enhanced S-cone syndrome

Enhanced S-cone Syndrome (ESCS): A Rare Inherited Retinal Degeneration

Enhanced S-cone syndrome (ESCS) is a rare inherited autosomal recessive retinal degeneration, characterized by increased sensitivity to blue light. This condition affects the retina's ability to function properly, leading to visual impairments.

Key Features:

• Increased sensitivity to blue light: Patients with ESCS have an enhanced sensitivity to blue light, which can cause discomfort and visual disturbances.
• Night blindness: Night blindness is a common symptom of ESCS, occurring from early in life.
• Impaired central vision: Central vision is affected, making it difficult for patients to perform daily tasks that require good visual acuity.
• Rods and red/green cone receptors degeneration: Rods and red/green cone receptors are degenerated, while S-cones (short-wavelength cones) are enhanced.

Causes:

ESCS is caused by disease-causing variants in the nuclear receptor subfamily 2, group E, member 3 (NR2E3) gene. This gene plays a crucial role in regulating photoreceptor development and cell-type specific phototransduction [9][10].

Diagnosis:

Diagnosing ESCS can be challenging, but it is essential to consider this condition in patients with presumed intermediate uveitis of unclear etiology that is irresponsive to conventional treatment, particularly in young patients [11]. A comprehensive eye examination and genetic testing can help confirm the diagnosis.

References:

• [1] Enhanced S-cone syndrome is a rare inherited autosomal recessive retinal degeneration.
• [9] ESCS is mainly caused by mutations in the NR2E3 gene that encodes the nuclear receptor class 2, subfamily E, member 3.
• [10] An autosomal recessive retinopathy in which patients have increased sensitivity to blue light; perception of blue light is mediated by what is normally the least populous cone photoreceptor subtype, the S (short wavelength, blue) cones.
• [11] Enhanced S-cone syndrome, and by extension the larger group of inherited retinal degenerations (IRDs), should be considered a diagnostic possibility in any patient with a presumed intermediate uveitis of unclear etiology that is irresponsive to conventional treatment.

Common Signs and Symptoms of Enhanced S-Cone Syndrome

Enhanced S-cone syndrome (ESCS) is a rare inherited progressive retinal degeneration that can cause severe vision loss. The clinical signs encompass a combination of symptoms, including:

• Nyctalopia: Difficulty seeing at night or in low light conditions, which was the most common presenting symptom in 83.33% of cases [3].
• Diminution of vision: A decrease in visual acuity, affecting 50% of patients [3].
• Floaters: Seeing small spots or cobwebs floating in front of the eyes, reported by 7.14% of patients [3].
• Nummular pigmentation: Deep round pigmentation at the level of the retinal pigment epithelium (RPE), usually located in the mid-peripheral retina, along with yellow-white dots and constricted field of vision [1][2][5].

These symptoms can vary in severity and may be associated with a constricted field of vision. Patients typically present with night blindness from the first decade, with or without reduced vision [6]. The visual loss may be associated with various fundus appearances, including nummular pigmentation, yellow-white dots, and constricted field of vision [8].

It's essential to note that ESCS is a rare condition, and these symptoms can have varying degrees of severity. If you suspect someone has ESCS or any other eye-related issue, it's crucial to consult an eye care professional for proper diagnosis and treatment.

References: [1] ER de Carvalho (2021) - Cited by 44 [2] ER de Carvalho (2021) - Cited by 44 [3] A Naik (2019) - Cited by 8 [5] ER de Carvalho (2021) - Cited by 44 [6] S Hull (2014) - Cited by 40 [8] I Audo (2008) - Cited by 132

Diagnostic Tests for Enhanced S-Cone Syndrome

Enhanced S-Cone Syndrome (ESCS) is a rare inherited progressive retinal degeneration that can cause severe vision loss. Diagnosing ESCS requires a combination of clinical findings, electrophysiologic testing, and genetic analysis.

• Electroretinography (ERG): ERG is a crucial diagnostic tool for ESCS. It measures the electrical activity of the retina in response to light stimulation. In patients with ESCS, ERG typically shows a pattern of night blindness, maculopathy, and enhanced S-cone sensitivity [1][2].
• Psychophysical testing: Psychophysical tests, such as dark adaptation and visual field assessments, can help confirm the diagnosis of ESCS by demonstrating impaired night vision and visual field defects [3].
• Genetic testing: Genetic testing for mutations in the NR2E3 or NRL genes can confirm the diagnosis of ESCS. This is particularly useful for differential diagnosis with other conditions that may present with similar clinical features, such as nyctalopia [4].

References:

[1] Marmor MF, Jacobson SG, Foerster MH. Diagnostic clinical findings of a new syndrome with night blindness, maculopathy, and enhanced S cone sensitivity. Am J Ophthalmol 1990;110:124-134.

[2] de Carvalho ER. Clinical history, examination, imaging, and electrophysiologic findings of 56 patients (age range, 1–75 years) diagnosed with ESCS were reviewed. Diagnosis was confirmed by ERG, psychophysical testing, and/or mutation analysis in the NR2E3 or NRL genes.

[3] Yzer S. Regardless of the clinical presentation, the diagnosis of ESCS will need to be confirmed by ERG, psychophysical testing, and/or mutation analysis in the NR2E3 or NRL genes.

[4] de Carvalho ER. Clinical history, examination, imaging, and electrophysiologic findings of 56 patients (age range, 1–75 years) diagnosed with ESCS were reviewed. Diagnosis was confirmed by ERG, psychophysical testing, and/or mutation analysis in the NR2E3 or NRL genes.

Note: The above information is based on search results from various medical sources and may not be comprehensive or up-to-date. It's essential to consult a qualified healthcare professional for accurate diagnosis and treatment of Enhanced S-Cone Syndrome.

Treatment Options for Enhanced S-cone Syndrome

Enhanced S-cone syndrome (ESCS) is a rare genetic disorder that affects the retina, leading to visual impairment. While there is no cure for ESCS, various treatment options can help manage the condition and improve visual function.

• Oral Acetazolamide: A study published in 2009 found that oral acetazolamide, a carbonic anhydrase inhibitor, was effective in treating macular retinoschisis (RS) associated with ESCS [1][2]. This treatment can help reduce fluid accumulation in the retina and improve visual function.
• Low Vision Aids: Visual aids such as magnifying glasses, telescopes, or closed-circuit television (CCTV) devices can be beneficial for individuals with ESCS. These tools can enhance visual perception and aid in daily activities [4].
• Cataract Surgery: In some cases, cataract surgery may be necessary to improve vision in individuals with ESCS. This surgical procedure involves removing the cloudy lens of the eye and replacing it with an artificial one [4].

Current Medical Management

The current medical management for ESCS includes treating foveomacular schisis and cystoid macular edema (CME) with carbonic anhydrase inhibitors, while choroidal neovascularization is managed separately [5]. A comprehensive treatment plan should be tailored to the individual's specific needs and visual symptoms.

References

[1] Iannaccone et al. (2009). Treatment of adult-onset acute macular retinoschisis in enhanced s-cone syndrome with oral acetazolamide. [3]

[2] Iannaccone et al. (2009). Original article. Treatment of Adult-Onset Acute Macular Retinoschisis in Enhanced S-cone Syndrome With Oral Acetazolamide. [3]

[4] Orphanet summary on ESCS

[5] Current medical management for ESCS, including treatment of foveomacular schisis and CME with carbonic anhydrase inhibitors.

Note: The above information is based on the search results provided in the context section.

Understanding Differential Diagnosis in Enhanced S-Cone Syndrome

Enhanced S-cone syndrome (ESCS) is a rare inherited progressive retinal degeneration that can cause severe vision loss. When diagnosing ESCS, it's essential to consider differential diagnosis, which involves ruling out other conditions that may present similar symptoms.

Conditions to Consider:

• Nyctalopia: Night blindness is a common symptom of ESCS, but it can also be caused by other conditions such as Vitamin A deficiency, cataracts, and autoimmune disorders [6][8].
• Variable visual acuity loss: ESCS patients may experience varying degrees of visual acuity loss, which can also be seen in other retinal dystrophies [9].
• Constricted field of vision: A constricted field of vision is another symptom of ESCS, but it can also be caused by conditions such as glaucoma and optic neuropathy.

Key Considerations:

• Genetic testing: Molecular confirmation of disease-causing variants in the NR2E3 gene or diagnostic full-field electroretinography (ffERG) can help establish a diagnosis of ESCS [5][8].
• Funduscopic findings: New funduscopic findings, such as macular schisis and atrophic changes, may be present in patients with ESCS and can aid in differential diagnosis [3].

Differential Diagnosis:

The differential diagnosis for ESCS includes conditions that present similar symptoms, such as nyctalopia, variable visual acuity loss, and constricted field of vision. A comprehensive evaluation, including genetic testing and funduscopic examination, is essential to rule out other conditions and establish a diagnosis of ESCS.

References:

[3] S Yzer · 2013 · Cited by 70 — New funduscopic findings in patients with enhanced S-cone syndrome (ESCS) may help clinicians in diagnosing this rare autosomal recessive retinal dystrophy. [5] by ER de Carvalho · 2021 · Cited by 44 — Diagnosis was established by molecular confirmation of disease-causing variants in the NR2E3 gene (n = 38) or by diagnostic full-field ... [6] Aug 23, 2023 — Differential diagnosis: Nyctalopia has a broad differential and includes conditions such as Vitamin A deficiency, cataracts, autoimmune ... [8] by ER de Carvalho · 2021 · Cited by 44 — Previously reported symptoms of patients with ESCS include nyctalopia, variable visual acuity loss, and constricted field of vision.33, 34, 35 The clinical ...