Drusen de la tête du nerf optique ou œdème papillaire ?

Optic nerve sheath diameter and axial length in patients with optic disc drusen: a cross-sectional study

AIM

Measuring the optic nerve sheath diameter (ONSD) and the anteroposterior axial length of the eye in patients with optic disc drusen (ODD).

METHODS

A total of 43 healthy volunteers and 41 patients with ODD were included in the study. The ONSD and axial length were measured in the posterior position using an ultrasound device (E-Z Scan AB5500 +) probe with a 10 MHz frequency. The ONSD was measured 3 mm behind the globe wall. Receiver operating characteristic (ROC) curve analysis was performed to determine patients with ODD using ONSD. Any p-value of < 0.05 was accepted to demonstrate significance.

RESULTS

The ONSD was significantly higher (5.2 mm and 4.8 mm, p = 0.006, respectively), and the axial length was shorter (21.82 ± 2.15 mm and 23.27 ± 1.96 mm, p = 0.002, respectively) in the ODD group. The spherical equivalent was more commonly seen as hypermetropic in the ODD group (1.00 [- 0.85 to 1.75]). In the ROC analysis to determine the ONSD value in ODD diagnosis, the area under the curve was 0.6754 (95% confidence interval 0.559-0.788, p = 0.006). ONSD cutoff of 5.70 mm had a sensitivity of 0.366 and a specificity of 0.907 to diagnose ODD.

CONCLUSION

In this study, the ONSD was significantly higher in the ODD group. The axial length was shorter in the ODD group. This study is the first in the literature to evaluate the ONSD in patients with optic disc drusen. Further studies are needed in this regard.

Visual field defects due to optic nerve drusen in Afro-Caribbean patients: A case series of 16 eyes

INTRODUCTION

Optic Nerve Head Drusen (ONHD) are very rare among black patients but may cause more severe visual defects in these patients. The goal of our study was to describe the frequency of visual field defects secondary to OND in Afro-Caribbean patients and study the characteristics of their physical examination, color vision and contrast sensitivity.

METHODS

We carried out a prospective study at the Martinique university medical center on patients of African descent with ONHD diagnosed on fundus examination and B-scan ultrasonography. All patients received a complete neuro-ophthalmological examination. The primary study endpoint was the frequency of visual field defects. Secondary study endpoints were the results of ETDRS visual acuity, Pelli-Robson contrast sensitivity chart, and 15 hue color vision test.

RESULTS

Sixteen eyes of 10 patients from 11 to 68 years of age were included. Forteen eyes (87%) had exposed ONHD. Eleven eyes (69%) showed a visual field defect: 9 eyes (69%) had an enlarged blind spot, and 9 eyes (69%) had an arcuate scotoma. 3 eyes (19%) had loss of ETDRS visual acuity, and 12 eyes (75%) showed loss of Pelli-Robson contrast sensitivity. Five eyes (31%) had an abnormal color vision test.

CONCLUSION

This is one of the largest case series of ONHD in Black patients. The frequency of visual field defects was high but comparable to that of studies in other ethnic groups. Larger comparative studies are necessary to confirm these results.

A study of optic nerve head drusen in 38 pseudoxanthoma elasticum (PXE) patients (64 eyes). Location of optic nerve head drusen in PXE

PURPOSE

To investigate the prevalence and location of optic nerve head drusen and their potential association with other PXE-related ophthalmic abnormalities.

MATERIALS AND METHODS

Thirty-eight of the 155 patients (57 male and 98 female aged 49±17 years) included in this retrospective study had optic nerve head drusen. All of the patients underwent a comprehensive ophthalmic examination, including color images using red-free, blue and red filters, autofluorescence imaging and late-phase ICG frames. Comparative analysis of both groups (optic nerve head drusen or not) was conducted using R statistical software.

RESULTS

The prevalence of optic nerve head drusen in our cohort was 24.5%. In this study, no evidence of a significant link between optic nerve head drusen and other fundus abnormalities was detected. They were more commonly located in the nasal sector than in the temporal sector of the optic disc (P<0.001). They were more frequently situated superonasally than inferonasally (P<0.004), superotemporally (P<0.001) or inferotemporally (P<0.03). No central visual field defect was observed in OND+ patients who were unaffected by macular disorders.

DISCUSSION

We hypothesized this predominantly nasal primary location may result from greater sensitivity in the nasal optic nerve fibers which follow a much more angular path once they arrive in the scleral canal, accounting for accumulation of axoplasmic debris.

CONCLUSION

In PXE, optic nerve head drusen are mostly located in the superonasal quadrant, causing progressive optic nerve invasion but probably no central visual field defects.

Congenital optic nerve anomalies

OBJECTIVE

To update the current knowledge about congenital optic disc anomalies.

METHODS

A comprehensive literature search was performed in the major biomedical databases.

RESULTS

Patients with these anomalies usually have poor vision in infancy. Refractive errors are common, and serous retinal detachment may develop in some of these anomalies. It is critically important to clinically differentiate between these congenital optic disc anomalies, as central nervous system malformations are common in some, whereas others may be associated with systemic anomalies.

CONCLUSIONS

Congenital optic disc anomalies are a heterogeneous group of pathologies with characteristic fundus appearance and systemic associations. We should always try to make a correct diagnosis, in order to ask for specific tests, as well as to provide an adequate follow-up.