Hipoplasia segmentar superior de nervo óptico: diagnóstico diferencial com glaucoma / Superior segmental optic nerve hypoplasia: differential diagnosis with glaucoma

Resumo As alterações congênitas do nervo óptico são raras. A hipoplasia é a forma mais comum de alteração congênita do nervo óptico. Acredita-se que seja correlacionada à interrupção do desenvolvimento fetal e ao baixo peso ao nascer. Apresenta-se como uma anomalia não progressiva com acuidade visual geralmente preservada. Relatamos um caso de uma paciente com hipoplasia segmentar superior com hipertensão ocular após uso de corticoide, cursando com diminuição da camada de fibras nervosas. Os pacientes portadores de hipoplasia devem ser acompanhados com mais rigor caso tenham fatores de risco para glaucoma e deve ser considerada como um diagnóstico diferencial para o glaucoma de pressão normal.

Abstract Introduction: Congenital changes of the optic nerve are rare. Hypoplasia is the most common form of congenital alteration of the optic nerve. It is believed to be correlated with interruption of fetal development and low birth weight. It presents as a non-progressive anomaly with generally preserved visual acuity. We related a case of a patient with superior segmental hypoplasia with ocular hypertension after corticosteroid use, with a decrease in the nerve fiber layer. Patients with hypoplasia should be followed more closely if they have risk factors for glaucoma and should be considered as a differential diagnosis for normal pressure glaucoma.

Multimodal Imaging in a Case of Fovea Plana Associated with Situs Inversus of the Optic Disc

Fovea plana is a congenital condition characterized by anatomic absence of the foveal pit. It may be isolated or associated with congenital ocular anomalies. In this report, we present a case of fovea plana associated with situs inversus of the optic disc, optic disc hypoplasia, tilted optic disc, and prepapillary vascular loop and with best corrected visual acuity of 20/32. The aim of this report is to demonstrate the coexistence of very rare multiple optic disc anomalies and fovea plana, and also to emphasize that the use of multimodal imaging methods facilitates the identification of rare anomalies.

Radial peripapillary capillary density in superior segmental optic hypoplasia measured with OCT angiography.

BACKGROUND: To investigate the diagnostic power of radial peripapillary capillary (RPC) density, measured with optical coherence tomography angiography (OCT-A), in patients with superior segmental optic hypoplasia (SSOH). METHODS: Forty subjects with SSOH and 40 age- and axial length-matched control subjects were retrospectively registered for this study. SSOH was defined as intraocular pressure less than 21 mmHg with the presence of two of the following: superior rim thinning, superior entrance of the central retinal artery, scleral halo, and pale optic disc; as well as non-progressive visual field loss. RPC density was measured with swept-source OCT-A (Triton, Topcon) overall, in the quadrants, and in the 12 clock-wise sectors. Changes in RPC density were also compared in SSOH patients and age-matched patients with mild- or moderate-stage of glaucoma. RPC density was compared in pairs of groups with Welch's t-test. Diagnostic power was assessed with the area under the receiver operating characteristics curve (AUC). RESULTS: Overall cpRNFLT was significantly different in the normal (106.7 ± 9.5 µm) and SSOH (77.2 ± 13.7 µm, p <  0.001) subjects. RPC density overall and in the superior, nasal, and inferior quadrants was significantly lower in the SSOH group (all, p <  0.001), but not in the temporal (p = 0.756) quadrant. The diagnostic power of RPC density was highest in the superior quadrant (AUC = 0.928) and the 1 o'clock sector (0.896). Comparing the SSOH and glaucoma patients showed that there were no significant differences in RPC density either overall (p = 0.391) or in the superior quadrant (p = 0.268), while RPC density was significantly higher in the inferior (p = 0.005) and temporal quadrants (p <  0.001) and lower in the nasal quadrant (p = 0.029). CONCLUSIONS: Low RPC density was found in the three non-temporal quadrants of the optic nerve head in SSOH patients, in comparison to normal subjects. Regionally, RPC density in SSOH was lower in the nasal quadrant and higher in the inferior and temporal quadrants in comparison to glaucoma patients. Measuring RPC density with OCT-A may help the diagnosis of SSOH and may improve the management of glaucoma.

Usefulness of Optical Coherence Tomography Angiography in the Differential Diagnosis Between Superior Segmental Optic Hypoplasia and Normal-tension Glaucoma.

PURPOSE: The differential diagnosis of superior segmental optic hypoplasia (SSOH) and normal-tension glaucoma (NTG) is an issue in the ophthalmologic field. To date, several modalities have been developed to solve this issue; however, no standard methods have been established. Recently, optical coherence tomography angiography (OCTA) has been introduced to better evaluate the volumetric angiography images. Therefore, in this study, we investigated the usefulness of OCTA in differentiating between SSOH and NTG. MATERIALS AND METHODS: In this retrospective study, we included 26 patients with SSOH who had definite visual field defects and 40 patients with NTG who had only inferior visual field defects. Age, sex, intraocular pressure, refractive error, retinal nerve fiber layer thickness, and visual field defects were compared between the groups. In addition, we analyzed and compared the peripapillary vessel density (VD) measured on OCTA between the groups. The area under the receiver operating characteristic curves were obtained for each parameter. RESULTS: On Cirrus HD-OCT, the retinal nerve fiber layer in patients with SSOH was thinner in the superonasal segment and thicker in the superotemporal segment compared with patients with NTG. In the analysis of OCTA, the peripapillary VD of the superonasal segment was significantly lower in the SSOH group than in the NTG group, while it was significantly higher in the superotemporal segment in the SSOH group than in the NTG group. The optimal superonasal-to-superotemporal ratio cutoff was 0.8828, with a sensitivity of 95% and specificity of 92.3%, for the diagnosis of SSOH (area under the receiver operating characteristic curve=0.962). CONCLUSIONS: Our findings suggest that the superonasal-to-superotemporal VD ratio measured on OCTA may be used to distinguish between SSOH and NTG. However, further large-scale studies are required to verify our findings.

Electroretinograms in idiopathic infantile nystagmus, optic nerve hypoplasia and albinism.

PURPOSE: To study electroretinograms in infantile nystagmus syndrome associated with idiopathic infantile nystagmus, optic nerve hypoplasia, and albinism. METHODS: A total of 30 children with idiopathic infantile nystagmus, 18 with optic nerve hypoplasia, and 18 with albinism were studied. Three electroretinogram protocols were applied according to child's age: 58 (mean: 2.0 years) were recorded with skin electrode to Great Ormond Street Hospital protocol, 11 (mean: 5.3 years) with skin electrode to International Society for Clinical Electrophysiology of Vision protocol, and 7 children (mean: 12.2 years) with HK electrode to International Society for Clinical Electrophysiology of Vision protocol. The electroretinograms were compared to those of age-matched controls. RESULTS: Electroretinogram waveforms in idiopathic infantile nystagmus, optic nerve hypoplasia, and albinism were comparable to controls in all protocols. Electroretinogram amplitudes in idiopathic infantile nystagmus group showed increased white scotopic and photopic electroretinograms in 26 children (skin electrode to Great Ormond Street Hospital protocol), no difference to the controls in 3 children (skin electrode to International Society for Clinical Electrophysiology of Vision protocol), and increased rod electroretinogram in 3 children (HK electrode to International Society for Clinical Electrophysiology of Vision protocol). Optic nerve hypoplasia group showed increased white scotopic, photopic, and blue electroretinograms in 15 children (skin electrode to Great Ormond Street Hospital protocol); increased 30-Hz electroretinogram in 3 children (HK electrode to International Society for Clinical Electrophysiology of Vision protocol); and reduced combined rod-cone, cone, and 30-Hz electroretinograms in 3 children (skin electrode to International Society for Clinical Electrophysiology of Vision protocol). Albinism group showed increased white scotopic, photopic, and 30-Hz electroretinograms in 17 children (skin electrode to Great Ormond Street Hospital protocol), while it showed reduced cone and 30-Hz electroretinograms in 5 children (skin electrode to International Society for Clinical Electrophysiology of Vision protocol). Implicit times were shorter in albinism. CONCLUSION: Electroretinogram waveforms in idiopathic infantile nystagmus, optic nerve hypoplasia, and albinism were normal with mostly increased electroretinograms, while reduced electroretinograms did not show a specific pattern as in early-onset retinal dystrophies.