scholarly journals Preliminary Clinical Exploration of Scleral Lens Performance on Normal Eyes

2018 ◽  
Vol 2 (2) ◽  
pp. e14-e21
Author(s):  
Melissa Barnett ◽  
Jonathon Ross ◽  
Blythe Durbin-Johnson
Keyword(s):  
Visual Acuity ◽  
Contact Lens ◽  
Healthy Subjects ◽  
Contact Lenses ◽  
Front Surface ◽  
Contact Lens Wear ◽  
Factors Associated ◽  
Rigid Contact ◽  
Lens Wear ◽  
Spectacle Correction

Abstract Objectives: The purpose of this study was to evaluate the performance (i.e. vision, comfort and fit) of spherical and front-surface toric scleral lenses in subjects with regular, healthy corneas. Methods: Scleral lenses were fitin the eyes (n = 16) of healthy subjects (n = 9) with regular corneas, absent of pathology, and studied using an observational, multi-visit design. Lens fit was objectively evaluatedby an experienced practitioner.Following 1 month of successful lens wear, participants completedsubjective satisfaction surveys regarding the scleral lens wearing experience. Results:  According to participant surveys, scleral lenses were subjectively preferred over soft toric or gas permeable contact lenses in 88% of eyes, including in all eyes fit with a front-surface toric scleral lens (n = 3). Seventy-five percent (75%) of eyes achieved visual acuity of 0.1 logMAR or better, while all eyes with prior spectacle wear achieved visual acuity with a scleral lens within 1 Snellen line of spectacle correction. Seventy-five percent (75%) of eyes achieved good subjective comfort with a scleral lens. No participants reported poor subjective vision and/or comfort. Conclusions:  Our findings suggest that subjects preferred the performance of a scleral lens (spherical or front-surface toric) compared to a soft toric or gas permeable contact lens. Moreover, scleral lenses may provide a viable, alternative contact lens modality option for patients considering discontinuation of traditional soft toric and/or rigid contact lens wear; so long as the factors associated with hypoxia remain minimized. Key Words:  scleral lens; scleral contact lens; front-surface toric scleral lens; lens performance; normal eyes; healthy eyes

scholarly journals The short-term effects of PMMA contact lens wear on keratometric behaviour: results for a single keratoconic cornea*

2010 ◽  
Vol 69 (2) ◽  
Author(s):  
E. Chetty ◽  
W. D. H. Gillan
Keyword(s):  
Contact Lens ◽  
Contact Lenses ◽  
Corneal Curvature ◽  
Short Term ◽  
Multivariate Statistical ◽  
Contact Lens Wear ◽  
Rigid Contact ◽  
Dioptric Power ◽  
Control Study ◽  
Lens Wear

Keratometric behaviour is a multifaceted issue that many researchers have investigated for years. Many internal and external influences can have an effect on the cornea’s keratometric behaviour. This investigation forms a small part of a larger study that aims at determining the effects that rigid contact lenses might have on keratometric behaviour. This pilot study examined the keratometric behaviour of a single, mildly keratoconic cornea that was fitted with a polymethyl methacrylate (PMMA) contact lens. Sixty successive auto-keratometric measurements were taken immediately before and immediately after three hours of contact lens wear. The data obtained was transformed to dioptric power matrices and were analysed using multivariate statistical methods. This study showed that, at least in one keratoconic cornea, there appeared to be a statistically significant change in corneal curvature under the influence of a PMMA contact lens. The contact lens had also appeared to decrease variation in corneal curvature. There was no control study done on this eye therefore the effects of diurnal variation, if any, could not be established. (S Afr Optom 2010 69(2) 69-76)

scholarly journals Contact Lens Visual Rehabilitation in Keratoconus and Corneal Keratoplasty

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
Yelda Ozkurt ◽  
Mehmet Atakan ◽  
Tugba Gencaga ◽  
Sezen Akkaya
Keyword(s):  
Contact Lens ◽  
Contact Lenses ◽  
Soft Contact ◽  
Visual Rehabilitation ◽  
Adequate Treatment ◽  
Contact Lens Wear ◽  
Soft Contact Lenses ◽  
Thinning Process ◽  
Lens Wear ◽  
Spectacle Correction

Keratoconus is the most common corneal distrophy. It’s a noninflammatory progressive thinning process that leads to conical ectasia of the cornea, causing high myopia and astigmatism. Many treatment choices include spectacle correction and contact lens wear, collagen cross linking, intracorneal ring segments implantation and finally keratoplasty. Contact lenses are commonly used to reduce astigmatism and increase vision. There are various types of lenses are available. We reviewed soft contact lenses, rigid gas permeable contact lenses, piggyback contact lenses, hybrid contact lenses and scleral-semiscleral contact lenses in keratoconus management. The surgical option is keratoplasty, but even after sutur removal, high astigmatism may stil exists. Therefore, contact lens is an adequate treatment option to correct astigmatism after keratoplasty.

scholarly journals The short-term effects of PMMA and RGP contact lens wear on keratometric behaviour: a pilot study*

2010 ◽  
Vol 69 (4) ◽  
Author(s):  
E. Chetty ◽  
W. D. H. Gillan
Keyword(s):  
Contact Lens ◽  
Contact Lenses ◽  
Control Sample ◽  
Control Group ◽  
Diurnal Changes ◽  
Short Term ◽  
Contact Lens Wear ◽  
Rigid Contact ◽  
Lens Wear ◽  
Short Term Effects

This article represents the preliminary findings of a larger study that included 24 subjects that were equally divided into three groups, namely, the PMMA (polymethyl methacrylate) group, the RGP(rigid gas permeable) group and the control group. The aim of this study was to establish the short term effects (if any) of PMMA and RGP contact lens wear on keratometric behaviour. A controlsubject was also included in the study to establish a reference fornormal diurnal changes in keratometric behaviour. Fifty successive auto-keratometric measurements were taken before and immediately after three hours of rigid contact lens wear for the first subject in the PMMA group and the first subject in the RGP group (experimental samples). Fifty successive auto-keratometric measurements were also taken on the first subject of the control group before and immediately after three hours of no lens wear (control sample). Data collected were analysed using multivariate statistical methods that in the past have been used infrequently in this area of study. This investigation revealed that, at least in these two randomly selected subjects, rigid contact lens wear appears to  influence keratometric behaviour (PMMA contact lenses more so than RGP contact lenses). (S Afr Optom 2010 69(4) 173-181)

Tribological classification of contact lenses – From coefficient of friction to sliding work: Can contact lens wear help you burn calories?

2018 ◽  
Vol 41 ◽  
pp. S41
Author(s):  
Samuele Tosatti ◽  
Olof Sterner ◽  
Rudolf Aeschlimann ◽  
Stefan Zuercher ◽  
Charles Scales ◽  
...  
Keyword(s):  
Coefficient Of Friction ◽  
Contact Lens ◽  
Contact Lenses ◽  
Contact Lens Wear ◽  
Lens Wear

scholarly journals Personal hygiene risk factors for contact lens-related microbial keratitis

2020 ◽  
Vol 5 (1) ◽  
pp. e000476
Author(s):  
Anna Stellwagen ◽  
Cheryl MacGregor ◽  
Roger Kung ◽  
Aristides Konstantopoulos ◽  
Parwez Hossain
Keyword(s):  
Risk Factors ◽  
Risk Factor ◽  
Contact Lens ◽  
Contact Lenses ◽  
Healthcare Services ◽  
University Hospital ◽  
Personal Hygiene ◽  
Microbial Keratitis ◽  
Contact Lens Wear ◽  
Lens Wear

ObjectiveMicrobial keratitis is a sight-threatening complication of contact lens wear, which affects thousands of patients and causes a significant burden on healthcare services. This study aims to identify compliance with contact lens care recommendations and identify personal hygiene risk factors in patients who develop contact lens-related microbial keratitis.Methods and analysisA case–control study was conducted at the University Hospital Southampton Eye Casualty from October to December 2015. Two participant groups were recruited: cases were contact lens wearers presenting with microbial keratitis and controls were contact lens wearers without infection. Participants underwent face-to-face interviews to identify lens wear practices, including lens type, hours of wear, personal hygiene and sleeping and showering in lenses. Univariate and multivariate regression models were used to compare groups.Results37 cases and 41 controls were identified. Showering in contact lenses was identified as the greatest risk factor (OR, 3.1; 95% CI, 1.2 to 8.5; p=0.03), with showering daily in lenses compared with never, increasing the risk of microbial keratitis by over seven times (OR, 7.1; 95% CI, 2.1 to 24.6; p=0.002). Other risks included sleeping in lenses (OR, 3.1; 95% CI, 1.1 to 8.6; p=0.026), and being aged 25–39 (OR, 6.38; 95% CI, 1.56 to 26.10; p=0.010) and 40–54 (OR, 4.00; 95% CI 0.96 to 16.61; p=0.056).ConclusionThe greatest personal hygiene risk factor for contact lens-related microbial keratitis was showering while wearing lenses, with an OR of 3.1, which increased to 7.1 if patients showered daily in lenses. The OR for sleeping in lenses was 3.1, and the most at-risk age group was 25–54.

scholarly journals Impact of Rigid Gas Permeable Contact Lenses Removal on Anterior and Posterior Corneal Surfaces in Keratoconus Patients

2019 ◽  
Author(s):  
Motohiro Itoi ◽  
Koji Kitazawa ◽  
Hisayo Higashihara ◽  
Chie Sotozono
Keyword(s):  
Contact Lens ◽  
Contact Lenses ◽  
Corneal Thickness ◽  
Anterior Segment ◽  
Corneal Surface ◽  
Contact Lens Wear ◽  
Surface Areas ◽  
The Impact ◽  
Lens Wear ◽  
Anterior Posterior

AbstractPurposeTo evaluate the impact of removal of rigid gas-permeable (RGP) contact lenses on the anterior and posterior cornea surfaces of eyes with keratoconus.MethodsEight eyes of 8 patients with keratoconus (KC) (age 34.3 ± 15.3 years; range 19–60 years) were enrolled. Anterior segment optical coherence tomography (AS-OCT) was performed at 1, 5, 10, 20, and 60 minutes after the patients removed their RGP contact lenses. Measurements included anterior and posterior best-fit sphere (BFS); elevation values and corneal surface areas; corneal thickness at the thinnest point; and the anterior-posterior ratio of the corneal surface (As/Ps) between 1 minute and 60 minutes after RGP contact lens removal.ResultsAnterior and posterior elevation values and corneal surface areas showed significant increases, whereas anterior and posterior BFS and central corneal thickness decreased significantly (P < 0.01) between 1 minute and 60 minutes after RGP contact lens removal. No statistically significant differences were found in the As/Ps ratio during the first hour after suspending RGP contact lens wear.ConclusionsWe found that the patients with keratoconus experienced significant changes in both the anterior and posterior corneal shape for 60 minutes after removal of RGP contact lenses.

scholarly journals Corneal changes following short-term rigid contact lens wear

2012 ◽  
Vol 35 (3) ◽  
pp. 129-136 ◽  
Author(s):  
Garima Tyagi ◽  
Michael J. Collins ◽  
Scott A. Read ◽  
Brett A. Davis
Keyword(s):  
Contact Lens ◽  
Short Term ◽  
Contact Lens Wear ◽  
Rigid Contact ◽  
Lens Wear
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