# Osmotic regulation in the cone dystrophy, CDSRR

> **NIH EY R21** · UNIVERSITY OF IOWA · 2026 · $440,263

## Abstract

Project Summary
Vision is our primary sense. We rely on vision for everything from building our sense of reality,
to navigating obstacles, identifying threats, and reading text and emotions. Untreatable vision
loss beginning in childhood is often emotionally devastating and incurs a lifetime of healthcare
expenses. This is the situation for people with Cone Dystrophy with Supernormal Rod
Response (CDSRR), alternatively referred to as KCNV2 Retinopathy. In CDSRR there is a
decline of vision in early childhood, followed by progressive macular degeneration by early
adulthood. The hindrance to developing sight preserving treatments for CDSRR is that the
etiology of macular degeneration is unknown. CDSRR is caused by mutations in a
photoreceptor-specific potassium channel, Kv2.1/Kv8.2. As such CDSRR can be considered a
disease of disrupted potassium homeostasis in the outer retina. Regulated potassium flux is
essential for the electrical response of photoreceptors to light and can create osmotic gradients
that drive water transport. Since photoreceptors have a high rate of mitochondrial respiration,
generating excess metabolic wastewater that must be exported, we propose that loss of
Kv2.1/Kv8.2 potassium channels in CDSRR reduces clearance of wastewater from
photoreceptors, activating chronic osmotic stress signaling. In this project, we will use state-of-
the-art imaging biomarkers and transcriptomics to evaluate osmotic regulation in mouse models
of CDSRR.

## Key facts

- **NIH application ID:** 11303692
- **Project number:** 1R21EY037416-01A1
- **Recipient organization:** UNIVERSITY OF IOWA
- **Principal Investigator:** BRUCE A. BERKOWITZ; Sheila A Baker
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** EY
- **Fiscal year:** 2026
- **Award amount:** $440,263
- **Award type:** 1
- **Project period:** 2026-05-01T00:00:00 → 2028-04-30T00:00:00

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11303692

## Citation

> US National Institutes of Health, RePORTER application 11303692, Osmotic regulation in the cone dystrophy, CDSRR (1R21EY037416-01A1). Retrieved via AI Analytics 2026-05-19 from https://api.ai-analytics.org/grant/nih/11303692. Licensed CC0.

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