[Corneal scars: confocal images as the basis of qualifying for PTK or PK]

The study aimed to evaluate corneal scars of various origin using confocal microscopy in order to qualify patients for phototherapeutic keratectomy or penetrating keratoplasty.

We studied 21 patients with scars of various origins in 28 corneas. The age of patients (9 women and 12 men) ranged from 27 to 47 years (mean 31.8). In 10 patients (17 corneas) scars were caused by superficial or profound inflammatory processes of viral, bacterial or fungal origin. In 7 patients (7 corneas) the causative factor was blunt or lacerating injury (linear and planar) and in 4 patients (4 corneas) scars developed after the removal of foreign bodies. All corneas were examined using a ConfoScan-P4 scanning slit confocal microscope (Tomey).

Post-inflammation scars differed in microscopic appearance, depending on the etiology and clinical state, which affected the mode of treatment. Three scars caused by penetrating trauma were qualified for penetrating keratoplasty. Out of 4 scars caused by non-penetrating trauma, 2 were treated by PTK and 2 by penetrating keratoplasty. In patients with impaired vision after the removal of corneal foreign bodies, confocal microscopy revealed focal areas of increased illumination and intracorneal encrustations.

Confocal microscopy enabled us to determine the structure of corneal scar and the depth at which each scar was located, which helped us to choose between PTK and penetrating keratoplasty. The presence or absence of needle-like structures allowed us to detect inflammatory processes within the scar and to evaluate the state of the remaining corneal tissue.