Annular Array Ultrasound in Ophthalmology
Condition: Posterior Vitreous Detachment; Diabetic Retinopathy
MeSH terms: Retinal Diseases; Diabetic Retinopathy; Vitreous Detachment
Study type: Observational

Summary: 
      The objective of this research is to improve the care of ocular disease and disorders, in
      particular the changes in the eye associated with diabetes, by providing clinicians with
      dramatically improved ultrasonic images of the entire eye. The research combines advanced
      high-frequency, high-resolution ultrasonic annular arrays transducers with new processing
      techniques designed to overcome several limits that have been reached with conventional high
      frequency ultrasound systems. The investigators propose that diagnosis of eye diseases using
      annular arrays can be more effective than the conventional ultrasound images by at least 50%;
      i.e., that for every 2 posterior vitreous detachments detected conventionally, 3 will be
      detected with the annular arrays.
    

Detailed description: 
      The goal of this study is to develop and evaluate advanced annular-array transducer
      technology for rapid, high-definition imaging. The study will assess high frequency
      ultrasound (HFU, 40 & 20 MegaHertz) annular arrays in imaging posterior vitreous detachments
      (PVDs) associated with diabetic retinopathy, the leading cause of blindness in the US
      working-age population according to Prevent Blindness America. Current HFU instruments do not
      use linear arrays for such applications because of a variety of technical and cost reasons.
      Instead, current HFU instruments use mechanically scanned, single-element transducers, which
      provide fine-resolution images over a very limited depth of field (DOF). For ophthalmic
      applications, a shallow DOF causes most ocular anatomy to be imaged with poor definition
      compared to the in-focus region; therefore, because only a small portion of the eye is in
      focus at a given time, detection and assessment of ocular conditions such as PVD are prone to
      inaccuracies and false-negative determinations. Annular-array transducers offer a promising
      approach to significantly extend DOF and to increase the depth range over which fine-lateral
      resolution is provided. The investigators will validate system performance using animal
      experiments and human-subject examinations. First, in vivo animal experiments will be
      conducted to evaluate a 40-MegaHertz (MHz) annular array for anterior-segment imaging and a
      20-MHz annular array for posterior segment and full-globe imaging. The investigators will
      test the hypothesis that 20-MHz annular arrays improve detection of PVD. Validation of this
      hypothesis will significantly improve our ability to assess disease status in diabetic
      retinopathy.
    

Intervention name(s): annular array ultrasound exam
Intervention type(s): Procedure
Intervention description(s): For this research study you will be asked to sit in a chair. You will be given 2 drops of a numbing solution. The ultrasound camera will be enclosed in a sterile membrane and will be placed gently upon your eye. You may be asked to gaze at a light source while measurements are being made. The procedure will last about 10-15 minutes from start to finish.
Observational model: Case-Only
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        University-based Ophthalmology Practice
      
Keywords: Annular Array Ultrasound; Ultrasound Exam; Posterior Vitreous Detachment; PVD; Diabetic Retinopathy