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Microsurgery Advanced Design Laboratory (MADLAB), Doheny Retina Institute, Doheny Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
Correspondence to:
Mark S Humayun
MD, PhD, Doheny Retina Institute, Doheny Eye Institute, Department of Ophthalmology, Keck School of Medicine, University of Southern California, 1450 San Pablo Street (Room 3600), Los Angeles, CA 90033, USA; humayun@usc.edu
Keywords: retinal pick; arteriovenous adventitial sheathotomy; branch retinal vein occlusion; transvitreal arteriovenous- crossing manipulation without vitrectomy; optical coherence tomography
Although arteriovenous adventitial sheathotomy (AAS) has been proposed as an alternative treatment for patients with branch retinal vein occlusion (BRVO) complicated by macular haemorrhage, persistent macular oedema after grid laser photocoagulation, and macular ischaemia, the inner retinal incision may increase the risk of retinal detachment and spontaneous vitreous haemorrhage.1–3 Han et al.2 recently proposed that incomplete separation of the common adventitial sheath without lysis may achieve comparable results. Thus, we propose transvitreal limited arteriovenous crossing manipulation (LAM) without vitrectomy as an alternative to AAS.
Case report
A 70 year old man with a medical history of hypertension, presented with BRVO of 14 weeks’ duration, visual acuity of 7/200, intraretinal macular haemorrhages, macular oedema assessed by ocular coherence tomography, and capillary non-perfusion on fluorescein angiography (fig 1). After informed consent and institutional review board approval was obtained, the patient underwent LAM without vitrectomy using the 25 gauge transconjunctival standard vitrectomy system (MADLAB, Bausch & Lomb, St Louis, MO, USA). Next, the blunt, flexible extendable pick (MADLAB) was introduced into the vitreous, and, once extended, makes a slit in the internal limiting membrane approximately 1.5 mm next to the pathological arteriovenous crossing. Then, LAM was initiated by first lifting the proximal portion of the artery followed by the portion distal to the crossing. Then, the artery was lifted at the crossing site, stretching but not severing the common adventitial sheath. Visualisation of clot dislodgement and reperfusion were noted. No vitrectomy was performed and no vitreous cutter was used during the procedure. There was no evidence of posterior vitreous detachment.
Figure 1 Preoperative fundus photography, fluorescein angiography, and optical coherence tomography. (A) Fundus photography of the left eye exhibiting severe intraretinal haemorrhage and macular oedema secondary to superotemporal secondary order branch retinal vein occlusion. Arrowhead denotes site of occlusion. The course of the vein is outlined by the white dots underneath and points towards 2 o’clock from the optic disc. (B) Fluorescein angiography of the left eye at 12 seconds exhibiting widespread blocked fluorescence secondary to haemorrhage, hyperfluorescence of the vessel wall, and extensive capillary dropout estimated at 10 disc diameters with vessel "pruning." Arrowhead denotes site of occlusion. The course of the occluded vein is better outlined in this angiogram by the underlying white dots. (C) Fluorescein angiography of the left eye at 4 minutes exhibiting consistent capillary dropout, blocked fluorescence secondary to haemorrhage, and extensive leakage along capillary vessel walls. Arrowhead denotes site of occlusion. (D) Optical coherence tomography of the left eye exhibiting extensive macular oedema with large cystic spaces in the foveal region. Foveal thickness was calculated to be 512 μm.
At the 2 month postoperative visit, the patient’s visual acuity was 20/40. Fundus photography and fluorescein angiography revealed markedly decreased intraretinal haemorrhages and good macular perfusion, respectively. Macular thickness decreased from 512 μm to 133 μm on optical coherence tomography (fig 2). No cataract progression was noted and intraocular pressure remained stable throughout the postoperative course. The patient has remained stable for over 12 months.
Figure 2 Postoperative fundus photography, fluorescein angiography, and optical coherence tomography. (A) Fundus photography of the left eye exhibiting marked resolution of intraretinal haemorrhage and macular oedema, particularly in the foveal region. Arrowhead denotes site of previously complete occlusion. The course of the now ghost vessel is outlined by the white dots underneath. (B) Fluorescein angiography of the left eye at 10 seconds exhibiting noticeably decreased blocked fluorescence secondary to haemorrhage, continued hyperfluorescence of the vessel wall, and extensive but decreased capillary dropout estimated at approximately 5 disc diameters. Persistent, but less severe, vessel "pruning" was also evident. Arrowhead denotes site of previously complete occlusion. (C) Fluorescein angiography of the left eye at 6 minutes exhibiting decreased capillary dropout, persistent blocked fluorescence secondary to haemorrhage, and decreased leakage along capillary vessel walls. Decreased leakage is particularly noted in the foveal region. Arrowhead denotes site of occlusion. The course of the occluded vein is outlined in this angiogram by the underlying white dots. (D) Optical coherence tomography of the left eye exhibiting markedly decreased macular oedema and the absence of cystic spaces. Foveal thickness was calculated to be 133 μm.
Comment
Our group has previously published a case report of 25 gauge AAS with vitrectomy where improvement was noted in visual acuity, macular thickness (as measured by optical coherence tomography), and refixation (as shown by scanning laser ophthalmoscopy).4 Han et al2 postulated that incomplete separation of the common adventitial sheath may be an alternative to AAS. The LAM without vitrectomy procedure may provide a minimally invasive way of clot dislodgment and reperfusion without need for large retinal incisions near retinal vessels as with AAS.
Although this intervention may suggest benefit, it is certainly possible that the macular oedema spontaneously resolved as a result of reperfusion from recanalisation. We are uncertain as to which of these factors (LAM or recanalisation) resulted in significant improvement. It is our belief that the reperfusion after the procedure was mainly responsible for the dramatic clearing of haemorrhage and the resolution of the macular oedema. A prospective, randomised trial examining the potential benefits of 25 gauge without vitrectomy and 20 gauge AAS with vitrectomy procedures for BRVO is warranted.
References
Opremcak EM, Bruce RA. Surgical decompression of branch retinal vein occlusion via arteriovenous crossing sheathotomy: a prospective review of 15 cases. Retina 1999;19:1–5.
Han DP, Bennett SR, Williams DF, et al. Arteriovenous crossing dissection without separation of the retina vessels for treatment of branch retinal vein occlusion. Retina 2003;23:145–51.
Mason J 3rd, Feist R, White M Jr, et al. S. eathotomy to decompress branch retinal vein occlusion: a matched control study. Ophthalmology 2004;111:540–5.
Fujii GY, de Juan E Jr, Humayun MS. Improvements after sheathotomy for branch retinal vein occlusion documented by optical coherence tomography and scanning laser ophthalmoscope. Ophthalmic Surg Lasers Imaging 2003;34:49–52.