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Characterizing Rate of progression in USHer syndrome type 2 (CRUSH) study

Characterizing Rate of progression in USHer syndrome type 2 (CRUSH) study - CRUSH

Status
Active, not recruiting
Phases
Unknown
Study type
Observational
Source
NL-OMON
Registry ID
NL-OMON46184
Enrollment
50
Registered
2018-12-05
Start date
2019-02-11
Completion date
Unknown
Last updated
2026-04-14

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

progression of the hearing and vision loss in Usher syndrome Usher syndrome

Interventions

None listed

Sponsors

Radboud Universitair Medisch Centrum
Lead Sponsor

Eligibility

Age
18 Years to 99 Years

Inclusion criteria

Inclusion criteria: - clinically diagnosed with rod-cone degeneration and congenital hearing loss, and at least two; pathogenic or likely pathogenic mutations in one of the Usher type 2 genes; - Willing and able to complete the informed consent process; - Ability to return for all study visits over 48 months; - Age >= 18 years.;Both eyes must meet all of the following: - Clinical diagnosis of a rod-cone degeneration; - Clear ocular media and adequate pupil dilation to permit good quality photographic imaging; - Ability to perform kinetic and static perimetry reliably; - Baseline visual acuity ETDRS letter score of 54 or more [approximate Snellen equivalent 20/80 or better]; - Stable fixation ; - Clinically determined [on Octopus 900 Pro] kinetic visual field III4e area 10° or more in the study

Exclusion criteria

Exclusion criteria: A potential subject who meets any of the following criteria will be excluded from participation in this study: - Mutations in genes that cause autosomal dominant RP, X-linked RP, or presence of biallelic mutations in autosomal recessive RP/retinal dystrophy genes other than the Usher gene - Expected to enter experimental treatment trial at any time during this study - History of more than 1 year of cumulative treatment, at any time, with an agent associated with pigmentary retinopathy (including hydroxychloroquine, chloroquine, thioridazine, and deferoxamine);If either eye has any of the following, the patient is not eligible: - Current vitreous hemorrhage - Current or any history of rhegmatogenous retinal detachment - Current or any history of (e.g., prior to cataract or refractive surgery) spherical equivalent of the refractive error worse than -8 Diopters of myopia - History of intraocular surgery (e.g., cataract surgery, vitrectomy, penetrating keratoplasty, or LASIK) within the last 3 months - Current or any history of confirmed diagnosis of glaucoma (e.g., based on glaucoma visual field, nerve changes, or glaucoma filtering surgery) - Current or any history of retinal vascular occlusion or proliferative diabetic retinopathy - Expected to have cataract removal surgery during the study - History or current evidence of ocular disease that, in the opinion of the investigator, may confound assessment of visual function - History of treatment for retinitis pigmentosa that could affect the progression of retinal degeneration (including participation in a clinical trial within the last year or a retained drug delivery device);If either ear has any of the following, the patient is not eligible: - The audiometric PTA(1-2-4kHz) for the best hearing ear should not exceed 75dB HL. Patients with (bilateral) cochlear implants cannot participate in the study. - A planned cochlear implantation during the study.

Design outcomes

Primary

MeasureTime frame
- Visual field sensitivity measured by static perimetry with topographic analysis (Hill of Vision) - Best corrected E-ETDRS visual acuity - Mean retinal sensitivity as measured by fundus-guided microperimetry - EZ area as measured by SD-OCT - Rod- and cone-mediated retinal function as measured by FST - Retinal function using full-field ERG amplitudes and timing in response to rod- and cone-specific stimuli - Hearing function and perception of sounds and words - Vestibular function

Secondary

MeasureTime frame
None

Countries

Netherlands

Outcome results

None listed

Source: NL-OMON (via WHO ICTRP) · Data processed: Apr 17, 2026