Biosketch / Results /

Karen Holopigian-Cahill

Professor, Department of Ophthalmology

Contact Info

462 First Avenue
New York, NY 10016


Research Summary

Our research involves the electrophysiological examination of the sites and mechanisms of rod and cone function in patients with retinal diseases, including diabetes, open-angle glaucoma, AIDS, and retinitis pigmentosa, an inherited, progressive degenerative disease. Our research has a twofold purpose: 1) to provide prognostic information to ophthalmologists and patients and 2) to provide information about the mechanisms and pathogenesis of the disease. Currently, we use the full-field, flash electroretinogram (ERG) to measure the electrical response of the eye to brief, high intensity flashes. We then use a model of receptor activity to derive fits to these data and estimate the parameters of Rmax (maximum response amplitude) and log S (sensitivity). The results on patients with diabetes indicated that, for the majority of the patients, Rmax was normal, but log S was reduced, consistent with deficits in photoreceptor transduction. Analysis of b-wave and oscillatory potential parameters provided evidence for rod and cone postreceptoral abnormalities not accounted for by receptoral changes. Presently, we are applying this technique to the visual processing of patients with open-angle glaucoma to determine whether recent anatomical reports of outer retinal losses in these patients can be verified using electrophysiological techniques.

Research Interests

Electrophysiological Analysis of Rod/Cone Activity in Retinal Disease

A primer on common statistical errors in clinical ophthalmology
Holopigian, Karen; Bach, Michael
2012-02-05; 1573-2622,Documenta ophthalmologica - id: 114196, year: 2010 Journal Article

Scotopic sensitivity and color vision with a blue-light-absorbing intraocular lens
Greenstein, Vivienne C; Chiosi, Flavia; Baker, Paul; Seiple, William; Holopigian, Karen; Braunstein, Richard E; Sparrow, Janet R
2012-02-05; 0886-3350,Journal of cateract & refractive surgery - id: 71300, year: 2007 Comparative Study; Journal Article

Eccentricity-dependent changes in local onset and offset responses in patients with progressive cone dystrophy
Holopigian, K; Wynn, P; Seiple, W; Carr, R E; Hood, D C
2012-02-05; 0042-6989,Vision research - id: 73870, year: 2007 Journal Article

A prospective study of rod and cone function in patients with dominantly inherited, progressive cone dystrophy
Holopigian, K; Greenstein, VC; Seiple, W; Gallardo, JM; Noble, KG; Carr, RE
2012-02-05; 0146-0404,Investigative ophthalmology & visual science. IOVS - id: 56199, year: 2005

Multifocal visual evoked potentials to cone specific stimuli in patients with retinitis pigmentosa
Holopigian, K; Shuwairi, S M; Greenstein, V C; Winn, B J; Zhang, X; Carr, R E; Hood, D C
2012-02-05; 0042-6989,Vision research - id: 61418, year: 2005 Journal Article