1. Ocular Injury After Thermal Blast from a Propane Tank Aruoriwo Oboh-Weilke, MD Florian A. Weilke, MD The authors have no financial interest in this subject matter

2. PURPOSE We report a case of a patient who suffered second degree burns to his face and presented with significant foreign body deposits in his conjunctiva, epithelial, sub-epithelial and stromal layers of his cornea after a propane tank fire related blast injury. The foreign bodies were of various compositions. The patient achieved excellent visual recovery after removal of the superficially embedded foreign particles, conservative management of the deeply embedded materials and aggressive lubrication of the ocular surface.

3. INTRODUCTION Thermal blast injuries can cause damage to the ocular and facial structures through several mechanisms. Potential damage from heat which can lead to 2 nd and 3 rd degree burns of the facial and eyelid structures. Damage to the globe from flames is usually limited by Bell’s phenomenon and rapid-reflex eyelid closure 1. Potential damage from heat which can lead to 2 nd and 3 rd degree burns of the facial and eyelid structures. Damage to the globe from flames is usually limited by Bell’s phenomenon and rapid-reflex eyelid closure 1. The other significant source of damage is from foreign particles, propelled at a high velocity from the blast. The other significant source of damage is from foreign particles, propelled at a high velocity from the blast.

4. INTRODUCTION Some of these structures may remain embedded in the cornea and result in a focal inflammatory response known as ophthalmia nodosum 1. They may also remain inert or migrate. Some of these structures may remain embedded in the cornea and result in a focal inflammatory response known as ophthalmia nodosum 1. They may also remain inert or migrate. Embedded particles also pose an infection risk. Embedded particles also pose an infection risk.

5. CASE REPORT A 43 year old male patient presented for a cornea evaluation by a referring ophthalmologist. The patient stated that he attempted to light a propane fired torch when uncontrolled combustion occurred, most likely due to a leak from the pressure regulator. The patient was standing on a gravel roadway at the time of the accident and his face was close to the torch at the time of the injury. The patient stated that he attempted to light a propane fired torch when uncontrolled combustion occurred, most likely due to a leak from the pressure regulator. The patient was standing on a gravel roadway at the time of the accident and his face was close to the torch at the time of the injury.

6. CASE REPORT He was evaluated and treated at the local Emergency Room for his facial burns and was seen by an ophthalmologist 24 hours later. Emergency Room for his facial burns and was seen by an ophthalmologist 24 hours later. The patient presented to me for a cornea evaluation 72 hours after his injury. On presentation he was complaining of pain and severe foreign body sensation.

7. CASE REPORT The exam revealed areas of erythema and blistering of his face, upper and lower eyelids, singed eyebrows and eyelashes. BCVA was 20/150 OD and 20/200 OS Pupils and IOPs were normal. There was severe bilateral injection and chemosis, 360 degrees with multiple embedded foreign bodies in the interpalpebral fissure nasally and temporally. Foreign particles were also present in the corneal epithelium, sub-epithelium and stroma. The foreign bodies were a mixture of metal, gravel and some unidentified refractile- appearing substance. They were too numerous to count There were large epithelial defects bilaterally. No foreign bodies were identified in the anterior chamber, angle, lens or iris. The posterior segment was unremarkable.

8. 72hrs after injury

10. RESULTS Saline lavage of the cornea and the cul-de-sac was performed. This removed some of the debris that was not embedded in the ocular surface. After topical anesthesia was applied, using a bent 25 gauge needle, the superficial particles were extracted without any difficulties. The patient was put on frequent preservative- free artificial tears, a cycloplegic and an antibiotic/steroid ointment

11. RESULTS 4 weeks after the injury the patient’s VA without correction was OD 20/20, and OS 20/25 +2. The epithelial surface of both corneas was fairly smooth. There were residual foreign particles in the stroma without significant inflammation. 7 months after the injury, the patient’s VA remains stable and the foreign materials in the cornea appear inert and have not shown any migration.

12. 28 days after injury

14. 4 months after injury

15. DISCUSSION Patients with severe blast injuries involving the facial structures and ocular structures sometimes have a delay in being referred to an ophthalmologist due to the severity of the injury to other parts of their body. Spencer et al report that prompt ophthalmologic examination and the early use of prophylactic ocular surface lubrication protect the cornea and decrease the need for surgical intervention 2. In a review of blast injuries to the eye by Zerihun, iris, conjunctival, corneal foreign-bodies, and corneal/ scleral lacerations were the most frequent types of injury seen 3 It is advisable to remove metallic foreign particles as materials left in the cornea may lead to persistent epithelial defects and inflammation 1.

16. DISCUSSION There are several tools that can be applied in evaluating and treating these patients. Anterior Segment Optical Coherence Tomography can be useful in establishing the location and size of these particles which in turn aids in management and follow-up 4. Patients with an irregular surface from corneal foreign bodies can also be treated with Phototherapeutic keratectomy 5

17. CONCLUSION Thermal blast accidents can cause significant injuries to the face and ocular structures. These injuries can also lead to the deposition of foreign objects in superficial and deep layers of the cornea. While it is important to remove the superficial foreign bodies, overly aggressive attempts at the removal of deep foreign particles could lead to corneal perforations or disruption of the corneal stroma. If there is no resultant inflammation or infection, these deeply embedded foreign bodies can be managed by close observation as it is possible to obtain good visual results without surgical intervention 1. Thermal blast accidents can cause significant injuries to the face and ocular structures. These injuries can also lead to the deposition of foreign objects in superficial and deep layers of the cornea. While it is important to remove the superficial foreign bodies, overly aggressive attempts at the removal of deep foreign particles could lead to corneal perforations or disruption of the corneal stroma. If there is no resultant inflammation or infection, these deeply embedded foreign bodies can be managed by close observation as it is possible to obtain good visual results without surgical intervention 1.

18. REFERENCES 1 External Disease and Cornea. Basic and Clinical Science Course 2007-2008; 404-406 2 Ophthalmic plastic reconstructive surgery 2002 May;18(3):196-201. 3 Blast injuries of the eye. Zerihun N. Trop Doct. 1993 Apr;23(2):76-8. 4 Anterior segment optical coherence tomography in eye injuries. Graefes Arch Clin Exp Ophthalmol. 2008 Sep 3. 5 Phototherapeutic keratectomy of diffuse corneal foreign bodies caused by gunpowder explosion. Yan Ke Xue Bao. 2005 Jun;21(2):70- 73

19. ACKNOWLEDGEMENT I would like to thank Dr Kindy for my participation in the care of this patient