only develop a partial loss of retinal tissue and a steepened foveal contour. Macular cysts and retinal detachments show a localized intraretinal or subretinal accumulation of optically clear serous fluid.
OCT is effective in staging idiopathic macular holes according to the criteria developed by Gass [3,4]/ which may be important in evaluating surgical intervention. Stage 1 impending macular holes may be distinguished by a reduced or absent foveal pit and the presence of an optically clear space beneath the fovea suggesting a foveolar detachment. Evidence of traction by the posterior hyaloid on the fovea may be present- Stage 2 holes have an attached operculum corresponding to a partial break in the outer retinal tissue. A full-thickness retinal dehiscence with a complete break in the outer retinal tissue and variable amounts of surrounding macular edema is observed in a Stage 3 hole. An operculum may be present and is completely separated from the edges of the hole. Stage 4 holes are characterized by their complete loss of tissue and a detachment of the posterior hyaloid involving the fovea and optic disc.
Vitreomacular traction has been implicated in the pathogenesis of hole formation [4-9]. OCT can assess the status of the vitreoretinal interface which is useful in evaluating the risk of hole formation, especially in the fellow eyes of patients with a unilateral macular hole [3L Several studies have shown the protective value of vitreous detachment in preventing hole formation [8,9]. OCT tomograms identify a detached vitreous by the presence of a faint membrane anterior to the retina corresponding to the posterior hyaloid. Fellow eyes with a high risk of progression to a full-thickness hole display a perifoveal vitreous detachment with foveal adhesion and loss of the normal foveal pit contour. This perifoveal vitreous detachment characteristically heralds the onset of a Stage 1 hole and emphasizes the role of vitreous traction in hole formation.
Quantitative information maybe directly extracted from the OCT tomograms, including the diameter of the hole, and the extent of surrounding subretinal fluid accumulation. The high resolution obtained in the tomograms suggests that OCT may be a useful method of precisely monitoring hole progression, or recovery after surgery. OCT images of successful surgical repair of macular holes demonstrate complete hole closure with a normal appearing fovea, providing an in vivo alternative to histopathology [10-11].
Atypical macular holes do not exhibit the typical inverse anvil shape of a classic Stage 3 hole with surrounding retinal edema. Many occur in the setting of age-related macular degeneration, displaying irregular edges, retinal thinning and atrophy, and increased reflectivity from the choroid due to pigmentary atrophy or chorioretinal scarring.
Case 3-1* Stage 2 Macular Hole and Successful Surgery
A 54-year-old woman was examined after she noted worsening vision in her right eye over several months, Her visual acuity in this eye was 20/70. Dilated ophthalmoscopy (A) revealed a full-thickness macular hole with a surrounding cuff of subretinal fluid. Fluorescein angiography (B) demonstrated a faint, focal area of hyper-fluorescence in the fovea consistent with a window defect and a partial break in the retinal tissue
OCT examination (C) was performed and showed a full-thickness loss of tissue in the fovea with a diameter of approximately 350 jam. A small operculum was attached to the edge of the hole consistent with a partial break in the outer retina and a Stage 2 classification. A region of slightly reduced optical reflectivity and increased retinal thickness was evident in the region surrounding the hole correlating with the clinical finding of fluid accumulation. The retinal thickness reached a maximum of 370 um in this area compared with a measurement of approximately 200 ¡urn at the temporal margin of the image.
Case 3-1 continued
One week later the patient underwent pars plana vit- ^^^^^^^^B^^^Hfl rectomy, injection of autologous serum, and post-opera- ff^^^^H^^^H
tive intraocular gas tamponade with SF6, Six weeks after the operation her vision had improved to 20/20 and fundus examination (D) showed reapproximation of the edges the
Optical Coherence Tomography
A post-operative OCT image (E) also demonstrated D
hole closure with an apparently intact photoreceptor layer.
Was this article helpful?