Anti-aquaporin-4 IgG in patients presenting with unilateral optic neuritis: a cohort study

Optic neuritis [ON] can be the first presentation of multiple sclerosis [MS] or neuromyelitis optica [NMO]. Anti-aquaporin-4 IgG [AQP4 IgG] is a highly specific and moderately sensitive biomarker for NMO. This study was designed to assess the rate of seropositivity for AQP4 IgG, and the short-term outcome of patients presenting with single isolated ON [SION]. A cohort of 41 consecutive patients experiencing severe [< 20 / 200] SION [not fulfilling the diagnostic criteria for MS or NMO], was prospectively recruited. Blood sampling was carried out immediately after the diagnosis of ON, and AQP4 IgG was tested qualitatively, using an indirect immunofluorescence kit. After clinical and paraclinical investigations, all the patients were followed up for a short-term period of at least 18 months. The seroprevalence among the initial ON patients was 9.7% [4 / 41]. The short-term conversion rate to MS and NMO was estimated to be about 7.3 and 4.9%, respectively. The conversion rate to NMO in initially seropositive patients was greater than that for the whole cohort [2/4 [50%] vs. 2/41 [4.9%]; P = 0.035; Odds ratio: 19.5, 95% confidence interval: 1.73 to 219.50]. AQP4 IgG seropositive SION patients were more likely to develop NMO in comparison to the total SION population. Further studies, with a longer follow-up period and larger sample sizes are warranted to assess the clinical and prognostic value of assessing AQP4 IgG in SION

Stereoacuity following LASIK

To evaluate the effect of laser in situ keratomileusis [LASIK] on stereoacuity [SA]. This prospective study includes 200 patients scheduled for LASIK. SA was evaluated preoperatively and one week, one month and three months postoperatively using the Random Dot test. Patients with preoperative SA worse than 480 sec/arc were excluded from the study. The study included 138 female [69%] and 62 male [31%] subjects. Spherical equivalent was -0.5 to -12.0 D. Mean preoperative SA was 124.80 +/- 124.64 [range 480-15] sec/arc which deteriorated to 138.30 +/- 126.48 sec/arc one week after surgery [P=0.158] but improved to 111.30 +/- 112.15 sec/arc [P=0.002] one month and 103.65 + 112.20 sec/arc [P = 0.001] three months postoperatively. Overall, stereoacuity decreased in 9.5%, increased in 32.5% and remained unchanged in 58% of patients [P = 0.007]. Patients with anisometropia had worse SA; eventually, SA increased in 5 non-amblyopic anisometropic patients. Despite the overall improvement in mean SA after LASIK, a minority of patients experienced decreased SA. Anisometropic patients without amblyopia seem to have a chance for improved SA after LASIK

Etiology of oculomotor nerve paralysis

To determine the etiology of oculomotor nerve paralysis over a one year period at a university-based hospital. This observational case series was conducted on consecutive patients with a clinical diagnosis of isolated oculomotor nerve paresis who were referred to the neuro-ophthalmology clinic at Farabi Eye Hospital, Tehran, Iran during 2001-2002. All patients were evaluated for hypertension and diabetes mellitus. In patients with confirmed diabetes mellitus or hypertension, oculomotor nerve palsy was diagnosed as ischemic. However if no recovery was observed up to four months, the patient underwent MRI and MRA. The etiology of oculomotor nerve palsy was classified into six categories including ischemia, trauma, aneurysm, neoplasm, miscellaneous and idiopathic. During the period of the study, 28 eyes of 28 patients [17 male and 11 female subjects] with mean age of 50.5 years were enrolled. Blepharoptosis was observed in 89.3%. Pupil reaction was normal in 50%, sluggish in 14.3% and absent in 35.7%. Pupil size was normal in 57.1% and mydriatic in 42.9%. The paralysis was ischemic in 42.8%, traumatic in 14.3%, aneurysmal in 7.1%, neoplastic in 7.1%, miscellaneous in 10.7% and idiopathic in 17.8% of the cases. In the present series, ischemia was the most common cause of oculomotor nerve palsy in which the most prevalent underlying disorder was diabetes mellitus