Double Seronegative Neuromyelitis Optica Spectrum Disorder with Longitudinally Extensive Transverse Myelitis and Optic Neuritis: A Challenging Case Report.

Neuromyelitis optica spectrum disorder (NMOSD) is a rare antibody-mediated neuroinflammatory disease of the central nervous system, typically manifesting in the optic nerves, spinal cord, and other regions of the central nervous system. We hereby report a case of a 16-year-old girl who presented with a six-month history of transverse myelitis with an acute episode of bilateral retrobulbar optic neuritis. MRI revealed patchy contrast enhancements over bilateral retrobulbar intraorbital optic nerves together with long-segment spinal cord hyperintensities (C2 to T2 level). Visual evoked potential testing during the acute presentation showed the absence of P100 bilaterally. However, both serum AQP4-IgG and MOG-IgG were reported to be negative. Despite remarkable improvement in bilateral optic nerve functions, she continued to have disabling bilateral lower limb spasticity, contractures, and loss of bilateral lower limb sensation after five cycles of plasma exchange. This case summarizes the challenges to diagnosing double seronegative NMOSD and its immediate therapeutic significance.

Evaluation of visual outcomes after toric intraocular lens implantation

Purpose: To evaluate postoperative visual acuity, refractivestatus and rotational stability of toric intraocular lens (IOL)in correcting pre-existing corneal astigmatism.Methods: A total of 69 patients with topographic cornealastigmatism of 1.0 Diopter (D) and above who underwentcataract surgery between June 2015 and December 2016were included in this retrospective observational study. Allpreoperative toric IOL calculations were performed usingimmersion biometry. Appropriate formula to calculate toricIOL power was applied (SRK/T, Holladay 1 or Hoffer Qformula). All patients undergone similar uncomplicatedphacoemulsification with implantation of AcrySoft IQ SN6ATtoric IOL of different powers. Visual outcome, refractivestatus and axis of lens were evaluated at six weekspostoperatively. Ethical approval from the Ministry of HealthMedical Research Ethics Committee was obtained prior tocommencement of study.Results: The mean refractive astigmatism decreased from1.69 D ±1.10 (SD) to 0.81 D ± 0.40 (SD) at six weekspostoperatively. The mean postoperative sphericalequivalent was at -0.37 D ±0.64 (SD). Mean LogMAR foruncorrected and corrected distance visual acuity in sixweeks postoperative patients was at 0.29 ±0.16 (SD) and 0.12±0.12 (SD) respectively. Intraoperative to 6 weeks ofpostoperative comparison of IOL axis alignment showed lowlevels of rotation (mean 3.21 ±2.52 degrees).Conclusion: Cataract surgery with implantation of toric IOLwas stable and effective in improving pre-existing regularcorneal astigm