Keratocyte loss after different methods of de-epithelialization

Area of Science:

• Ophthalmology
• Corneal Biology
• Cellular Response to Injury

Background:

• Corneal stromal cells, known as keratocytes, are crucial for maintaining corneal structure and transparency.
• Superficial corneal injuries can impact keratocyte populations and lead to inflammation.
• Understanding the differential response of keratocytes to various injury methods is vital for clinical practice.

Purpose of the Study:

• To compare the effects of different superficial de-epithelialization methods on rabbit corneal stromal cells.
• To assess the inflammatory response associated with each injury type.

Main Methods:

• Rabbit corneas were subjected to de-epithelialization using mechanical methods, chemicals (ethanol, proparacaine, cocaine), or an excimer laser.
• Histologic analysis was performed 24 hours post-injury to quantify keratocyte numbers and inflammatory cell infiltration.
• Control groups received no treatment.

Main Results:

• All de-epithelialization methods significantly decreased keratocyte counts compared to controls.
• 0.5% proparacaine and 100% ethanol resulted in a more pronounced keratocyte reduction than mechanical injury, 4% cocaine, or excimer laser.
• All injury groups exhibited increased polymorphonuclear leukocytes, indicating inflammation. Mechanical methods with or without proparacaine showed the least inflammation, while laser injury induced more inflammation.

Conclusions:

• Superficial corneal injury, regardless of method, leads to a significant loss of keratocytes and acute inflammation within 24 hours.
• Chemical agents, particularly 100% ethanol, should be used with caution due to their detrimental effect on keratocytes.
• Further research is needed to determine the clinical relevance of these findings in human corneas.