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Editor,—Subhyaloidal haemorrhage in the premacular space may cause a sudden loss of central vision in eyes, where macular function was good before the incidence. It can be caused by different disorders such as vitreoretinal traction of different origins, trauma, Valsalva retinopathy, or occur spontaneously—for example, following partial detachment of the posterior hyaloid membrane. Different therapeutic approaches have been adopted for treatment of this situation. Spontaneous resorption of the haemorrhage can be awaited, which may be limited by the frequently slow course of resolution. Nd:YAG laser photodisruption of the posterior hyaloid membrane has been described to achieve distribution of the haemorrhage in the vitreous, which resulted in accelerated clearing and visual improvement.1 Pars plana vitrectomy can be performed for complete surgical separation of the posterior hyaloid membrane and removal of the whole haemorrhage.
We report on a case of acute premacular subhyaloidal haemorrhage, which was treated successfully by subsequent injection of recombinant tissue plasminogen activator (rtPA) and sulphur hexafluoride gas (SF6).
A 55 year old healthy woman (apart from medically controlled arterial hypertension) presented with a 1 day history of acute decrease of central vision to 20/200 in her right eye. Visual acuity in the left eye was 20/20, and there was no history of other or previous ocular disorders. Funduscopy revealed a subhyaloidal haemorrhage in the right eye which extended between the temporal vascular arcades (Fig 1). A small retinal area with intraretinal haemorrhages, retinal oedema, and epiretinal fibrovascular proliferation following occlusion of a small venous branch above the temporal superior arcade could be identified as the origin of the haemorrhage. Scatter laser photocoagulation was performed in the area of venous occlusion immediately. After 2 days, the surgical procedure was performed similar to the pneumatic displacement therapy of subretinal haemorrhages: after peribulbar anaesthesia, oculopression was applied twice for 10 minutes to reduce intraocular pressure. Then, 25 μg of rtPA (Actilyse, Boehringer-Ingelheim, Germany) were injected in the central vitreous cavity via pars plana. Following another two courses of oculopression, 0.3 ml of SF6 were injected in the vitreous cavity after 30 minutes. For further reduction of intraocular pressure, a limbal paracentesis was carried out and aqueous humour was released.
On the first postoperative day, detachment of the superior half of the posterior hyaloid membrane could be observed with diffuse intravitreal blood, and visual acuity had increased to 20/25. After 2 weeks, the fundus image was almost clear and the patient experienced no further visual impairment. During a 4 month follow up, visual acuity returned to 20/20. No increase in intraocular pressure was noted during the whole follow up period. At 4 months, funduscopy showed regular findings except for the small area of venous occlusion (Fig 2), the crystalline lens showed no increase in opacification compared with the preoperative findings and to the other eye.
In many cases, subhyaloidal premacular haemorrhage demands therapeutic intervention. Although the finding theoretically can be observed and spontaneous resorption of the haemorrhage can be awaited, this procedure may not be accepted by the patient because of the possible slow course of resolution. Additionally, adequate treatment of the underlying cause of haemorrhage may be delayed with potential risks for further damage to ocular structures. To induce distribution of the premacular blood in the vitreous cavity and consequently accelerate clearing, Nd:YAG laser photodisruption of the posterior hyaloid membrane has been described.1 However, this form of treatment may result in damage to the underlying retinal tissue, especially in cases of thin subhyaloidal blood layers, of increased vitreous opacification, and of reduced patient compliance. Certainly, visual function can almost instantly be restored by pars plana vitrectomy with surgical separation of the posterior hyaloid membrane and evacuation of all blood. However, vitrectomy—even though a routine procedure—has numerous risks and side effects. The progression of lens nuclear sclerosis even after uneventful vitrectomy is a well known complication, which occurs in almost all cases. Intraoperative retinal breaks and postoperative proliferative vitreoretinopathy may result in retinal detachment and severe loss of visual function. The intravitreal injection of rtPA and SF6 gas has recently been reported by different authors to induce pneumatic displacement of subretinal haemorrhage in cases of age related macular degeneration.2 3 A significant reduction of central scotoma size with this comparably minimally invasive procedure has been pointed out, especially considering the minor side effects compared with the potential complications after vitrectomy with subretinal surgery.
To our knowledge this is the first report on the application of this surgical technique for the indication of central subhyaloidal haemorrhage. The intravitreal injection of fibrinolytic agents such as urokinase to induce resolution of vitreous haemorrhage of different origins has already been described in the previtrectomy era4 and has been investigated experimentally.5 More recently, induction of posterior vitreous separation by injection of rtPA has been shown both experimentally6 and clinically.7 Plasmin formed from vitreal plasminogen by rtPA breaks up extracellular matrix proteins of the hyaloid membrane, thus inducing separation. Additionally, these breaks may allow blood to pass the membrane even before further detachment, as we were able to see in our case, where diffuse distribution of blood in the vitreous cavity had already occurred 30 minutes after injection of rtPA. Vitreous separation and further distribution of blood is then promoted by the injected gas bubble, which constantly rolls across the posterior pole if prone positioning is maintained by the patient in the early postoperative period.
The low risk profile of the procedure has been pointed out for its use in subretinal haemorrhage.2 3 Retinal break formation after intravitreal gas injection is a well known complication. Therefore, before gas injection a thorough examination of the peripheral retina should be carried out to detect any pre-existing breaks or degenerations. The relatively small gas volume injected to achieve coverage of the posterior pole for this indication should further lower the risk of secondary break formation. Compared with vitrectomy, cataract formation or progression does not occur after intravitreal injection of fluid or gas as we know from retinal detachment surgery.
This case demonstrates the effective treatment of a dense central subhyaloidal haemorrhage by the injection of rtPA and SF6. The minimally invasive procedure resulted in restoration of useful visual function within a day after surgery and in recovery to full visual acuity within 2 weeks. No side effects could be attributed to the procedure compared with the potential risks of vitrectomy.