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Optometry and Vision Science : Official... Aug 2021The range of clear and single binocular vision differs between 3D displays and clinical prism vergences, but this difference is unexplained. This difference prevents...
SIGNIFICANCE
The range of clear and single binocular vision differs between 3D displays and clinical prism vergences, but this difference is unexplained. This difference prevents clinicians from predicting the range of clear and single binocular vision in 3D-viewing patients. In this study, we tested a hypothesis for this difference.
PURPOSE
The purpose of this study was to determine whether changing fixation target size in 3D viewing significantly affects the vergence ranges and, if so, then to determine whether the target size effect is driven by fusional vergence gain changes, threshold of blur changes, or both.
METHODS
Twenty-one visually normal adults aged 18 to 28 years viewed 3D images at 40 cm in an electronic stereoscopic. The fixation target, a Maltese cross, moved in depth at 2∆/s by way of changing crossed or uncrossed disparity until blur and diplopia ensued. We used four target sizes: (1) small (width × height, 0.21° × 0.63°), (2) medium (1.43° × 4.3°), (3) large (3.6° × 10.8°), and (4) 3D (size changing congruently with disparity). The effect of target size on responses was tested by mixed ANOVAs.
RESULT
Mean convergence blurs and breaks increased with target size by 40% (P < .001) and 71% (P < .001), respectively, and in divergence by 33% (P = .03) and 30% (P = .04), respectively. The increases in break magnitude with target size implicate fusional vergence gain change in the size effect. Increasing target size raised the threshold of blur from 1.06 to 1.82 D in convergence and from 0.97 to 1.48 D in divergence (P = .008).
CONCLUSIONS
Growing fixation target size in 3D viewing increases fusional vergence gain and blur thresholds, which together increase the limits of clear and single binocular vision. Therefore, the clarity of a 3D image depends not only on its disparity but also on the size of the viewed image.
Topics: Adult; Convergence, Ocular; Diplopia; Humans; Imaging, Three-Dimensional; Vision Disparity; Vision, Binocular
PubMed: 34460455
DOI: 10.1097/OPX.0000000000001745 -
BMC Ophthalmology Jun 2023To characterize the quality of vision after SMILE, FS-LASIK, and ICL implantation and evaluate the related factors.
BACKGROUND
To characterize the quality of vision after SMILE, FS-LASIK, and ICL implantation and evaluate the related factors.
METHODS
131 eyes of 131 myopic patients (90 female, 41 male) who underwent refractive surgeries including SMILE (35 patients), FS-LASIK (73 patients), and ICL implantation (23 patients) were analyzed. The Quality of Vision questionnaires were completed 3 months after surgery, and the results were characterized and analyzed with baseline characteristics, treatment parameters, and postoperative refractive outcomes using logistic regression analysis to find out predicted factors.
RESULTS
Mean age was 26.5 ± 4.6 years (range: 18 to 39 years) and mean preoperative spherical equivalent was - 4.95 ± 2.04 diopters (D) (range: -1.5 to -13.5). Safety and efficacy index was comparable between different techniques: the safety index was 1.21 ± 0.18, 1.22 ± 0.18, and 1.22 ± 0.16 and the efficacy index were 1.18 ± 0.20, 1.15 ± 0.17, 1.17 ± 0.15 for SMILE, FS-LASIK and ICL respectively. The mean overall QoV score was 13.40 ± 9.11, with mean frequency, severity, and bothersome score of 5.40 ± 3.29, 4.53 ± 3.04, and 3.48 ± 3.18 respectively, and there was no significant difference between different techniques. Overall, the symptom with the highest scores was glare, following fluctuation in vision and halos. Only the scores of halos were significantly different among different techniques (P < 0.000). Using ordinal regression analysis, mesopic pupil size was identified as a risk factor (OR = 1.63, P = 0.037), while postoperative UDVA was a protective factor (OR = 0.036, P = 0.037) for overall QoV scores. Using binary logistic regression analysis, we found that patients with larger mesopic pupil size had an increased risk to experience glare postoperatively; compared to ICL, patients who underwent SMILE or FS-LASIK tended to report fewer halos; patients with better postoperative UDVA were less likely to report blurred vision and focusing difficulty; with larger residual myopic sphere postoperatively, patients experienced focusing difficulties and difficulty judging distance or depth perception more frequently.
CONCLUSIONS
SMILE, FS-LASIK, and ICL had comparable visual outcomes. Overall, glare, fluctuation in vision, and halos were the most frequently experienced visual symptoms 3 months postoperatively. Patients with ICL implanted tended to report halos more frequently compared with SMILE and FS-LASIK. Mesopic pupil size, postoperative UDVA, and postoperative residual myopic sphere were predicted factors for reported visual symptoms.
Topics: Adult; Female; Humans; Male; Young Adult; Corneal Stroma; Keratomileusis, Laser In Situ; Lasers, Excimer; Myopia; Refraction, Ocular; Treatment Outcome; Vision, Ocular; Visual Acuity; Lens Implantation, Intraocular
PubMed: 37365492
DOI: 10.1186/s12886-023-03045-6 -
Anesthesiology Apr 2002The goal of this project was to describe the frequency and natural history of perioperative changes in vision.
BACKGROUND
The goal of this project was to describe the frequency and natural history of perioperative changes in vision.
METHODS
The authors performed a prospective evaluation of changes in visual accommodation and acuity in adult patients undergoing various surgical procedures. Patients were evaluated preoperatively and at 1 and 3 days postoperatively. For patients who had persistent blurring of vision on the third postoperative day, surveillance was extended to 1.5 yr to determine how long the visual changes persisted and if the patients required eye-care provider attention for the condition.
RESULTS
Twenty-eight of 671 patients (4.2%) reported new onset of blurred vision lasting at least 3 days after surgery. Seven of these 28 patients (1% of total) required either new corrective lens or changes in eyeglass or contact prescriptions because of persistent blurry vision. Most of the remaining patients reported resolution of blurry vision within 1 to 2 months. No significant risk factors for this problem were identified.
CONCLUSIONS
In this surgical population, changes in visual acuity manifest primarily by blurred vision were reported at a surprisingly high frequency. For many of these patients, the blurring resolved within 2 months without complication, but 25% of patients who had blurred vision for 3 days or longer required visits to eye-care providers and either new corrective lens or changes in existing prescriptions.
Topics: Adult; Age Factors; Aged; Female; Humans; Male; Middle Aged; Postoperative Complications; Prospective Studies; Risk Factors; Vision Disorders
PubMed: 11964592
DOI: 10.1097/00000542-200204000-00012 -
Asia-Pacific Journal of Ophthalmology... Dec 2020Prolonged and continuous daily use of digital screens, or visual display terminals (VDTs), has become the norm in occupational, educational, and recreational settings.... (Review)
Review
Prolonged and continuous daily use of digital screens, or visual display terminals (VDTs), has become the norm in occupational, educational, and recreational settings. An increased global dependence on VDTs has led to a rise in associated visual complaints, including eye strain, ocular dryness, burning, blurred vision, and irritation, to name a few. The principal causes for VDT-associated visual discomfort are abnormalities with oculomotor/vergence systems and dry eye (DE). This review focuses on the latter, as advances in research have identified symptomology and ocular surface parameters that are shared between prolonged VDT users and DE, particularly the evaporative subtype. Several mechanisms have been implicated in VDT-associated DE, including blink anomalies, damaging light emission from modern devices, and inflammatory changes. The presence of preexisting DE has also been explored as an inciting and exacerbating factor. We review the associations between digital screens and DE, mechanisms of damage, and therapeutic options, hoping to raise awareness of this entity with the goal of reducing the global morbidity and economic impact of screen-associated visual disability.
Topics: Asthenopia; Computer Terminals; Dry Eye Syndromes; Humans; Tears
PubMed: 33181547
DOI: 10.1097/APO.0000000000000328 -
Journal of Vitreoretinal Diseases 2023To report a case of painless posterior scleritis presenting as a choroidal nodule in a patient with history of a tumor being treated with pembrolizumab. A case and its...
To report a case of painless posterior scleritis presenting as a choroidal nodule in a patient with history of a tumor being treated with pembrolizumab. A case and its findings were analyzed, and a relevant literature review was performed. : A 20-year-old woman with a history of ependymoma presented with painless blurred vision in the right eye after being started on pembrolizumab for a tumor recurrence. Fundoscopy showed a solitary amelanotic choroidal lesion with surrounding subretinal fluid in the affected eye. Ultrasonography showed moderate internal reflectivity and fluid in Tenon capsule consistent with nodular posterior scleritis. After a course of systemic steroids and discontinuation of the pembrolizumab, the choroidal lesion completely resolved. : Clinicians should be aware of posterior scleritis as an ocular complication of this class of medications.
PubMed: 37927317
DOI: 10.1177/24741264231163396 -
Continuum (Minneapolis, Minn.) Aug 2014Abnormal spontaneous eye movements, including nystagmus and saccadic intrusions, are often encountered in neurologic practice and can cause disabling visual symptoms,... (Review)
Review
PURPOSE OF REVIEW
Abnormal spontaneous eye movements, including nystagmus and saccadic intrusions, are often encountered in neurologic practice and can cause disabling visual symptoms, such as oscillopsia and blurred vision. This article reviews the spectrum of abnormal spontaneous eye movements and describes their characteristics, etiology, and management.
RECENT FINDINGS
The number of prospective, controlled, and masked clinical trials evaluating candidate treatments for abnormal spontaneous eye movements has increased significantly over the past decade. The findings of recent clinical trials are highlighted, and the dosing and potential side effects of proposed medical treatments are summarized.
SUMMARY
Abnormal spontaneous eye movements are often encountered in neurologic practice. Recent clinical trials provide an evidence base to guide treatment decisions for these disorders.
Topics: Adult; Central Nervous System; Female; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Nystagmus, Pathologic; Ocular Motility Disorders
PubMed: 25099105
DOI: 10.1212/01.CON.0000453307.50604.b6 -
The Korean Journal of Parasitology Aug 2013Ocular toxoplasmosis is a disease caused by the infection with Toxoplasma gondii through congenital or acquired routes. Once the parasite reaches the retina, it... (Review)
Review
Ocular toxoplasmosis is a disease caused by the infection with Toxoplasma gondii through congenital or acquired routes. Once the parasite reaches the retina, it proliferates within host cells followed by rupture of the host cells and invasion into neighboring cells to make primary lesions. Sometimes the restricted parasite by the host immunity in the first scar is activated to infect another lesion nearby the scar. Blurred vision is the main complaint of ocular toxoplasmic patients and can be diagnosed by detection of antibodies or parasite DNA. Ocular toxoplasmosis needs therapy with several combinations of drugs to eliminate the parasite and accompanying inflammation; if not treated it sometimes leads to loss of vision. We describe here clinical features and currently available chemotherapy of ocular toxoplasmosis.
Topics: Animals; Antiprotozoal Agents; Humans; Toxoplasma; Toxoplasmosis, Ocular
PubMed: 24039281
DOI: 10.3347/kjp.2013.51.4.393 -
Malaysian Family Physician : the... 2008The invention of computer and advancement in information technology has revolutionized and benefited the society but at the same time has caused symptoms related to its... (Review)
Review
The invention of computer and advancement in information technology has revolutionized and benefited the society but at the same time has caused symptoms related to its usage such as ocular sprain, irritation, redness, dryness, blurred vision and double vision. This cluster of symptoms is known as computer vision syndrome which is characterized by the visual symptoms which result from interaction with computer display or its environment. Three major mechanisms that lead to computer vision syndrome are extraocular mechanism, accommodative mechanism and ocular surface mechanism. The visual effects of the computer such as brightness, resolution, glare and quality all are known factors that contribute to computer vision syndrome. Prevention is the most important strategy in managing computer vision syndrome. Modification in the ergonomics of the working environment, patient education and proper eye care are crucial in managing computer vision syndrome.
PubMed: 25606136
DOI: No ID Found -
Biomedicines Mar 2021Phosphodiesterase type 5 (PDE5) inhibitors such as Viagra (sildenafil citrate) have demonstrated efficacy in the treatment of erectile dysfunction (ED) by inducing... (Review)
Review
Phosphodiesterase type 5 (PDE5) inhibitors such as Viagra (sildenafil citrate) have demonstrated efficacy in the treatment of erectile dysfunction (ED) by inducing cyclic guanosine monophosphate (cGMP) elevation followed by vasodilation and increased blood flow. It also exerts minor inhibitory action against PDE6, which is present exclusively in rod and cone photoreceptors. The effects of sildenafil on the visual system have been investigated in a wide variety of clinical and preclinical studies due to the fact that a high dose of sildenafil may cause mild and transient visual symptoms in some patients. A literature review was performed using PubMed, Cochrane Library and Clinical Trials databases from 1990 up to 2020, focusing on the pathophysiology of visual disorders induced by sildenafil. The aim of this review was not only to gather and summarize the information available on sildenafil clinical trials (CTs), but also to spot subpopulations with increased risk of developing undesirable visual side effects. This PDE inhibitor has been associated with transient and reversible ocular side effects, including changes in color vision and light perception, blurred vision, photophobia, conjunctival hyperemia and keratitis, and alterations in the electroretinogram (ERG). Sildenafil may induce a reversible increase in intraocular pressure (IOP) and a few case reports suggest it is involved in the development of nonarteritic ischemic optic neuropathy (NAION). Reversible idiopathic serous macular detachment, central serous retinopathy and ERG disturbances have been related to the significant impact of sildenafil on retinal perfusion. So far, sildenafil does not seem to cause permanent toxic effects on chorioretinal tissue and photoreceptors as long as the therapeutic dose is not exceeded and is taken under a physician's direction to treat a medical condition. However, the recreational use of sildenafil can lead to harmful side effects, including vision changes.
PubMed: 33809319
DOI: 10.3390/biomedicines9030291