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2.
J Vis Exp ; (204)2024 02 23.
Article in English | MEDLINE | ID: mdl-38465936

ABSTRACT

The standard visual acuity measurements rely on stationary stimuli, either letters (Snellen charts), vertical lines (vernier acuity) or grating charts, processed by those regions of the visual system most sensitive to the stationary stimulation, receiving visual input from the central part of the visual field. Here, an acuity measurement is proposed based on discrimination of simple shapes, that are defined by motion of the dots in the random dot kinematograms (RDK) processed by visual regions sensitive to motion stimulation and receiving input also from the peripheral visual field. In the motion-acuity test, participants are asked to distinguish between a circle and an ellipse, with matching surfaces, built from RDKs, and separated from the background RDK either by coherence, direction, or velocity of dots. The acuity measurement is based on ellipse detection, which with every correct response becomes more circular until reaching the acuity threshold. The motion-acuity test can be presented in negative contrast (black dots on white background) or in positive contrast (white dots on black background). The motion defined shapes are located centrally within 8 visual degrees and are surrounded by RDK background. To test the influence of visual peripheries on centrally measured acuity, a mechanical narrowing of the visual field to 10 degrees is proposed, using opaque goggles with centrally located holes. This easy and replicable narrowing system is suitable for MRI protocols, allowing further investigations of the functions of the peripheral visual input. Here, a simple measurement of shape and motion perception simultaneously is proposed. This straightforward test assesses vision impairments depending on the central and peripheral visual field inputs. The proposed motion-acuity test advances the capability of standard tests to reveal spare or even strengthened vision functions in patients with injured visual system, that until now remained undetected.


Subject(s)
Motion Perception , Visual Fields , Humans , Sensory Thresholds/physiology , Visual Acuity , Motion Perception/physiology , Psychophysics
3.
Semin Ophthalmol ; 37(5): 602-610, 2022 Jul 04.
Article in English | MEDLINE | ID: mdl-35125052

ABSTRACT

PURPOSE: Open-angle glaucoma (OAG), accounting for 90% of all glaucoma cases, is a progressive optic nerve neuropathy. It may lead to irreversible loss of visual field and complete blindness. When conservative treatment becomes insufficient to stop OAG progression, a surgical intervention is considered. Currently, canaloplasty procedure is being introduced instead of conventional trabeculectomy for invasive OAG treatment. The aim of the study is to asses safety and efficacy of canaloplasty. METHODS: This prospective study included 67 eyes that received 360° canaloplasty with placement of a tensioning suture. Primary OAG (n = 35), secondary OAG in pseudoexfoliative syndrome (n = 13), and pigmentary glaucoma (n = 19) patients were included. Control check-ups were conducted pre-operatively and in a 18-month follow-up time. Study endpoints involved reduction in IOP values and in the number of glaucoma medications after the intervention. RESULTS: The intervention led to a significant 38% reduction in IOP value from the preoperative baseline to 18 months after the intervention. The number of medications decreased significantly by 89%. At 18 months postoperative, 79% eyes did not require any glaucoma medications. The incidence of complications after canaloplasty was low, and none of the adverse effects were vision threatening. A surgically-induced astigmatism was the most frequent complication. Pigmentary glaucoma patients were the most beneficial subgroup, with 50% reduction in IOP, the highest success rate, and 98% reduction in the number of medications used. CONCLUSION: This study proved that canaloplasty is an efficient and safe procedure in OAG eyes.


Subject(s)
Filtering Surgery , Glaucoma, Open-Angle , Filtering Surgery/methods , Follow-Up Studies , Glaucoma, Open-Angle/complications , Glaucoma, Open-Angle/surgery , Humans , Intraocular Pressure , Prospective Studies , Treatment Outcome
4.
Transl Vis Sci Technol ; 10(1): 9, 2021 01.
Article in English | MEDLINE | ID: mdl-33505776

ABSTRACT

Purpose: Damage of retinal representation of the visual field affects its local features and the spared, unaffected parts. Measurements of visual deficiencies in ophthalmological patients are separated for central (shape) or peripheral (motion and space perception) properties, and acuity tasks rely on stationary stimuli. We explored the benefit of measuring shape and motion perception simultaneously using a new motion-based acuity task. Methods: Eight healthy control subjects, three patients with retinitis pigmentosa (RP; tunnel vision), and 2 patients with Stargardt disease (STGD) juvenile macular degeneration were included. To model the peripheral loss, we narrowed the visual field in controls to 10 degrees. Negative and positive contrast of motion signals were tested in random-dot kinematograms (RDKs), where shapes were separated from the background by the motion of dots based on coherence, direction, or velocity. The task was to distinguish a circle from an ellipse. The difficulty of the task increased as ellipse became more circular until reaching the acuity limit. Results: High velocity, negative contrast was more difficult for all, and for patients with STGD, it was too difficult to participate. A slower velocity improved acuity for all participants. Conclusions: Proposed acuity testing not only allows for the full assessment of vision but also advances the capability of standard testing with the potential to detect spare visual functions. Translational Relevance: The motion-based acuity task might be a practical tool for assessing vision loss and revealing undetected, undamaged, or strengthened properties of the injured visual system by standard testing, as suggested here for two patients with STGD and three patients with RP.


Subject(s)
Motion Perception , Retinitis Pigmentosa , Humans , Retinitis Pigmentosa/diagnosis , Scotoma , Visual Acuity , Visual Fields
5.
Klin Oczna ; 117(2): 123-9, 2015.
Article in Polish | MEDLINE | ID: mdl-26638552

ABSTRACT

Levofloxacin 0.5% ophthalmic solution is a fluoroquinolone antibacterial agent with a broad spectrum of activity against Gram positive and negative bacteria. For those reasons it is highly effective in treating common external infections of the eye including blepharitis, conjunctivitis, keratitis. In terms of microbial eradication and clinical cure rate it is significantly more effective than ofloxacin 0.3% ophthalmic solution, and non inferior to moxifloxacin ophthalmic solution. After topical administration of levofloxacin 0.5% ophthalmic solution it achieves concentration exceeding MIC90 for most clinically relevant pathogenes in tears, conjunctiva, cornea as well as anterior chamber. Thus it can be used in prophylaxis in patients undergoing ocular surgery. Because of its postantibiotic effect and high concentration in tears three times daily regimen is as effective as most frequent administration in patients with conjunctivitis, which leads to better compliance. Despite the wide use of topical and systemic levofloxacin, most common ocular pathogens remain clinically susceptible. Topical levofloxacin is well tolerated, it rarely causes systemic or ocular adverse events with the majority of treatment-related adverse effects being of mild to moderate severity. It also does not effect the wound healing.


Subject(s)
Anti-Bacterial Agents/administration & dosage , Endophthalmitis/drug therapy , Eye Infections, Bacterial/drug therapy , Levofloxacin/administration & dosage , Surgical Wound Infection/drug therapy , Endophthalmitis/prevention & control , Humans , Postoperative Complications/prevention & control , Surgical Wound Infection/prevention & control
6.
Klin Oczna ; 113(1-3): 47-51, 2011.
Article in English | MEDLINE | ID: mdl-21853951

ABSTRACT

PURPOSE: Evaluation of the measurement accuracy using a new optical biometer LenStar LS 900 (Haag Strait) and comparison according to the IOL Master V.5 (Zeiss) device. METHODS: In a prospective clinical study biometric measurements along with artificial lens power calculation using the LenStar LS 900 device were performed. A total number of 106 patients qualified for a cataract extraction procedure were included in the study. Measurements along with lens power calculation were repeated using the IOL Master V.5. device. Results were elaborated using Pearson's correlation and Bland-Altman plot. RESULTS: Measurements were performed in 204 eyes of 106 patients. Mean values and ranges of biometry results were as follows: 23.46 +/- 2.81 mm [20.79-29.80] for IOL Master, and 23.47 +/- 2.83 mm [20.79-29.86] for LenStar LS 900. In keratometry for flat meridian (K1) the following data was obtained: mean 43.24 +/- 3.22 D [range 38.27-47.94] for IOL Master and 42.44 +/- 3.15 D [38.27-47.94] for LenStar LS 900. For steep meridian (K2) the data obtained were 44.14 +/- 3.40 D; [39.29-49.13] and 43.27 +/- 3.34 D [38.61-48.4] respectively. The obtained calculation results for each eye were as follows: mean 21.23 +/- 8.07, [range 3.25-28.99] for Hagis formula, 21.14 +/- 6.90; [4.83-27.6] for SRK II, 21.04 +/- 7.78; [3.05-28.05] for SRK/T, 21.09 +/- 8.13; [2.43-28.61] for Holladay using IOL Master and 21.41 +/- 8.23; [2.99-29.15] for Haigis; 21.24 +/- 7.00; [4.6-27.71] for SRK II, 21.13 +/- 7.90; [2.76-28.18] for SRK/T; 21.09 +/- 8.13; [2.16-28.76] for Holladay using LenStar LS 900. CONCLUSIONS: The LenStar LS 900 device enables to perform accurate and repetitive biometric measurements and implant power calculations. Implant calculation results obtained using the LenStar LS 900 device are comparable to those achieved using the IOL Master V.5 device, which has been commonly accepted as standard for over a decade. The use of both devices is limited by significant lens opacification and posterior capsule calcification. In such cases, additional ultrasound biometry should be performed. Keratometry results obtained using both devices should not be used alternatively because of the different measurement methods and different refraction indexes. The LenStar LS 900 device comparing to the IOL Master additionally enables pachymetry, macular retinal thickness, lens thickens and pupil diameter measurement. Accuracy of those measurements should be studied in the future.


Subject(s)
Biometry/instrumentation , Biometry/methods , Cataract/pathology , Lasers , Tomography, Optical Coherence/instrumentation , Tomography, Optical Coherence/methods , Diagnostic Techniques, Ophthalmological , Humans , Interferometry/methods , Lenses, Intraocular , Poland , Prospective Studies , Reproducibility of Results , Sensitivity and Specificity
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