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Show Journal of Neuro- Ophthalmology 16( 2): 110- 114, 1996. > 1996 Lippincott- Raven Publishers, Philadelphia Binasal Field Defects in Primary Empty Sella Syndrome D. G. Charteris, F. R. C. S., and J. F. Cullen, F. R. C. S. Two cases of radiologically proven primary empty sella syndrome with binasal field defects are described. The association of these two entities is discussed. Key Words: Binasal visual field defect- Primary empty sella syndrome- CT scan- Pituitary fossa. Empty sella syndrome is the term applied to the partial or complete anatomical absence of the pituitary gland identified by pneumoencephalography or CT scanning ( 1- 3). The condition is divided into primary empty sella ( without prior surgical or ra-diotherapeutic intervention) and secondary empty sella ( following surgery or radiotherapy). Varied visual field defects have been reported, more commonly in secondary empty sella ( 1- 12). Pituitary dysfunction has been described in cases of primary empty sella ( 1,12,13). This report documents two cases where binasal visual field defects occurred in patients with radio-logically proven primary empty sella syndrome. CASE REPORTS Manuscript received January 11, 1995; accepted March 22, 1995. From the Princess Alexandra Eye Pavilion, The Royal Infirmary of Edinburgh, Edinburgh EH3 9HA, Scotland, U. K. Address correspondence and reprint requests to Mr. D. G. Charteris, Vitreoretinal Unit, Moorfields Eye Hospital, City Road, London EC1V 2PD, U. K. Casel A 38- year- old woman was referred to the eye outpatient department with a complaint of visual disturbance in her right eye for three months. Visual acuities were 20/ 40 in the right and 20/ 30 in the left eye. The visual field of her right eye had a relative central scotoma extending to between 5 and 10° from fixation, the left field was full. Examination of the eyes was otherwise unremarkable, and there was no previous history of eye disease. Fluorescein angiography revealed minimal dye leakage from a resolving macular branch vessel occlusion. No underlying cause was found for the vascular occlusion, and no treatment was undertaken. Six months later, angiography showed resolution of the leakage; however, the field defect remained unchanged. When reviewed two years later, she was noted to have binasal field defects as well as the central scotoma in the right eye ( Fig. 1). Visual acuity remained 20/ 40 right, 20/ 30 left. Her optic discs were normal. Lateral skull radiography suggested erosion of the dorsum sella but did not show expan- 110 BINASAL VISUAL FIELD DEFECTS 111 Hospital No I I FIG. 1. Case 1. Binasal field defect and right central scotoma ( Goldmann fields). / Neuro- Ophthalmol, Vol. 16, No. 2, 1996 222 D. G. CHARTERIS AND J. F. CULLEN FIG. 2. Case 1. CT scan showing low- density pituitary fossa ( arrow). sion of the pituitary fossa. A CT scan showed the contents of the pituitary fossa to be of very low density ( Fig. 2), and a diagnosis of empty sella syndrome was made. No medical or surgical intervention was undertaken. The optic discs and visual fields remained unchanged after two years of follow- up. It was noted that she had been investigated for infertility and menstrual irregularity 13 years previously. She had had two children following treatment with clomiphene. After this, her menstrual irregularity returned, and this culminated in a hysterectomy and bilateral oophorectomy two years later. Around this time she had headaches with a cyclical quality. She had no other previous illnesses of note. Case 2 A 39- year- old woman was investigated for complaints of general malaise, tiredness, and left- sided headaches of two months duration. Lateral skull radiographs and tomograms of the pituitary fossa suggested an enlargement of the fossa with a double outline of the floor. Endocrine investigations were normal. She was referred for neuro- ophthalmological assessment. Her visual acuity was 20/ 40 right and left. Visual field examination revealed binasal inferior qu'adrantanopia ( Fig. 3). Her eyes were otherwise normal. There were no significant previous illnesses or eye problems. A CT scan was carried out, the pituitary fossa showed intact walls, with no gross enlargement, but a lowered density within the fossa. Pneumoencephalography showed air in the fossa outlining a relatively small pituitary gland. A diagnosis of empty sella was proposed. It was felt that no treatment was indicated and she was kept under review. Over the next seven years her visual field was essentially unchanged. She still suffered from frequent headaches. There appeared to be a slight increase in the field defects after seven years, and repeat skull radiography, and CT scans were performed. These investigations revealed a slightly enlarged fossa with some thinning of the floor and filled with cerebrospinal fluid ( Fig. 4). At this time both optic discs were noted to be moderately pale but not cupped. The diagnosis of empty sella syndrome was confirmed. No active intervention was undertaken and the fields have remained unchanged over a further three- year follow- up. DISCUSSION In case 1 the field defects were produced by two distinct mechanisms, the right central scotoma was produced by a retinal vascular occlusion, but there was no intraocular pathology to account for the nasal field defects. The history of infertility and menstrual irregularity in this case is notable in view of the association of primary empty sella syndrome with pituitary dysfunction ( 1,12,13). Binasal hemianopia is an uncommon visual field defect usually caused by two discrete lesions located either in the optic nerves or retinae ( 14,15). It has been postulated that binasal hemianopia may be caused by raised intracranial pressure distending the third ventricle and pushing the optic nerves against the carotid arteries ( 14). This is the first report to highlight the association of these two entities, although several previous papers have reported cases of primary empty sella having binasal field involvement ( 4,8,10,11). This evidence would suggest that primary empty sella syndrome should be part of the differential diagnosis of the rare cases of binasal visual field defect not explained by ocular pathology. In both cases the field defect appeared to be truly hemianopic in that the edge of the defect ran / Neuro- Ophthalmol, Vol. 16, No. 2, 1996 BINASAL VISUAL FIELD DEFECTS 113 Hoaplt » l No Name 348 PupU diameter mn W R G B Colour !* S Ji J. J _ o ~ i • K„~ m iv V Conducted by . I l l I FIG. 3. Case 2. Binasal inferior quadrantanopia ( Goldmann fields). / Neuro- Ophthalmol, Vol. 16, No. 2, 1996 224 D. G. CHARTERIS AND ]. F. CULLEN FIG. 4. Case 2. Pituitary fossa of CSF density ( arrow) CT scan. along the midline. The origin of these field defects may be due to a compromised blood supply to the lateral parts of the chiasm and optic nerves as the chiasm descends into the pituitary fossa and is pulled away from the carotid arteries. Recent work suggests that ischemic changes cause a flattening of the chiasmal bar and that chiasmal herniation is not essential for visual impairment in empty sella syndrome ( 12). 10. 11. 12. 13. 14. 15. REFERENCES Neelon FA, Goree JA, Lebovitz HE. The primary empty sella: clinical and radiographic characteristics and endocrine function. Medicine 1973; 52: 73- 92. Berke JP, Buxton LF, Kokmen CW. The " empty" sella. Neurology 1975; 25: 1137- 43. Jordon RM, Kendall JW, Kerber CW. 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