Autoimmune optic neuropathy (AON), sometimes called autoimmune optic neuritis, may be a forme fruste of systemic lupus erythematosus (SLE) associated optic neuropathy. AON is more than the presence of any optic neuritis in a patient with an autoimmune process, as it describes a relatively specific clinical syndrome. AON is characterized by chronically progressive or recurrent vision loss associated with serological evidence of autoimmunity. Specifically, this term has been suggested for cases of optic neuritis with serological evidence of vasculitis by positive ANA, despite the lack of meeting criteria for SLE. The clinical manifestations include progressive vision loss that tends to be steroid-responsive and steroid dependent. Patients with defined SLE that go on to develop optic neuritis should be better identified as lupus optic neuritis. Signs and symptoms
AON was first described in 1982. It presents with visual loss and signs of optic nerve dysfunction, such as loss of color vision, afferent pupil defect, and sometimes abnormalities of the optic disc. The clinical features of AON can be variable and present in several unilateral or bilateral forms:

Acute anterior or retrobulbar optic neuritis sometimes associated with pain. Anterior or retrobulbar ischemic optic neuropathy not associated with pain. Chronic progressive vision loss that mimics a compressive lesion.The main features that differentiate AON from the more common typical demyelinating optic neuritis is the poor recovery of vision and the chronic or recurrent or bilateral course of AON. Furthermore, the workup for multiple sclerosis including MRI, will be negative.
Pathology
Histopathologically, several characteristics are frequently visible in urethral diverticula. These include nephrogenic adenoma, chronic inflammation associated with fibrosis around the glands, small or absent epithelium, chronic cystitis, cystitis cystica, cystitis glandularis, squamous metaplasia, and adenomatous metaplasia.Approximately 1/3 of diverticula are compound or multiple, and some can extend to surround the urethra. Diagnosis
Urethral diverticulum is often an incidental finding. It can be diagnosed using magnetic resonance imaging and/or micturating cystourethrography. Other studies that can be used to diagnose urethral diverticulum include intravenous urography, urethroscopy, and/or ultrasound. Conditions that should be distinguished from urethral diverticulum in a differential diagnosis include overactive bladder, Gartners duct cyst, Gartners duct abscess, ectopic caeco-ureterocele, interstitial cystitis, pelvic inflammatory disease, endometriosis, and cancer. Treatment
The primary treatment for urethral diverticulum is surgical. In women the surgery is conducted transvaginally, usually when there is no acute inflammation to better aid dissection of the delicate tissues. Prognosis
Left untreated, urethral diverticulum can cause significant morbidity (sickness).During surgery, there is a risk for complications due to the highly vascular nature of the tissue. The urethral sphincters and its smooth muscle, as well as the neck of the bladder, can be injured regardless of the surgical approach. Other complications from surgery can include urinary incontinence, stress incontinence, a urethrovaginal fistula, or recurrent diverticula. Horseshoe-shaped diverticula and diverticula that completely surround the urethra are both associated with worse outcomes, as are those located close to the bladder, and large (over 3–4 cm) diverticula.