Related Experiment Videos
Respirator retina
Abstract:
Retinas from 14 comatose patients, who had been sustained with a respirator for one or more days before death, had selective characteristic alterations (ie, autophagy, cell swelling, and coagulation necrosis) of inner nuclear layer in a patchy pattern in posterior fundus. Bipolar cells were most often affected, but amacrine and horizontal cells also were substantially damaged. Cells of Müller and vascular cells were largely spared. These lesions are ascribed to oligemia (ischemia) since the inner nuclear layer is a microscopic vascular watershed (boundary zone) between the choroidal and retinal circulations.
Insights
Comatose patients on respirators showed specific retinal damage, primarily affecting inner nuclear layer cells like bipolar cells. This damage is linked to reduced blood flow (oligemia) in a critical retinal boundary zone.
Area of Science:
- Ophthalmology
- Neurology
- Pathology
Background:
- Comatose patients requiring mechanical ventilation may experience systemic physiological changes.
- The retina's inner nuclear layer is a critical area for visual processing and is known to be sensitive to ischemic events.
Purpose of the Study:
- To investigate characteristic pathological alterations in the retinas of comatose patients sustained by a respirator.
- To determine the specific cell types affected within the inner nuclear layer and hypothesize the underlying cause of these changes.
Main Methods:
- Post-mortem examination of retinal tissue from 14 comatose patients.
- Microscopic analysis to identify cellular changes such as autophagy, cell swelling, and coagulation necrosis.
- Correlation of observed retinal lesions with patient's clinical status (respirator support duration).
Main Results:
- Selective, patchy alterations were observed in the inner nuclear layer of the posterior fundus.
- Bipolar cells were most frequently affected, with significant damage also noted in amacrine and horizontal cells.
- Müller cells and vascular cells showed relative sparing; lesions were attributed to oligemia (ischemia) in the vascular watershed.
Conclusions:
- The inner nuclear layer of the retina is vulnerable to ischemic damage in comatose patients on ventilators.
- Specific cellular pathology (autophagy, swelling, necrosis) characterizes retinal ischemia in this patient group.
- The findings highlight the retina's susceptibility to compromised circulation, particularly in the boundary zone of its vascular supply.