Solar maculopathy: prognosis over one year follow up

Impact of Solar Eclipses on Vision: Insights from Optical Coherence Tomography and Optical Coherence Tomography Angiography Analysis

PURPOSE

Solar retinopathy, resulting from solar eclipse exposure, poses risks to visual health. This study explores acute and chronic phase findings using clinical examinations and optical coherence tomography (OCT) and optical coherence tomography angiography (OCT-A) with a focus on longitudinal assessment.

METHODS

Seven eyes with a history of unprotected solar eclipse exposure were included. Clinical examination, fundus photography, OCT, and OCT-A imaging were performed at initial assessment, as well as at one-month and six-month follow-up intervals. Data analysis included descriptive statistics.

RESULTS

The cases, exposed without protection, underwent assessments, revealing variable visual acuity, outer retinal layer, and Henle fiber layer changes during follow-up. Regression of hyperreflectivity within the outer retinal and Henle fiber layers was observed over time in all eyes, although persistent microdefects within the outer retinal layer were noted in specific cases. OCT-A imaging revealed a larger foveal avascular zone, which persisted over a six-month period in select cases. Additionally, affected eyes exhibited a decrease in superficial vascular density, with subsequent improvement noted during the six-month period.

CONCLUSION

Solar retinopathy can result in visual impairment, accompanied by alterations observed in the Henle fiber layer using OCT. Additionally, OCT-A findings indicate possible vascular involvement. This study underscores the significance of adopting protective measures during solar eclipses and emphasizes the value of employing longitudinal multimodal imaging techniques to comprehend the pathophysiology of the condition.

Solar retinopathy: A literature review

Solar retinopathy (SR) refers to retinal injury that results from unprotected excessive exposure to light. It has been associated with direct sungazing, sunbathing, laser pointers, and welding arc exposure. Symptoms are typically bilateral and are characterized by asymmetric decreased vision, central or paracentral scotoma, photophobia, metamorphopsia, and headache. In most cases, recovery occurs spontaneously with no specific treatment within weeks to 6 months after exposure. However, few cases have been reported in the literature using steroids in acute SR because of their anti-inflammatory effects. The aim of this review is to present an update about this entity, describing the pathogenesis, risk factors, and diagnostic methods, with focus on management and outcomes of SR.

Long-term anatomical and functional findings of solar maculopathy

BACKGROUND

Solar maculopathy (SM) is a rare cause of acquired maculopathy related to direct viewing of the sun. Primary symptoms include central scotomata, blurred vision and/or metamorphopsia due to thermal/photochemical damage to foveal photoreceptors.

METHODS

Patients were identified from clinic records surrounding a solar eclipse. Clinical examination and multimodal retinal imaging were performed at each follow-up visit. Informed consent was provided by each patient for publication of anonymized data.

RESULTS

Seven affected eyes of 4 patients (mean 21.75 years, all female) were identified with mean presenting visual acuity (VA) of LogMAR 0.18. Well-defined photoreceptor ellipsoid zone (EZ) defects were identified on optical coherence tomography (OCT) for all eyes. VA improved for all eyes (median 12 letter improvement) over a mean 5.7-year follow-up (range 5 months to 11 years).

CONCLUSIONS

While no effective treatment has been identified for SM, VA can significantly improve in some cases, but persistent scotomata are reported and may be debilitating; thus, prevention by public health measures remains critical.

Case Report: Asymmetric Changes of Ophthalmic Findings in Bilateral Solar Eclipse Maculopathy

SIGNIFICANCE

A more profound understanding of the relationship between ophthalmic findings and eye dominance is needed to guide the timely and proper treatment of binocular photic maculopathy or other macular degeneration.

PURPOSE

A patient with binocular solar maculopathy presented with asymmetric ophthalmic manifestations and changes during 14 months of observation. Early recognition of solar maculopathy can be vital for early diagnosis and better prognosis.

CASE REPORT

A 21-year-old man was reported to have blurred vision after staring directly at an annular solar eclipse several times for a few seconds on June 21, 2020. His Snellen best-corrected visual acuity declined to 20/50 in both eyes. He was right-eye dominant according to the hole-in-the-card test. The funduscopy found a yellow spot in the center of both maculae. Spectral-domain optical coherence tomography images revealed a full-thickness hyperreflectivity extending from the inner retinal layers to the retinal pigment epithelium (RPE) along with a localized disruption of the ellipsoid portion of the inner segments and RPE in both eyes. The medical history and clinical manifestations described previously supported the diagnosis of solar maculopathy. Spectral-domain optical coherence tomography images during follow-up indicated a diminishing disruption of the ellipsoid portion of the inner segments and RPE without treatment. Interestingly, the nondominant left eye made a better anatomical recovery. Finally, the Snellen best-corrected visual acuity remained 20/20 in both eyes after 14 months.

CONCLUSIONS

Binocular solar maculopathy can present asymmetrically and recover asymmetrically as well. The dominant eye suffered more obvious damage and poorer anatomical recovery than the nondominant eye.

Foveal photoreceptor disruption in ocular diseases: An optical coherence tomography-based differential diagnosis

Fovea centralis, located at the center of the macula, is packed with cone photoreceptors and is responsible for central visual acuity. Isolated foveal photoreceptor disruption may occur in a variety of hereditary, degenerative, traumatic, and toxic chorioretinal diseases. These have been known previously by multiple synonyms including macular microhole, foveal spot, and outer foveal microdefects. A common clinical feature underlying these conditions is the presence of apparently normal fovea or subtle hypopigmented lesion at the foveal or juxtafoveal area. A detailed history along with high-resolution optical coherence tomography is often helpful to derive a conclusive diagnosis in majority of these cases. Focal photoreceptor disruption usually involves loss or rarefaction of ellipsoid/interdigitation zone, either in isolation or associated with external limiting membrane or retinal pigment epithelium disruption in the fovea. Vitreomacular interface (VMI) disorders including vitreomacular traction, posterior vitreous detachment, epiretinal membrane, and impending macular hole possibly remain the most common cause. Retinal dystrophies such as cone dystrophy, occult macular dystrophy, and achromatopsia may present with diminution of vision and normal appearing fundus in a younger age group. Other causes include photic retinopathy (e.g., from a history of sun gazing, or laser pointer exposure), blunt trauma, drug exposure (e.g., poppers maculopathy or tamoxifen retinopathy), and acute retinal pigment epitheliopathy (ARPE). Visual prognosis depends on the underlying etiology with complete recovery common in the subset of patients with VMI, and ARPE, whereas persistent outer retinal defects are the rule in other conditions. We discuss the differential diagnoses that lead to isolated foveal photoreceptor defects. Identifying and understanding the underlying disease processes that cause foveal photoreceptor disruption may help predict visual prognosis.

Anatomical and functional features of photic retinopathy: a spectral domain optical coherence tomography-based longitudinal study

BACKGROUND

Photic retinopathy may lead to permanent foveal structural injury, leading to irreversible visual acuity loss.

METHOD

This prospective observational study evaluated 51 eyes of 30 patients with photic retinopathy. Optical coherence tomography (OCT) imaging was performed for all the eyes at baseline and final follow-up. All the eyes showed a focal outer retinal defect on spectral-domain OCT (SD-OCT) at the junction of the inner and outer photoreceptor segments. SD-OCT was used to measure central macular thickness, maximum horizontal dimension of the defect, maximum defect thickness, and the photic retinopathy index (PRI) through the foveal raster scan.

RESULTS

Although PRI improved significantly at the final follow-up from baseline with a 17% improvement in PRI after a period of 6 months in photic retinopathy eyes, visual acuity declined for 14% of the patients and was stable for 84%. There was mild correlation of visual acuity with baseline PRI. Baseline PRI was significantly higher in eyes with poorer presenting visual acuity (VA). In total, 33.3% of the eyes showed partial ellipsoid zone recovery at 6 months. The area under curve of the receiver operator characteristic curve for partial ellipsoid zone recovery with the mean baseline PRI as the independent variable was poor at 0.612.

CONCLUSION

OCT-based ultrastructural features in photic retinopathy seem to have poor correlation with presenting or final visual acuity. To the best of our knowledge, this is the largest study on longitudinal OCT evaluation of photic retinopathy eyes in literature.

Solar retinopathy: a new setting of red, green, and blue channels

Purpose:

To introduce a new color imaging technique using improved settings of red, green, and blue channels for improved delineation of retinal damage in patients with solar retinopathy.

Method:

A retrospective case series of patients with poor vision secondary to solar retinopathy were analyzed. All patients underwent visual acuity, refraction, and dilated fundus examination. A spectral domain–optical coherence tomography of the macula and color fundus imaging using optimized red, green, and blue color setting was performed. Patients were reviewed over a 6-month period. The data were analyzed for statistical significance using an independent t test and a receiver operating characteristic curve.

Results:

In total, 20 eyes of 10 patients were included between 2009 and 2017. The mean age was 24.9 ± 18.1 years. Best corrected visual acuity at first consultation was 0.78 ± 0.11 and after 6 months was 0.83 ± 0.09. Spectral domain–optical coherence tomography demonstrated retinal abnormalities at the myoid zone, ellipsoid zone, and the outer segment of photoreceptors. Receiver operating characteristic curve analysis showed an improving effect (area under the curve = 0.62; 95% confidence interval = 0.42–0.79). The color channels parameters, which improve visualization of the lesions were found to be 67-0.98-255 for the R-guided setting, 19-0.63-121 for the B-guided setting, and 7-1.00-129 for the G-guided setting. The ideal red, green, and blue setting was in 24-0.82-229.

Conclusion:

The use of a new setting of red, green, and blue channels could improve the diagnosis and monitoring of solar retinopathy, hence improving patient care.