Publications by authors named "Tak Chuen Simon Ko"

Cone-rod dystrophy (CORD) is a type of progressive hereditary retinal dystrophies that causes cone predominant photoreceptor degeneration characterized by wide genotypic and phenotypic heterogeneity. Macular cyst (MC) occurs very infrequently in the pediatric age group and has rarely been described in CORD. We report a case of young-onset CORD that was affected by an isolated mutation complicated by the development of MC.

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Hybrid peripheral nerve sheath tumors (HPNST) are recently classified tumors from the World Health Organization Classification of soft tissue tumors that display combined features of more than one peripheral nerve sheath tumor. Acknowledgment is important because of its association with the development of neurofibromatosis type 1, type 2, and schwannomatosis. Orbital involvement is rare and only six cases of HPNST have been documented on literature.

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Purpose: Primary orbital schwannoma (POS) is a slow growing, benign encapsulated peripheral nerve sheath tumor that occurs infrequently within the orbit. Recurrence of POS is extremely rare. Previous speculations for reasons of recurrence include incomplete excision and tumor seeding.

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Background: Microphthalmia, anophthalmia, coloboma (MAC) complex is a spectrum of ocular abnormalities that occur in isolation or as part of a syndrome. Genetic abnormalities have been shown to account for 80% of cases in bilateral anophthalmia or severe microphthalmia, where 25-30% were attributed to chromosomal defects in this subset of MAC patients. To date, chromosome 9 short arm (9p) abnormalities have not been shown to associate with development of MAC.

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Purpose: To report the germicidal range ultraviolet (UV) irradiation-induced phototoxicity because of unprotected exposure to the UV lamps for presumed household disinfection of SARS-CoV-2 in a domestic setting.

Methods: We report on a family of 3 adults who experienced photophobia, intense eye pain, epiphora, blurred vision, and a burning sensation over the face and neck area after a short period of unprotected exposure to the UV germicidal lamps.

Results: An initial examination revealed erythema and tenderness over the face and neck area, reduced visual acuity of 6/12, and conjunctival injections bilaterally in all 3 patients.

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Purpose: Tsukamurella is an important and emerging organism that causes opportunistic human infection. We present the largest case series of Tsukamurella species-associated ophthalmic infections, with an emphasis on clinical spectrum, risk factors, treatment, and outcome.

Methods: A case series of culture-positive Tsukamurella species in ocular microbiological specimens was identified retrospectively from 2005 to 2018.

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