Laser-Induced Maculopathy Masquerading as Hereditary Macular Dystrophy.

There has been an emergence of permanent macular injury due to the misuse of handheld laser pointers. The clinical phenotype of laser-induced maculopathy can mimic hereditary retinal dystrophies. This report describes the clinical phenotype and the results of multimodal imaging in a 27-year-old woman who was referred with a bilateral progressive decrease in vision over 2 months. She was initially diagnosed elsewhere with hereditary macular dystrophy. Examination of her fundus showed bilateral creamy-to-gray irregular lesions in the posterior pole. The results of multimodal imaging of her retina suggested self-inflicted laser-induced maculopathy. The patient was referred to a psychiatrist with a working diagnosis of factitious disorder. A high index of suspicion and the utilization of multimodal imaging allowed early and correct diagnosis and prevented further loss of vision. Copyright:

Introduction

Lasers can produce a highly monochromatic coherent beam that is collimated and has limited divergence.[1] Because of the short exposure time to lasers and the presence of natural protective mechanisms, such as the blink reflex, they are generally harmless. However, misuse of lasers may cause permanent retinal damage.[2] Recently, there has been an emergence of permanent macular injury due to the misuse of handheld laser pointers.[3] The absence of a pathognomonic pattern of retinal lesions along with a patient's denial makes the diagnosis challenging. Here, we present a case initially diagnosed as hereditary macular dystrophy; however, the results of the multimodal retinal imaging suggested self-inflicted macular burns caused by a handheld laser.

Case Report

A 27-year-old otherwise healthy woman was referred to our clinic with a history of bilateral progressive decrease in vision over 2 months. Her past ocular history was unremarkable. In her initial evaluation elsewhere, she was diagnosed with hereditary macular dystrophy (Stargardt's disease). This was probably based on the presence of small yellow bilateral lesions in the macular area. She then visited our clinic with a corrected Snellen visual acuity of 20/50 in the right eye and 20/80 in the left eye. Her color vision was markedly decreased in both eyes. Her biomicroscopic anterior segment examination was unremarkable. Examination of the dilated fundus showed a clear vitreous with creamy-to-gray irregular lesions in the posterior pole, as well as, small yellow foveal spots and epithelial changes in the retinal pigment [Figure 1a].

Figure 1

Examinations at presentation. (a) Color fundus photographs of the right and left eyes showing retinal pigment epithelial changes at the macula. (b) Fundus autofluorescence imaging of both eyes showing variable hypoautofluorescent lesions surrounded by areas of hyperautofluorescence involving the macula, and some lesions are linear (white arrows). (c) spectral-domain optical coherence tomography of both eyes showing outer retinal atrophy, clumping of the pigment epithelial layer, and right parafoveal pigment epithelial detachment. (d) Fundus fluorescein angiography of both eyes revealed hypofluorescent lesions surrounded by a rim of hyperfluorescence, indicating scars; some lesions are in a linear pattern (yellow arrows)

A thorough uveitis examination was performed, including a fluorescent treponemal antibody absorption test, purified protein derivative test, and QuantiFERON-TB Gold test, all of which provided negative results. Fundus autofluorescence revealed hyperautofluorescent and hypoautofluorescent lesions, some with a linear configuration [Figure 1b].

Results of spectral-domain optical coherence tomography (OCT) showed small detachments in the pigment epithelium with parafoveal outer segment disruption in the left eye [Figure 1c]. The fluorescein angiography showed early small hypofluorescent spots surrounded by a hyperfluorescent rim and a few linear lesions [Figure 1d]. OCT angiography of both eyes showed an absence of blood flow at the level of the choriocapillaris, which corresponded to the areas affected by the laser burns [Figure 2].

Figure 2

(a and d) En face optical coherence tomography angiography (12.0 mm × 12.0 mm) images of both eyes segmented at the level of the choriocapillaris showing an absence of flow signal in the affected areas. (b and c) En face OCT-A (6.0 mm × 6.0 mm) magnified images showing a signal void at the choriocapillaris level corresponding to the affected areas

Based on the findings from the multimodal imaging, when the patient was asked about the possible use of a handheld laser pointer, she reported a history of using a red laser pointer with her siblings as a child but denied any recent history of self-induced laser ocular burns or insult to her as a child. Because of the patient's denial and presence of bilateral retinal burns, the patient was referred to a psychiatrist. The initial impression was that these macular injuries were probably the signs of a factitious disorder, which was further confirmed by a psychiatric evaluation.

At the last follow-up, 4 months after her initial presentation, her visual acuity improved to 20/20 in the right eye but remained 20/80 in the left eye. Examination of her fundus revealed multiple irregular scars involving the macula of both eyes. Her OCT results revealed bilateral outer retinal atrophy, with the left eye affected more than the right eye [Figure 3].

Figure 3

Examinations at the last follow-up. (a and b): Color fundus photographs of the right and left eyes showing multiple irregular scars involving the macula. (c and d) Spectral-domain optical coherence tomography of both eyes showing outer retinal atrophy affecting macula, with the left eye affected more than the right eye

Ethical statement

This study followed the tenets of the Declaration of Helsinki and was approved by the Institutional Review Board of King Khaled University Hospital. Written informed consent was obtained from the participant.

Discussion

Laser pointers of different power levels and wavelengths (red, green, and blue) are commonly available. The World Health Organization recommended, “Laser pointers higher than Class 2” are too powerful for general use and “present an unacceptable risk in the hands of consumers because they may cause eye injury.”[1] Class 2 laser products have a maximum power of 1 mW and fall within the visible wavelength range of 400 − 700 nm2. The degree of harm depends on the power. However, even when low-power lasers are used, photothermal injury to the retina may occur with prolonged exposure. Moreover, the human lens focuses the laser farther into the retina, which theoretically increases the power of the laser.

Reports of handheld laser-induced maculopathy have been increasing recently.[3] Torp-Pedersen et al.,[3] reported that more laser pointer ocular injuries were self-inflicted than inflicted by assaults. The results of multimodal imaging suggested self-inflicted laser injury and showed disease bilaterality, lesions in the central and superior parts of the macula, linear distribution of some lesions, and a bizarre distribution of other lesions. The self-inflicted lesions affecting mainly the central and the superior part of the macula are related to Bell's phenomenon.[4] Iris atrophy has been reported in some of these cases[4] but was absent in our patient. This is probably because the patient would foveate while exposing the eye to the laser. Foveation concentrates the laser on the fovea and has been reported in some cases of self-inflicted laser maculopathy. Contrastingly, in cases of macular injury by accidental laser exposure, the laser beam strikes different parts of the eye, including the iris.

Visual improvement after 4 months was probably due to the discontinuation of self-injury by laser. However, the visual acuity did not improve in the left eye due to the more extensive and irreversible damage.

The patient's clinical presentation with bilateral macular lesions and decreased color vision mimicked that of macular dystrophy. This is similar to previous studies that had reported such presentations.[56] However, the acute presentation of asymmetric lesions in the eyes and the rapid formation of macular scars was mismatched with the diagnosis of hereditary retinal dystrophy. It is essential to be skeptical when lesions appear linear and too smeared in the macula, which is not typically observed in macular dystrophies. This will save the resources and time of genetic testing for cases that have typical features of macular dystrophies. Another interesting finding was that the bilateral macular burns were the symptoms of a factitious disorder. Our patient was a single temporary resident living with her family; her brothers supported the family financially. She was recently employed and had started to support the family. Unfortunately, she lost her interest in the job and became unemployed. She thus conducted self-harm to seek attention and stop working. However, she kept denying self-inflicted laser injury but did admit playing with a red laser as a child with her siblings. We also asked her about any possible assault involving a laser, which our patient denied as well. A referral to a psychiatrist to prevent further self-induced lesions[7] is essential as these patients may end up losing more vision if the self-harm continues, eventually causing permanent laser burns and loss of vision.

Conclusion

Self-inflicted handheld laser-induced maculopathy is an emerging problem that has been increasing. This type of laser injury causes permanent loss of vision. A high index of suspicion and the use of multimodal imaging can help to distinguish this type of lesion from other macular lesions.

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 initial s 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.