Visual impairment – differential diagnoses

Visual disturbances can appear acute, subtle, uni- or bilaterally, and make according to severity and dynamism high demands for fast diagnostic assessment and treatment. On the basis of 5 patients with visual impairment/loss, we describe differential diagnoses, suitable diagnostic ways, and therapeutic approaches (see below Figure).

Tab. 1:

Age	1: 13-y, f	2: 15-y, m	3: 16-y, f	4: 17-y, m	5: 14-y. m
Vision (visual acuity)	unilateral loss of vision left eye (0)	bilateral loss of vision (0.25)	Unilateral visual impairment right eye (0.63)	Bilateral visual impairment (0.4)	Unilateral visual impainnent right eye (0.67)
Pain	+	–	+	–	–
				1(2) lesion(s) T2
cMRI	Normal	Normal	Normal	Supratentorial i.e. right p.o. Chiasma abnormality extending over more than 3 vertebral segm	Optic neuritis right
Spinal MRI	Normal	Normal	Normal		Normal
OKB	negative	negative	negative	negative	negative
AQP4	negative	negative	negative	negative	negative
OCT	abnormal	normal	normal	abnormal	abnormal
VEP	latency longer Cortisone,	amplitude reduced	–	latency longer	latency longer
Therapy	Plasmapheresis, GLAT	Idebenone	vit B 12	Cortisone, GLAT	Cortisone, %

Diagnosis: 1. Autoimmune-induced optic neuritis: under plasmapheresis (7 ×) visual acuity 0.8 left could be re-established. VEP: extension of latency left. Now under GLAT in stable state. 2. LHON: mtDNA-genome mutation: m.14484T>C homoplasmic. 3. Vitamin B 12 deficiency: Laboratory values: Holotranscobalamin 20 pmol/L (norm > 50); vitamin B 12 155 pg/mL (norm > 400), under substitution with vitamin B 12 complete recovery. 4. MS (DD Devic-disease) despite spinal cord MRI with signal abnormality extending over more than 3 vertebral segments Devic-disease is not yet proven; under therapy with GLAT stable state. VEP: latency lowered, visual acuity nearly normal. 5. Optic neuritis (DD ON vs. CIS): Visual acuity 1.0 bilateral (remission), VEP: latency discrete longer right eye: P100 130 ms.

Conclusion: A disturbance of vision is always a severe clinical sign and in particular considering the age of the patients the reconstitution of vision is aim of every diagnostic and therapy. Fine differences in anamnesis and clinic should be perused and rare diseases should be included in differential diagnostic work-up. In special cases, therapeutic strategies in form of an individual off-label treatment should be considered under estimation of potential risks.