superior altitudinal visual field defect causes

If it is homonymous, is the defect complete or incomplete? What field defect results when a stroke affects the occipital lobe but spares the anterior portion of the occipital lobe? 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]. What are the bilateral VF defect patterns? Retro-chiasmal 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. Thus the nasal visual field extends to 60% of the horizon, whereas the temporal field extends to a further 30-40. 3.3.2 Assessing the Quality of the Visual Field. 2023 Stanford School of Medicine | Terms of Use | optic disc or nerve problem) peripheral (along the visual pathways from the optic chiasm back). 4. Diagnosis is clinical. 8. of visual field defects should be considered in clinical management decisions. [27], A few case reports have reported photophobia as the main presenting symptom in some patients with chiasmal disease.[29]. Often patients are unaware of peripheral field loss; directed questions towards functional changes such as increased rate of car accidents due to being unaware of cars approaching in the periphery, etc., may alert the clinician to a visual field deficit. 7. 6. 3.22b). 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 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 injuries).Examination allows localization by correlating the shape of defects to the abnormal portion of the visual pathways. In an optic tract lesion, there may be a relative afferent pupillary defect (typically in the eye with greater visual field loss), or a special type of optic atrophy called band or bow-tie optic atrophy representing nasal fiber loss in the eye with the temporal visual field defect. If the middle cerebral artery is patent when the PCA is occluded, this focal area of the occipital lobe may be spared. Goldmann visual field showing a bitemporal hemianopsia. Asymmetric tumors may preferentially involve one side of the chiasm or an optic nerve, and most commonly presents as a supertemporal quadrantanopsia. Altitudinal defect with near complete loss of the superior visual field, characteristic of moderate to advanced glaucomatous optic neuropathy (left eye). A variety of retinal or more central pathologies can cause visual field deficits that are limited to particular regions of visual space. Bilateral occipital lobe lesions will produce bilateral homonymous hemianopias, which may be asymmetric (Fig. The number scale labeled Total Deviation in Fig. A recorded number of 0 indicates that the patient could not detect even the brightest stimulus at that point. The nasal visual field extends to 60% of the horizon, whereas the temporal field. [25] When a filter is placed in front of one eye and a moving object at a constant distance away is viewed, the person perceives the object as having depth, when in reality it is moving in the same plane. Philadelphia, Wolters Kluwer, 2017. [38], Pituitary adenoma debulking, or partial excision, is often carried out via transfrontal, transsphenoidal, or transpterional approaches. Special attention should be directed to the horizontal and vertical axes of the visual field to see if there is a change in vision across an axis. The reported conditions and locations in the visual system that cause "conventional" AVFDs and their bilateral occurrence are reviewed. Ezzat S, Asa SL, Couldwell WT, Barr CE, Dodge WE, Vance ML, McCutcheon IE. [21], Cushing syndrome can result from both exogenous and/or endogenous sources, which makes the diagnostic workup of a patient presenting with Cushing syndrome very challenging. [5], Characteristically lesions at the level of the optic chiasm produce a bitemporal hemianopia. Endocrinology is often involved to help evaluate hormonal levels and guide medical management. The adenoma grows precipitously because of the removal of the feedback inhibition of adrenal corticosteroids on the pituitary tissue. This page has been accessed 291,679 times. Retro-chiasmal lesions almost always give rise to homonymous field defects with only one, exception. (1=superior nasal, 2=inferior nasal, 3=inferior temporal, 4=superior temporal, 5= fovea) . [5], The patient may have a unilateral or bilateral optic neuropathy or develop an optic neuropathy in one eye and a contralateral superotemporal defect in the fellow eye (i.e., the junctional scotoma). Kirk LF Jr, Hash RB, Katner HP, Jones T. Cushing's Disease: Clinical Manifestations and Diagnostic Evaluation. 3.28). 3.2 Techniques to Evaluate the Visual Field. 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. The lower visual field falls on the superior retina (above the fovea). 15. Ono M, Miki N, Kawamata T, Makino R, Amano K, Seki T, Kubo O, Hori T, Takano K. Prospective study of high-dose cabergoline treatment of prolactinomas in 150 patients. The ocular symptomatology of pituitary tumours. Pituitary adenomas are a collection of tumors that arise from the pituitary gland. Is the test normal or not? H53.439 is a billable ICD-10 code used to specify a medical diagnosis of sector or arcuate defects, unspecified eye. Clinical Pathways in Neuro-ophthalmology. The visual field of each eye overlaps centrally. 3. Identifier: 926-4: Title: Release Hallucinations: Ocular Movements: Normal: Creator: Shirley H. Wray, M.D., Ph.D., FRCP, Professor of Neurology Harvard Medical School . Young woman referred for inferior visual field defect Ocular Surgery News | A 23-year-old female preschool teacher was referred to the New England Eye Center by an outside ophthalmologist for. [27] This binocular diplopia occurs in the presence of intact ocular motility. Hemifield slide diplopia from altitudinal visual field defects. [3] Gigantism most commonly occurs from mammosomatotroph adneomas. Depending on the size and location of the tumor, as well as the anatomical relationship of the chiasm to the pituitary stalk, the severity and symmetry of the visual field defect may vary. 3.19, Fig. Lesions of the lateral geniculate nucleus typically cause a contralateral homonymous hemianopia. 3. Why are altitudinal visual field defects common in ischemic optic neuropathies? Automated static perimetry or kinetic perimetry are used to formally assess visual fields. There remains in each eye a temporal crescent of visual field for which there are no corresponding points in the other eye. Standard automated perimetry is often utilized by ophthalmologists and pituitary surgeons to document indication and follow progression of visual involvement. visual field loss indicates a prechiasmal pathology, while bilateral visual field loss indicates a chiasmal or retrochiasmal pathology. Deep lesions of the parietal lobe often impair optokinetic nystagmus when stimuli are moved in the direction of the damaged parietal lobe. [19] Acromegaly most commonly occurs from DGSA. It looks like an almost complete inferior altitudinal defect. 7. What are the findings of a left optic tract lesion? Causes of visual field defects are numerous and include glaucoma, vascular disease, tumours, retinal disease, hereditary disease, optic neuritis and other inflammatory processes, nutritional deficiencies, toxins, and drugs. What are the findings of a parietal lobe lesion? Characterization of the visual field defect often allows precise localization of the lesion along the visual pathways. Transcription factors are helpful in determining if the tumor is actually two or more separate tumors in the same area, or if the tumor actually co-expresses two different pituitary hormones. 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. [2], Many animal studies have suggested one or more genetic factors that may contribute to the formation of pituitary adenomas. 3.3.1 Understanding a Humphrey Visual Field Printout Extraocular muscle paresis may also suggest Pituitary apoplexy, which must considered in the setting of rapidly progressive vision loss and diplopia. o [teenager OR adolescent ], Loss of all or part of the superior or inferior half of the visual field; does not cross the horizontal median, More common: Ischemic optic neuropathy, hemicentral retinal artery occlusion Central Retinal Artery Occlusion and Branch Retinal Artery Occlusion Central retinal artery occlusion occurs when the central retinal artery becomes blocked, usually due to an embolus. Altitudinal Visual Field Defects. [31], The pituitary gland is best seen on coronal sections and normally enhances with contrast. Cover one of the patients eyes. The nasal fibers of the ipsilateral eye (53% of all fibers) cross in the chiasm to join the uncrossed temporal fibers (47% of all fibers) of the contralateral eye. [5] It is successful at decreasing levels of thyroid-stimulating hormone (TSH), and normalizes hyperthyroidism in around 75%. Instruct the patient to count fingers presented within the central 30 degrees (in each of four quadrants around fixation). Adenomas that have subtle features, such as hypotestosteronism, may also lead to a delay in discovery. - 80.86.180.77. 3. 3.10 indicates the amount each point deviates from the age-adjusted normal values. Mammosomatotroph adenomas in addition to expressing GH, also express PRL, though at a lesser extent. The Prevalence of Pituitary Adenomas: A Systematic Review. NAION) Optic Chiasm: * Nasal fibres (temporal visual field) decussate at the chiasm * Bitemporal hemianopia 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. Best Practice No 172: Pituitary Gland Pathology. Sellar lesions and visual loss: key concepts in neuro-ophthalmology. If there's a problem superiorly, you're gonna cause a problem inferiorly. It can be arteritic or nonarteritic. 3.10 indicates the amount each point deviates from the age-adjusted normal values. Although numerous automated perimetries are available, the Humphrey strategies, in particular, the Swedish Interactive Thresholding Algorithm (SITA) standard and SITA fast programs, are the most commonly used. 6. Ask the patient to count fingers in two quadrants simultaneously. Side effects are three times more frequent in bromocriptine compared with cabergoline, which may include gastrointestinal, cardiovascular, or neurological symptoms. [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. A right RAPD (contralateral to lesion) because more fibers (53%) in the optic tract come from the opposite eyes nasal retina, having crossed in the chiasm. Ironside JW. Nasal retina of the right eye ([2red]) in Fig. Once the lesion is localized anatomically, a directed workup looks for an etiology. What are the findings of an occlusion of the posterior cerebral artery? An unusual presentation of optic neuritis and the Pulfrich phenomenon. Altitudinal visual field defect (VFD), which involves the loss of visual sensation in the horizontal half of the visual field, is caused mainly by anterior ischemic optic neuropathy (AION), 1, 2, 3 or rarely by compressive neuropathy due to a tumor or aneurysm. Biousse V and Newman NJ. Automated perimetry is more sensitive, quantitative, and reproducible, but it is more time consuming and requires good patient cooperation and attention (Fig. A Homonymous hemianopia denser superiorly (pie in the sky) 5. [5] These stains do not correlate well with other features of pituitary tumors, such as the type of secreted hormone and cell type. Medical treatment is considered the primary treatment for prolactinomas. 2. 7. Google Scholar, Raj A (2001) Altitudinal visual field defect. 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 a small homonymous scotomatous defect if there is inadequate collateral circulation (Fig. 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. extends to a further 3040 beyond that; this part of the visual field is represented on the contralateral anterior parieto-occipital sulcus. In this case report, a woman presented with seizures secondary to haemorrhagic infarction of the anterior part of the parieto-occipital sulcus. [6], Silent-subtype III is a plurihormonal pituitary adenoma that derives from the Pit-1 lineage and expresses one or more hormones in scattered foci. 6. Management of prolactinomas is often in conjunction with an endocrinologist in regards to medication administration and decisions regarding indication for surgical resection. Distinction of densely vs sparsely granulated adenomas is mainly through low molecular weight cytokeratin (LMWK) immunohistochemistry. With gadolinium contrast these lesions will remain less intense compared to the normal gland and will enhance late. The ability of the patient to perform the test can be evaluated by measurements of reliability reported on the printout. CAS Macular sparing is visual field loss that preserves vision in the center of the visual field, otherwise known as the macula. 13. [48], Pituitary apoplexy is a life-threatening complication of pituitary adenoma caused by a sudden hemorrhage or infarction of the tumor. Applied anatomy for pituitary adenoma resection. Use OR to account for alternate terms These numbers are then converted to a gray scale representation of the field (upper right, Fig. 5. Thyrotrophic adenomas are one of the rarest types of secreting pituitary adenomas. Most incidentalomas are adenomas, and are not uncommon. Therefore, the nasal visual field loss is more prevalent in NAION.9 Other types of visual field defects that can occur include nasal step, superior altitudinal field defect (observed in our patient), scotoma, temporal wedge defect and visual field constriction. Ischemia of the optic nerve can produce a similar defect. 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. 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. If it is homonymous, is the defect complete or incomplete? Is the test reliable (as indicated by the technician for Goldmann visual fields and by the reliability parameters for automated perimetry)? [3][7], Previously, pituitary adenomas were also divided by their staining pattern on histology[3] but this classification is no longer clinically significant due to the more specific immunohistochemistry stains that can differentiate the hormones being secreted. 2. 1.27) when stimuli are moved in the direction of the damaged parietal lobe (Fig. The visual loss can be due to a unilateral or bilateral optic neuropathy, bitemporal hemianopsia from chiasmal compression, or rarely homonymous hemianopsia from optic tract involvement. This is because more fibers in the optic tract come from the opposite eye, having crossed in the chiasm. Note the responses on a chart representing the visual field. [12] There is evidence as well that adult pituitary stem cells may contribute to the development of pituitary adenomas. 1. Somatotroph Adenomas (Growth Hormone Adenomas), Findings associated with endocrine disturbance, No Ophthalmologic Involvement/No Surgery/Medical Therapy. 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. The incidence of pituitary adenomas presenting as monocular visual field defects was reported to be 9% (in a series of 1,000 patients). Pearls . On T2-weighted images, the adenoma is more indistinct, as it appears isointense or only slightly hyperintense in comparison with the surrounding gland. In: Miller NR, Newman NJ, eds. 2. glaucoma) * Peripheral constriction (Eg. As these adenomas grow, they tend to extend superiorly and may eventually compress the optic chiasm and various cranial nerves. You cannot reliably test the visual field of an uncooperative or very sick patient. 3.25). There have been attempts to develop an objective perimetry by projecting stimuli on to discrete areas of the retina and using electroretinographic or pupillometric responses as end points, but these methods remain experimental. Crooke cell adenomas, another subset of corticotroph adenomas, have characteristic morphology on immunohistology stains with a ring of LMWK and PAS positive granules along the periphery. Neuroanatomy of the visual pathway and the blood supply. 1 ). A 69-year-old-female developed a BSAH with macular involvement that was initially considered as malingering due to the obscurity of this symptom. The cytoplasm of these cells may be acidophilic, basophilic, or chromophobic, and is generally uniform in its appearance. 2. The visual field is the "spatial array of visual sensations available to observation in introspectionist psychological experiments". A contralateral homonymous hemianopia that is small and centrally located. While there may be many subtle or obvious signs of endocrine disturbance, description of these signs is beyond the scope of this discussion. Mostly temporal pallor of the left optic nerve from atrophy of the temporal retina in the left eye. Occlusion of the PCA often results in sparing of the tip of the occipital lobe, thereby sparing the macular representation, which is vascularized by terminal branches of the MCA (Fig. A homonymous hemianopsia denser inferiorly (opposite of pie in the sky) For example, the pituitary tumor-transforming gene (PTTG) has been shown to be overexpressed in hormone-secreting adenomas. 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. 3.21 show different homonymous hemianopias. Learning points Thieme Foroozan, R. Visual findings in chiasmal syndromes. Characterization of the visual field defect often allows precise localization of the lesion along the visual pathways. 3.12 and Fig. Enter the email address you signed up with and we'll email you a reset link. Kirkham TH. The temporal crescent syndrome. 3.7). 1. Rarely, pituitary adenomas can compress the optic tract and produce a homonymous hemianopsia. Hypercortisolism now most commonly results as a result of iatrogenic therapeutic modalities. The quality of the field is examiner-dependent, and it does not detect subtle changes. 1. This process is experimental and the keywords may be updated as the learning algorithm improves. Bilateral occipital lobe lesions will produce bilateral homonymous hemianopias, which may be asymmetric (Fig. The nasal retinal fibers of each eye cross in the chiasm to the contralateral optic tracts, and the temporal fibers remain uncrossed. 3.30). Relative to the point of fixation: The underlying diagnosis is often serious and can threaten long-term vision and even the patients well-being. [11] Mutations in the aryl hydrocarbon receptor interacting protein (AIP) gene are associated with an increased risk of aggressively invasive growth hormone-secreting pituitary adenomas. 1 However, glaucoma patients often dont present with an initial chief complaint of visual field loss, unless the disease is quite advanced. 2.Blind Right Eye (Right Optic Nerve) A lesion of the optic nerve and, of course, of the eye itself, produces unilateral monocular blindness. 3.5). 3.2.1 Visual Field Testing at Bedside Florio T. Adult Pituitary Stem Cells: From Pituitary Plasticity to Adenoma Development. (B) Automated perimetry in the right eye is normal; left eye shows an inferior altitudinal defect. The slow-growing nature of these tumors tends to cause optic atrophy before the tumor enlarges sufficiently to compress the third ventricle or produce sufficient mass effect to increase intracranial pressure (ICP). In the example provided in Fig. 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. 3.31). Reliability measurements are reported in the upper left corner and include the number of fixation losses (2/13), false-positive errors (0%), and false-negative errors (3%) during the test. Stacy Smith, Andrew Lee, Paul Brazis. 5. 3.4.2 Retrochiasmal Visual Pathways She later presented with right-sided visual disturbance; her examination confirmed temporal crescent syndrome. This corresponds to superior, bitemporal, and central vision loss. What values indicate an unreliable Humphrey Visual Field? Marini F, Falchetti A, Luzi E, Tonelli F, Luisa BM. Clinical Pathways in Neuro-ophthalmology. The only constant symptom is painless vision loss. 3.2 Techniques to Evaluate the Visual Field 1. PubMed Central What are the findings of bilateral occipital lobe lesions? Macular lesions produce central or paracentral defects, whereas most degenerative retinopathies, such as retinitis pigmentosa, produce progressive constriction of the peripheral and midperipheral visual field (Fig. 6. A congruent visual field defect presents with the same exact shape in the field of both eyes. 3.10), which provides a gross picture of the size and severity of the field defects present. The altitudinal defect can be unilateral or bilateral. Preoperative Peripapillary Retinal Nerve Fiber Layer Thickness as the Prognostic Factor of Postoperative Visual Functions After Endoscopic Transsphenoidal Surgery for Pituitary Adenoma. 3.4 Topographic Diagnosis of Visual Field Defects 7. As discussed above, a significant portion of pituitary adenomas are asymptomatic or indolent, leading their discovery to be incidental. [20] The elevated levels of serum cortisol lead to a constellation of signs and symptoms that is known as Cushing Syndrome, due to Cushing disease. Unspecified diagnosis codes like H53.439 are acceptable when clinical information is . Is the test reliable (as indicated by the technician for Goldmann visual fields and by the reliability parameters for automated perimetry)? 4. 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. 3.22d). [18] Acidophil stem cell adenomas (ASCA) additionally have elevated GH and IGF-1. Thyrotrophic adenomas will usually induce a hyperthyroid state due to the high levels of TSH, however hypo and euthyroidism is also possible. Neuro-ophthalmology Illustrated-2nd Edition. Automated Static Perimetry 4. Types of Field Defects Merck and the Merck Manuals Merck & Co., Inc., Kenilworth, NJ, USA is a global healthcare leader working to help the world be well. A Homonymous hemianopia denser superiorly (pie in the sky), 1. the types and severity of visual field defects in the Optic Neu-rititsTreatmentTrial(ONTT) . [1], Pituitary adenomas often recur following resection. We do not control or have responsibility for the content of any third-party site. [5], Cushing disease is a subset of Cushing syndrome that is caused by excess production of ACTH from a corticotroph adenoma. Remember also that visual input is processed in the contralateral hemisphere, so a right sided visual . Depending on the etiology of the optic neuropathy, arcuate defects, altitudinal defects, and central, paracentral, or centrocecal scotomas are observed (Fig. 13. It has a smaller incidence of side effects when compared to bromocriptine, and various studies suggest that it has a comparable effect of normalizing hyperprolactinemia and shrinking tumor size. 3.24). If it is homonymous, is the defect complete or incomplete? Many of the features of GH-secreting adenomas are related to the stimulation of insulin-like growth factor I (IGF-I or somatomedin C) by the liver in response to excess growth hormone. 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. [6] These tumors stain positively with periodic acid-Schiff (PAS) because of the carbohydrates present in POMC, the precursor molecule to ACTH. [6], Most pituitary adenomas are soft, well-circumscribed lesions that are confined to the sella turcica. PubMedGoogle Scholar. Because more fibers in the optic tract come from the opposite eye (crossed fibers), a relative afferent pupillary defect (RAPD) is often observed in the eye contralateral to an optic tract lesion (see discussion later in this chapter). [6] High prolactin levels cause amenorrhea, galactorrhea, and infertility in women, and hypogonadism and impotence in men. What are the findings of bilateral occipital lobe lesions? What field defect results when a stroke only affects the anterior portion of the occipital lobe? We describe a case of a young lady of 25 years of age with blurring of vision in the upper visual field of the right eye with otherwise intact visual acuity as the only presenting symptom. What field defect results when a stroke only affects the anterior portion of the occipital lobe? 3.22b) of the right optic nerve. Bilateral hypertensive optic disc edema in the setting of Cushing's disease may mimic papilledema. A junctional scotoma. Retina The tip of the occipital lobe, where the macular or central homonymous hemifields are represented, often has a dual blood supply from terminal branches of the PCA and of the middle cerebral artery (MCA). This has been termed "post-fixational blindness", and is caused by the two blind temporal hemifields overlapping during convergence. Some patients with complete bitemporal hemianopsia will complain of a complete loss of depth perception. 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 There are only sporadic case reports of altitudinal hemianopia in the published data. The far periphery can be assessed by finger wiggle. 5. Octreotide can shrink thyrotropin-secreting tumors in a third of reported cases. These questions are archived at https://neuro-ophthalmology.stanford.edu Preoperative MRI evaluation of pituitary macroadenoma: imaging features predictive of successful transsphenoidal surgery. Patients undergoing radiation therapy tend to have a slower recovery and time to improvement.[5]. Silent-type III pituitary adenomas can be clinically aggressive but has good treatment response to radiation and temozolomide. In the setting of a prolactin secreting tumor, galactorrhea-amenorrhea is termed Forbes-Albright syndrome. 3.20, and Fig. 3.31). [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).