INTRODUCTION

Solar retinopathy is a form of photochemical and photothermal retinal damage that results from gazing directly at the sun. Solar retinopathy has been reported after viewing a solar eclipse without proper eye protection, from sun gazing as a part of religious rituals, from sun gazing associated with cognitive impairment (eg, in schizophrenia, bipolar disorder, or substance abuse), and from unintended sun gazing when flying a drone.1–6 Photosensitizing drugs may increase the risk of solar retinopathy with ocular sun exposure.7 In addition to sun exposure, retinal damage may occur from exposure to other light sources, including arc welding torches and laser pointers.8,9 Although a number of retinal imaging methods may be used in assessing the retina for cases in which solar retinopathy either is suspected or has been previously diagnosed, the preferred imaging method is spectral domain optical coherence tomography. Various macular findings may be detected on optical coherence tomography in solar retinopathy, including disruption of the retinal pigment epithelium, the outer retina, and the inner retina. Other potential findings include outer retinal cyst-like microdefects, full-thickness macular hole, and epiretinal membrane.10

In this paper, we describe a case in which a young woman who had been sun gazing was diagnosed with bilateral solar retinopathy and an associated permanent central scotoma in 1 eye. The novel aspect of this case is that the patient’s sun-gazing behavior was derived from participation in a viral sun-gazing TikTok trend (#Sungazing), in which it is falsely purported that there are health benefits in looking directly at the sun.

TikTok is a video-sharing social media platform with more than 150 million users in the United States and 1 billion users worldwide.11,12 The application is commonly used by young adults and teens, with ages 24 years and younger making up 44.4% of users.13 The app gained popularity from its tailored video algorithm, which enables rapid video sharing to a large audience. Videos encourage users to comment on them, thereby boosting engagement with and spreading of the videos. This makes the spreading of information, including misinformation, easy, fast, and convincing.14 Sungazing videos, which have received more than 70 million views and become a viral trend on the application, include the claim that staring into the sun for 10 to 15 seconds during the first and last 15 minutes of daylight each day can improve vision.15 Suggested techniques for sun gazing vary from video to video. After the case report, we discuss the mechanisms of retinal injury with sun exposure, the clinical appearance of solar retinopathy, retinal imaging techniques for detection and follow-up, and differential diagnoses. No identifiable health information was included in this case report.

Bausch + Lomb

CASE REPORT

Initial Examination

A 21-year-old woman presented for an eye examination. Her family and personal medical history were unremarkable. She was missing a small portion of her central vision in the left eye, which she first noticed in June, 2 months prior to the examination. She reported no subjective visual changes for the right eye. The only medication reported was an oral iron and magnesium supplement that she was taking based on TikTok videos. Notably, the patient took any opportunity during the examination to scroll through TikTok on her phone.

Entering, uncorrected, Snellen distance visual acuities were 20/20-1 in the right eye and 20/30-1 in the left eye, with the left eye improving to 20/20-1 with pinhole. With monocular testing of the left eye, the patient consistently skipped the second and third letters of every line of acuity that she read, suggesting that her eyes moved very little during acuity testing. With binocular testing, all letters of the 20/20 row were read. The visual fields were full to confrontations, and pupils, extraocular muscles, and stereopsis were normal. Amsler grid testing revealed metamorphopsia in the left eye, with the patient reporting that the central squares were fuzzy and distorted. There was no distortion of the Amsler grid reported when viewing with the right eye. Manifest refraction revealed plano -0.50 × 175 in the right eye and +0.25 -0.50 × 003 in the left eye. The best-corrected visual acuity was 20/20 binocularly, 20/20-1 in the right eye, and 20/20-2 in the left eye. The patient continued to miss the central letters of each line of visual acuity when viewing with the left eye through the manifest refraction.

The slit lamp examination was unremarkable. The intraocular pressures were 12 mm Hg (right eye) and 13 mm Hg (left eye). Given that the patient was missing letters during acuity testing, and given the distortion noted on the Amsler grid, an optical coherence tomography scan was performed. Although the foveal contour was relatively normal in each eye, spectral domain optical coherence tomography revealed a small, cyst-like disruption involving the myoid zone, the ellipsoid zone, and the interdigitation zone in the left eye. There was also subtle disruption of the retinal pigment epithelium in that eye (Figure 1A). Disruption of the outer retina was also found in the right eye (Figure 2A). The defect in the right eye was so subtle that it required manual segmentation to be detected. An Octopus 600 visual field screener was performed and was normal for both eyes.

Figure 1
Figure 1.Horizontal spectral domain optical coherence tomography macular scans of the fovea of the left eye (A) 2 months after sun exposure and (B) 4 months after sun exposure. There is a cystic space in the outer retinal layers (arrow).
Figure 2
Figure 2.Horizontal spectral domain optical coherence tomography macular scans of the fovea of the right eye (A) 2 months after sun exposure and (B) 4 months after sun exposure. The cystic space in the outer retinal layers (arrow) is less obvious in this eye compared with the left eye.

In addition to an injury from extended sun gazing, a number of differential diagnoses for the patient’s macular findings were considered at that time.16–20 These differential diagnoses will be discussed later. In spite of the long list of differential diagnoses, solar retinopathy was at or near the top of the list at this point in the examination for the following reason. Given the patient’s propensity for scrolling on TikTok, as the patient’s pupils were dilating, she was asked about the sun-gazing trend on TikTok. The patient described TikTok videos that promote the “merits” of sun gazing, and she admitted to participating in this practice. She reported that she noticed the small blind spot in the left eye shortly after her first sun-gazing experience. During that event, she had stared at the sun for “probably less than a minute” in the early afternoon on a clear day, not during the first 15 minutes of sunrise or last 15 minutes before sunset. She only looked away from the sun when the light intensity became unbearable.

Dilated fundus evaluation revealed that the optic disc, posterior segment, and periphery were mostly unremarkable in both eyes. However, the foveal reflex in the left eye was abnormal. The superior portion of the fovea in that eye appeared as a well-defined crescent with a red hue. Only the inferior portion of the foveal reflex was apparent in the left eye.

Given the clinical findings and the patient’s history of sun gazing, a diagnosis of solar retinopathy was made. The patient was informed that vision was unlikely to improve, and she was educated on the dangers of sun gazing and the importance of sun protection. The patient was scheduled for a follow-up in 6 weeks and was sent home with an Amsler grid.

Follow-Up Examination

The patient returned for a follow-up 2 months later. She reported that there were no changes in vision since her last visit. There were no changes in her medical or ocular history, although she had begun applying castor oil on her eye lids, another common ophthalmologic trend circulating on TikTok. Some online claims about the benefits of castor oil include vision improvement, eyelash growth, and reduced floaters.

Uncorrected visual acuities were similar to those from the previous examination (20/25 in the right eye and 20/30-2 in the left eye). The patient once again skipped the second and third letters of acuity lines when viewing with the left eye. The patient’s vision was 20/25-2 in the left eye with pinhole viewing. In viewing an Amsler grid, the patient no longer noted metamorphopsia in the left eye. Pupils, stereopsis, visual fields, extraocular muscles, intraocular pressures, and ocular surfaces were all normal.

The patient refused dilation. Undilated fundus examination revealed no changes from the previous examination. The abnormal foveal reflex in the left eye was unchanged. Spectral domain optical coherence tomography scans were obtained on the left eye (Figure 1B) and right eye (Figure 2B). An analysis of spectral domain optical coherence tomography scans at this examination, 4 months after the retinal injury, showed disruption of the outer retinal layers similar to that seen at the initial encounter. The patient was reeducated on the stable and nonprogressive nature of the condition, and she was informed that there is no established treatment for solar retinopathy. The importance of ultraviolet protection was reiterated, and the patient was advised to exercise caution when taking medical advice from noncertified individuals on social media platforms.

DISCUSSION

Mechanisms of Damage in Solar Retinopathy

Solar retinopathy can occur from 2 different light-tissue interactions, which are either photochemical or photothermal in nature. Photothermal retinal damage, which requires a temperature change of 10 to 20 °C, can occur but is only of concern with a dilated pupil or when viewing the sun with improperly filtered binoculars or a telescope.21,22 With a normal pupil size, the calculated change in retinal tissue temperature from viewing the sun is approximately 4 °C.23 Therefore, the predominant mechanism of solar retinopathy is a photochemical process. The solar radiation that reaches the Earth’s surface consists of ultraviolet, visible light, and infrared radiation. Although the ocular surface of the eye is exposed to all 3 of these bands, because of the absorption of the crystalline lens, very little ultraviolet-A reaches the retina.24 High-energy visible light, specifically high-energy visible-II light, does reach the retina, and suprathreshold dosages could result in outer retinal damage.25

The sun is intense enough to induce photochemical retinal damage and has a maximum permissible exposure time of 0.6 seconds.22 Typically, maximum permissible exposures for lasers or light sources have a 1 log unit built-in buffer before physiological changes occur, so viewing the sun for 6 seconds or longer likely will result in temporary or permanent retinal changes. Extended gazing at the sun induces a photochemical process that results in retinal damage owing to the relatively high-energy photons from the high-energy visible-III and high-energy visible-II light range. The emitted photons from the sun bombard endogenous chromophores such as melanin, lipofuscin, heme, flavoproteins, and photopigments within the retinal pigment epithelium and the photoreceptors. The excess light exposure to high-energy photons results in the formation of reactive oxygen species that ultimately damage cellular proteins.26 If irreparable cellular damage occurs, then the photoreceptor and retinal pigment epithelium cells will either undergo apoptosis, necroptosis, autophagy, or phagocytosis. With the eventual absence of photoreceptors, an outer retinal microdefect may develop.

Clinical Appearance of Solar Retinopathy

The quality of visual functioning as well as the clinical appearance of solar retinopathy evolve and are dependent on when the patient is examined after injury.27,28 Bilaterality varies from patient to patient.29 Often, visual function completely recovers over weeks or months, but some patients, such as the one described in this case report, have permanent loss of vision. In terms of spectral domain optical coherence tomography findings, within several hours after injury, photoreceptor damage appears as a vertical band of hyperreflectivity at the level of the photoreceptors that extends anteriorly by varying amounts.27,28 The hyperreflective area corresponds to a yellow-white spot seen on fundus examination at the fovea.27 There may be a hyporeflective discontinuity in the outer retina involving, for example, the ellipsoid zone and the interdigitation zone.

In weeks, months, and years after injury, the hyperreflective area likely recedes, whereas the hyporeflective gap in the outer layers may remain or may develop. The photoreceptors may appear as a hyporeflective band on spectral domain optical coherence tomography, suggesting apoptosis and atrophy, and on fundus examination, the fovea may appear redder with surrounding pigment mottling.27

Additional tests may aid in the diagnosis of solar retinopathy. Fundus autofluorescence shows hypoautofluorescence in areas of retinal pigment epithelial disruption, and relative to the macula, a hyperautofluorescent ring may appear around the area of hypoautofluorescence. Fluorescein angiography shows hyperfluorescence in areas of retinal pigment epithelial disruption, and adaptive optics scanning light ophthalmoscopy shows a disturbed photoreceptor mosaic that correlates to the shape of the patient’s reported scotoma. These changes may or may not improve over time. Optical coherence tomography angiography may be normal initially, but ultimately an increase in the size of the foveal avascular zone may occur,28 whereas en face optical coherence tomography shows the same reflective findings as spectral domain optical coherence tomography.27

Solar Retinopathy Treatment

Currently, there are no established treatments for solar retinopathy.30,31 There are small case studies in which positive effects have been reported with the use of oral steroids or posterior sub-Tenon steroid injections in the acute or semiacute phases of sun exposure, but larger studies are needed to establish the efficacy of these treatments. One single-case study reported improvements in solar retinopathy when steroid treatment was initiated 7 weeks after sun exposure.31

Differential Diagnoses

Several differential diagnoses were considered in addition to solar retinopathy.16–20 The patient was specifically questioned about and denied any exposure to laser light. Acute retinal pigment epitheliitis (Krill or Krill’s) disease can be characterized by focal hyperreflectivity similar to that in acute solar retinopathy.19,32 However, in Krill disease, small macular pigmentary changes are seen with a surrounding hypopigmented halo. Another outer retinal inflammatory disorder such as multiple evanescent white dot syndrome or acute macular neuroretinopathy was considered, but multiple evanescent white dot syndrome includes a number of small white dots in the posterior pole along with foveal granularity (ie, a yellow, stippled appearance) and acute macular neuroretinopathy includes petalloid reddish-brown perifoveal lesions.33,34 Based on the patient’s age and initial complaint, central serous chorioretinopathy was considered very early on, but like other pachychoroidal diseases, this disorder is characterized by choroidal thickening with dilation of the choroidal blood vessels.35 Given the outer foveal microdefects noted on spectral domain optical coherence tomography, particularly in the left eye, other causes of such microdefects were considered including posterior vitreous detachment, blunt trauma, macular telangiectasia, and Stargardt disease.16,17 The patient’s age, symptoms, and clinical findings were not consistent with any of these latter diagnoses.

CONCLUSION

With increased social media usage, more patients are being exposed to health-related information online.14,15 A recent investigation of 37 ophthalmology-relevant hashtags on TikTok revealed a significant portion of ophthalmologic content is created by non-eyecare providers.14 In a 2024 paper, the hashtag “#Sungazing” was found to have accumulated 76.9 million views, promoting the idea that staring into the sun enhances vision.15 This dangerous and misleading trend can influence impressionable individuals to predispose themselves to solar retinopathy, which can result in a permanent visual acuity deficit, central or paracentral scotoma, and metamorphopsia.

The increasing use and influence of social media apps highlights the increasing responsibility of health care providers to stay up to date on social media trends. In the last decade, social media platforms have become the primary news outlet for many patients. Understanding what trends are circulating better equips providers on how to readily debunk these harmful health care myths and to caution against future ones.

TAKE HOME POINTS

  • Practitioners should be aware of TikTok trends that could negatively impact vision.

  • Optical coherence topography is critical in evaluating a patient with solar retinopathy.

  • Manual segmentation of optical coherence tomography images may be required to detect the full extent of retinal involvement.

  • The clinical and optical coherence tomography appearance of solar retinopathy may vary in acute versus chronic stages.

  • Atrophic changes and scarring particularly in the outer retinal layers may be a result of sun gazing.

ACKNOWLEDGMENTS

We thank Dr William Patton, OD, for his help with this case.