Cataracts and Visual Axis Opacities

2013 ◽  
Author(s):  
John P. Berdahl ◽  
Thomas W. Samuelson
Keyword(s):  
Visual Acuity ◽  
Anterior Chamber ◽  
Visual Fields ◽  
Glaucoma Surgery ◽  
Convincing Evidence ◽  
Filtering Surgery ◽  
Cataract Formation ◽  
Visual Axis ◽  
Chronic Corticosteroid ◽  
The Many

Glaucoma surgery can result in worsened visual acuity. This worsening may result from alterations to the ocular structures in the visual axis during or following surgery. This outcome is often troublesome for advanced glaucoma patients with severely restricted visual fields as they are very dependent on the remaining central island of vision. In patients with less severe glaucoma, postsurgical loss of acuity may be their first symptom of glaucoma. Many conditions result in decreased visual acuity following glaucoma surgery, and appropriate management of these complications is important for maintaining visual acuity. Cataract is the most common cause of decreased visual acuity after filtering surgery. Filtering surgery increases the 5-year risk of developing a visually significant cataract by 78%. The reason for cataract formation following trabeculectomy is unclear. The most accepted hypothesis is that aqueous dynamics are altered by trabeculectomy surgery. A surgical peripheral iridectomy is typically performed as part of a trabeculectomy, which permits aqueous to pass directly from the posterior chamber to the anterior chamber without first supplying nutrition to the anterior lens. This theory is consistent with the observation that cataracts are more common after laser peripheral iridotomy. Inadvertent puncture of the lens capsule during trabeculectomy surgery is also a potential cause (see Chapter 7). Another proposed cause of cataract formation is postoperative inflammation, although plausible, convincing evidence is lacking. Increased cataract formation has been observed with the use of mitomycin-C (MMC) and may be due either to increased aqueous outflow bypassing the lens or direct toxicity to the lens. Surgical complications such as intraoperative or postoperative flat anterior chamber with lens-cornea touch increase the risk of cataract formation. Additionally, postoperative medications, especially corticosteroids, are also known to be associated with cataract formation. The risk of cataract formation from topical ocular steroids is difficult to determine because of the many confounding variables.. However, the odds ratio of cataract formation from systemic and inhaled chronic corticosteroid use is approximately 1.5–2.0. The surgeon should bear potential steroid effects in mind during the postoperative period in phakic patients.

Vitreous Prolapse and Lens Injury

2013 ◽  
Author(s):  
Paul J. Harasymowycz
Keyword(s):  
Anterior Chamber ◽  
Extended Period ◽  
Clinical Situation ◽  
Lens Capsule ◽  
Surgical Trauma ◽  
Cataract Formation ◽  
Visual Axis ◽  
Lens Extraction ◽  
Vitreous Prolapse ◽  
Clinically Significant

During trabeculectomy, when a sclerostomy and iridectomy are performed, the structures immediately posterior to the iris, namely the zonules, lens capsule, ciliary processes, and anterior hyaloid face may be violated, resulting in a variety of intraoperative and postoperative complications. Lens injury, including cataract formation, and vitreous prolapse are 2 of the complications that may occur intraoperatively. Cataract formation is one of the most common occurrences after trabeculectomy, reported in approximately 50% of cases. While development of the cataract is usually a slow process, it occurs more frequently in patients with a history of diabetes, postoperative flat anterior chambers, or intraocular inflammation, as well as in a patient with a negative spherical equivalent (preoperative lens status) and pseudoexfoliation syndrome. Older age is a risk factor, since natural cataract development may be accelerated; however, cataracts may develop in up to 25% of younger (<55 years of age) patients undergoing trabeculectomy. The utilization of postoperative steroids has also been implicated in the development of posterior subcapsular opacities. Although not a common occurrence, cataracts may also develop soon after surgery due to direct intraoperative surgical trauma to the lens. If the opacity is focal and does not encroach on or obstruct the visual axis, no further action may be needed. If there is obvious rupture of the lens capsule causing clinically significant inflammation that may compromise bleb development, urgent lens extraction should be performed. If the clinical situation permits, it is desirable to wait at least 3 months until the bleb matures. Rapidly forming cataracts may also develop due to prolonged contact between the lens and the cornea, such as occurs intraoperatively if forceps inadvertently indent the cornea while retracting the conjunctiva during a limbus-based trabeculectomy. Similarly, the lens may opacify if the anterior chamber is flat for an extended period of time before the scleral flap sutures are adequately tied. Likewise, postoperative hypotony with a flat anterior chamber may lead to cataract formation (see Chapter 10).

Short-term anterior chamber inflammation in phacoemulsification with and without Ex-Press glaucoma implant

2019 ◽  
Vol 30 (3) ◽  
pp. 533-537
Author(s):  
Shmuel Graffi ◽  
Beatrice Tiosano ◽  
Modi Naftali ◽  
Nakhoul Nakhoul ◽  
Michael Mimouni ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Intraocular Pressure ◽  
Anterior Chamber ◽  
Medical Center ◽  
Glaucoma Surgery ◽  
Consecutive Series ◽  
Device Implantation ◽  
Significant Difference ◽  
Clinically Significant ◽  
Retrospective Comparative Study

Purpose: The aim of this study was to investigate the incidence of clinically significant anterior chamber inflammation in a combined surgery, namely, phacoemulsification and Ex-Press miniature glaucoma device implantation, compared to phacoemulsification alone. Methods: A retrospective comparative study of a consecutive series of 210 participants above 18 years of age diagnosed with significant cataract and who required glaucoma surgery, namely, Ex-Press miniature glaucoma device implantation or cataract alone in one or both eyes. All were operated on by a single experienced glaucoma surgeon in a single medical center. A total of 231 eyes were included in this study. All cases underwent an uneventful surgery and were examined the day following the surgery for visual acuity, intraocular pressure, and signs of excessive anterior chamber inflammation (Standardization of Uveitis Nomenclature grading ⩾ 3). Results: The combined group included 55 eyes of 51 patients, of whom 15 (27.3%) demonstrated excessive anterior chamber inflammation. The phacoemulsification group included 176 eyes of 159 patients, of whom 12 (6.7%) demonstrated excessive anterior chamber inflammation. Visual acuity and intraocular pressure measurements showed no statistically significant difference between the two groups. Conclusion: The Ex-Press glaucoma device is efficient, safe, and known for its inert nature. However, combination of this procedure with phacoemulsification surgery might result in a condition encouraging excessive inflammation, which eventually could lead to excessive anterior chamber inflammations if not treated vigorously. Emphasizing and recognizing the risks, especially in glaucoma patients, is important.

scholarly journals Intracameral Air and Fibrin Glue for the Management of Late Bleb Leak following Glaucoma Surgery

2019 ◽  
Vol 10 (1) ◽  
pp. 47-52
Author(s):  
Mohammed R. Hayat ◽  
Fatema S. Mollah ◽  
Kamal Kishore
Keyword(s):  
Visual Acuity ◽  
Anterior Chamber ◽  
Fibrin Glue ◽  
Pars Plana Vitrectomy ◽  
Glaucoma Surgery ◽  
Steroid Injections ◽  
Delayed Onset ◽  
Pars Plana ◽  
Bleb Leak

Background and Objectives: To report a case of delayed-onset bleb-associated endophthalmitis (BAE) with bleb leak successfully managed with pars plana vitrectomy, intravitreal antibiotics, intracameral air, and fibrin glue. Patient and Methods: A 66-year-old pseudophakic female presented with BAE and bleb leak. A 25-gauge pars plana vitrectomy, cultures, and intravitreal antibiotics and steroid injections were performed. The infusion was switched to air filling the anterior chamber and bleb with air. Fibrin glue (Tisseel®) was applied over the leaking bleb. Results: BAE and bleb leak resolved with return of visual acuity to 20/25 and a functioning bleb with no recurrence of bleb leak after 1 year of follow-up. Conclusion: The combination of intracameral air and fibrin glue may have a role in the management of bleb leaks.

scholarly journals Ocular biometric changes after trabeculectomy

2019 ◽  
Vol 147 (5-6) ◽  
pp. 341-347
Author(s):  
Marija Radenkovic ◽  
Gordana Stankovic-Babic ◽  
Jasmina Djordjevic-Jocic ◽  
Maja Zivkovic ◽  
Marija Trenkic-Bozinovic ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Anterior Chamber ◽  
Axial Length ◽  
Spontaneous Recovery ◽  
Open Angle Glaucoma ◽  
Anterior Segment ◽  
Anterior Chamber Depth ◽  
Glaucoma Surgery ◽  
Biometric Analysis ◽  
The Difference

Introduction/Objective. Trabeculectomy is a conventional filtration procedure in surgical glaucoma treatment. Even after successful trabeculectomy, the patient?s visual acuity can be reduced. Studies (1991) showed that changes in visual acuity occur due to changes of corneal curvature and anterior chamber depth. Anterior chamber depth change for 1 mm results in about 2 diopters change in refractive sphere. Simultaneous with anterior segment changes, anti-glaucoma surgery effect can also be manifested in posterior segment of the eye: choroidal thickness, axial length and the ocular perfusion. Axial length reduction after trabeculectomy was supposed according to biometry, more pronounced if intraocular pressure is higher preoperatively, or in the first postoperative week with spontaneous recovery to preoperative values one year after surgery. A study was conducted at the Clinic for Eye Diseases in Nis to determine the difference in pre/post-operative values of biometry on 60 patients with glaucoma. Methods. In this study we used retrospective-prospective biometric analysis in patients with open-angle glaucoma. Results. Anterior chamber depth was significantly different during the observed period, for 1.1 mm in first week (p < 0.0001) in the whole group and glaucoma type. The mean axial length varies considerably during the observed period, shorter for 0.39 mm in first week (p < 0.05). Conclusion. By analyzing biometric parameters, a postoperative difference of biometry with spontaneous recovery was determined. There is a difference in postoperative visual acuity of patients compared to preoperative, with spontaneous recovery at the end of the follow-up.

Pediatric Free-floating Anterior Chamber Cyst of the Iris Pigment Epithelium

2018 ◽  
Vol 1 ◽  
pp. 3
Author(s):  
Joshua S Agranat ◽  
Yoshihiro Yonekawa
Keyword(s):  
Optical Coherence Tomography ◽  
Anterior Chamber ◽  
Incidental Finding ◽  
Pigment Epithelium ◽  
Anterior Segment ◽  
Ultrasound Biomicroscopy ◽  
Optical Coherence ◽  
Visual Axis ◽  
Associated Malignancy ◽  
Anatomic Locations

Iris pigment epithelial (IPE) cysts are a subset of iris cysts that arise from the IPE. They are spontaneously erupting epithelial-lined cavities that are found in various anatomic locations of the iris, including the iris pupillary margin, midzone, periphery, and free floating in the vitreous or anterior chamber. We report the case of an asymptomatic 13-year-old boy with an incidental finding of a dislodged anterior chamber cyst diagnosed on routine examination. Modern multimodal image analysis of the cyst including anterior segment optical coherence tomography and ultrasound biomicroscopy (UBM) was utilized to characterize the microstructural anatomy of the lesion. The patient was managed conservatively without complications. Cysts of the IPE typically do not affect vision or ocular health and can be monitored and observed after ascertaining no associated malignancy. Initial diagnostic investigation can include UBM and anterior segment optical coherence tomography. Intervention should be reserved only for cases where the cyst growth leads to obstruction of the visual axis and/or other secondary complications.

scholarly journals From Abbott Thayer to the present day: what have we learned about the function of countershading?

2008 ◽  
Vol 364 (1516) ◽  
pp. 519-527 ◽  
Author(s):  
Hannah M Rowland
Keyword(s):  
Empirical Work ◽  
Quantitative Measure ◽  
Convincing Evidence ◽  
Colour Pattern ◽  
Protective Effects ◽  
Empirical Testing ◽  
Background Matching ◽  
Visual Characteristics ◽  
Subjective Evidence ◽  
The Many

Of the many visual characteristics of animals, countershading (darker pigmentation on those surfaces exposed to the most lighting) is one of the most common, and paradoxically one of the least well understood. Countershading has been hypothesized to reduce the detectability of prey to visually hunting predators, and while the function of a countershaded colour pattern was proposed over 100 years ago, the field has progressed slowly; convincing evidence for the protective effects of countershading has only recently emerged. Several mechanisms have been invoked for the concealing function of countershading and are discussed in this review, but the actual mechanisms by which countershading functions to reduce attacks by predators lack firm empirical testing. While there is some subjective evidence that countershaded animals match the background on which they rest, no quantitative measure of background matching has been published for countershaded animals; I now present the first such results. Most studies also fail to consider plausible alternative explanations for the colour pattern, such as protection from UV or abrasion, and thermoregulation. This paper examines the evidence to support each of these possible explanations for countershading and discusses the need for future empirical work.

scholarly journals Conventional glaucoma implants and the new MIGS devices: a comprehensive review of current options and future directions

Eye ◽  
2021 ◽  
Author(s):  
Inês C. F. Pereira ◽  
Rosanne van de Wijdeven ◽  
Hans M. Wyss ◽  
Henny J. M. Beckers ◽  
Jaap M. J. den Toonder
Keyword(s):  
Anterior Chamber ◽  
Aqueous Humour ◽  
Alternative Pathway ◽  
Glaucoma Surgery ◽  
Future Directions ◽  
Plate Design ◽  
Glaucoma Drainage Devices ◽  
Abnormal Increase ◽  
Preventable Blindness ◽  
Glaucoma Implants

AbstractGlaucoma is a progressive optic neuropathy that is the second leading cause of preventable blindness worldwide, after cataract formation. A rise in the intraocular pressure (IOP) is considered to be a major risk factor for glaucoma and is associated with an abnormal increase of resistance to aqueous humour outflow from the anterior chamber. Glaucoma drainage devices have been developed to provide an alternative pathway through which aqueous humour can effectively exit the anterior chamber, thereby reducing IOP. These devices include the traditional aqueous shunts with tube-plate design, as well as more recent implants, such as the trabeculectomy-modifying EX-PRESS® implant and the new minimally invasive glaucoma surgery (MIGS) devices. In this review, we will describe each implant in detail, focusing on their efficacy in reducing IOP and safety profile. Additionally, a critical and evidence-based comparison between these implants will be provided. Finally, we will propose potential developments that may help to improve the performance of current devices.

Vision through Various Scuba Facemasks

1974 ◽  
Vol 16 (4) ◽  
pp. 395-405 ◽  
Author(s):  
S. M. Luria ◽  
Steven H. Ferris ◽  
Christine L. McKay ◽  
Jo Ann S. Kinney ◽  
Helen M. Paulson
Keyword(s):  
Visual Acuity ◽  
Optical Properties ◽  
Visual Fields ◽  
Differential Susceptibility ◽  
Visual Performance ◽  
Visual Process ◽  
Hand Eye Coordination ◽  
Size Estimates

The visual performance using five commercially avaible facemasks was compared. Measurements were made of visual fields, visual acuity, stereoacuity, hand-eye coordination, accuracy of distance estimates, and accuracy of size estimates at both near and far distances. In addition, the optical properties of the masks were measured and the susceptibility of each mask to fogging was tested. There were significant differences among the masks for every visual process tested. Some masks were superior for one purpose and inferior for another purpose. For example, the mask which had lenses designed to compensate for the optical distortions found under water improved size and distance estimates and hand-eye coordination, but degraded acuity and stereoacuity. The results were not expplained on the basis of differential susceptibility to fogging.

Arteriovenous malformations in the optic apparatus: systematic literature review and report of four cases

2021 ◽  
pp. 1-11
Author(s):  
Visish M. Srinivasan ◽  
Phiroz E. Tarapore ◽  
Stefan W. Koester ◽  
Joshua S. Catapano ◽  
Caleb Rutledge ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Visual Field ◽  
Visual Function ◽  
Arteriovenous Malformations ◽  
Vascular Malformations ◽  
Visual Fields ◽  
Optic Tract ◽  
Visual Disturbance ◽  
Visual Field Defects ◽  
Subtotal Resection

OBJECTIVE Rare arteriovenous malformations (AVMs) of the optic apparatus account for < 1% of all AVMs. The authors conducted a systematic review of the literature for cases of optic apparatus AVMs and present 4 cases from their institution. The literature is summarized to describe preoperative characteristics, surgical technique, and treatment outcomes for these lesions. METHODS A comprehensive search of the English-language literature was performed in accordance with established Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to identify all published cases of AVM in the optic apparatus in the PubMed, Web of Science, and Cochrane databases. The authors also searched their prospective institutional database of vascular malformations for such cases. Data regarding the clinical and radiological presentation, visual acuity, visual fields, extent of resection, and postoperative outcomes were gathered. RESULTS Nine patients in the literature and 4 patients in the authors’ single-surgeon series who fit the inclusion criteria were identified. The median age at presentation was 29 years (range 8–39 years). Among these patients, 11 presented with visual disturbance, 9 with headache, and 1 with multiple prior subarachnoid hemorrhages; the AVM in 1 case was found incidentally. Four patients described prior symptoms of headache or visual disturbance consistent with sentinel events. Visual acuity was decreased from baseline in 10 patients, and 11 patients had visual field defects on formal visual field testing. The most common visual field defect was temporal hemianopia, found in one or both eyes in 7 patients. The optic chiasm was affected in 10 patients, the hypothalamus in 2 patients, the optic nerve (unilaterally) in 8 patients, and the optic tract in 2 patients. Six patients underwent gross-total resection; 6 patients underwent subtotal resection; and 1 patient underwent craniotomy, but no resection was attempted. Postoperatively, 9 of the patients had improved visual function, 1 had no change, and 3 had worse visual acuity. Eight patients demonstrated improved visual fields, 1 had no change, and 4 had narrowed fields. CONCLUSIONS AVMs of the optic apparatus are rare lesions. Although they reside in a highly eloquent region, surgical outcomes are generally good; the majority of patients will see improvement in their visual function postoperatively. Microsurgical technique is critical to the successful removal of these lesions, and preservation of function sometimes requires subtotal resection of the lesion.

Distracted Driving and Driving Patterns in Older Drivers With Glaucoma

2021 ◽  
pp. 155982762110428
Author(s):  
Purva Jain ◽  
Jonathan T. Unkart ◽  
Fabio B. Daga ◽  
Linda Hill
Keyword(s):  
Visual Acuity ◽  
Visual Field ◽  
Visual Fields ◽  
Distracted Driving ◽  
Night Vision ◽  
Driving Ability ◽  
Safe Driving ◽  
Ability To Drive ◽  
Acuity Score

Limited research exists examining self-perceived vision and driving ability among individuals with glaucoma, and this study assessed the relationship between glaucoma, visual field, and visual acuity with driving capability. 137 individuals with glaucoma and 75 healthy controls were asked to evaluate self-rated vision, self-perceived driving ability, and self-perceived distracted driving. Visual acuity and visual field measurements were also obtained. Multivariable linear regressions were run to test each visual measure with driving outcomes. The average age was 72.2 years, 57.3% were male, and 72.5% were White. There were significant associations for a one-point increase in visual field and quality of corrected vision (RR = 1.06; 95% CI = 1.03–1.10), day vision (RR = 1.05; 95% CI = 1.03–1.08), night vision (RR = 1.08; 95% CI = 1.05–1.13), visual acuity score and higher quality of corrected of vision (RR = .41; 95% CI = .22-.77), day vision (RR = .39; 95% CI=.22–.71), and night vision (RR = .41; 95% CI = .18–.94); visual acuity score and ability to drive safely compared to other drivers your age (RR = .53; 95% CI = .29–.96). Individuals with poorer visual acuity and visual fields rate their vision and ability to drive lower than those with better vision, and this information will allow clinicians to understand where to target interventions to enhance safe driving practices.

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