Bilateral Optic Nerve Hypoplasia with Normal Visual Acuity

IntroductionIn patients with optic nerve hypoplasia (ONH), the visualisation of the optic disc can be challenging and the definitive diagnosis difficult to ascertain without fundus photography. The use of MRI for diagnosis has been reported as a diagnostic alternative with conflicting results. We retrospectively analysed a disease registry to determine the reliability of orbital MRI measurements of the optic nerve diameter to diagnose ONH, and the correlation with vision outcomes.Materials and methodsFrom a cohort of 140 patients with ONH (13% unilateral) that had reached age 5 years, we identified 43 subjects who had orbital MRI in addition to fundus photography performed prior to 2 years of age. We compared measurements of the optic nerve diameter from orbital MRI scans to the standard relative optic disc size (disc diameter/disc-macula (DD/DM) distance) by fundus photography. All patients had visual acuity tested at age 5 years. Spearman’s correlation coefficient was used to determine the correlation of orbital MRI measurements and fundus photography with the diagnosis of ONH, and with vision outcomes.ResultsRelative disc size (DD/DM)<0.35 showed 100% sensitivity and 100% specificity for the diagnostic confirmation of ONH. The optic nerve diameter measurements by orbital MRI displayed a moderate correlation (rs=0.471; p<0.001) with DD/DM and moderate sensitivity for the diagnosis of ONH. Final visual acuity correlated well with DD/DM measurements by fundus photography (rs=−0.869; p<0.001) and moderately with optic nerve diameter by orbital MRI (rs=−0.635; p<0.001).DiscussionOrbital optic nerve diameter from MRI scans has moderate reliability in diagnosing ONH and predicting vision outcomes. Fundus photography for measurements of the optic nerve size should remain the reference for diagnostic confirmation of ONH. These data further support the prognostic value of fundus photography for eventual vision outcomes in this population.

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Optic Nerve Hypoplasia With Good Visual Acuity

Archives of Ophthalmology ◽

10.1001/archopht.1972.01000030257005 ◽

1972 ◽

Vol 88 (3) ◽

pp. 255-258 ◽

Cited By ~ 25

Author(s):

H. B. Gardner ◽

A. R. Irvine

Keyword(s):

Visual Acuity ◽

Optic Nerve ◽

Optic Nerve Hypoplasia ◽

Good Visual Acuity

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Unexpected amaurosis occurring after peribulbar anesthesia: Exploring the causes in two cases

European Journal of Ophthalmology ◽

10.1177/1120672120984399 ◽

2020 ◽

pp. 112067212098439

Author(s):

Amina Rezkallah ◽

Nezar Gargori ◽

Philippe Denis ◽

Véronique Waldmann ◽

Thibaud Mathis ◽

...

Keyword(s):

Visual Acuity ◽

Optic Nerve ◽

Injection Site ◽

Anterior Segment ◽

Volume Effect ◽

Light Perception ◽

Ophthalmic Examination ◽

Normal Visual Acuity ◽

Disposable Needle ◽

Peribulbar Anesthesia

Peribulbar anesthesia (PB) is known to be safer than retrobulbar (RB) anesthesia. To our knowledge, no amaurosis has been described after PB. We report here the cases of two patients who underwent PB before membrane peeling. The injections were administered with a 25-gauge, 22-mm bevel disposable needle. The anesthetic used was ropivacaine 1% with a volume of 8 ml and 75 µg of clonidine as an adjuvant (7.5 µg/ml). Given that complete akinesia was not achieved, a second injection of 2 ml was administered in the supero-medial injection site. Thirty minutes after the PB, the first patient experienced amaurosis with no light perception (LP). The ophthalmic examination was normal. Visual acuity recovered after 1 day. Regarding the second patient, the loss of VA was observed 20 min after the PB. IOP was 20 mmHg. The anterior segment and fundus exam were normal. Rubin found the PB technique to be as effective and safer than RB injection, as the needles are not supposed to enter the RB space and Davis and Mandel found no amaurosis after PB. PB is administered via the extraconal injection of an anesthetic agent. These amaurosis might be explained by the fact that some anesthetic may have penetrated the RB space. In cases where two PB injections are administered, the anatomy is expected to change due to the volume effect of the first injection. The second injection is higher risk as it is administered closer to the optic nerve.

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