Spontaneous silent sinus syndrome (imploding antrum syndrome): case series of 16 patients.

INTRODUCTION: Silent sinus syndrome (SSS) is a rare idiopathic collapse of the maxillary sinus and orbital floor. We present the second largest series of sixteen patients with SSS and describe their management. METHODS: A cohort of 16 patients with spontaneous SSS between 1999 and 2009 were reviewed at the Royal National Throat Nose and Ear Hospital. All patients were initially referred from a postgraduate ophthalmic hospital, Moorfields Hospital. RESULTS: Fourteen patients required endoscopic sinus surgery to re-establish maxillary sinus drainage and the remaining two settled with intranasal medical therapy consisting of steroids and decongestions. Follow- up ranged from 6 months to 4 years with a mean of 2.6 years. An improvement in enophthalmos and was seen in all surgically treated patients with a mean improvement of 2.2mm and range 0.5-4mm. DISCUSSION: SSS arises from congestion of the ostiomeatal complex resulting in negative pressure within the maxillary sinus and a gradual implosion of the antral cavity. Endoscopic sinus surgery successfully re-establishes maxillary aeration in our series and leads to clinical and aesthetic improvement in the degree of enophthalmos and has avoided the need for orbital floor repair in all but two cases.

Predicting visual outcome following retinectomy for retinal detachment.

AIM: To evaluate outcome following retinectomy surgery and to identify factors that predict visual outcome. METHODS: This was a retrospective uncontrolled interventional case-series of patients who underwent retinectomy surgery at Moorfields Eye Hospital (London, UK) during a 2-year period. We recorded peri-operative factors with the potential to influence functional outcome including aetiology of retinal detachment; type of ocular trauma; preoperative visual acuity and intraocular pressure; grade of PVR; extent and position of retinectomy; peri-operative complications; tamponade agent and prophylactic 360 degrees laser retinopexy. RESULTS: The authors identified 145 patients who underwent retinectomy surgery. After a mean follow-up period of 23.2 months (6-58 months) 16% of eyes had visual acuity of 20/60 or better, 33% had visual acuity of between 20/60 and 20/400, and 51% had visual acuity less than 20/400. Visual acuity was improved or stable in 76% of eyes and the rate of complete retinal reattachment was 68%. For each stepwise increase in the grade of PVR there was an approximately 15% increased risk of final visual acuity of less than 20/40. The use of additional 360 degree prophylactic laser retinopexy prior to removal of silicone oil was associated with a higher rate of final retinal reattachment. CONCLUSIONS: This study provides important information to help surgeons inform and counsel their patients about visual prognosis following retinectomy surgery. Furthermore, the study demonstrates that the aetiology of retinal detachment, the stage of PVR and the use of 360 degrees laser retinopexy have significant predictive value for visual outcome. SUMMARY: Retinectomy is a valuable technique in the management of complex retinal detachment but is associated with a significant risk of retinal redetachment and poor visual outcome. In this large study, we identified that the aetiology of retinal detachment, the stage of proliferative vitreoretinopathy and the use of 360 degrees prophylactic laser retinopexy are predictive of functional outcome.

Masked orbital abscess in Wegener's granulomatosis.

Two patients with chronic Wegener's granulomatosis presented with worsening proptosis and visual acuity. Both patients had been maintained on long-term corticosteroids, which led to masking of the signs of orbital sepsis with potentially life-threatening implications.

An experimental study on the effect of encircling band procedure on silicone oil emulsification.

AIM: Silicone oil is a useful tamponading material used in complex vitroretinal surgery. However, the use of silicone oil is associated with emulsification which can lead to vision threatening complications. The authors developed an experimental model to study the effect of encircling band on silicone oil emulsification. METHODS: Two identical artificial eye chambers were constructed with circumferential indentations placed at the sphere's equator (mimicking an encircling band indentation), and filled with varying amounts of Silicone Oil 1000 centistrokes (Adato, Bausch and Lomb, UK) and balanced salt solution. The chambers were then placed on a horizontal rotating shaker, mimicking physiological saccadic eye movements, which spun the chambers at 100 Hz for 5 days at 37 degrees C. Emulsification was then quantified by dark field microscopy, digital photography, and manual counting by a masked observer. RESULTS: The mean (standard deviation (SD)) values of silicone emulsification bubbles were as follows: in the 90% silicone oil filled chamber with no encircling band, 139.1 (SD 313.4); in the 90% silicone oil filled chamber with encircling band, 10.9 (SD 22.2) (p<0.0001); in the 75% silicone oil filled chamber with no encircling band, 103.6 (SD 272.6); in the 75% silicone oil filled chamber with encircling band, 18.5 (SD 32), (p = 0.001). CONCLUSIONS: The emulsification of silicone oil results from friction between the silicone oil and aqueous liquids. The results from this study suggest silicone oil emulsification is reduced by (1) more complete silicone oil fill and (2) indentation from an encircling band. The authors hypothesise that both these measures resulted in reduced emulsification by reducing silicone oil/aqueous movement and resulting shearing forces.

Preoperative assessment of secondary intraocular lens implantation for aphakia: a comparison of 2 techniques.

PURPOSE: To compare the preoperative evaluation of secondary intraocular lens (IOL) implantation in aphakic adults following cataract extraction in childhood using slitlamp examination and high-frequency ultrasound (HFU). METHODS: In a prospective case series, patients who had had lensectomies for congenital cataracts without primary implantation IOL were evaluated for secondary IOL insertion. Slitlamp examination and HFU were performed to study the degree of ciliary sulcus support and iridocapsular adhesions. The choice of IOL (posterior sulcus supported or anterior chamber) was compared using the 2 techniques. RESULTS: Nine eyes of 5 patients (3 men and 2 women aged 15 to 40 years) were assessed for secondary IOL insertion. Clinical slitlamp examination suggested that 3 of 9 eyes had inadequate sulcociliary support, but HFU of these eyes revealed more than adequate capsular remnants. In all 9 eyes, sulcus-supported posterior chamber IOLs were implanted. No postoperative complications were observed, and no patients required surgery for dislocated IOL. CONCLUSIONS: High-frequency ultrasound is a useful adjunct for the preoperative assessment of secondary ciliary sulcus-supported IOL implantation in aphakic patients who had congenital cataract extraction without IOL implantation. In patients in whom inadequate dilation precludes the detection of capsular support, posterior ciliary sulcus-supported secondary IOL implantation should be considered preoperatively. Although the technique enhances surgical planning and informed patient consent, the final decision occurs at the time of surgery with direct visualization of the ciliary sulcus support.

Rat brain serotonin neurones that express neuronal nitric oxide synthase have increased sensitivity to the substituted amphetamine serotonin toxins 3,4-methylenedioxymethamphetamine and p-chloroamphetamine.

Substituted amphetamines such as p-chloroamphetamine and the abused drug methylenedioxymethamphetamine cause selective destruction of serotonin axons in rats, by unknown mechanisms. Since some serotonin neurones also express neuronal nitric oxide synthase, which has been implicated in neurotoxicity, the present study was undertaken to determine whether nitric oxide synthase expressing serotonin neurones are selectively vulnerable to methylenedioxymethamphetamine or p-chloroamphetamine. Using double-labeling immunocytochemistry and double in situ hybridization for nitric oxide synthase and the serotonin transporter, it was confirmed that about two thirds of serotonergic cell bodies in the dorsal raphé nucleus expressed nitric oxide synthase, however few if any serotonin transporter immunoreactive axons in striatum expressed nitric oxide synthase at detectable levels. Methylenedioxymethamphetamine (30 mg/kg) or p-chloroamphetamine (2 x 10 mg/kg) was administered to Sprague-Dawley rats, and 7 days after drug administration there were modest decreases in the levels of serotonin transporter protein in frontal cortex, and striatum using Western blotting, even though axonal loss could be clearly seen by immunostaining. p-Chloroamphetamine or methylenedioxymethamphetamine administration did not alter the level of nitric oxide synthase in striatum or frontal cortex, determined by Western blotting. Analysis of serotonin neuronal cell bodies 7 days after p-chloroamphetamine treatment, revealed a net down-regulation of serotonin transporter mRNA levels, and a profound change in expression of nitric oxide synthase, with 33% of serotonin transporter mRNA positive cells containing nitric oxide synthase mRNA, compared with 65% in control animals. Altogether these results support the hypothesis that serotonin neurones which express nitric oxide synthase are most vulnerable to substituted amphetamine toxicity, supporting the concept that the selective vulnerability of serotonin neurones has a molecular basis.