Perception of tilt following counter‐rotation surgery

Background: Macular translocation surgery (MTS) is one of the treatment options for age-related macular degeneration (AMD) followed by counter-rotation surgery (CRS) to correct the resulting tilt. The objective of this paper is to determine the perception of tilt following CRS and identify factors that influence the perception of tilt in the presence of residual cyclorotation following CRS. Methods: Thirty-four AMD patients treated with MTS and CRS were investigated; and all measurements were made preoperatively, and after each surgical procedure. Fundus photographs were analysed with computer software to determine the degree of retinal rotation and reliability was assessed by two independent assessors. The degree of perceptual rotation was measured with Maddox rod and the subjective appreciation of tilt was established by direct questioning. Fixation preference was determined by cover test and convergence. Bagolini glasses were used to determine binocular outcome. Results: Post CRS, 20 of the 34 patients had adapted to tilt. There was a significant difference of 5° ± 7° (95% confidence intervals: 1-8°, t = 2.9, degree of freedom = 19, P = 0.008) between the degree of rotation measured from the fundus photographs and the Maddox rod measurement following CRS. Patients with residual retinal rotation less than or equal to 15° did not appreciate tilt in free space. More importantly, fixation with the operated eye and ignoring the image from the non-operated eye was significantly associated with being free of tilt in natural viewing conditions (P < 0.05). Conclusion: Despite the presence of residual cyclorotation of the macula following CRS of up to 27°, a significant proportion (59%) of patients did not perceive the world as tilted in natural viewing conditions. Differences between retinal rotation and perceptual tilt provide evidence of sensory adaptation. It was patients who fixed with their operated eye and ignored the image from the non-operated eye who did not perceive tilt post CRS

Intravitreal bevacizumab for retinal vein occlusion and early growth of epiretinal membrane: a possible secondary effect?

Aims To report the early development of epiretinal membranes (ERM) in eyes with retinal vein occlusions (RVO) treated with intravitreal bevacizumab and to describe possible mechanisms that may be involved in the growth and contraction of these lesions. Methods Retrospective and interventional study that included 25 eyes of 25 patients with RVO (16 eyes with central retinal vein occlusion and nine eyes with branch retinal vein occlusion). After an initial 2.5 mg/0.1 ml intravitreal bevacizumab injection all patients were followed-up every 6 weeks. Re-treatments were based on visual acuity and optical coherence tomography findings. Results Twenty-five eyes were treated with bevacizumab and followed for 8.3 (range 4.5-13.5) months. Four eyes developed an ERM within 6-7 weeks after the administration of bevacizumab. ERM was not associated with further deterioration of visual acuity or metamorphopsia in these patients. A rebound of macular oedema was observed in one patient with ERM and in two other patients. No other side effects were observed. Conclusions Intravitreal bevacizumab may be associated with an early growth of ERM in eyes with RVO, although a causative relationship cannot be established. Future randomised clinical trials are necessary to determine the efficacy and safety profile of this novel therapy

Does the Presence of an Epiretinal Membrane Alter the Cleavage Plane during Internal Limiting Membrane Peeling?

Purpose: To determine whether the presence of a clinically and/or microscopically detectable epiretinal membrane (ERM) alters the cleavage plane during internal limiting membrane (ILM) peeling. Design: Retrospective, observational, immunohistochemical study of ILM specimens using archival formalin-fixed, paraffin-embedded tissue. Participants: Fifty-one patients who had had ILM excision. Methods: Fifty-one ILM specimens peeled during vitrectomy for various etiologies were examined by light microscopy. The removal of ILM was assisted using Trypan blue (n = 30), indocyanine green (n = 7), or brilliant blue G (n = 14). Monoclonal antibodies to glial fibrillary acidic protein and to neurofilament protein were used to detect glial or neuronal cells respectively on the vitreous or retinal surfaces of the ILM. Specimens were divided into 2 groups: ILM peeled for full-thickness macular hole (MH; n = 31) and ILM peeled after removal of clinically detectable ERM (n = 20). Main Outcome Measures: Primary outcome measure was the localization of immunohistochemical markers to neuronal or glial cells on the vitreous or retinal surfaces of ILM. The secondary outcome measure was the correlation of the results of the primary measure with the dyes used to facilitate ILM peeling. Results: Glial and/or neuronal cells were detected on the retinal surface of the ILM in 10 of 31 (32%) of the MH ILM specimens and in 13 of 20 (65%) of the ILM peeled after ERM excision; the difference was significant (P = 0.02). There was no association between the presence of neuronal and glial cells with the type of dye used (P = 0.2). Of the 23 ILM specimens with cells attached to the retinal surface, 21 (91%) were associated with clinical and/or histologic evidence of ERM and 2 (9%) were not. The correlation between the presence of cells on the vitreous and the retinal surfaces of ILM was high (P < 0.0001). Conclusions: The findings suggest that ERM may be associated with sub-ILM changes that alter the plane of separation during ILM peeling. This study does not confirm any influence of dyes on the cleavage plane during surgery. Financial Disclosure(s): The authors have no proprietary or commercial interest in any of the materials discussed in this article. Ophthalmology 2010; 117: 320-323 (C) 2010 by the American Academy of Ophthalmology