Manifest refraction is the familiar test where the eye doctor rotates lenses in front of the eye, asking the patient, "Which is better (or clearer), this one or this one?" Corneal topography is considered a more quantitative test, and for purposes of aligning a toric IOL, most surgeons use a measurement called simulated keratometry (SimK), which is calculated by the internal programming of the corneal topography machine, to determine the astigmatic meridian on the surface of the cornea. The astigmatic meridian can also be identified using corneal wavefront technology or paraxial curvature matching. Type of surgery
Implants with or without removal of natural crystalline
Phakia is the presence of the natural crystalline lenses. Phakic IOL (PIOL) refers to an intraocular lens implanted without removal of the patients original crystalline lens, and this is performed solely to correct refractive error in the presence of a clear crystalline lens. Aphakia is the absence of the natural crystalline lens. The aphakic state is usually due to surgery to remove a cataractous lens, but post-surgical aphakia is rare nowadays because of the ubiquity of intraocular lenses. Rarely, aphakia can be post-traumatic or congenital in nature. Aphakic IOL refers to a lens implanted secondarily in an eye already aphakic from previous surgery or trauma some time ago. Pseudophakia is the substitution of the natural crystalline lens with an IOL, as is often done after cataract extraction or to correct refractive error.
Marburg acute multiple sclerosis, also known as Marburg multiple sclerosis or acute fulminant multiple sclerosis, is considered one of the multiple sclerosis borderline diseases, which is a collection of diseases classified by some as MS variants and by others as different diseases. Other diseases in this group are neuromyelitis optica (NMO), Balo concentric sclerosis, and Schilders disease. The graver course is one form of malignant multiple sclerosis, with patients reaching a significant level of disability in less than five years from their first symptoms, often in a matter of months.Sometimes Marburg MS is considered a synonym for tumefactive MS, but not for all authors. Pathogenesis
Marburg MS has been reported to be closer to anti-MOG associated ADEM than to standard MS It has been reported to appear sometimes post-partum

MOG antibody‐associated demyelinating pseudotumor
Some anti-MOG cases satisfy the MS requirements (lesions disseminated in time and space) and are therefore traditionally considered MS cases. After the discovery of the anti-MOG disease this classification is into revision. Diagnosis
It took its name from Otto Marburg. It can be diagnosed in vivo with an MRI scan. If Marburg disease occurs in the form of a single large lesion, it can be radiologically indistinguishable from a brain tumor or abscess. It is usually lethal, but it has been found to be responsive to Mitoxantrone and Alemtuzumab, and it has also been responsive to autologous stem cell transplantation. Recent evidence shows that Marburgs presents a heterogeneous response to medication, as does standard MS.