ExPRESS miniature glaucoma shunt for intractable secondary glaucoma in superior vena cava syndrome - a case report

Background: The aim of this study was to clarify the pathogenic mechanism and to evaluate an intervention for intractable secondary glaucoma in superior vena cava (SVC) syndrome. Case presentation: A 66-year-old female with underlying hypertension, diabetes mellitus, ischaemic heart disease and end-stage renal disease complained of bilateral puffy eyelids for 3 months. Over three years, the patient experienced a progressive, marked face and neck swelling, which was accompanied by dyspnoea and nocturnal coughing. The patient has been under haemodialysis for the past 5 years; there were several occurrences of vascular access re-establishment for susceptibility to vascular thrombosis, and she was also diagnosed with SVC syndrome 2 years after haemodialysis. The patient's best-corrected visual acuity (BCVA) was 20/60 in the right eye and 20/400 in the left eye. Pneumatic tonometry revealed a gradual increase in the intraocular pressure (IOP), even with the use of three types of anti-glaucoma agents. The ratio was 0.7 and bilaterally symmetric; optical coherence tomography indicated a thinning of the superior and inferior retina nerve fibre layers, and standard automated perimetry showed partial to generalized depression in both eyes. Filtering surgery for the left eye was performed, but postoperatively, the IOP increased gradually over three months. The subsequent placement of the ExPRESS miniature glaucoma device p200 effectively lowered the IOP. Postoperatively, the IOP of the left eye remained under 20 mmHg without a further decrease in visual acuity, while the right eye, which was controlled with only medication, had an IOP of greater than 30 mmHg. Because this patient refused cardiovascular intervention, conventional trabeculectomy was used to redirect the aqueous humour to the subconjunctival space to form a bleb, but failed. Fortunately, the subsequent ExPRESS implant effectively facilitated aqueous outflow through the intrascleral space, resulting in the maintenance of a normal IOP at 6 months, postoperatively. Conclusion: Sustained high IOP may occur after conventional filtration surgery for secondary glaucoma in SVC syndrome. To facilitate aqueous outflow, an ExPRESS glaucoma implant can be used to effectively control the IOP.