[Phototherapeutic keratectomy of diffuse corneal foreign bodies caused by gunpowder explosion]

To investigate the clinical effects of phototherapeutic keratectomy (PTK) on the treatment of diffuse corneal foreign bodies caused by gunpowder explosion.

From Dec, 1999 to Dec, 2003, 39 eyes of 25 patients with diffuse foreign bodies on cornea caused by gunpowder explosion were investigated in this study. All foreign bodies located in one third of superficial cornea and conjunctiva. Besides slit-lamp biomicroscope examination and cornea thickness measurement, ultra-sound B, VEP and ERG were used to exclude the possibility of damage of posterior ocular segments. Then the PTK was performed at every 100-150 pulse-interval. In case of damaging to deep cornea, the total pulse was less than 500 and corneal thickness was measured during the operation. After operation, vision acuity, recovery of corneal epithelium, haze, intraocular pressure and ametropia were checked and the patients were followed up for 6 months.

Compared with traditional therapies used for diffused corneal foreign bodies, PTK generally took shorter time (10 minutes). It could erase most foreign bodies on cornea and had little injury to normal corneal tissue. Commonly, the corneal epithelial layer recovered completely within one week. The vision acuity after PKT was improved notablely. The mean value of vision acuity at 10th day of post-operation is 0.6 (vs < 0.3 in all patients before operation). There were 38 eyes with gentle hyperopia and 1 eye with moderate hyperopia. The complication of PTK can be controlled during operation or after operation by drugs.

PTK is a facile, effective, hypo-cost method for the treatment of diffused foreign bodies on cornea damaged by gunpowder explosion.