Perception is the ability to see, hear, or become aware of external stimuli through the senses. Visual stimuli are electromagnetic waves that interact with the eye and elicit a sensation. Sensations, indeed, imply the detection, resolution, and recognition of objects and images, and their accuracy depends on the integrity of the visual system. In clinical practice, evaluating the integrity of the visual system relies greatly on the assessment of visual acuity, that is to say on the capacity to identify a signal. Visual acuity, indeed, is of utmost importance for diagnosing and monitoring ophthalmological diseases. Visual acuity is a function that detects the presence of a stimulation (a signal) and resolves its detail(s). This is the case of a symbol like “E”: the stimulus is detected, then it is resolved as three horizontal bars and a vertical bar. In fact, within the clinical setting visual acuity is usually measured with alphanumeric symbols and is a three-step process that involves not only detection and resolution, but, due to the semantic content of letters and numbers, their recognition. Along with subjective (psychophysical) procedures, objective methods that do not require the active participation of the observer have been proposed to estimate visual acuity in non-collaborating subjects, malingerers, or toddlers. This paper aims to explain the psychophysical rationale underlying the measurement of visual acuity and revise the most common procedures used for its assessment.
Background and Objective: Subthreshold laser therapy has emerged as a therapeutic alternative to traditional laser photocoagulation for certain ophthalmic diseases including central serous chorioretinopathy (CSCR), diabetic macular edema (DME), macular edema secondary to branch retinal vein occlusion (BRVO), and age-related macular degeneration (AMD). The objective of this paper is to review and discuss the clinical applications of subthreshold laser and the mechanisms of different subthreshold laser techniques including subthreshold micropulse laser (SMPL), selective retina therapy (SRT), subthreshold nanosecond laser (SNL), endpoint management (EpM), and transpupillary thermotherapy (TTT).
Methods: A narrative review of English literature and publicly available information published before November 2021 from literature databases and computerized texts. We discuss the currently available subthreshold laser systems and the advancements made to perform different subthreshold laser techniques for various ophthalmic diseases. We highlight various clinical studies and therapeutic techniques that have been conducted to further understand the effectiveness of subthreshold laser in the clinical setting. We conclude the article by covering emerging subthreshold laser systems that are currently being developed for future clinical use. The PubMed database was utilized for peer-reviewed articles and pertinent information on subthreshold systems was cited from publicly available online websites covering specific systems.
Key Content and Findings: Various subthreshold laser systems have been developed to treat certain retinal diseases. Several systems are currently in development for future clinical applications.
Conclusions: While conventional laser photocoagulation has been effective in treating various retinal diseases, subthreshold laser systems aim to provide a therapeutic effect without visible signs of damage to the underlying tissue. This technology may be particularly effective in treating macular disorders. Further clinical studies are needed to evaluate their role in the management of retinal diseases.
Background and Objective: Intraocular lymphoma (IOL) is a heterogenous category of rare malignancies that are often misdiagnosed and underrecognized. The rarity of IOL impedes clinical research and contributes to difficulty in standardizing its management. In this article we review the existing scientific literature to identify the current diagnostic tools and discuss comprehensive management of various categories of IOL. Our objective is to increase disease recognition of IOL as a whole and explore updated management options for each subtype.
Methods: PubMed and Embase were searched for publications using the terms ‘intraocular lymphoma’, ‘vitreoretinal lymphoma’, ‘uveal lymphoma’, ‘iris lymphoma’, ‘choroidal lymphoma’ and ‘ciliary body lymphoma’ published from 1990 to June 2021. Inclusion criteria were English language articles. Exclusion criteria were non-English language articles, case reports and animal studies.
Key Content and Findings: IOL often presents in middle-aged and older patients with symptoms of floaters and vision changes, but a broad array of clinical signs and symptoms are possible depending upon subtype. IOL can be subdivided by location of involvement into vitreoretinal and uveal lymphoma. These subtypes express key differences in their pathophysiology, clinical presentation, histology, prognosis, and treatment. Primary vitreoretinal lymphomas (PVRL) generally originate from B-lymphocytes and are associated with central nervous system (CNS) lymphoma. Ophthalmic findings include retinal pigment epithelium changes with yellow subretinal deposits known as “leopard spotting.” Primary uveal lymphomas generally originate from low-grade B-lymphocytes invading the choroid and carry an improved prognosis compared to vitreoretinal lymphomas. Funduscopic findings of primary uveal lymphoma include yellow to pink-yellow choroidal swelling with infiltrative subconjunctival “salmon-patch” lesions. Diagnosis for IOL is often delayed due to insidious onset, low prevalence, and tendency to mimic diseases such as uveitis. Diagnosis may be challenging, often relying on biopsy with specialized laboratory testing for confirmation of IOL. Optimal treatment regimens are currently debated among experts. Management of IOL is best coordinated in association with neuro-oncology clinicians due to the tendency for intracranial involvement.
Conclusions: IOL represents a group of multiple malignancies with distinct clinicopathologic features. Future outlook for treatment and prognosis of IOL is likely to improve with less invasive molecular diagnostic techniques and increased awareness. Clinicians should be circumspect in all patients with possible IOL and promptly refer to oncologic specialists for rapid evaluation and treatment.
Background: Bacillary layer detachment (BALAD) is a phenomenon characterized by fluid accumulation at the myoid region of the inner photoreceptor segments identifiable on optical coherence tomography (OCT) imaging. This finding has been recently described in patients with diverse primary diagnoses which share the common feature of serous exudation in the posterior pole. However, thus far there have been very few reports in the literature of BALAD in patients with posterior scleritis.
Case Description: A 16-year-old male presented with unilateral vision changes that acutely worsened overnight to significant unilateral vision loss. He was eventually diagnosed with idiopathic posterior scleritis with associated BALAD on OCT. Similar to other reported cases of BALAD, he experienced anatomic restoration of the outer retina followed by good visual recovery after treatment with high dose steroid, ultimately with complete recovery of both retinal anatomy and vision within 4 months.
Conclusions: This case provides further evidence that posterior scleritis can be a cause of BALAD. The rapid presentation and excellent visual and anatomical outcome of this case is entirely consistent with known descriptions of BALAD in a variety of other conditions, further supporting the categorization of BALAD as an entity which retinal specialists should be able to recognize as distinct from other forms of intraretinal fluid, retinal detachment, and retinoschisis.
Background: Bacillary layer detachment (BALAD) is a phenomenon characterized by fluid accumulation at the myoid region of the inner photoreceptor segments identifiable on optical coherence tomography (OCT) imaging. This finding has been recently described in patients with diverse primary diagnoses which share the common feature of serous exudation in the posterior pole. However, thus far there have been very few reports in the literature of BALAD in patients with posterior scleritis.
Case Description: A 16-year-old male presented with unilateral vision changes that acutely worsened overnight to significant unilateral vision loss. He was eventually diagnosed with idiopathic posterior scleritis with associated BALAD on OCT. Similar to other reported cases of BALAD, he experienced anatomic restoration of the outer retina followed by good visual recovery after treatment with high dose steroid, ultimately with complete recovery of both retinal anatomy and vision within 4 months.
Conclusions: This case provides further evidence that posterior scleritis can be a cause of BALAD. The rapid presentation and excellent visual and anatomical outcome of this case is entirely consistent with known descriptions of BALAD in a variety of other conditions, further supporting the categorization of BALAD as an entity which retinal specialists should be able to recognize as distinct from other forms of intraretinal fluid, retinal detachment, and retinoschisis.
