Corneal Side Effects Of Prolonged Use Of Benoxinate Eye Drops; Abuse By Welders.

To evaluate the corneal side effects associated with the prolonged and excessive use of Benoxinate hydrochloride eye drops among welders, who frequently misuse them for temporary pain relief from welding-related eye injuries.

Prof. Dr. Hazem Yassin ophthalmology centres.

A 40-year-old male welder with a 2-year history of frequent and excessive use of Benoxinate eye drops for pain relief from welding-related eye discomfort presented with severe ocular symptoms; sudden drop of vision, severe pain and photophobia in both eyes. Clinical examinations were performed, including slit-lamp biomicroscopy, corneal fluorescein staining, and corneal sensitivity testing. Diagnostic imaging was conducted using:

• Visual Evoked Potentials (VEP)
• Electroretinography (ERG)
• Anterior Segment Optical Coherence Tomography (AS-OCT)
• Ultrasound Biomicroscopy (UBM)

The patient with chronic and excessive use of Benoxinate eye drops presented with: severe ocular pain, photophobia and sudden drop in vision in both eyes (HM). Slit-lamp examination revealed: corneal melting, corneal perforation and anterior synechiae. AS-OCT and UBM showed: Corneal thinning, complete disruption of the corneal layers with iris prolapse at the site of perforation and loss of AC depth. VEP and ERG demonstrated: abnormal responses suggesting optic nerve involvement.
   Management: Penetrating Keratoplasty (PKP) OU with anterior segment reconstruction, including peripheral iridectomy, to restore the anterior chamber and prevent further complications as elevation of IOP.

Vision improved to 0.2 OD and 0.25 OS post operative.

The case illustrate the severe ocular consequences of prolonged benoxinate eye drop use, leading to corneal perforation, anterior synechiae, and sudden vision loss with optic nerve involvement. Diagnostic tools, such as VEP, ERG, AS-OCT, and UBM, were crucial in diagnosing and assessing the extent of the damage. Surgical intervention with penetrating keratoplasty, anterior segment reconstruction, and peripheral iridectomy was necessary to address the complications. These cases highlight the need for increased clinical awareness, public education, and regulatory measures to prevent the misuse of topical anesthetics, particularly in high-risk occupations like welding.