The visual acuity may or may not be involved depending on extension to one or both optic nerves. 3.4). 3.13). Radiation therapy (external beam or gamma-knife) is considered a second-line treatment. - 80.86.180.77. Symptoms include night blindness and loss read more ), nonphysiologic vision loss, Rare: Bilateral occipital disease, tumor or aneurysm compressing both optic nerves, Loss of all or part of the lateral half of both visual fields; does not cross the vertical median, More common: Chiasmal lesion (eg, pituitary adenoma, meningioma, craniopharyngioma, aneurysm, glioma), Enlargement of the normal blind spot at the optic nerve head, Papilledema, optic nerve drusen, optic nerve coloboma, myelinated nerve fibers at the optic disk, drugs, myopic disk with a crescent, A loss of visual function in the middle of the visual field, Macular disease, optic neuropathy (eg, ischemic Ischemic Optic Neuropathy Ischemic optic neuropathy is infarction of the optic disk. Current methods of visual field testing all require the subject to indicate whether the stimulus is seen or not. What are the findings of an occlusion of the posterior cerebral artery? 3.22) produce atrophy of three groups of retinal ganglion cell fibers: 1. Bilateral occipital lobe lesions will produce bilateral homonymous hemianopias, which may be asymmetric (Fig. At the level of the chiasm, the crossing inferonasal fibers travel anteriorly toward the contralateral optic nerve before passing into the optic tract. 14. (one eye with horizontal blindness) . Does the visual field defect involve one eye or two eyes? Similar to bitemporal hemianopia, the presenting ocular manifestation is dependent on the type of tropia involved. Most patients show improvement of visual acuity, visual fields, or both following surgical treatment. 3.9). 3.22b). Lesions of the parietal lobe often impair optokinetic nystagmus (see Fig. It causes sudden, painless, unilateral, and usually severe vision loss. 3.2). . Fundus examinations were bilateral normal. This page was last edited on January 17, 2023, at 09:56. Most isolated congruent homonymous hemianopias are due to an occipital infarction in the territory of the posterior cerebral artery (PCA). [33], Microadenomas are best seen on unenhanced T1-weighted coronal or sagittal scans. 1. The reported conditions and locations in the visual system that cause "conventional" AVFDs and their bilateral occurrence are reviewed. [43] The outcome is affected by the severity of symptoms - for example, sudden ophthalmoplegia due to pituitary apoplexy would have a different result than a slow-growing prolactinoma. While a majority of patients with endogenous Cushing syndrome have thyrotrophic adenomas (called Cushing Disease - see below), other tumors should also be considered as part of the endocrinologic workup, including adrenal tumors and especially ACTH-secreting small cell carcinoma of the lung. Suprasellar and sellar lesions can produce optic neuropathies in one or both eyes; a junctional scotoma (ipsilateral visual loss and contralateral superotemporal visual field loss) or the junctional scotoma of Traquair (monocular hemianopic visual field loss); or chiasmal bitemporal hemianopsia (including paracentral bitemporal hemianopsia from Hypercortisolism now most commonly results as a result of iatrogenic therapeutic modalities. [5] While some forms of pituitary adenoma can be managed medically, most pituitary adenomas that have demonstrable visual field loss are treated surgically. Left homonymous hemianopia Lesion: in the right temporo-parietal region affecting the right optic radiation MRI shows haematoma of the right temporo . Note the responses on a chart representing the visual field. 3.10 indicates the amount each point deviates from the age-adjusted normal values. Fernndez-Balsells MM, Murad MH, Barwise A, Gallegos-Orozco JF, Paul A, Lane MA, Lampropulos JF, Natividad I, Perestelo-Prez L, Ponce de Len-Lovatn PG, Erwin PJ, Carey J, Montori VM. The patient reported blurred vision and a grey appearance to the inferior visual field of her left eye that first appeared roughly 3 weeks prior, but had not increased in severity. It uses a threshold strategy, in which the stimulus intensity varies and is presented multiple times at each location so that the level of detection of the dimmest stimulus is determined. Causes of altitudinal visual field defect (inferior or superior): Retinal cause: Branch retinal artery occlusion Branch retinal vein occlusion Retinal coloboma Optic nerve lesions: Ischemic optic neuropathy (arteritic and nonarteritic) Papilledema Optic disc coloboma Causes of floaters: Normal aging Vitreous hemorrhage Posterior vitreous detachment 3.8). Examination of the visual fields helps to localize and identify diseases affecting the visual pathways (Fig. In: Miller NR, Newman NJ, eds. Presenting Visual Symptom of Chiasmal Compression. Monocular field loss, can be in a variety of patterns * Central / paracentral scotoma * Arcuate defect (Eg. [1][3] Various articles have reported both male and female predilections. (altitudinal) visual field defect? While the patient is asked to fixate on a central target, a white or colored circular stimulus is slowly moved from the periphery toward the center of the screen until the patient reports seeing the stimulus. Enter search terms to find related medical topics, multimedia and more. Springer, Berlin, Heidelberg. Mostly temporal pallor of the left optic nerve from atrophy of the temporal retina in the left eye. Rarely these cells will be strongly acidophilic and are classified as densely granulated prolactinomas. Thammakumpee K, Buddawong J, Vanikieti K, et al. These tests average about 3minutes (fast) and 6 minutes (standard) per eye. 1. Wilbrands knee is composed of fibers originating in the inferonasal retina which after traversing via the optic nerve and crossing in the chiasm go anteriorly into the contralateral optic nerve up to 4 mm before passing posteriorly to the optic tract. The pattern on the devia- . [38], Pituitary adenoma debulking, or partial excision, is often carried out via transfrontal, transsphenoidal, or transpterional approaches. What are the monocular VF defect patterns? Bilateral hypertensive optic disc edema in the setting of Cushing's disease may mimic papilledema. Adapted from Bagheri N, Duraani AK: The Wills Eye Manual, ed. 3.19, Fig. In addition to the visual field defects, there may be decreased visual acuity, which is always the same in both eyes (Fig. While the exact pathophysiology is not completely understood, it is hypothesized that when the degree of overlap between one eye's temporal visual field and the contralateral eye's nasal visual field decreases to a certain point, the brain is unable to maintain fusion. Natural history of nonfunctioning pituitary adenomas and incidentalomas: a systematic review and metaanalysis. It looks like an almost complete inferior altitudinal defect. 4. The timeframe of recovery ranges from early (within 24 hours after surgery, between 24-72 hours after starting medical therapy) to late (6 months to 3 years). 5. PubMedGoogle Scholar. This disease classically affects older patients with vasculopathic risk factors and sleep apnea. More common: Ischemic optic neuropathy. If there's a problem superiorly, you're gonna cause a problem inferiorly. It can be arteritic or nonarteritic. Ischemic Optic Neuropathy Ischemic optic neuropathy is infarction of the optic disk. The homogenicity of the images suggests the relative solidity of the tumor. And these will respect the horizontal midline. The nasal visual field extends to 60% of the horizon, whereas the temporal field. [5], Cushing disease is a subset of Cushing syndrome that is caused by excess production of ACTH from a corticotroph adenoma. The underlying diagnosis is often serious and can threaten long-term vision and even the patients well-being. 11. Retrochiasmal lesions involving the visual pathways produce a contralateral homonymous hemianopia. 3.20, and Fig. 6. If it is homonymous and incomplete, is the defect congruent (same defect shape and size in each eye)? Why are altitudinal visual field defects common in ischemic optic neuropathies? [5] It is successful at decreasing levels of thyroid-stimulating hormone (TSH), and normalizes hyperthyroidism in around 75%. The altitudinal defect can be unilateral or bilateral. These headaces are often localized to the brow or periorbital region. A lesion in this area will give rise to monocular visual field defect affecting the contralateral eye. 12. classified as to the shape and type of deficit for the superior and inferior hemifields separately. The ability of the patient to perform the test can be evaluated by measurements of reliability reported on the printout. In this case, the more negative a number, the more abnormal that point. 4. Multiple Endocrine Neoplasia Type 1 (MEN1) Syndrome. Thus the nasal visual field extends to 60% of the horizon, whereas the temporal field extends to a further 30-40. [3] One review found an average incidence of 16.7% (14.4% in autopsy studies and 22.5% in radiologic studies). Heteronymous altitudinal visual field defects comprises of a superior hemifield defect in one eye and a inferior hemifield defect in the other. Fideleff HL, Boquete HR, Surez MG, Azaretzky M. Prolactinoma in children and adolescents. Retro-chiasmal lesions almost always give rise to homonymous field defects with only oneexception. Lesion group 3 results in mostly temporal atrophy of the left optic nerve (Fig. Thieme 3.22d). 60 degrees superiorly If it respects the vertical meridian, is the defect bitemporal or homonymous? What are the bilateral VF defect patterns? They may also develop hyperpigmentation, which occurs due to the stimulation of melanocytes by POMC. Andrew G. Lee . with this distinction but evaluating the potential for aggressiveness of the tumor (e.g., tumor invasion, mitotic count and Ki-67 labeling index) may still be useful. Central, Cecocentral, Paracentral, Arcuate/Sector, Nasal Step, Altitudinal, Enlarged blind spots, Temporal Crescent Defect. 7. A left optic tract syndrome includes the following: Bowtie atrophy of the right optic nerve, Mostly temporal pallor of the left optic nerve. Is the test reliable (as indicated by the technician for Goldmann visual fields and by the reliability parameters for automated perimetry)? Characterization of the visual field defect often allows precise localization of the lesion along the visual pathways. An altitudinal visual field defect is a condition in which there is defect in the superior or inferior portion of the visual field that respects the horizontal midline. A variety of retinal or more central pathologies can cause visual field deficits that are limited to particular regions of visual space. Proposed treatments are often geared towards decreasing the traction on the chiasm surgically or by decreasing medical therapy and allowing the tumor to regrow. Visual Field Deficits. Microincidentalomas (<1 cm) have been reported to be more common than macroincidentalomas (4-20% vs. 0.2% on CT, 10-38% vs. 0.16% on MRI, respectively). When the macula . The number scale labeled Total Deviation in Fig. 3.22d), 2. Junctional scotoma, Bitemporal defects, Homonymous hemianopia defects (w/wo macular sparing, spared temporal crescent). The VF defect is a homonymous hemianopia with sparing of the temporal crescent on the same side as the hemianopia. Present stimuli consisting of dots of white light projected one at a time onto the inner surface of the bowl, usually moving from the unseen periphery into the patients field of view. Several case studies have shown that children born without a chiasm and lesions that do not affect the chiasm or diencephalon can also cause see-saw nystagmus; tumor resection can sometimes result in resolution of nystagmus.[1][5][31][32]. Learning points [4], Papilledema is a rare finding in pituitary adenomas. The tip of the occipital lobe, where the macular central homonymous hemifields are represented, often has a dual blood supply from terminal branches of the posterior cerebral artery and of the middle cerebral artery. Borchert MS, Lessell S, Hoyt WF. A 46-year-old woman with a monocular superior altitudinal visual defect due to an aneurysm in the supraclinoid portion of the internal carotid artery appeared to have compressed the optic nerve and secondarily caused posterior ischemic optic neuropathy. [10][14][15], Thyroid transcription factor (TTF-1) is identified by the WHO 2017 classification that some posterior lobe adenomas have been shown to express. Figure 1. What are the monocular VF defect patterns? Incomplete homonymous hemianopias may help localize the lesion based on their congruity: Two patterns of visual field loss occur when the lesion is secondary to an ischemic lesion in the territory of the choroidal arteries (anterior or posterior) (Fig. (This rule does not apply to optic tract lesions that are suspected when the homonymous hemianopia is associated with a RAPD on the side of the hemianopia and bilateral optic nerve pallor). Questions: This may present either as decreased central acuity or as a loss in peripheral visual fields.[24]. What are the findings of a left optic tract lesion? Cover one of the patients eyes. Bedside visual field testing is quick and easy but has relatively poor reliability, depending on the patients ability to identify and describe the visual field defect. Bilateral homonymous hemianopias Vision tends to return to normal or almost normal without treatment in a couple Patients undergoing radiation therapy tend to have a slower recovery and time to improvement.[5]. [13] Various cell markers have also been implicated in the behaviors of various pituitary tumors, including type of hormone produced, recurrence, regression, and response to treatment. The visual field and retina have an inverted and reversed relationship. Patients with pituitary adenomas without compression can be followed annually by serial exam and imaging. 3. Instruct the patient to count fingers presented within the central 30 degrees (in each of four quadrants around fixation). These axons are destined for the lateral geniculate nucleus, where they synapse with neurons whose axons then form the optic radiations. 2. o [ abdominal pain pediatric ] A Homonymous hemianopia denser superiorly (pie in the sky), 1. 1. Bone window scans help assess erosions and extensions into the sphenoid sinus. Signs that you may have a visual field defect include: Bumping into things Knocking over objects when reaching Having difficulty reading Getting into a car accident Lesions of the occipital lobe produce a contralateral homonymous hemianopia, which is most often congruent. 3.4 Topographic Diagnosis of Visual Field Defects. Goldmann visual field showing a bitemporal hemianopsia. 3.15, Fig. 4. A Homonymous hemianopia denser superiorly (pie in the sky) 6. 1. Some patients with complete bitemporal hemianopsia will complain of a complete loss of depth perception. Treatment for the nonarteritic read more or Leber hereditary neuropathy Leber hereditary optic neuropathy Hereditary optic neuropathies result from genetic defects that cause vision loss and occasionally cardiac or neurologic abnormalities. Tumor extension into the cavernous sinus can affect cranial nerves III, IV, V, or VI and produce a limited or total cavernous sinus syndrome. 3.10 indicates the amount each point deviates from the age-adjusted normal values. 3.21 show different homonymous hemianopias. These numbers are then converted to a gray scale representation of the field (upper right, Fig. Scotoma - this is a type of visual field defect. 4. 8. Only the central 10, 24, or 30 degrees is usually tested. The number scale to the right in Fig. All rights reserved. Have the patient cover one eye and stare into the opposite eye on your face with his or her open eye to maintain central fixation. The diagnosis is confirmed by CT or MRI. Results must be interpreted critically (reliability and repeatability) and in conjunction with other clinical signs, symptoms and examination findings. 3 Visual Fields An embolic infarction of either a distal MCA or PCA branch can result in exclusive ischemia of the tip of the occipital lobe, thereby producing only a small homonymous hemianopia if there is inadequate collateral circulation. This is because more fibers in the optic tract come from the opposite eye, having crossed in the chiasm. Kumar V, Ramanathan US, Mushtaq B, Shah P (2002) Artefactual uniocular altitudinal visual field defect. The equivalent concept for optical instruments and image sensors is the field of view (FOV).. Some common types of visual field defects and their more common differentials are outlined below. If a quadrant of the visual field is consistently ignored, a subtle field defect (or neglect) has been revealed. Boxerman JL, Rogg JM, Donahue JE, Machan JT, Goldman MA, Doberstein CE. It can quickly establish the pattern of visual field loss in the ill, poorly attentive, or elderly patient who requires continued encouragement to maintain fixation and respond appropriately. 3.6, Fig. It uses a threshold strategy, in which the stimulus intensity varies and is presented multiple times at each location so that the level of detection of the dimmest stimulus is determined. Loss of all or part of the superior or inferior half of the visual field; does not cross the horizontal median . Of the cranial nerves, cranial nerve III (oculomotor nerve) is most commonly affected with variable involvement of pupillomotor fibers. At the level of the chiasm, the crossing inferonasal fibers travel anteriorly toward the contralateral optic nerve before passing into the optic tract. 1 However, glaucoma patients often dont present with an initial chief complaint of visual field loss, unless the disease is quite advanced. In this case report, a woman presented with seizures secondary to haemorrhagic infarction of the anterior part of the parieto-occipital sulcus. Clinical Pathways in Neuro-ophthalmology. Visual fields are also commonly documented prior and following neurosurgical intervention. [12] There is evidence as well that adult pituitary stem cells may contribute to the development of pituitary adenomas. Guaraldi F, Salvatori R. Cushing syndrome: maybe not so uncommon of an endocrine disease. 3. 3.10), which provides a gross picture of the size and severity of the field defects present. LH deficiency is manifested by decreased energy and libido in men due to decreased testosterone levels, and amenorrhea in premenopausal women. A left optic tract syndrome includes the following: 6. Lights of different sizes and brightness allow the drawing of isopters. Biousse V and Newman NJ. 13. 2012. Gynecomastia can be seen in both men and women. extends to a further 3040 beyond that; this part of the visual field is represented on the contralateral anterior parieto-occipital sulcus. 3.11): The main symptom of hemianopia is losing half of your visual field in one or both eyes. The most common cause is a retinal break (a tear or, less commonly, a hole) (rhegmatogenous read more, Less common: Glaucoma Overview of Glaucoma Glaucomas are a group of eye disorders characterized by progressive optic nerve damage in which an important part is a relative increase in intraocular pressure (IOP) that can lead to irreversible read more , optic nerve lesion, optic nerve coloboma, A small, bow-shaped (arcuate) visual field defect that follows the arcuate pattern of the retinal nerve fibers; does not cross the horizontal median, Damage to ganglion cells that feed into a particular part of the optic nerve head, More common: Glaucoma Overview of Glaucoma Glaucomas are a group of eye disorders characterized by progressive optic nerve damage in which an important part is a relative increase in intraocular pressure (IOP) that can lead to irreversible read more, Less common: Ischemic optic neuropathy Ischemic Optic Neuropathy Ischemic optic neuropathy is infarction of the optic disk. 1. Dept of Ophthal & Optometry,AKH, Medical University of Wien Dept of Ophthal & Optometry,AKH, Wien, Austria, Department of Ophthalmology, Goethe University of Frankfurt am Main Department of Ophthalmology, Frankfurt am Main, Germany, 2015 Springer-Verlag Berlin Heidelberg (outside the USA), Khan, K., Almarzouqi, S.J., Morgan, M.L., Lee, A.G. (2015). 6. 3.18). It is the technique of choice for patients with optic nerve lesions, papilledema, chiasmal compressive lesions, and other progressive visual disorders. It can be repeated to monitor if the defects are growing or shrinking as a measure of whether the disease process is worsening or improving. Stacy Smith, Andrew Lee, Paul Brazis. [25], Diplopia may be due to a paretic diplopia from ocular motor cranial nerve (e.g., III, IV, VI) paresis from lateral extension of tumors into the cavernous sinus, or a non-pareteic diplopia as a result of "hemifield slide" (described below). Preoperative MRI evaluation of pituitary macroadenoma: imaging features predictive of successful transsphenoidal surgery. Use to remove results with certain terms What are the findings of a left optic tract lesion? the types and severity of visual field defects in the Optic Neu-rititsTreatmentTrial(ONTT) . 3.30). Visual field defects seen in each eye's visual field and the image perceived by the patient: a) right HH; b) left HH; c) left HH with macular sparing; d) right superior quadrantanopia, 'pie in the sky'; e) inferior quadrantanopia 'pie on the floor' Figure 2. (A) Right optic disc shows mild superior disc oedema; left optic disc has more diffuse swelling and peripapillary haemorrhage. In the setting of a prolactin secreting tumor, galactorrhea-amenorrhea is termed Forbes-Albright syndrome. 5. Patients will complain of symptoms consistent with the mass effects of a pituitary tumor. https://doi.org/10.1007/978-3-642-35951-4_1155-1, DOI: https://doi.org/10.1007/978-3-642-35951-4_1155-1, Publisher Name: Springer, Berlin, Heidelberg, eBook Packages: Springer Reference MedicineReference Module Medicine, Over 10 million scientific documents at your fingertips, Not logged in 2.Blind Right Eye (Right Optic Nerve) A lesion of the optic nerve and, of course, of the eye itself, produces unilateral monocular blindness. Patients with pituitary adenomas have a variable history, dependent on the functional (secretory) status of the tumor, its size, and any mass effect. Occipital Lobe: Sparing the Temporal Crescent. The test involves the following steps: Altitudinal Visual Field Defects. Stacy Smith, Andrew Lee, Paul Brazis. Octreotide has the most effect on tumor shrinkage, and pegvisomant has no effect on tumor size or growth hormone secretion but may have better effect on the overall systemic effects of elevated growth hormone. Thinning or notching of the superior or inferior neuroretinal rim is indicative of loss of retinal nerve fiber layer (RNFL) and ganglion cell death. Pearls Bedside visual field testing is quick and easy but has relatively poor reliability, depending on the patients ability to identify and describe the visual field defect. Visual field testing is useful when evaluating patients complaining of visual loss (especially when the cause of visual loss is not obvious after ophthalmic examination) or patients with neurologic disorders that may affect the intracranial visual pathways (e.g., pituitary tumors, strokes involving the posterior circulation, and traumatic brain Wilbrands knee is composed of fibers originating in the inferonasal retina which after traversing via the optic nerve and crossing in the chiasm go anteriorly into the contralateral optic nerve up to 4 mm before passing posteriorly to the optic tract. The nasal visual field extends to 60% of the horizon, whereas the temporal fieldextends to a further 3040 beyond that; this part of the visual field is represented on the contralateral anterior parieto-occipital sulcus. Where is the lesion of a junctional scotoma? Brought to you by Merck & Co, Inc., Rahway, NJ, USA (known as MSD outside the US and Canada) dedicated to using leading-edge science to save and improve lives around the world. Marini F, Falchetti A, Luzi E, Tonelli F, Luisa BM. 5. These keywords were added by machine and not by the authors. Surgical outcome of oculomotor nerve palsy in pituitary adenoma. Rarely juxtaposed homonymous quadrantanopic or hemianopic visual field defects can mimic bilateral altitudinal visual field loss. 3. What are the bilateral VF defect patterns? A congruent visual field defect presents with the same exact shape in the field of both eyes. 100 to 110 degrees temporally. A contralateral homonymous hemianopia that is small and centrally located. What are the findings of a parietal lobe lesion? Present stimuli consisting of dots of white light projected one at a time onto the screen, randomly presented (not moving). Place the patients head on a chin rest on the open side of a white hemispheric bowl. Of all conditions causing the chiasmal syndrome, pituitary adenomas are the most common (50-55%). While there may be many subtle or obvious signs of endocrine disturbance, description of these signs is beyond the scope of this discussion. A comparative scale on the bottom relates the degree of grayness on the gray scale to the change in decibel levels from the numeric grid. Currently, rather than classifying a tumor as hormone-producing or functional adenoma, pituitary tumors are definedby their cell lineage and are further divided based on immunohistological stains and tumor markers. Causes. Treatment for the nonarteritic read more (usually nonarteritic), optic disk drusen, high myopia, Loss of all or part of the medial half of both visual fields; does not cross the vertical median, More common: Glaucoma Overview of Glaucoma Glaucomas are a group of eye disorders characterized by progressive optic nerve damage in which an important part is a relative increase in intraocular pressure (IOP) that can lead to irreversible read more , bitemporal retinal disease (eg, retinitis pigmentosa Retinitis Pigmentosa Retinitis pigmentosa is a slowly progressive, bilateral degeneration of the retina and retinal pigment epithelium caused by various genetic mutations. 4. (1=superior nasal, 2=inferior nasal, 3=inferior temporal, 4=superior temporal, 5= fovea) . Because the nerve fiber layer arising from the peripheral retina arches over the fovea, superior or inferior nerve fiber layer damage results in arcuate-shaped visual field defects. 3.22d) 3. 2. 2. A patient with altitudinal visual loss is more likely to have a carotid or cardiac embolic source compared with patients with diffuse or constricting patterns of vision loss. The temporal crescent syndrome. The reason these look like arcs and come off the blind spot is that they represent the loss of bundles of nerves as they come out of the optic nerve head. 7. We report a patient who had an ischemic stroke with a pure bilateral superior altitudinal hemianopia resulting from bilateral ischemia in the optic radiation. References: Retrochiasmal lesions normally cause homonymous visual field defects; the only exception is the temporal crescent or half moon syndrome, caused by a lesion in the anterior part of the contralateral parieto-occipital sulcus. If only the fibers nasal to the macula are damaged, only the nasal and temporal optic disc may be atrophic, often described as "bow-tie" or "band-shaped" pattern in both eyes in a bitemporal hemianopsia and only in the eye with the temporal visual field loss (nasal fiber loss) in a homonymous hemianopsia from an optic tract lesion. 3.4 Topographic Diagnosis of Visual Field Defects What are the findings of an occlusion of the posterior cerebral artery? The rule of congruency states that the more congruent the homonymous hemianopia, the more posterior the lesion. Bowtie atrophy of the right optic nerve Uncorrected refractive errors or disturbances in the normally clear media (such as cataract) cause a general loss of sensitivity of the visual field. You cannot reliably test the visual field of an uncooperative or very sick patient. These numbers are then converted to a gray scale representation of the field (upper right, Fig. Thyrotrophic adenomas are one of the rarest types of secreting pituitary adenomas. 5. In an undiagnosed patient with a history suspicious for pituitary disease, this often confirms the presence of a compressive chiasmal lesion. Expansion may lead to bony erosion of the anterior clinoid processes and sella turcica, as well as extending into the cavernous and sphenoid sinuses. [5] Vison loss due to compression first affects the superotemporal visual fields, then inferotemporal, inferonasal and finally superonasal fields. These questions are archived at https://neuro-ophthalmology.stanford.edu Postsynaptic fibers from the lateral geniculate nucleus form the optic radiations, which separate into the inferior fibers (temporal lobe) and the superior fibers (parietal lobe) as they progress posteriorly toward the occipital cortex (Fig. In: Miller NR, Newman NJ, eds. Interestingly, monocular temporal (uncrossed fibers) or nasal (crossed fibers) hemanopic visual field loss can also occur from a lesion at the junction of the optic nerve and chiasm. Lateral Geniculate Nucleus Pituitary or sella sequence magnetic resonance imaging (MRI) with and without contrast is the study of choice for most sellar and parasellar lesions, but high-resolution CTs with fine cuts (1.5-3 mm) have also been shown to be very helpful in the differential diagnosis especially if calcification is seen (e.g., craniopharyngioma or meningioma). ACTH triggers the adrenal glands to secrete cortisol. 3.15, Fig. Defects are more difficult to quantify than with automated perimetry.