Foveo-macular retinitis, solar retinopathy, and trauma

Macular microhole and foveal red spot syndrome: a critical review of the literature

PURPOSE

The purpose of this article is to review the literature on nomenclature, natural history, clinical features, diagnosis, management, and prognosis of both macular microhole (MMH) and foveal red spot syndrome (FRS).

METHODS

A PubMed primary literature search (February 1, 2020) utilizing the terms macular microhole, foveal red spot syndrome, and outer retinal hole was conducted. All chosen articles were case reports or case series. Articles qualified for inclusion if they documented symptoms, imaging findings, or followed patients longitudinally.

RESULTS

A total of 14 studies from 1988 to 2019 that evaluated either MMH, FRS, or both were included in the review. No comparative study between the two defects was found. Studies often used the terms FRS and MMH interchangeably to reference both partial- and full-thickness lesions of the macula. Spectral-domain optical coherence tomography (SD-OCT) was most frequently able to identify these lesions and revealed an absence of all neural retinal layers from the inner limiting membrane (ILM) to the retinal pigment epithelium (RPE) in the full-thickness lesions while the partial-thickness lesions most often involved the photoreceptor layer (PRL) and less frequently the external limiting membrane (ELM). OCT revealed that vitreomacular traction (VMT) was involved in the natural history of both FRS and MMH for a significant subset of patients.

CONCLUSION

The terms MMH and FRS have been used interchangeably in the literature. Advances in OCT have revealed that MMHs and FRSs are distinct but sometimes overlapping entities. We suggest that MMH and FRS are similar entities defined as one or more sharply defined lesions in the fovea of the eye < 150 μm in size. MMHs are a full-thickness defect of the entire neuroretina at the center of the foveola while FRSs are partial-thickness lesions. Current literature suggests that there may be subtle differences in the pathogenesis, clinical features, and diagnosis between MMH and FRS; however, prognosis and management for both are favorable. Lastly, we suggest that the terms outer lamellar macular microholes and full-thickness macular microholes may be the more appropriate terminologies to refer to FRS and MMH, respectively.

Photic maculopathy: A review of the literature (ii)

The human retina, as transducer of light energy, is especially exposed to light toxicity. Solar maculopathy has been the only form of photic maculopathy for millennia, often secondary to the observation of an eclipse. During the last century, technological advances have led to the appearance of new forms of photic maculopathy, related to the exposure to new forms of artificial light, such as welding devices and lasers. In recent years the general use of laser pointers has led to an upturn in interest in this pathology. The aim of this review is to offer an integrated view of the different types of photic maculopathy. Due to the extension of the topic, the review is presented divided into 2 parts. In this second part, atomic bomb maculopathy, laser maculopathy, iatrogenic forms of photic maculopathy, and foveomacular retinitis are presented.

MACULAR MICROHOLES

PURPOSE

To describe the clinical features and natural course of microholes of the macula.

METHODS

We reviewed the charts of 31 patients (35 eyes) with punctate foveal defects, or "microholes," of the macula. Patients were seen between 1980 and 2005 at a tertiary referral center. Clinical, photographic, and optical coherence tomography findings were reviewed.

RESULTS

All eyes had one or more well defined, punctate foveal lesions 35 microm to 150 microm in size. There was no gender predilection, and patient ages ranged from 6 years to 69 years. Visual acuity was > or =20/40 in 29 of 35 eyes. None of the eyes had foveal transmission defects shown by fluorescein angiography. A defect in the outer retina was demonstrated in five of seven patients who underwent optical coherence tomography. The lesions were nonprogressive, with no patients developing stage 3 or 4 macular holes.

CONCLUSION

Macular microholes are small lamellar defects in the outer retina or retinal pigment epithelium that occur through a variety of mechanisms, including spontaneous vitreoretinal interface changes, trauma, phototoxicity, and other unrecognized causes. The condition is nonprogressive, occurs in patients of all ages, and is compatible with good visual acuity.

Macular microholes: pathogenesis and natural history

AIMS

To study the natural history and evaluate optical coherence tomography (OCT) and the retinal thickness analyser (RTA) in patients with macular microholes.

METHODS

The medical records of 22 patients with a well demarcated red intraretinal foveal or juxtafoveal defect were reviewed. Fluorescein angiography (FA), RTA, and OCT were performed. The main outcome measures were visual acuity (VA), and OCT and RTA characteristics of microholes. Long term follow up was available in 13 eyes of 12 patients.

RESULTS

The patients had a mean age of 50 years and a mean refractive error of -0.93 dioptres. The presenting symptom was a central scotoma in 14 eyes and metamorphopsia in eight eyes. All patients had a corrected VA ranging from 20/16 to 20/125, with 20 out of 24 eyes (83%) having a VA > or =20/40. Symptoms remained stable or improved in 16 out of 22 patients (72%). OCT 2 findings were normal but an abnormality of the outer retina and/or a defect of the retinal pigment epithelium (RPE) were demonstrated on OCT 3 in 15 of 18 eyes (83%). The RTA topographic map demonstrated a defect at the site of the microhole in two out of 12 eyes.

CONCLUSION

Although biomicroscopic examination suggested an inner foveal defect, the OCT 3 scans demonstrated a localised abnormality of the outer retina and/or RPE which could not be resolved using OCT 2. Macular microholes have a favourable long term prognosis with stable VA. Bilateral involvement is uncommon.

Solar eclipse observation: some simple devices

The terrestrial solar irradiance is evaluated in view of the energy absorbed by the retina and the blue light hazard. The evaluated irradiance is compared with the known safety standard, to determine the safety requirement of solar eclipse observation devices. Simple devices are then proposed. The first is a folded pinhole camera, giving a magnified sun image from a relatively small box. The second is a pinhole projector, used to display the image in a large room, while the third is a compact multimirror periscope enabling one to see the sun sharper than with a pinhole camera.

Microholes of the fovea centralis

Foveal microholes are a possible cause of unilateral or bilateral small central visual defects in the absence of other macular pathology. In 18 eyes of 17 patients we noted the following features: small, dark-reddish holes in the centre of the fovea ranging from 50 to 150 micron in size; normal adjacent retinal pigment epithelium and neuroepithelium; unilateral in most cases; males and females are equally affected; mean age 40 years; insidious onset; no history of direct eye trauma or sungazing; non-progressive; relatively favourable visual outcome; no relationship with regular macular holes; aetiology unknown. These distinctive features justify reporting these patients as an important separate group.