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The retina, optic nerve and vitreous humour
Published in Mary E. Shaw, Agnes Lee, Ophthalmic Nursing, 2018
Vitreous floaters are small opacities in the vitreous humour that can stimulate the retina by casting a shadow on it. The mind projects the corresponding dark form onto the appropriate field of vision. Most people experience a mild degree of vitreous floaters. When looking at a uniform background, they will see minute specks in their field of vision. As long as these specks move with eye movement, they are not potentially dangerous.
Miscellaneous conditions
Published in Thomas H. Williamson, Vitreoretinal Disorders in Primary Care, 2017
Symptomatic vitreous floaters are common over the age of 30 years but are mostly ignored by the individual. Some have considerable debris in the vitreous either from pathology or from general degeneration. Some individuals do not tolerate even small floaters often related to their personality types or to activities that they perform. Patients with multifocal lens implants may find vitreous opacities more problematic.
Macro- and Microscale Properties of the Vitreous Humor to Inform Substitute Design and Intravitreal Biotransport
Published in Current Eye Research, 2021
Nguyen K. Tram, Courtney J. Maxwell, Katelyn E. Swindle-Reilly
The phase separation of the vitreous compromises its ability to function as a protective structure for the surrounding ocular tissues and causes complications including rhegmatogenous retinal detachment, macular holes, vitreous hemorrhage, and vitreous floaters.51 Vitreous floaters, which can be seen as floating shadows in one’s field of vision, are large fibrous aggregations floating in pockets of liquefied vitreous that cast shadows on the retina, interfering with vision. When the liquid pockets develop at the back of the eye, areas of high stress develop where the vitreous connects to the retina, potentially causing retinal tears or macular holes. Thereafter, the liquid component of the vitreous might leak underneath the retina layer through the tear in the retina, lifting the retina away from the choroid and causing retinal detachment. Blood from the retinal vessels may bleed into the vitreous, creating vitreous hemorrhage which might necessitate surgical removal of the tissue if the vitreous hemorrhage does not clear on its own. The degree of phase separation of the vitreous humor has been correlated to signs of cataract formation52 due to the diminished oxygen gradient and the ability of oxygen to travel from the retina to the lens via convectional mixing. Considering the serious complications with the phase-separated vitreous humor, it is important to understand the changing mechanical properties of the aging vitreous.
Evaluation of Available Online Information Regarding Treatment for Vitreous Floaters
Published in Seminars in Ophthalmology, 2021
Meghana Kalavar, Sasha Hubschman, Julia Hudson, Ajay E. Kuriyan, Jayanth Sridhar
For vitreous floaters, a common eye complaint with generally benign pathology and controversial therapeutic options, this issue is particularly salient. The majority of the population experiences vitreous floaters in their lifetime, including up to 76% of smartphone users.4 Vitreous floaters often occur as a result of molecular changes to the collagen extracellular matrix in the eye, and patients describe floaters as bubbles, dark spots, bugs or cobwebs in the temporal visual field.5 While vitreous floaters can occur for many reasons, including inflammation, they most commonly occur due to aging.5 Objectively quantifying the severity of floaters is challenging as patients do not usually have a loss of visual acuity, although correlation with contrast sensitivity has been demonstrated.6,7 Since the impact floaters have on a patient’s quality of life is primarily subjective, the treatment is predominantly patient-driven, increasing the likelihood that patients will turn to the internet for information. Given the benign nature of most floaters, the most common management in the absence of retinal pathology is observation.8 When treatment is considered, options include Nd-Yag laser vitreolysis, cataract surgery combined with deep anterior vitrectomy, and pars plana vitrectomy.9
The Role of Dexamethasone Implant in the Management of Tubercular Uveitis
Published in Ocular Immunology and Inflammation, 2018
Aniruddha Agarwal, Sabia Handa, Kanika Aggarwal, Mansi Sharma, Ramandeep Singh, Aman Sharma, Rupesh Agrawal, Kusum Sharma, Vishali Gupta
None of the patients who received intravitreal dexamethasone implant developed significant post-injection inflammation (≥ 2 step increase in anterior chamber/vitreous cells) or endophthalmitis. The most common local ocular adverse event was ocular pain or redness followed by vitreous floaters (10 eyes). The mean pre-injection baseline IOP was 14.88 ± 2.68 mm Hg. On the first post-injection day, the mean IOP was 16.9 ± 6.47 mm Hg (p = 0.25). The mean IOP at 4 weeks was 19.2 ± 5.47 (p = 0.02) and 16.4 ± 5.82 mm Hg (p = 0.18) at 3 months. Four patients had IOP > 21 mm Hg in the first month after the injection and 2 patients showed an IOP rise ≥10 mm Hg from baseline. All the patients were managed using topical anti-glaucoma medications. Two patients (two eyes) required cataract surgery during the first 6 months after injection of dexamethasone implant due to progression of cataract.