ROCK inhibition reduces morphological and functional damage to rod synapses after retinal injury

Area of Science:

• Ophthalmology
• Neuroscience
• Cell Biology

Background:

• Retinal detachment (RD) causes synaptic damage, specifically disjunction of the rod photoreceptor-bipolar synapse.
• This synaptic disruption contributes to poor visual recovery following retinal reattachment surgery.
• Current treatments for retinal diseases involving subretinal injections can cause iatrogenic RD.

Purpose of the Study:

• To investigate the structural and functional damage to the rod-bipolar synapse following iatrogenic retinal detachment.
• To evaluate the efficacy of a Rho-kinase (ROCK) inhibitor in preserving synaptic integrity and function after retinal detachment.

Main Methods:

• A porcine model of iatrogenic retinal detachment was established, mimicking human therapeutic procedures.
• Synaptic disjunction was quantified using image analysis of confocal sections.
• Rod-specific function was assessed using dark-adapted full-field electroretinograms.

Main Results:

• Synaptic disjunction was observed as early as 2 hours after detachment and persisted for 2 days, even after spontaneous reattachment.
• ROCK inhibition significantly reduced synaptic damage in detached retinas, regardless of injection method (subretinal or intravitreal).
• Reduced synaptic injury correlated with improved rod-driven responses in electroretinograms.

Conclusions:

• ROCK inhibition effectively prevents synaptic damage in a model of iatrogenic retinal detachment.
• This neuroprotective effect translates to improved visual function after retinal reattachment.
• ROCK inhibitors represent a promising adjunctive therapy for iatrogenic RD and other retinal degenerative conditions.