1/5. diplopia secondary to aniseikonia associated with macular disease.OBJECTIVE: To provide an explanation for diplopia and the inability to fuse in some patients with macular disease. methods: We identified 7 patients from our practices who had binocular diplopia concurrent with epiretinal membranes or vitreomacular traction. A review of the medical records of all patients was performed. In addition to complete ophthalmologic and orthoptic examinations, evaluation of aniseikonia using the Awaya New aniseikonia Tests (Handaya Co Ltd, tokyo, japan) was performed on all patients. RESULTS: All patients were referred for troublesome diplopia. Six of the patients had epiretinal membranes and 1 had vitreomacular traction. All 7 patients had aniseikonia, ranging from 5% to 18%. In 5 of the patients the image in the involved eye was larger, and in the other 2 patients it was smaller than in the fellow eye. All patients had concomitant small-angle strabismus and at least initially did not fuse when the deviation was offset with a prism. Response to optical management and retinal surgery was variable. CONCLUSIONS: aniseikonia caused by separation or compression of photoreceptors can be a contributing factor to the existence of diplopia and the inability to fuse in patients with macular disease. Concomitant small-angle strabismus and the inability to fuse with prisms may lead the clinician to the incorrect diagnosis of central disruption of fusion. Surgical intervention does not necessarily improve the aniseikonia.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
2/5. Field-dependent aniseikonia associated with an epiretinal membrane a case study.PURPOSE: aniseikonia is a binocular anomaly in which the two eyes perceive images of different sizes and/or shapes. It is usually assumed to be constant as a function of visual field angle (VFA) (i.e., angular distance from the line of sight). This is correct for optically induced aniseikonia, such as the aniseikonia that is associated with anisometropia and probably also pseudophakia. The purpose of this article is to show that if the aniseikonia is of retinal origin, then the aniseikonia may no longer be constant as a function of VFA (i.e., field-dependent aniseikonia). DESIGN: Case report, with the patient having a unilateral epiretinal membrane. methods: The aniseikonia was measured in vertical and horizontal directions with a customized version of the aniseikonia Inspector software. The VFA was made variable by changing the dimensions of the comparison targets in the direct comparison procedure. MAIN OUTCOME MEASURE: aniseikonia as a function of VFA. RESULTS: The patient exhibited good repeatable aniseikonia, ranging from 23% to 2.5% for VFAs ranging from 0.36 degrees to 5.7 degrees . Higher angles had lower aniseikonia. A control subject did not show this field-dependent aniseikonia. CONCLUSIONS: aniseikonia may vary with VFA due to a retinal cause such as an epiretinal membrane. The problem with field-dependent aniseikonia is that it cannot be corrected fully with conventional optics, which exhibit an approximately constant magnification as a function of VFA. Nevertheless, by correcting 5% to 10% aniseikonia, which showed up in the VFA measurement range at 2 degrees to 3 degrees , our patient had improved visual comfort, especially for reading.- - - - - - - - - - ranking = 3keywords = membrane (Clic here for more details about this article) |
3/5. The ultrastructure of well-healed lenticules in keratomileusis.Two well-healed hyperopic keratomileusis homoplastica lenticules, one 4 years old, the other 5 months old, were removed from the same patient following postoperative complications of triplopia and aniseikonia. The lenticules were examined by light and electron microscopy. Both lenticules were repopulated with keratocytes throughout the lamellae. Degenerated keratocytes were observed in the 5-month-old lenticule and recipient stroma, and in the 4-year-old lenticule; no degenerated keratocytes were seen in the recipient stroma of the 4-year-old lenticule. These findings may have resulted from toxic constituents of the solutions used to preserve the donor cornea. The basement membrane was thickened in both lenticules. The epithelial cell layer was irregular in the periphery of the lenticule where Bowman's membrane was disrupted. These findings suggest that careful surgical technique that minimizes damage to Bowman's layer and basement membrane may promote more rapid epithelial healing. The histologic results suggest that the cause of this patient's triplopia was irregular astigmatism.- - - - - - - - - - ranking = 1.5keywords = membrane (Clic here for more details about this article) |
4/5. aniseikonia, metamorphopsia and perceived entoptic pattern: some effects of a macular epiretinal membrane, and the subsequent spontaneous separation of the membrane.Following cryo surgery for retinal hole repair, visual effects in the senior author's eyes were caused by an epiretinal membrane. Subjectively, metamorphopsia was noted, and entoptically perceived radial striae were observed centred near fixation. After subsequent cataract surgery, metamorphopsia was not detectable. Several months later, the centre of the striate entoptic pattern was observed to be centered several degrees from fixation. Concurrently, loss of contrast in the central visual field was noted. In time, both the entoptic pattern and the contrast effects became less visible (contrast improved much faster). The epiretinal membrane had spontaneously separated from the fovea. Repeated measurements of aniseikonia were obtained before cataract surgery, and after cataract surgery both prior to, and after the separation of the epiretinal membrane. Inferences are drawn.- - - - - - - - - - ranking = 5.5keywords = membrane (Clic here for more details about this article) |
5/5. Visual function after foveal translocation with scleral shortening in patients with myopic neovascular maculopathy.PURPOSE: To document the visual outcome after successful foveal translocation with intentional retinal detachment and scleral shortening for the treatment of myopic neovascular maculopathy. methods: Two severely myopic patients with subfoveal neovascular membranes underwent surgical translocation of the fovea to an area of healthy retinal pigment epithelium by means of scleral shortening and intentional retinal detachment. In the postoperative period, monocular and binocular visual function were studied. RESULTS: In one patient, best-corrected visual acuity improved from 20/150 to 20/20 postoperatively. In the second patient, acuity initially improved from 20/70 to 20/30. In both patients, the fixation point shifted from the site of the neovascular membrane. Oblique astigmatism developed and was managed with hard contact lenses. diplopia and subjective torsion occurred transiently. Micropsia occurred in one patient. Peripheral fusion assessed by Worth four-dot testing after resolution of diplopia disclosed suppression in the nondominant eye in both cases. CONCLUSIONS: Foveal translocation with intentional retinal detachment and scleral shortening was useful in improving visual acuity in two patients with myopic neovascular maculopathy. diplopia and aniseikonia occurred but resolved over time as suppression developed. This technique is promising for patients with myopic neovascular maculopathy.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |