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Case of unilateral peripheral cone dysfunction.

Mochizuki Y, Shinoda K, Matsumoto CS, Klose G, Watanabe E, Seki K, Kimura I, Mizota A - Case Rep Ophthalmol (2012)

Bottom Line: A severe constriction of the visual fields was found in both eyes but more in the right eye.The photopic full-field electroretinograms (ERGs) were reduced in the right eye but normal in the left eye.Although the visual dysfunction was initially suspected to be due to psychological problems from the results of subjective tests, objective tests indicated a peripheral cone dysfunction in the right eye.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, Juntendo University Urayasu Hospital, Chiba, Tokyo, Japan.

ABSTRACT

Purpose: Peripheral cone dystrophy is a subgroup of cone dystrophy, and only 4 cases have been reported. We present a patient with unilateral peripheral cone dysfunction and report the functional changes determined by electrophysiological tests and ultrastructural changes determined by spectral domain optical coherence tomography (SD-OCT).

Case: A 34-year-old woman complained of blurred vision in both eyes. Our examination showed that her visual acuity was 0.05 OD and 0.2 OS. A relative afferent pupillary defect was present in her right eye. The results of slit-lamp examination, ophthalmoscopy, and fluorescein angiography were normal except for pallor of the right optic disc. SD-OCT showed a diffuse thinning of the retina in the posterior pole of the right eye. A severe constriction of the visual fields was found in both eyes but more in the right eye. The photopic full-field electroretinograms (ERGs) were reduced in the right eye but normal in the left eye. The multifocal ERGs were severely reduced throughout the visual field except in the central area of the right eye. The multifocal ERGs from the left eye were normal. The pattern visual evoked responses were within the normal range in both eyes. She had a 5-year history of sniffing paint thinner.

Results: Although the visual dysfunction was initially suspected to be due to psychological problems from the results of subjective tests, objective tests indicated a peripheral cone dysfunction in the right eye. The pathophysiological mechanism and the relationship with thinner sniffing were not determined.

Conclusions: Our findings indicate that peripheral cone dysfunction can occur unilaterally. Electrophysiology and SD-OCT are valuable tests to perform to determine the pathogenesis of unusual ocular findings objectively.

No MeSH data available.


Related in: MedlinePlus

Full-field and multifocal electroretinograms (ERGs) recorded from our patient with unilateral peripheral cone dystrophy. Full-field ERG showed that rod responses are symmetrical in both eyes, but the responses of cone system are flat in the right eye while normal in the left eye. The multifocal ERGs are severely attenuated in the peripheral retinal area while that from the central area is normal in the right eye. The response density in the left eye was normal.
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Figure 2: Full-field and multifocal electroretinograms (ERGs) recorded from our patient with unilateral peripheral cone dystrophy. Full-field ERG showed that rod responses are symmetrical in both eyes, but the responses of cone system are flat in the right eye while normal in the left eye. The multifocal ERGs are severely attenuated in the peripheral retinal area while that from the central area is normal in the right eye. The response density in the left eye was normal.

Mentions: The amplitudes of the full-field scotopic b-waves of the ERGs were within normal range in both eyes (fig. 2), and that of the mixed rod:cone ERGs were also within normal range. The oscillatory potentials (OPs) and the photopic cone ERGs were unrecordable in the right eye, i.e., less than the noise level (5 μV for OPs and 20 μV for the photopic cone ERGs), and the flicker ERGs were highly attenuated by approximately 95% of that of the right eye. The responses from the left eye were essentially normal except that the amplitude of the scotopic rod ERGs was at the lower limit of the normal range.


Case of unilateral peripheral cone dysfunction.

Mochizuki Y, Shinoda K, Matsumoto CS, Klose G, Watanabe E, Seki K, Kimura I, Mizota A - Case Rep Ophthalmol (2012)

Full-field and multifocal electroretinograms (ERGs) recorded from our patient with unilateral peripheral cone dystrophy. Full-field ERG showed that rod responses are symmetrical in both eyes, but the responses of cone system are flat in the right eye while normal in the left eye. The multifocal ERGs are severely attenuated in the peripheral retinal area while that from the central area is normal in the right eye. The response density in the left eye was normal.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC3369245&req=5

Figure 2: Full-field and multifocal electroretinograms (ERGs) recorded from our patient with unilateral peripheral cone dystrophy. Full-field ERG showed that rod responses are symmetrical in both eyes, but the responses of cone system are flat in the right eye while normal in the left eye. The multifocal ERGs are severely attenuated in the peripheral retinal area while that from the central area is normal in the right eye. The response density in the left eye was normal.
Mentions: The amplitudes of the full-field scotopic b-waves of the ERGs were within normal range in both eyes (fig. 2), and that of the mixed rod:cone ERGs were also within normal range. The oscillatory potentials (OPs) and the photopic cone ERGs were unrecordable in the right eye, i.e., less than the noise level (5 μV for OPs and 20 μV for the photopic cone ERGs), and the flicker ERGs were highly attenuated by approximately 95% of that of the right eye. The responses from the left eye were essentially normal except that the amplitude of the scotopic rod ERGs was at the lower limit of the normal range.

Bottom Line: A severe constriction of the visual fields was found in both eyes but more in the right eye.The photopic full-field electroretinograms (ERGs) were reduced in the right eye but normal in the left eye.Although the visual dysfunction was initially suspected to be due to psychological problems from the results of subjective tests, objective tests indicated a peripheral cone dysfunction in the right eye.

View Article: PubMed Central - PubMed

Affiliation: Department of Ophthalmology, Juntendo University Urayasu Hospital, Chiba, Tokyo, Japan.

ABSTRACT

Purpose: Peripheral cone dystrophy is a subgroup of cone dystrophy, and only 4 cases have been reported. We present a patient with unilateral peripheral cone dysfunction and report the functional changes determined by electrophysiological tests and ultrastructural changes determined by spectral domain optical coherence tomography (SD-OCT).

Case: A 34-year-old woman complained of blurred vision in both eyes. Our examination showed that her visual acuity was 0.05 OD and 0.2 OS. A relative afferent pupillary defect was present in her right eye. The results of slit-lamp examination, ophthalmoscopy, and fluorescein angiography were normal except for pallor of the right optic disc. SD-OCT showed a diffuse thinning of the retina in the posterior pole of the right eye. A severe constriction of the visual fields was found in both eyes but more in the right eye. The photopic full-field electroretinograms (ERGs) were reduced in the right eye but normal in the left eye. The multifocal ERGs were severely reduced throughout the visual field except in the central area of the right eye. The multifocal ERGs from the left eye were normal. The pattern visual evoked responses were within the normal range in both eyes. She had a 5-year history of sniffing paint thinner.

Results: Although the visual dysfunction was initially suspected to be due to psychological problems from the results of subjective tests, objective tests indicated a peripheral cone dysfunction in the right eye. The pathophysiological mechanism and the relationship with thinner sniffing were not determined.

Conclusions: Our findings indicate that peripheral cone dysfunction can occur unilaterally. Electrophysiology and SD-OCT are valuable tests to perform to determine the pathogenesis of unusual ocular findings objectively.

No MeSH data available.


Related in: MedlinePlus