Sequelae of carbide-related thermo-chemical injury: A retrospective analysis

Abstract

Purpose: To describe the outcomes of eyes with calcium carbide (CaC₂)-related thermo-chemical injury.

Methods: This study included 28 eyes of 23 patients who presented with calcium carbide-related ocular burns. Only patients with more than three months of follow-up were included. Group A included 16 eyes with Dua's Grade I-III burns, while Group B included 12 eyes with Grade IV-VI burns. Electronic medical records were reviewed to provide data on the etiology of burn, presenting clinical signs and visual acuity, sequelae, and surgical interventions performed, both in the acute and chronic phases.

Results: The overall mean age was 28.48 ± 11.8 years. Fifteen patients were injured while using carbide to create an explosion to scare away animals on farms. The median presenting BCVA (best-corrected visual acuity) in Group A (20/160) was significantly better than in Group B [(20/2000) (P = 0.002)]. Five eyes in Group A and one eye in Group B underwent medical management. There was no difference in the duration of follow-up for both groups (P = 0.24). The median final BCVA in Group A (20/32) was significantly better than in Group B [(20/200) (P = 0.02)]. Two eyes in Group A and nine eyes in Group B developed LSCD. Two eyes in Group B were phthisical at the last visit.

Conclusion: Calcium carbide-related ocular injuries can result in significant visual morbidity in young adults. Early presentation and management may improve outcomes. Prevention of these injuries by increasing awareness and increasing advocacy efforts is necessary.

Keywords: Calcium carbide; carbide gun; firecracker; thermal injury.

Figure 1

a-c Depicting the same eye, (a) LE Grade III injury, amniotic membrane transplantation (AMT) performed; (b) At 5 months follow-up, central nebulo-macular corneal scar seen with early partial LSCD superonasally; (c) Corneal scar with partial LSCD superonasally at 8 months follow-up post-injury, managed conservatively. d–f depicting the same eye, (d) RE, Grade III injury with multiple corneal foreign bodies noted, AMT and tarsorrhaphy performed; (e) At 6 weeks follow-up, retained AM noted superiorly with underlying corneal scarring with a superior symblepharon; (f) At 4 months follow-up, superior corneal scar with partial LSCD and superior symblepharon; g-i depicting the same eye, (g) RE, Grade III injury, AMT and tarsorrhaphy performed; (h) At 1-year follow-up, a supertemporal symblepharon, partial LSCD was noted, symblepharon release with conjunctival autografting was done; (i) At 15 months, the stable ocular surface was noted

Figure 2

a-c Depicting the same eye; (a) RE Grade VI injury, Persistent epithelial defect noted 2 months post-injury, VA-CFCF; (b) Post SLET, 1-week follow-up; (c) At 5 weeks follow up, epithelised cornea noted with some residual stromal scar, VA-20/160. d–f depicting the same eye; (d) RE Grade VI injury, amniotic membrane transplantation (AMT) done; (b) Total LSCD noted 3 months post-injury, VA-HM, SLET was planned. (c) Three months post SLET, VA of 20/160 recovered with recurrence of partial LSCD superiorly

Figure 3

(a) Histopathology of the corneal button after carbide injury (10x, Hematoxylin and eosin stain) showing stromal necrosis and scattered mixed inflammatory cells (encircled). The DM was fragmented and folded (asterisks); (b) Von Kossa Histochemical stain (40x) showed brown calcium deposits in between stromal fibers and over the DM (rectangle); (c) Pearl’s stain (40x) for iron showed iron granules in the stroma (arrow); (d) Immunohistochemical stain (10x) showed loss of collagen-I in the stroma (10x); (e and f) Immunohistochemical stain (5x and 20x) showed faint expression of collagen-IV in the stroma (brown discoloration of stroma)