CASE REPORT
Year : 2022 | Volume
: 1 | Issue : 2 | Page : 95--99
Is visual field test important in hypertensive-diabetics?
Mayor O Atima, Ayodele J Orugun, Idakwo Ugbede, Oyeronke O Komolafe
ECWA Eye Hospital, Kano, Nigeria
Correspondence Address:
Mayor O Atima
ECWA Eye Hospital, P. O. Box 14, Kano
Nigeria
How to cite this article:
Atima MO, Orugun AJ, Ugbede I, Komolafe OO. Is visual field test important in hypertensive-diabetics?.J Niger Acad Med 2022;1:95-99
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How to cite this URL:
Atima MO, Orugun AJ, Ugbede I, Komolafe OO. Is visual field test important in hypertensive-diabetics?. J Niger Acad Med [serial online] 2022 [cited 2023 Jun 2 ];1:95-99
Available from: http://www.jnam.com/text.asp?2022/1/2/95/365603 |
Full Text
Introduction
Bilateral reduction in vision is a common presenting complaint in an ophthalmic clinic. Normal vision is 6/6, but patients could present with less visual acuity. The International Classification of Disease (ICD11) classified vision into two groups: distance and near visual impairment. Distance visual impairment is graded into:
Mild = visual acuity worse than 6/12–6/18
Moderate = visual acuity worse than 6/18–6/60
Severe = worse than 6/60–3/60
Blindness = visual acuity worse than 3/60
Near vision impairment is graded into:
Near visual acuity worse than N6 at 40 cm
Common causes of reduction in vision include refractive errors, cataract, and glaucomatous optic atrophy.[1]
Visual field is the entire area that can be seen when an eye is fixed straight at a point or target that extend 90° temporally, 60° nasally, and 70° and 50° inferiorly and superiorly, respectively. The visual pathway is divided into afferent and efferent pathways. The afferent pathways consist of retinal ganglion cells, optic nerve, chiasma, optic tract, and optic radiation extending from the lateral geniculate body to the visual cortex. The afferent consist of the pupil and its associated autonomic pathways and neural mechanisms for ocular motility. Visual field tests are primarily indicated in neurological and neuro-ophthalmic diseases but not usually in diabetic cases.[2]
The visual cortex is located in the occipital lobe (Brodmann area 17 and 18). Occipital lobe infarctions commonly present with a total loss of vision (cerebral visual impairment), which could be gradual or sudden.[3],[4]
We saw a diabetic case with a bilateral moderate visual impairment with normal ocular findings. We present a case of bilateral occipital lobes stroke who presented only with a reduction in vision in both eyes.
Case Presentation
A 56-year-old man, known hypertensive and diabetic for 10-year duration, presented with a progressive painless reduction in vision in both eyes of a month duration with no other ocular complaints. There was no other history to suggest confabulation or hallucination There was no history of trauma or known past history of cerebrovascular accident.
The general examination showed a middle-aged man, not pale, not ill-looking, afebrile, acyanosed, and no peripheral edema. His body mass index was 29.
Ophthalmic examination showed a visual acuity of 6/36 in the right eye (RE) and 6/24 in the left eye (LE) with best-corrected visual acuity of 6/24 and 6/18 with refraction in the RE and LE, respectively. Perceptual visual dysfunction test was not done as the patient had a good cognitive and motor function.
Extra-ocular motility was full in all directions of gaze, and the anterior segments were normal. Intraocular pressures were 12 mmHg in both eyes.
Posterior segment showed a clear vitreous. Fundal examination with an indirect ophthalmoscopy using a 78D lens revealed a pink disc, normal neuroretinal rim with a vertical cup disc ratio of 0.6 bilaterally, which was normal. The retinal arteries showed an obvious narrowing with focal irregularities (Scheie grade 2 hypertensive vasculopathy) and normal foveal reflex. The color vision test using Ishihara chart was normal The Humphrey visual field (Carl Zeiss Model 750 3605) was used in assessing the visual field. A Swedish interactive thresholding algorithm fast 24-2 threshold test, with stimulus size III, 31.5 Asb, was used. This revealed mainly congruous superior homonymous quadrantanopia [Figure 1]A and B and normal retinal nerve fiber layers [Figure 2] with optical coherence tomography (Carl Zeiss).{Figure 1} {Figure 2}
The Transasia CE machine (model: Chem 5 v 3 SR NO: S0873) was used to access the lipid profile: cholesterol, 4.00 mmol/L (3.80–6.50); triglyceride, 1.0 mmol/L (0.84–1.97); high density lipoprotein, 1.20 mmol/L (0.81–1.33); low density lipoprotein, 1.56 mmol/L (2.03–3.29). The patient had a well-controlled blood sugar with fasting blood sugar been 6.0 mmol/L.
Computerized tomography scan of the brain without contrast and angiography revealed bilateral hypodensities affecting 20%–40% of the occipital lobe [Figure 3]A and B.{Figure 3}
A diagnosis of cerebral visual impairment secondary to the bilateral occipital lobes infarction was made. A consult was sent to a neurologist and cardiologist to co-manage the patient. However, no feedback was received. Follow-up phone calls were also not successful.
Discussion
Our patient presented with only reduction in the central vision without any other clinical signs of neurological deficits.
Occipital lobe stroke patients mainly showed cortical blindness (this is bilateral) or unilateral loss of vision.[3],[4] Other forms of presentation that have been reported include ptosis,[5] vivid visual hallucinations, auditory hallucinations, and psychosis.[6]
Conclusion
Bilateral reduction in vision is a common complaint in an ophthalmic setup. Having excluded the common causes of decreased visual acuity in a middle-age patient with thrombotic predispositions, it is mandatory that visual field test be done in order to detect any potentially more debilitating nonocular pathologies. At the point of establishing a diagnosis of chronic systemic conditions, it is expected that best/evidence practices be applied. This includes a comprehensive eye/vision check as baseline parameters, which will include a visual field test, even though more emphasis is placed on the fundal photography.
With any nonrefractive visual loss, a central visual field is mandatory especially in the presence of normal anterior and posterior segment examinations.
Subsequent eye/vision checks depend on the eye/vision condition at the first consultation.
Financial support and sponsorship
Nil.
Conflict of interest
There are no conflicts of interest.
References
| 1 | Vision Loss Expert Group of the Global Burden of Disease Study. Causes of blindness and vision impairment in 2020 and trends over 30 years: Evaluating the prevalence of avoidable blindness in relation to “Vision 2020: The right to sight”. Lancet Glob Health 2020;9:144-60. |
| 2 | Boyd K Visual Field Testing. American Academy of Ophthalmology. Available at: https://www.aao.org/eye-health/tips-prevention/visual-field-testing. January 27, 2019. |
| 3 | Kiu KY, Sanihah A, Sharmini-Liza T, Tharakan J Recurrent bilateral occipital infarct with cortical blindness and Anton syndrome. Case Rep Ophthalmol Med 2014;2014:1-3. |
| 4 | Galetović D, Karlica D, Bojić L, Znaor L Bilateral cortical blindness—Anton syndrome: Case report. Coll Antropol 2005;29(suppl 1):145-7. |
| 5 | Vanikieti K, Poonyathalang A, Jindahra P, Cheecharoen P, Chokthaweesak W Occipital lobe infarction: A rare presentation of bilateral giant cavernous carotid aneurysms: A case report. BMC Ophthalmol 2018;18:25. |
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