Multimodal imaging including optical coherence tomography angiography in patients with type B Niemann-Pick disease

[Ocular manifestation of an adult Niemann-Pick disease type B]

Niemann-Pick disease is a rare, autosomal recessive inherited lysosomal storage disorder. The pathophysiological background for this condition is the deficiency or reduced function of the enzyme sphingomyelinase, as well as a deficiency in the intracellular cholesterol transporter protein. Due to the breakdown defect, sphingomyelin and cholesterol accumulate in the lysosomes of cells. The disease is divided into 5 subtypes (A, A/B, B, C, D). The authors present the case of a 24-year-old young man diagnosed with Niemann-Pick disease type B as a child, focusing on the ophthalmic manifestation of the disease. During the examination of the patient, fundus photographs and fundus autofluorescence imaging were taken, and optical coherence tomography (OCT), optical coherence tomography angiography (OCTA), and visual field (perimetry) examinations were performed. The characteristic macular halo and the cherry-red spot in the fovea were clearly visible during ophthalmoscopy and on the fundus photographs. The OCT images showed focal thickening with high reflectivity in the ganglion cell layer corresponding to the macular halo, and the area of the foveola was spared. With visual field examination, an intact field of vision was found on both eyes. Similar to the presented patient, symptoms in patients with the B subtype are milder, and besides the visceral symptoms, there are no neurological symptoms, and the specific ophthalmic abnormalities do not cause visual impairment. Currently, Niemann-Pick disease is considered a rare disease, and the diagnosis of the patients is often delayed or even missed due to non-specific or mild symptoms. Through consultation between medical specialties, ophthalmological examination can also contribute to the correct diagnosis in cases with mild general symptoms. Timely diagnosis can potentially lead to mitigation of symptoms thanks to the ever-expanding therapeutic options, stabilization of the disease progression, and increase of the patients' life expectancy. Orv Hetil. 2023; 164(46): 1838-1844.

Optical Coherence Tomography Findings in Cherry-Red Spot: Implications for Understanding Pathophysiology and Visual Prognosis

PURPOSE

To report optical coherence tomography (OCT) findings of cherry-red spots from Tay-Sachs and Niemann-Pick disease.

METHODS

Consecutive patients with Tay-Sachs and Niemann-Pick disease evaluated by the pediatric transplant and cellular therapy team, for whom a handheld OCT scan was obtained, were included. Demographic information, clinical history, fundus photography, and OCT scans were reviewed. Two masked graders evaluated each of the scans.

RESULTS

The study included 3 patients with Tay-Sachs disease (5, 8, and 14 months old) and 1 patient with Niemann-Pick disease (12 months old). All patients had bilateral cherry-red spots on fundus examination. In all patients with Tay-Sachs disease, handheld OCT revealed parafoveal ganglion cell layer (GCL) thickening, increased nerve fiber layer, and GCL reflectivity, and different levels of residual normal signal GCL. The patient with Niemann-Pick disease had similar parafoveal findings, but there was a thicker residual GCL. Sedated visual evoked potentials were unrecordable in all 4 patients despite 3 of them demonstrating normal visual behavior for age. Patients with good vision had relative sparing of the GCL on OCT.

CONCLUSIONS

The cherry-red spots in lysosomal storage diseases appear as perifoveal thickening and hyperreflectivity of the GCL on OCT. In this case series, residual GCL with normal signal proved to be a better biomarker for visual function than visual evoked potentials and could be considered for future therapeutic trials. [J Pediatr Ophthalmol Strabismus. 2023;60(6):435-440.].

Sutureless fixation of amniotic membrane using a soft ring for ocular surface diseases

PURPOSE

To evaluate the efficacy of sutureless amniotic membrane transplantation using a soft bioavailable ring in the management of ocular surface disorders.

METHODS

We present a modified technique using a soft, special designed bioavailable ring set (Amnioring) for sutureless amniotic membrane fixation to the ocular surface. A fresh amniotic membrane with a diameter greater than the outside diameter of the ring was folded inwardly over the ring such that the inner side of the ring was covered with the amniotic membrane. The ring was inserted onto the ocular surface.

RESULTS

The ring was inserted in 4 eyes of 4 consecutive patients with ocular surface disorders. The mean total operating time was 3 min. The ring fixated the amniotic membrane to the bulbar conjunctiva and provided a quick and easy sutureless placement of amniotic membrane. In all cases, pain was significantly relieved. The corneal epithelial defect and inflammation were markedly reduced.

CONCLUSIONS

This novel ring designed for sutureless placement of amniotic membrane provided very good anatomic and functional outcomes in patients with ocular surface disorders. It is less invasive, less time consuming and allows placement in the office conditions with low cost.