Spontaneous anatomical and functional recovery of bilateral electric shock maculopathy.

A 12-year-old boy presented with best-corrected visual acuity (BCVA) of 6/9 in both eyes following an episode of electric shock. Optical coherence tomography (OCT) showed disruption of the ellipsoid zone as well as retinal pigment epithelium (RPE) layer. Fundus autofluorescence (FAF) showed increased central hypoautofluorescence in both eyes. At 3-month follow-up, BCVA improved to 6/6 with OCT showing spontaneous resolution of maculopathy in both eyes with reorganized RPE layer and ellipsoid zone. To the best of our knowledge, this is the first case of bilateral electric shock maculopathy (ESM) with spontaneous anatomical as well as functional recovery. Ophthalmologists must be aware of various forms of ESM. OCT and FAF must be done in patients presenting with defective vision and history of electric shock for the diagnostic as well as prognostic evaluation.

Electrocution is a common mode of injury accounting for 5%–20% burns among all causes of burns.[1] Ocular complications resulting from electric shock injuries are well known but uncommon including eyelid skin burns, cataract, recurrent uveitis, optic neuropathy, and rarely maculopathies.[2] Cataract is the most common ocular manifestation of electrocution, but electric shock maculopathy (ESM) is very rarely reported in the literature. Herewith, we are reporting a case of ESM with spontaneous anatomical as well as visual recovery.

Case Report

A 12-year-old boy visited our outpatient department with a complaint of blurring of vision in both eyes for 2 weeks following an episode of electric shock. Electrocution resulted from domestic accident with hand being the entry point and feet being the exit point. It also caused a brief period of unconsciousness. There was no history of ocular trauma, sun gazing, or exposure to a solar eclipse or welding arc. On examination, best-corrected visual acuity (BCVA) was 6/9 in both eyes. Anterior segments of both eyes were unremarkable. Both fundi showed a dark red spot at the central fovea and otherwise were within normal limits [Fig. 1a and b]. Spectral domain-optical coherence tomography (SD-OCT) [SPECTRALIS HRA + OCT, Heidelberg] showed disruption of the ellipsoid zone as well as retinal pigment epithelium (RPE) layer [Fig. 2a and b]. Fundus autofluorescence (FAF) [SPECTRALIS HRA + OCT, Heidelberg] showed increased central hypoautofluorescence in both eyes [Fig. 3a and b]. Based on the history, clinical findings, and imaging, a diagnosis of ESM was made. The patient was treated conservatively and reviewed after 3 months. At the 3-month follow-up visit, his BCVA improved to 6/6 in both eyes. OCT showed near-complete resolution of maculopathy with reorganized ellipsoid zone and minimal irregularities in RPE layer [Fig. 2c and d]. FAF showed a slight improvement in central hypoautofluorescence of both eyes [Fig. 3c and d]. To the best of our knowledge, this is the first case of ESM in the literature with bilateral spontaneous complete anatomical and functional recovery.

Figure 1

Color fundus photograph of right and left eye (a and b, respectively) at the time of first presentation showing dark red spot at fovea appearing as cherry red spot

Figure 2

Optical coherence tomography image of right and left eye at the first visit showing disruption of ellipsoid zone and retinal pigment epithelium layer with intact external limiting membrane (a and b respectively). At 3-month follow-up, optical coherence tomography image showing intact external limiting membrane, spontaneously reorganized ellipsoid zone, and near normal retinal pigment epithelium layer (c and d, respectively)

Figure 3

Fundus autofluorescence image of right and left eye at the first visit showing increased central hypoautofluorescence (a and b, respectively) and relatively decreased central hypoautofluorescence at 3-month follow-up (c and d, respectively)

Discussion

ESM is a rare clinical entity with very few case reports available in the literature.[345678] Our case probably represents the mildest form of ESM characterized by disruption of RPE and photoreceptor layer and showing spontaneous resolution. However, the most commonly reported form of ESM is characterized by defect in RPE and outer retinal layers progressing to form outer lamellar hole with intact internal limiting membrane (ILM) over the bare RPE, with or without associated cystic changes noted on OCT. This form of ESM represents a more extensive or progressive damage from electric shock.[345] Full-thickness macular hole (FTMH) is a relatively rare form of ESM and represents the most severe injury from electric shock.[678]

Tissue damage from electric shock may occur through one or more mechanisms including direct transmission of electric current through the tissues causing cell membrane disruption, thermal burn of the tissues by absorbing thermal energy resulting from conversion of electrical energy, tissue ischemia caused by generalized vascular constriction, or mechanical injury resulting from high voltage shock wave.[69] There are various factors which make the macula, particularly, sensitive for electrocution-related damages. Foveal avascularity increases the risk of ischemic insult of macula following electric shock-induced multifocal choroidal ischemia.[610] Higher concentration of melanin pigments at macula due to thicker and more tightly packed submacular RPE cells causes more heat production and consequently more thermal damage.[411] Macula being one of the sites of strongest vitreoretinal adhesion carries more risk of mechanical injury resulting from concussive forces of the electric shock and vitreomacular traction due to thermal shrinkage of the vitreous body.[6]

FAF imaging of our case showed mild central hypoautofluorescence without any parafoveolar ring of hyperautofluorescence and correlated well with good visual prognosis. However, the case reported by Arya et al. showed an increased central hypoautofluorescence surrounded by decreased parafoveolar hypoautofluorescence, which corresponded to a drop in visual acuity and progression of OCT changes.[12] Although FAF imaging was not reported in other cases of ESM, the importance of perifoveal ring of hyperautofluorescence as a predictive marker for the progression of other macular disorders such as macular dystrophy, cone dystrophy, retinitis pigmentosa, and hydroxychloroquine toxicity is well established.[13] Hence, it may be considered for ESM also to get significant prognostic input.

ESM may remain stationary, regress spontaneously, or progress over a period. Cases have shown an improvement in BCVA with corresponding tomographic improvement while fundus picture remaining similar to or appearing better than the initial presentation.[34] Our case, probably being the mildest form of ESM, showed complete anatomical as well as visual recovery. Over a longer period, outer lamellar defect may undergo remodeling or gliosis and may be replaced by atrophic macular scar as reported by Bayar et al.[5] Arya et al. reported a decrease in BCVA with OCT showing ellipsoid zone defect progressing to OLH over a period of 3 months.[12] Case reported by Faustino et al. presented with outer lamellar hole with associated cystoid changes, which progressed to FTMH and rhegmatogenous retinal detachment in both eyes.[8]

The visual prognosis of ESM is generally good even with observation as seen in our as well as previously reported cases. Surgical intervention with ILM peeling and perfluoropropane (C3F8) gas tamponade has been described for one eye with outer lamellar defect with intact ILM.[11] Surgical intervention resulted in visual improvement from 6/30 to 6/19 with a decrease in lamellar hole size with persistent discontinuity of RPE and photoreceptor layers. The other eye of the same patient was kept under observation, and condition remained stable.[11] The presenting, as well as final visual outcome, depends on the severity of maculopathy and the presence of visually significant ocular comorbidities such as anterior segment and optic nerve involvement.[346] Hence, eyes presenting with outer retinal layer defect should be kept under observation with OCT and FAF imaging at every visit to monitor the progression or regression. For a better understanding of various aspects of this rare clinical entity, we have provided a comprehensive table of previously reported cases of ESM detailing mode of injury, presenting visual acuity, ocular comorbidities, features of maculopathy, management, and final visual acuity [Table 1].

Table 1

Summary of all previously reported cases of electric shock maculopathy

Conclusion

We describe a heretofore unreported case of ESM with documented bilateral spontaneous functional and anatomic recovery. This case report also highlights the possible role of FAF for prognostic evaluation of ESM. Ophthalmologists must be aware of the various forms of ESM. A history of electric shock exposure must be enquired in young patients presenting with such maculopathy without any history of sun gazing, exposure to solar eclipse, welding arc, or ocular trauma. Patients presenting with defective vision and history of electric shock must be examined on OCT, even in the absence of a clinically obvious maculopathy.[17]

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.