ONE YEAR STUDY OF CT SCAN IN PATIENTS WITII VISUAL FIELD LOSS Agbeja A.M. and Dutton G.N. Department of Ophthalmology, University College Hospital, Ibadan. Nigeria. ,.SUMMARY RESULTS .19 patients from the Neuro-Ophthalmology clinic of the 19 patients were assessed for the series. The age range was Western Infirmary, were found during a one year period, to 19-76 years. Twelve of them were females (Table 1). have various types of vis ual field loss and on the basis of this TABLE I were sent for CT Scanning. 12 out of the 19 patients had positive CT Scans, the other 7 had no demonstrable AGE TYPE OF HELD DEFECT CT SCAN REPORT pathology on CT Scan. 54 Homonymous Hemianopa Pituitary Adenoma 65 Inferior Defect Left Eye Suprasellar Mass Key Words - Visual Field -Cf Scan Head- 57 Generalised Constriction Right Eye Smpty Sellar 73 Let Homonymous Hemianopia Occipital infarct (R) 76 Left Homonymous Hemianopia Occipital infarct (R) RESUME 76 Left Homonymous Hemianopia Cerebral atrophy with ventricular dilatation. Sur une periode d 'un an, on a trouve 19 patients de la 70 Right Homonymous Hemianopia Bilateral occipital infarcts Occipital infarct (R) Clin.ique de Neuro-Ophtalmogie de I'Infirmerie Ouest ayant 69 Left Homonymous Hemianopia a 71 Left temporal and supronosal Anterior Communicatingdifferents types de perte de champs visuels qu.i ont conduit artery ansurysm faire un examen tomodensitometrique qu.i fur positif chez 12 64 Generalised constriction Temporal lobe infarct des 19 patients, les 7 autres n 'avaient pas des pathologie 73 Inattention Homonymous Hemic Diffuse cerebral atrophy visible l\ Pexarnen tomodensitornetrique. nopia 42 Bitemporal hemionopia Grossly enlarged INTRODucnON ethmoidal sinuses 34 Generalised constriction Normal The procedure of CT Scanning has become one of the most 19 Bitemporal Hemianopia Normal Paracentral scotoma Normal important and easily accessible investigations in Neuro= 2570 Generalised constriction Normal ophthalmology, in view of its accuracy of results and non 40 Enlarged blind Normal invasiveness (l,2,3).Most patients coming into the Neuro- 61 Generalised constriction Normal ophthalmology clinic would one time or the other undergo CT Scanning. 69 Enlarged blind spot Normal One or" the reasons for this study was to assess the cost- Of our series, one out of the 3 patients with pituitary effectiveness of the procedure of CT Scanning in Neuro- lesions had a homonymous hemianopia, one had an inferior ophthalmology patients, the other reason was to correlate the unilateral quadrantinopia and one had a unilateral generalised visual field loss with CT Scan findings. It was therefore constriction of field. None of the patients with pituitary decided to do a pilot study on patients with visual field loss to" lesions had bitemporal hemianopia. (Table II). see if the investigation of CT Scanning was absolutely necessary to further help in diagnosis and management of the TABLE n NUMBEU CTSCANpatients. TYPE OF HELD LOSS OF REPORT PA +VE VE PATIENTS AND METHODS Homonymous Hemianopia 7 7 - 1n a one year period, 1986-1987, all new patients referred to Bitemporal Hemianopia 2 1 1 the Ncuro-ophthalrnology clinic at the Western Infirmary, Generalised Constr iztion 5 2 3 Glasgow, who had definite demonstrable visual field loss, Field loss crossing horizontal Midline 2 2 - assessed and categorised by rwo.Opthalrnologisrs were sent for CT Scanning, some with contrast injections as deemed Paracentral scotoma 1 - 1 necessary bv the Neuro-radiologist, The C'T Scan not only Enlarged blind spot? (due to swollen included st;ndard cuts of the brain but also cuts of the orbit. disc) Most patients had previous skull X-rays. + Sh unt vessel 1 - 1 This was a prospective study with no fore-knowledge - Shunt vessel 1 - 1 of the clinical lesion, and so the CT Scans had to be assessed by 2 independent Neuro-radiologists, 12 7 Afri J. Neurol/ScilVot. 9 Jut. 90 34 UNIVERSITY OF IBADAN LIBRARY Visual Field Radiography, Radiographic Image Enchancement Agbeja A M., Dutton G.N. One of the 7 with normal CT Scans and a hitemporal hemianopia, the other 6 had varying field losses, namely, g~neralised constriction, later found to he hysterical, enlarged blind spot, and paracentral scotoma. So far, no definite diagnosis has been made in these 7 patients. All 5 patients with occipital lesions had a homonymous hemianopia. Inattention hemianopia was fOW1din a patient W.IOwas later demonstrated to have diffuse cerebral atrophy, the other patients with diffuse cerebral atrophy had a true homonymous hemianopia and also demonstrated cerebra- malacia. 3 of the patients with head injury had gcneralised constriction and one had a bitemporal hemianopia. Only 5 out of the 19 patients were aware of their visual field loss, the others wer found by visual field testing. Discussion Twelve out of the 19 patients we sent for CT Scanning were Fig III CT Scan of the patient with a suprasellar fOW1d to have demostrable pathology (63%). Three had mass. pituitary lesions, 5 had occipital lesions, 4 had other lesions and 7 were normal. (Fig J, II, III). What about the patients with X-ray findings but normal CT SCfU1s?4 out of the 7 with normal CT Scans had a positive skull X-ray finding. In most of these the Neuro-radiologists had been sure the CT Scans were normal, having had the X-ray information before the scan, but in one of them, after careful review by a third Neuroradiologist, the suggestion of an empty sella syndrome came up i.e. one with possible radiological mis- diagnosis. . All the 7 patients with homonymous hemianopia had a positive CT Scan, therefore, we would advocate that all patients with homonymous hemianopia have a CT Scan, since not all of them from our series had an occipital infarct. One of them had a pituitary adenoma which was treated with Bromocriptine and responded very well with a total disap- pearance of the homonymous hemianopia and recovery of visual acuity from 6/36 to 6/6 in the worse eye and 6/6 to 6/5 in the better eye. Only 2 of the patients required craniotomy, the sup- Fig I CT Scan of the patient with Pituitary ade- rasellar mass and the anterior communicating artery noma aneurysm pressing on the left optic nerve. Bitemporal hemianopia was previously thought to be pathgnomonic of pituitary lesions but the 2 patients in our series who had this type of field loss had no pituitary lesion, one had grossly enlarged ethmoidal sinuses and the other had a normal CT Scan even with contrast injection. Conclusion From the study, not all the homonymous hemianopia was due to occipital infarction, one out of the 7.had a pituitary adenoma. In this patient, the skull X-ray showed a marked expansion of the pituitary fossa but only the CT Scan could confirm the presence of a soft tissue space occupying lesion which enchanced with contrast. Some patients had normal CT Scans although 'the skull Xvrays suggested lesions. In these patients, it was necessary to Fig II CT Scan of the Patient with bilateral occipital proceed to CT 'Scanning with contrast to confirm the infarcts. presence or absence of a lesion which could further help in Afri. J Neurol/Sci/Vot. 9 Jut. 90 35 UNIVERSITY OF IBADAN LIBRARY Visu,~1Field. Radiography. fladiographic Image Enchancement Agbeja AM., Dutton G.N deter mining the cour-«: or management to he outlined Ior the 2. Newton T.H., Hasso A.1\:., Dillon \\'.1': lv\odern pat iciu ,. 1\:cu roradiologv, \'01 I I I: Com purer Tornogrnphv of Ihe The CT Scan ha-, therefore been found to be a uscf ul rool Head and Neck. San Anselmo. Calif. Clavadcl Pre". in p.u icnt-, xvit ]: delllfln'>!r:i\,k visuu] ficld 1o" csjxciallv in I!)f)f) t ho-«: wu h hornonvruou-, hcnu.u ropia. 11l0'>!oj whcu n in our ,eric, !lad occipital .m.rrct-, ,. \\'ri~ht .J.E., Lloyd G.:\.S .. Arnbro-,c J: Cornpuicr ivcd REFERENCES axial (ol11,,!!ral'h\' in the detection of 'race occupvinglesion», Am J. Ophthalmo] 197'5. HO: 7H-84. I. [akobicc, FA., ct all: Combined clinical and computed tj, oj orbit al ulioma and meningioma, Uplhalillolog~' I<.J~L<)I: 1,/-1 ')') : AlII J rveu/O!'SCI Vol 9 Jul. 90 UNIVERSITY OF IBADAN LIBRARY