We read with great interest the original article by Chaurasia and his colleague regarding corneal changes in xeroderma pigmentosum, a clinicopathologic report. They have postulated that endothelial cells can be damaged and reduced by exposure to ultraviolet (UV) light in patients with xeroderma pigmentosum (XP). Although there are many papers concerning the corneal pathologies in XP, the exact mechanism of corneal changes is unknown.
We have recently published an article about a 17-year-old woman with XP including bilateral mature cataract developing in the past couple of years without any ocular trauma or any history of inadequate diet or of previous corticosteroid use. Although we had used the stop-chop technique with very low ultrasonic energy during the standard cataract surgery for her left eye, corneal edema was more than we expected, and it took longer for the corneal edema to disappear. So we performed a specular microscopy on her right eye prior to cataract surgery, and the mean specular microscopic cell density was 923 ± 59 cells/mm 2 . Perhaps the endothelial cells were damaged and reduced by UV light exposure. So we used a quick chop technique and reduced the amount of energy during phacoemulsification to decrease the endothelial damage. The patient’s final best-corrected visual acuities were 20/20 and 20/30, respectively, at her final visit after 36 months of follow-up. After the submission, we saw a 21-year-old man with XP and mature cataracts without any causes leading to the cataracts. It has strengthened our theory that, apart from the effect of UV rays on the ocular surface, even the lens can be damaged; such damage is manifested as a cataract, and that cataract may be related to the improper working of the DNA repair mechanism of the lens epithelial cells in patients with XP.
Routine cataract surgery has been shown to induce an endothelial cell density loss of 6.3% to 12.8%. In a patient with XP and low endothelial cell density, cataract surgery may hasten the necessity of a corneal transplant. Because of this possibility, corneas of XP patients are examined carefully with specular microscopy before cataract surgery. In compromised corneas, it is of great significance to use a technique that is the least traumatic to the corneal endothelium and to reduce the amount of energy during phacoemulsification. Patients with XP and very low endothelial cell density may also undergo both cataract surgery and a corneal transplant at the same time. Combining 2 separate surgeries into a single procedure can help to reduce recovery time.
We also wonder whether the authors took any special precautions during the cataract surgeries in patients with XP to prevent corneal decompensation after surgery.
As a consequence, if possible, specular microscopy should be done routinely in patients with XP, particularly prior to cataract surgery, even when the clinical examination of the cornea shows it to be normal.