Phaeochromocytoma in pregnancy.

Hypertension during pregnancy is a common problem, causing significant maternal and fetal morbidity and mortality. Pre-eclampsia is by far the most common cause, affecting 5-10% of primigravid women. Phaeochromocytoma is a rare endocrine tumour causing hypersecretion of noradrenaline, adrenaline and/or dopamine. It is extremely rare during pregnancy and may be misdiagnosed with potentially catastrophic consequences. Delayed diagnosis remains a significant source of maternal and fetal morbidity and mortality. Recognition is critical, as the majority of maternal deaths have occurred when the diagnosis has been overlooked. Diagnosis of phaeochromocytoma is achieved by detecting increased catecholamines and metabolites (metanephrine and normetanephrine) on 24-h urine collection, as these levels are unaffected by pregnancy or pre-eclampsia. Definitive treatment of phaeochromocytoma is surgical and the laparoscopic approach has been shown to be safe and is preferred for most phaeochromocytomas. Medical preparation and treatment of hypertension is essential for safe surgery. Timing of adrenalectomy is either during the second trimester or as a staged procedure after Caesarean section delivery.

Long-term variations in optimal programming of cardiac resynchronization therapy devices.

The optimal follow-up and long-term programming of cardiac resynchronization therapy (CRT) devices are uncertain. The aim of this study was to quantify the temporal variations in programming parameters to optimize the follow-up of these devices. Before, during, and at specified intervals over 9 months after implant, 40 recipients of CRT devices were studied. At each visit, the patients were tested with a fixed sequence of stimulation parameters during echocardiographic and electrocardiographic (ECG) recordings. The optimal AV delay and inter-ventricular delays (V-V) were determined according to echocardiographic criteria. The echocardiographic data were, in turn, compared with the ECG recordings. Among the 40 patients, the optimal stimulation parameters remained unchanged throughout the follow-up in only three patients. In 18 patients, adjustments were required at each follow-up sessions. There was a trend toward reduction in the left ventricular (LV) predominance of the optimal V-V delay and an increase in the AV delay during follow-up. The mean optimal V-V delay at implant was 22 ms (-12 to +32 ms) with the LV activated first, versus 12 ms (-16 to +32 ms) at 9 months. The mean AV delay at implant was 115 ms versus 137 ms at 9 months. Individual changes could not be accurately predicted. The optimal stimulation parameters for CRT vary over time. Detailed, regular reevaluations, and reprogramming of optimal parameters may be appropriate.

Bifocal right ventricular cardiac resynchronization therapies in patients with unsuccessful percutaneous lateral left ventricular venous access.

Biventricular cardiac resynchronization therapy (CRT) with a lateral left ventricular (LV) lead cannot always be achieved. We report a single center experience of CRT utilizing a protocol that specifically required the implantation of a bifocal right ventricular (RV) lead system when lateral LV pacing could not be achieved. Consecutive candidates for CRT were included in the study. If strict criteria for lateral LV pacing were not met, they underwent implantation of a bifocal RV lead system with two 7F, active fixation leads, one placed septally at the apex, and the other in the high septal outflow tract. All patients were followed for 12 months and the two groups were compared. A biventricular (BiV) stimulation system was implanted in 44 patients, and a bifocal RV system in six. The demographic characteristics of the two groups were similar. Both groups experienced a similar improvement in functional capacity, increase in 6 minutes walking distance, and decreased need for hospitalizations. The mean increase in LV ejection fraction was 11% in the bifocal RV group versus 10% in the BiV group. Though the tissue Doppler indices of LV synchrony improved earlier in the BiV group, (19% vs 10%) the improvement was similar in both groups at 6 months (23% vs 20%). The clinical improvements conferred by CRT can be matched by a bifocal RV system in selected patients. This alternate approach should be considered when implantation of a LV lateral lead was unsuccessful.

Prevalence of factor V Leiden and activated protein C resistance in central retinal vein occlusion.

PURPOSE: Factor V Leiden is a common inherited mutation that is a significant risk factor for deep vein thrombosis. It results in resistance to activated protein C (APC). The association between factor V Leiden and central retinal vein occlusion (CRVO) remains controversial. This study was designed to determine the prevalence of APC resistance and the factor V Leiden mutation in patients with CRVO in a controlled study. METHODS: The study was designed as a case control study conducted in a tertiary care retina practice. The prevalence of APC resistance and factor V Leiden was determined by genetic testing of blood samples obtained from patients with CRVO and clinic control patients. RESULTS: Factor V Leiden was identified in 2.3% of patients with CRVO and 3.5% of clinic control patients. There was no significant association between the presence of factor V Leiden and CRVO (odds ratio, 1.13; 95% confidence interval, 0.65-1.98; P = 0.66). CONCLUSION: Factor V Leiden does not appear to be associated with CRVO. Routine screening of patients with CRVO does not appear to be warranted.

Use of a macular buckle in the treatment of exudative age-related macular degeneration.

BACKGROUND AND OBJECTIVE: To evaluate a macular buckle for exudative choroidal neovascularization secondary to age-related macular degeneration (ARMD). PATIENTS AND METHODS: Forty-two eyes with choroidal neovascular membranes (CNVM) secondary to ARMD underwent surgical placement of a macular buckle. A Gore-Tex strip (2.0-2.5 mm wide) was button-holed through a 5 mm diameter silicone sponge (9 mm long) and placed behind the macula underneath the CNVM by the same surgeon (Dr Peyman) in all cases. Follow-up ranged from 7-76 months (mean, 20.9 months). RESULTS: Of 12 eyes with classic subfoveal CNVM: 4 (33%) gained 2 or more lines of Snellen visual acuity; 3 (25%) gained 1 line, remained the same, or lost 1 line; and 5 (42%) lost 2 or more lines (range + 6 to - 6 lines). Of 22 eyes with ill-defined subfoveal CNVM: 12 (54%) gained 1 line, remained the same, or lost 1 line; and 10 (46%) lost 2 or more lines (range + 1 to - 8 lines). Eight eyes with ill-defined juxtafoveal CNVM had the following visual acuity outcomes: 5 eyes (62%) maintained the same level of Snellen visual acuity (gained 1, 0, or lost 1 line); and 3 (38%) got worse (lost 2 or more lines of Snellen visual acuity, range + 1 to - 6 lines). Ten eyes (24%) bled subretinally during the follow-up period (average 11.5 months, range 14 days to 27 months), all outside the area of indentation of the macular buckle. CONCLUSIONS: The macular buckle treatment for exudative subretinal choroidal neovascular membranes in ARMD stabilized visual decline and displaced significant subfoveal hemorrhage.

Symptomatic and asymptomatic visual loss in patients taking vigabatrin.

PURPOSE: To investigate the clinical, perimetric, and electrophysiologic findings in patients with visual field loss on long-term treatment with the antiepileptic medication vigabatrin. DESIGN: Consecutive observational case series. PARTICIPANTS: Forty-one consecutive subjects taking vigabatrin referred for screening ophthalmologic assessment were studied. Twelve subjects with evidence of peripheral visual field constriction are presented. METHODS: Twelve subjects with evidence of peripheral visual field constriction on 60-4 perimetry underwent central 30-2 and blue-on-yellow (B/Y) perimetry, as well as electroretinography (ERG), electro-oculography (EOG), and visual-evoked potential (VEP) testing. MAIN OUTCOME MEASURES: Visual acuity; fundus abnormalities; visual field loss; and ERG, EOG, or VEP abnormalities were the main outcome measures. RESULTS: Eight of the 12 subjects with constricted visual fields were asymptomatic. The central 30-2 perimetry demonstrated bilateral visual field constriction in 9 of 12 patients and the B/Y perimetry in 8 of 9 patients tested. Of the ten patients tested electrophysiologically, four had abnormal ERGs, five had abnormal EOGs, and three had delayed VEPs. CONCLUSIONS: The incidence of visual field constriction in patients taking vigabatrin may be higher, and asymptomatic visual field loss more common, than reported previously. The authors postulate a possible Muller cell dysfunction in the peripheral retina. Patients taking vigabatrin should have regular peripheral visual field examinations.

Management of submacular hemorrhage with intravitreal sulfur hexafluoride: a pilot study.

BACKGROUND: Some success has been reported with the intravitreal use of tissue plasminogen activator (tPA) and perfluoropropane gas in the management of large submacular hemorrhages. However, the dosage of tPA that has been used (100 micrograms) has a narrow margin of safety, and it remains to be shown that intravitreal tPA can cross the retina and effect subretinal clot lysis. We carried out a pilot study to evaluate the efficacy of intravitreally administered sulfur hexafluoride (SF6) gas alone in the management of large submacular hemorrhages secondary to age-related macular degeneration (AMD). METHODS: Three patients with large submacular hemorrhages secondary to AMD seen at a university-affiliated teaching hospital in Ottawa were treated with an intravitreal injection of 0.6 mL of SF6 gas. They were instructed to assume a prone position for 7 to 10 days. The patients were followed 3, 7, 14 and 28 days after the procedure and monthly thereafter for at least 6 months. Colour photography and fluorescein and indocyanine green angiography were performed immediately before and 2 weeks after the procedure and, thereafter, at the discretion of the treating ophthalmologist. RESULTS: In all three cases significant inferior displacement of the submacular blood was observed. Two patients showed an improvement of vision from counting fingers to 20/70 and to 20/200. In one case the submacular blood was displaced such that laser photocoagulation of a juxtafoveal choroidal neovascular membrane became possible. INTERPRETATION: The results suggest that intravitreally administered SF6 alone may have a role in the management of selected cases of neovascular AMD complicated by significant submacular hemorrhage. These results call into question the utility of adjunctive intravitreal tPA in such cases.

Internal resection of posterior uveal melanomas.

AIMS: To evaluate the safety and efficacy of internal resection in the treatment of malignant melanoma of the choroid. METHODS: 32 consecutive patients with histopathologically proved malignant choroidal melanomas were treated with internal resection. 29 of the 32 (90.6%) tumours were within 2 disc diameters of the optic nerve or fovea. The surgery was performed at two university centres by one of the authors. Follow up was between 1 and 85 months (mean 40.1 months). RESULTS: Three patients developed distant metastases and died of malignant melanoma (metastatic and mortality rate 9.4%). In one case, distant metastases developed in association with an intraocular recurrence. There have been no other intraocular recurrences. The most common postoperative complication was vitreous haemorrhage, which occurred in 12 patients (37.5%); cataract occurred in eight eyes; and three patients developed retinal detachment postoperatively. Three of the operated eyes have been enucleated (9.4%); a total of four (12.5%) have lost light perception. 10 patients (31.2%) had visual acuities of 6/60 or better and 18 of 32 (56.3%) were between 6/120 and light perception. CONCLUSION: These data suggest that the internal resection of posterior uveal melanomas is a reasonable globe saving management option. This treatment modality is particularly well suited to elevated tumours in close proximity to the optic nerve or fovea.

The adjunctive use of perfluoroperhydrophenanthrene (Vitreon) in diabetic vitrectomy.

OBJECTIVE: To evaluate the utility and efficacy of perfluoroperhydrophenanthrene in the management of retinal detachments secondary to severe proliferative diabetic retinopathy. PATIENTS AND METHODS: Forty consecutive patients with proliferative diabetic retinopathy and retinal detachments were entered into the study at nine participating clinical centers. Perfluoroperhydrophenanthrene (Vitreon) was used as an adjunct to pars plana vitrectomy and membranectomy. RESULTS: Preoperative diagnoses included combined traction and rhegmatogenous retinal detachments in 23 eyes (57.5%), traction retinal detachments in 13 eyes (32.5%), and recurrent rhegmatogenous retinal detachments in 4 eyes (10). Vitreous hemorrhage was present in 17 eyes (42.5%). Preoperative visual acuity ranged from light perception or hand motion in 28 eyes (70%) to 5/200 or greater in 12 eyes (30%). Vitreon was primarily used to flatten the retina following relaxing retinotomy in 12 eyes (30%), to displace subretinal fluid in a posterior-to-anterior direction without performing a drainage retinotomy in 15 eyes (37.5%), and to manage intraoperative complications such as iatrogenic tears in 8 (20%) and retinal dialysis in 5 eyes (12.5%). The retina flattened intraoperatively in all cases, facilitating administration of laser photocoagulation. Patients were followed for a minimum of six months (mean 13.2 months). At last follow up, the macula remained attached in 37 eyes (92.5%), including 31 (77.5%) in which the retina was totally attached. The retina remained detached in 3 eyes (7.5%). Visual acuity improved postoperatively in 20 patients (50%), was unchanged in 13 patients (32.5%), and worsened in 7 patients (17.5%). CONCLUSIONS: Perfluoroperhydrophenanthrene is a useful and effective intraoperative tool for the management of complex retinal detachments secondary to severe proliferative diabetic retinopathy.

The management of giant retinal tears using perfluoroperhydrophenanthrene. A multicenter case series. Vitreon Collaborative Study Group.

OBJECTIVE: The purpose of the study was to determine the predictors of success and evaluate the use of perfluoroperhydrophenanthrene as an intraoperative and postoperative tool in the management of giant retinal tears in a multicentered collaborative study. DESIGN: Multicentered prospective case series. PARTICIPANTS: Twenty-three centers consecutively enrolled 162 eyes of 161 patients with retinal tears 90 degrees or greater in circumferential extent. INTERVENTION: Perfluoroperhydrophenanthrene was used as an intraoperative surgical adjunct in all cases and left after surgery in 16 eyes (9.9%). MAIN OUTCOME MEASURES: Retinal reattachment and visual acuity. RESULTS: Intraoperative reattachment was achieved in 158 eyes (97.5%); 147 eyes (90.7%) remained attached at their most recent follow-up. Seventy-nine eyes (48.8%) experienced an improvement in their visual acuity, 26 eyes (16.0%) remained unchanged, and 57 (35.2%) worsened. Recurrent retinal detachment occurred in 80 patients (49.4%). Other significant postoperative complications included cataract formation in 20 (39.2%) of 51 eyes, macular pucker in 12 (7.4%), corneal decompensation in 10 (6.2%), and hypotony (intraocular pressure equal to or less than 5 mmHg) in 9 (5.6%). A chi-square analysis of preoperative characteristics showed that hypotony (P = 0.007), macular detachment (P = 0.020), a history of cataract extraction (P = 0.003), poor visual acuity (P = 0.000), giant tear extent greater than 180 degrees (P = 0.004), and higher grade proliferative vitreoretinopathy (P = 0.000) all predicted a poor visual outcome. Vitreon (Vitrophage, Inc., Lyons, IL) was left in 16 eyes (9.9%) for an extended postoperative retinal tamponade for between 3 and 1034 days (mean, 87.2 days). The Vitreon was well tolerated, and these eyes experienced a similar outcome and rate of retinal reattachment to the rest of the group. CONCLUSIONS: Vitreon is a safe and useful adjunct to pars plana vitrectomy in the management of giant retinal tears and may, additionally, be the perfluorocarbon liquid that can be used most safely as a temporary postoperative tool for extended retinal tamponade, reinforcing its role as a useful adjunct in the management of these complex retinal detachments.

Management of dry retinal folds.

BACKGROUND: To describe the surgical technique used in the management of two cases of dry retinal folds which occurred following retinal detachment surgery. METHODS: Two patients with persistent dry retinal folds. RESULTS: Patients underwent complete vitrectomy and membrane peeling, followed by injection of perfluorocarbon liquid. The retina was prodded and massaged flat with a silicone-tipped cannula under the perfluorocarbon liquid. The folds disappeared and the retina remained flat. CONCLUSION: The use of gentle manipulation under heavy perfluorocarbon liquids is an effective strategy for managing longstanding dry posterior retinal folds.