Benefits of Implementing Eye-Movement Training in the Rehabilitation of Patients with Age-Related Macular Degeneration: A Review

Age-related macular degeneration (ARMD) is one of the most debilitating eye-related illnesses worldwide. Eye-movement training is evolving to be a non-invasive, rapid, and effective method that is positively impacting vision and QoL (quality of life) in patients suffering from ARMD. This review aims to highlight why a greater adoption of eye-movement training in the clinical and research setting is of importance. A PubMed and ResearchGate search was performed for articles published between 1982 and 2020. Patients with advanced ARMD tend to experience a diminished QoL. Studies regarding eye-movement training for patients with central vision loss revealed overall significant improvements in reading speeds, fixation, and saccade performance. They also experienced less fatigue. In select studies, eye-movement training revealed an improvement in binocular vision, fixation, reading speed, and diminished reading exhaustion. The process of eye-movement training used in some of the studies was rather empirical. The latter requires standardization so that a uniform and applicable methodology can be adopted overall.

Factors Associated with Anatomic Failure and Hole Reopening after Macular Hole Surgery

A macular hole (MH), particularly an idiopathic macular hole (IMH), is a common cause of central vision loss. Risk factors for nonidiopathic MH include high myopia, cystoid macular edema, inflammation, and trauma. MH is primarily diagnosed using slit-lamp microscopy and optical coherence tomography (OCT). Half of the patients with stage I MHs are treated conservatively and may show spontaneous resolution. The main treatment methods for MHs currently include vitrectomy and stripping of the internal limiting membrane (ILM). However, in some patients, surgery does not lead to anatomical closure. In this review, we summarize the factors influencing the anatomical closure of MHs and analyze the potential underlying mechanisms.

Visual acuity and anatomical changes following vitrectomy for epiretinal membrane foveoschisis: a case series

Purpose To evaluate the visual outcome and macular anatomic structures on spectral-domain optical coherence tomography (SD-OCT) of patients with epiretinal membrane (ERM) foveoschisis who underwent vitrectomy. Methods A retrospective cohort, interventional, case series. Participants Fourteen patients (14 eyes) with central vision loss from an ERM foveoschisis underwent vitrectomy at Chiang Mai University Hospital from 2017 to 2018 and had a follow-up period of 12 months. Interventions The 23G vitrectomy with ERM and internal limiting membrane (ILM) peeling was performed by a single surgeon. Main outcomes Best-corrected visual acuity (BCVA) and anatomic appearance on SD-OCT were assessed at the time of preoperative evaluations and post-operative follow-ups at 1, 3, 6, and 12 months. Results Fourteen patients with a mean (SD) age of 67.9 (7.9) years and a mean (SD) visual acuity (VA) of 0.6 (0.1) LogMAR units were included in this study. Significant VA improvements were observed at the 3-month (0.43 (0.14) LogMAR unit), 6-month (0.45 (0.16) LogMAR unit) and 12-month (0.37 (0.21) LogMAR unit) post-operative visits compared to baseline, all with P-values < 0.001. At month 12, there were vision improvements of ≥3 lines in 8 (57.2%) patients, vision improvements of 1 or 2 lines in 2 (14.3%) patients, vision remained at the same line of pre-operation in 3 (21.4%) patients, and vision decreased by 1 line in 1 (7.1%) patient. Regarding the anatomical outcomes, 13 (92.9%) patients achieved anatomical foveal restoration, while one had persistent intraretinal schisis at the 12-month follow-up. The median time to achieve a foveal restoration was 3 months. No significant visual impairments were observed post-operatively. Conclusion In patients with central vision loss from ERM foveoschisis, vitrectomy with ILM stripping tended to improve both visual and anatomical outcomes.

Perspective on Vision Science-Informed Interventions for Central Vision Loss

Pathologies affecting central vision, and macular degeneration (MD) in particular, represent a growing health concern worldwide, and the leading cause of blindness in the Western World. To cope with the loss of central vision, MD patients often develop compensatory strategies, such as the adoption of a Preferred Retinal Locus (PRL), which they use as a substitute fovea. However, visual acuity and fixation stability in the visual periphery are poorer, leaving many MD patients struggling with tasks such as reading and recognizing faces. Current non-invasive rehabilitative interventions are usually of two types: oculomotor, aiming at training eye movements or teaching patients to use or develop a PRL, or perceptual, with the goal of improving visual abilities in the PRL. These training protocols are usually tested over a series of outcome assessments mainly measuring low-level visual abilities (visual acuity, contrast sensitivity) and reading. However, extant approaches lead to mixed success, and in general have exhibited large individual differences. Recent breakthroughs in vision science have shown that loss of central vision affects not only low-level visual abilities and oculomotor mechanisms, but also higher-level attentional and cognitive processes. We suggest that effective interventions for rehabilitation after central vision loss should then not only integrate low-level vision and oculomotor training, but also take into account higher level attentional and cognitive mechanisms.

Assessing functional reorganization in visual cortex with simulated retinal lesions

Macular degeneration (MD) causes central vision loss, removing input to corresponding representations in the primary visual cortex. There is disagreement concerning whether the cortical regions deprived of input can remain responsive, and the source of reported cortical responses is still debated. To simulate MD in controls, normally sighted participants viewed a bright central disk to adapt the retina, creating a transient ‘retinal lesion’ during a functional MRI experiment. Participants viewed blocks of faces, scrambled faces and uniform grey stimuli, either passively or whilst performing a one-back task. To assess the impact of the simulated lesion, participants repeated the paradigm using a more conventional mean luminance simulated scotoma without adaptation. Our results suggest our attempt to create a more realistic simulation of a lesion did not impact on responses in the representation of the simulated lesion. While most participants showed no evidence of stimulus-driven activation within the lesion representation, a few individuals (22%) exhibited responses similar to a participant with juvenile MD who completed the same paradigm (without adaptation). Reliability analysis showed that responses in the representation of the lesion were generally consistent irrespective of whether positive or negative. We provide some evidence that peripheral visual stimulation can also produce responses in central representations in controls while performing a task. This suggests that the ‘signature of reorganization of visual processing’, is not found solely in patients with retinal lesions, consistent with the idea that activity may be driven by unmasked top–down feedback.

Impact of living with a bilateral central vision loss due to geographic atrophy—qualitative study

ObjectiveGeographic atrophy (GA), a type of dry age-related macular degeneration, affects vision as central vision loss (CVL). The challenges faced due to bilateral CVL in activities of daily living and strategies taken to overcome those challenges are not very well understood in the Indian population. This qualitative study aims to understand the impact on everyday life activities and related adaptive and coping strategies in people with long-standing bilateral CVL due to GA in India.Design, participants, setting and methodsA qualitative study using a semistructured face-to-face interview was conducted on 10 people with bilateral CVL after obtaining written informed consent. The interviews were audio-recorded, and were transcribed verbatim. Thematic analysis was carried out to understand the challenges faced and adaptive methods due to the impact of CVL.ResultsTen participants (50% male) with a median age (IQR) of 72 (70, 74) years were interviewed. All the participants had best-corrected visual acuity of ≤6/60 in the better eye and reported an absolute central scotoma with the home Amsler chart. Qualitative thematic analysis identified four main themes: challenges in everyday living (difficulty in face identification, reading), challenges with lifestyle and socialisation (driving, cooking, reading for a longer duration, watching TV, socially inactive), psychological implications (depression, poor self-esteem, fear due to poor vision) and strategies to overcome the challenges (voice identification, technology support).ConclusionGA has a severe negative impact on the quality of life in people with CVL. Inability to recognise faces was the main reason for dependency on others and being socially disconnected. The findings will help clinicians in providing improved rehabilitative care.