Characteristics of 110 Patients with Functional Visual Loss
Sverdlichenko I, Brossard-Barbosa N, Micieli JA, Margolin E. Characteristics of 110 patients with functional visual loss. Am J Ophthalmol. 2023;250 171–176.
Five to 15% of patients who present to a neuro-ophthalmology practice with a complaint of vision loss are diagnosed with functional visual loss (FVL). To complicate matters, as many as 53% of these patients are also diagnosed with a coexistent organic cause for their loss of vision. To identify the characteristics of patients with FVL, the authors reviewed the records of 110 patients who were diagnosed with FVL at university-affiliated neuro-ophthalmology clinics.
The majority (73.8%) of patients were women with a mean age of 37 ± 15 years. The most common complaints were decreased vision (71.8%) followed by visual field defects (21.8%). In more than half of the patients the complaint was bilateral.
Visual acuity improved in 95.9% of patients when tested with fogging and/or a bottom-up technique. The most common visual field defects were generalised depression (42.5%) followed by concentric constriction/tunnel vision (12.5%).
Many patients had concurrent mental illness including depression (23.6%) and anxiety (22.7%) as well as other mental health conditions. A history of preceding trauma was present in 35% of patients.
These patients incur considerable costs to the health care system. They averaged 4.6 health care visits with 3.7 of these being to medical specialists. They also averaged 2.2 neuroimaging studies in addition to other testing. The authors point out the fact that there can be considerable savings in terms of cost and patient anxiety if these patients are referred promptly for neuro-ophthalmological consultation.
David Bellows
GLP-1 Receptor Agonists: The Miracle Pill for IIH?
Mitchell JL, Lyons HS, Walker JK, Yiangou A, Grech O, Alimajstorovic Z, et al. The effect of GLP-1RA exenatide on idiopathic intracranial hypertension: A randomized clinical trial. Brain. 13 March 2023:awad003. doi: 10.1093/brain/awad003. Epub ahead of print. PMID: 36,907,221.
Glucagon-like peptide-1 (GLP-1) receptor agonists are currently used as a treatment for diabetes and weight loss. The Birmingham, United Kingdom group previously showed that GLP-1 receptor agonists reduce cerebrospinal fluid secretion and intracranial pressure (ICP) in a rodent model, which led to their proposal of a randomised, double-blind, clinical trial of exenatide, a GLP-1 receptor agonist, for the treatment of idiopathic intracranial hypertension (IIH).
In this trial 15 IIH patients were randomly assigned to either exenatide (n = 7) or placebo (n = 8) and followed with telemetric ICP monitoring for 12 weeks. At 2.5 hours, the exenatide group had a mean ICP reduction of −4.2 mmHg compared with placebo, which was sustained at 24 hours (−4.7 mmHg) and 12 weeks (−4.1 mmHg). Vision also significantly improved in the exenatide arm compared with placebo. There was a trend toward improved headaches in the exenatide group. Surprisingly, despite the improvement in the ICP and visual acuity, there was no significant difference in the perimetric mean deviation or RNFL between the two arms. There was also no significant change in body mss index (BMI) at 12 weeks. Exenatide was fairly well tolerated other than being associated with nausea in many of the patients.
This study suggests that GLP-1 receptor agonists have the ability to acutely reduce ICP in IIH, which is independent of their ability to cause weight loss because this effect was noted 2.5 hours after administration and there was no significant difference in BMI at 12 weeks. These data are very promising and support a larger randomised clinical trial for GLP-1 receptor agonists for the treatment of IIH. It will be interesting to see if a larger study demonstrates improvement in perimetric mean deviation and papilloedema.
John Chen
Onset Before the Age of 9-years-old May be a Better Prognostic Indicator in Childhood-onset Leber’s Hereditary Optic Neuropathy
Barboni P, La Morgia C, Cascavilla ML, Hong EH, Battista M, Majander A, et al. Childhood-onset Leber hereditary optic neuropathy – clinical and prognostic insights. Am J Ophthalmol. 2023;249:99–107.
The authors conducted a retrospective study to investigate the features of childhood-onset Leber’s hereditary optic neuropathy (LHON). They included two cohorts of LHON patients with onset of visual loss before the age of 12 years old from Italy and the United Kingdom. A total of 68 patients were enrolled in this study. Among them, 14 patients (20.6%) were < 3 years, 27 patients (39.7%) were between 3–9 years, and 27 patients (39.7%) were between 9–12 years. Most of them had subacute bilateral visual loss (66.7%), followed by insidious bilateral (17.3%), unilateral (11.1%) and subclinical bilateral visual loss (4.9%). Generally, patients between 3–9 years old had better visual acuity outcome, mean deviation on visual field testing and higher mean ganglion cell layer thickness on optical coherence tomography. In addition, the proportion of strabismus was higher in patients < 3 years old (21.4%), followed by patients between 3–9 years old (7.4%) and 9–12 years old (7.4%). The author concluded that children who lose vision from LHON before 9-years-old may have a better visual prognosis than the older ones. LHON should be considered in children with unexplained subnormal vision with associated strabismus.
Hui-Chen Cheng
Retinal Plasticity May Exist in Early Childhood of Patients with Albinism
Lee H, Purohit R, Sheth V, Maconachie G, Tu Z, Thomas MG, et al. Retinal development in infants and young children with albinism: Evidence for plasticity in early childhood. Am J Ophthalmol. 2023;245:202–211.
Normal retinal development involves migration of the inner retinal layers (IRLs) away from the fovea, which is almost completed at birth, with elongation of the outer retinal layers (ORLs) over time. The authors conducted a prospective, comparative cohort optical coherence tomography (OCT) study to investigate the time course of foveal development after birth in infants with albinism. The authors enrolled 36 children with albinism, with a total of 181 OCT examinations in comparison to 297 control examinations. In patients with albinism a significant degree of IRL migration was taking place after birth in albinism, which resulted in a significantly thicker central macular thickness compared with controls. In addition, ongoing foveal ORL elongation was noted in albinism patients, although reduced in amplitude compared with controls. The authors concluded that the ongoing retinal development in young children with albinism, albeit at a reduced rate and magnitude compared with control subjects, indicated a period of retinal plasticity in early childhood and raised the possibility of improving visual function in these patients.
Hui-Chen Cheng
Nonarteritic Anterior Ischaemic Optic Neuropathy After Cataract Surgery: A Systematic Review and Meta-Analysis
Shew W, Wang MTM, Danesh-Meyer HV. Nonarteritic anterior ischemic optic neuropathy after cataract surgery: A systematic review and meta-analysis. J Neuroophthalmol. 2023;43:17–28.
In this meta-analysis of Medline, PubMed, Embase, and Cochrane Central registers, nine articles met the selection criteria with five studies suitable for the study. A total of 320 post-surgical nonarteritic anterior ischaemic optic neuropathy (psNAION) cases (within 1 year of surgery), 1,307 spontaneous NAION (sNAION) cases, 1,587,691 cataract surgeries, and 1,538,897 noncataract surgery controls were included. They found that the psNAION cases were older than sNAION by a mean of 7.6 years; otherwise, pooled odds ratios for baseline risk factors in psNAION vs. sNAION cases were not statistically significantly different. The psNAION cases occurring within the first year peaked within 72 hours and at 6 weeks after the surgery with 73% of cases occurring within 6 months. The authors concluded that the risk of NAION after cataract surgery is four times greater within the first year after surgery and usually occurs within 6 months. However, the absolute risk remains low at 1 in 1000–3100 surgeries and is unlikely to warrant extra mention for consenting.
Commentary: I agree that the risk is low for psNAION, however, as a neuro-ophthalmologist who has been referred quite a few of these patients, I believe a pre-operative conversation is warranted between the cataract surgeon and the patient and perhaps an alteration of the consent form reflecting this.
Michael Vaphiades
Optic Neuritis After SARS-CoV-2 Vaccination
Shemer A, Greenbaum A, Toledano A, Biron R, Dubinsky-Pertzov B, Or L. Optic neuritis after SARS-CoV-2 vaccination. J Neuroophthalmol. 2023;43:29–33.
In this retrospective chart review of patients admitted to the emergency department with optic neuritis from January 2021 to June 2021, seven patients were identified who developed optic neuritis after a recent COVID-19 vaccination with BNT162b2 (Pfizer-BioNTech). All patient developed optic neuritis after the second dose and a causal relationship could not be found. However, the authors encouraged a prospective monitoring and reporting system for all patients receiving COVID-19 vaccines, to further assess the spectrum of adverse events in large databases.
Commentary: I agree that the numbers are small in the article and the reader has to tease out the time frame after the second vaccine dose and the onset of optic neuritis (which varied from 3 weeks to 6 months). In addition, it is not clear how many total charts were reviewed. Also of interest, one patient had been previously diagnosed with multiple sclerosis and repeat magnetic resonance imaging showed brain lesions in-keeping with this disease. The other interesting fact is that the optic neuritis developed only after the second vaccine in their series.
Michael Vaphiades
Anaemia and Idiopathic Intracranial Hyper-tension: A Case-Control Study
Sverdlichenko I, Yu CW, Margolin E, Micieli JA. Anemia and Idiopathic Intracranial Hypertension: A Case-Control Study. J Neuroophthalmol. 2023;43:63–68.
In this prospective study 123 consecutive idiopathic intracranial hypertension (IIH) patients were recruited from neuro-ophthalmology clinics and matched by age and sex to 113 consecutive control patients attending neuro-ophthalmology clinics with diagnoses other than IIH. Complete blood counts (CBCs) were reviewed within 6 months of neuro-ophthalmology presentation, and anaemia was diagnosed when the haemoglobin level was <120 g/L in women and <130 g/L in men. Overall, IIH patients had a higher prevalence of anaemia (22.8%) compared with non-IIH neuro-ophthalmology patients (10.6%). The anaemia was mostly mild and may be explained by other factors related to worse health status and obesity, including low socioeconomic status, poor nutrition, and polycystic ovary syndrome. However, as a CBC is a widely available test and aneamia may influence the IIH disease course, the authors proposed that a CBC should be obtained in all patients with new papilloedema.
Commentary: The author’s proposal is sound given their study results and that many of IIH patients are prescribed medications which may impact the CBC, including the rare complication of acetazolamide and aplastic anaemia. One should also check a basic metabolic panel for the same reason of potential medication side effects.
Michael Vaphiades
White Dot Syndromes
Mount GR, Kaufman EJ. White dot syndromes. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan–. PMID: 32,491,777.
The white dot syndromes constitute a group of inflammatory chorioretinopathies. The common, defining clinical feature is the presence of multiple, discrete, white lesions located at the deeper levels of the retina and choroid. Several of the white dot syndromes are associated with a viral prodrome, although an aetiology is lacking for these conditions. Typically seen in young, otherwise healthy adults, the white dot syndromes most often present with symptoms of photopsia, floaters, decreased night vision, blurred vision, and visual field loss. These conditions can be acute in onset or transient without long-term visual consequence. Pearls are as follows.
Multiple evanescent white dot syndrome (MEWDS): young patients (age 20 to 50 years); women > men; often viral prodrome; typically unilateral; good visual prognosis; small white dots in the outer retina; and a ‘wreath-like’ pattern of hyperfluorescence on fluorescein angiography (FA).
Acute retinal pigment epitheliitis (ARPE): young patients (age 10 to 30 years); women = men; most often unilateral; small hyperpigmented lesions; and an excellent visual prognosis.
Acute posterior multifocal placoid pigment epitheliopathy (APMPPE): young patients (age 20 to 30 years); women = men; typically bilateral; flat grey or white placoid lesions at the level of the retinal pigment epithelium (RPE) and inner choroid; and a good visual prognosis.
Acute zonal occult outer retinopathy (AZOOR): young patients; often myopic; women > men; typically bilateral (though asymmetric); initially normal-appearing fundus followed by zonal RPE atrophy and pigmentary changes; no clear benefit from treatment; and a good visual prognosis, though may progress or recur.
Multifocal choroiditis and panuveitis (MCP): young to middle-age patients (age 20 to 60 years); women > men; bilateral; presence of anterior chamber and vitreous inflammation along with multiple yellow-white chorioretinal lesions with subsequent atrophy and scarring; complicated by cystoid macular oedema (CMO) and choroidal neovascularisation (CNV); and a poor visual prognosis, although treatment is generally required.
Birdshot chorioretinopathy: middle-aged patients (age 40 to 60 years); women > men; bilateral; difficulty with night vision; multiple cream-coloured lesions in a birdshot style; radiating pattern nasally predominant; associated vitritis, CMO, and retinal vasculitis; highly correlated with the presence of HLA-A29: ‘quenching’ on FA; and a guarded visual prognosis with treatment generally required.
Serpiginous choroiditis: middle-aged patients (age 30 to 60 years); men > women; bilateral (asymmetric); the geographic pattern of chorioretinal scarring; and a guarded to poor prognosis – treatment may require alkylating agents.
Punctate inner choroidopathy (PIC): young patients (under 40 years of age); women > men; bilateral; small punctate grey or yellow lesions in the posterior pole evolve to atrophic scars; absence of vitritis; associated with CNV; and a good visual prognosis, though more guarded with the development of CNV.
Many of the white dot syndromes are benign and self-limiting, negating the need for treatment. A few white dot syndromes are persistent and progressive, with significant visual consequences if untreated (MCP, serpiginous choroiditis, and birdshot chorioretinopathy). Treatment in these conditions initially involves using local or systemic corticosteroids with a transition to steroid-sparing systemic immunotherapy.
Michael Vaphiades
What is the Prevalence of Developmental Prosopagnosia?
DeGutis J, Bahierathan K, Barahona K, Lee E, Evans TC, Shin HM, et al. What is the prevalence of developmental prosopagnosia? An empirical assessment of different diagnostic cutoffs. Cortex. 2023;161:51–64.
Developmental prosopagnosia (DP) is a lifelong face recognition deficit. It has been diagnosed in different ways across different studies, resulting in differing prevalence rates. The authors estimated the range of DP prevalence by administering well-validated objective and subjective face recognition measures to an unselected web-based sample of 3116 subjects age 18–55 years-old and applying DP diagnostic cutoffs from the last 14 years. They found the estimated prevalence rates were as high as 5.42% when using different statistical approaches, higher than the widely reported 2–2.5%. They discuss the strengths and weaknesses of using more inclusive cutoffs, such as identifying mild and major forms of DP based on DSM-5.
Michael Vaphiades
Leptomeningeal Interfoliar Enhancement on Vessel Wall MR Imaging as a Unique Radiologic Finding of Susac Syndrome.
Cardozo P, Marrodán M, Gilmore A, Fiol MP, Chaves H. Leptomeningeal interfoliar enhancement on vessel wall MR imaging as a unique radiologic finding of Susac syndrome. AJNR Am J Neuroradiol. 2023;44:271–273.
This retrospective case series study reported leptomeningeal interfoliar enhancement revealed by a newer magnetic resonance imaging (MRI) technique – vessel wall MRI based on a black blood 3 dimensional (D) T1-weighted sequence in 6 Susac’s syndrome patients. The authors found that when using this newer MRI sequence contrast enhancement was more conspicuous than when using 3D-fluid attenuated inversion recovery and 3D gradient-echo T1-weighted imaging, hence there was higher sensitivity in distinguishing cases of Susac’s syndrome from other vascular conditions. More interestingly, they detected a unique pattern of diffuse, infratentorial, interfoliar enhancement in four out of the six patients, which consisted of multiple thin, short, enhancing foci scattered along the folia of cerebellar vermis and hemisphere. This is different from the leptomeningeal enhancement seen in meningitis or carcinomatosis, which tend to be more contiguous and/or thicker. Another interesting finding is that none of the patients in this series or other published reports showed arterial vessel wall enhancement. The author proposed that this is possibly because Susac’s syndrome affects small calibre vessels (pre-capillary arterioles), which is not detected using current vessel wall-MRI techniques.
June Zhang
Funding Statement
The author(s) reported there is no funding associated with the work featured in this article.
Disclosure statement
No potential conflict of interest was reported by the author(s).