No description available.

Yes / To determine if a gradual adaptation period is necessary for neophytes when fitted with modern hydrogel or silicone hydrogel reusable disposable contact lenses. Across four sites, 74 neophytes (18-28 years) were randomly assigned to a reusable lens cleaned nightly with Opti-Free® Puremoist® multi-purpose contact lens solution: Proclear® (hydrogel) or Biofinity® (silicone hydrogel) and an adaptation schedule: fast (10 h wear from the first day) or gradual (4 h on the first day, increasing their wear time by 2 h on each subsequent day until they had reached 10 h). Masked investigators graded ocular surface physiology and non-invasive tear breakup time (NIBUT) and a range of comfort, vision and lens handling subjective ratings (0-100 visual analogue scales) were recorded at the baseline visit and after 10 h of lens wear, 4-6 days and 12-14 days after lens fitting. Subjective scores were also repeated after 7 days. There was no difference (p > 0.05) in ocular surface physiology or NIBUT between fast and gradual adaptation groups at any time point in either lens type with the exception of increased corneal staining (p = 0.019) in the silicone hydrogel fast adaptation group after 4-6 days, but was similar by 12-14 days. Subjective scores were also similar across the visits and lens types with the exception of 'lens awareness' (p = 0.019) which was less in the gradual versus the fast adaptation silicone hydrogel lens group at 12-14 days. There seems to be no clinical benefit for recommending a gradual adaptation period in new wearers fitted with modern soft reusable disposable contact lenses. The findings of this work add to a growing body of evidence suggesting that such advice is unnecessary in regular soft contact lens wear, which has important ramifications for the initial clinical management of these patients. / BUCCLE

Yes / All neophyte contact lens wearers require training on how to handle contact lenses. Currently, almost no published information exists describing the most common approaches used by those involved in such training in soft contact lens wearers. This study aimed to gather information on the approaches taken by those conducting this training worldwide. An online survey was created in English and translated to Spanish and distributed internationally via social media, conference attendees, and professional contacts. The anonymous survey included information on workplace setting of respondents, information about the typical approaches used for application and removal of soft contact lenses, length of the appointment, and success rate with their approach. Survey responses were received between May 2021 and April 2022. A total of 511 individuals completed the survey and responses were received from 31 countries with 48.7% from the UK. The most common approach taught for application was to have the patient hold the upper eyelashes (84.7%) and to hold the lower eyelid with the same hand as the lens (89.4%). Lenses were applied directly to the cornea by 57.7% of the respondents. The most common approach taught for lens removal was to drag the lens inferiorly from the cornea prior to removal (49.3%). Most respondents did not use videos to aid the teaching appointment (62.0%); however, they felt that their approach was successful in most cases (90). Application and removal training sessions lasted a median of 30 min and contact lenses were typically dispensed after the instructor witnessing successful application and removal three times. Various methods are adopted globally for training of application and removal of soft contact lenses, with many advising a patient-specific approach is required for success. The results of this survey provide novel insights into soft contact lens handling training in clinical practice. / British & Irish University and College Contact Lens Educators (BUCCLE) receives sponsorship from CooperVision, Alcon, Bausch + Lomb and Johnson and Johnson. No specific grant was received for this study, and no sponsors had any input or involvement within this project. Nery Garcia-Porta is supported financially by a Maria Zambrano contract at USC under the grants call for the requalification of the Spanish university system 2021–2023, funded by the European Union—Next Generation EU.

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No description available.

The anterior refracting surface of the eye is the thin tear film that forms on the surface of the cornea. When a contact lens is on worn, the tear film covers the contact lens as it would a bare cornea, and is affected by the contact lens material properties. Tear film irregularity can cause both discomfort and vision quality degradation. Under normal conditions, the tear film is less than 10 microns thick and the thickness and topography change in the time between blinks. In order to both better understand the tear film, and to characterize how contact lenses affect tear film behavior, two interferometers were designed and built to separately measure tear film behavior in vitro and in vivo. An in vitro method of characterizing dynamic fluid layers applied to contact lenses mounted on mechanical substrates has been developed using a phase-shifting Twyman- Green interferometer. This interferometer continuously measures light reflected from the surface of the fluid layer, allowing precision analysis of the dynamic fluid layer. Movies showing this fluid layer behavior can be generated. The fluid behavior on the contact lens surface is measured, allowing quantitative analysis beyond what typical contact angle or visual inspection methods provide. The in vivo interferometer is a similar system, with additional modules included to provide capability for human testing. This tear film measurement allows analysis beyond capabilities of typical fluorescein visual inspection or videokeratometry and provides better sensitivity and resolution than shearing interferometry methods. The in vitro interferometer system has measured the formation and break up of fluid layers. Different fluid and contact lens material combinations have been used, and significant fluid layer properties have been observed in some cases. This dissertation discusses the design of this interferometer along with analysis methods used. Example measurement results of different contact lens are presented highlighting the capabilities of the instrument. This dissertation also provides the in vivo interferometer design, along with the considerations that must be taken when designing an interferometer for on-eye diagnostics. Discussions include accommodating eye movement, design of null optics for a range of ocular geometries, and laser emission limits for on-eye interferometry in general.

This thesis describes the impact of contact lens-related microbial keratitis in terms of incidence and severity. Disease outcome is defined by visual outcome, costs to the healthcare system, costs to the individual and duration of disease. A successful 12-month surveillance study was conducted of the populations of Australia and New Zealand to detect all cases of contact lens-related microbial keratitis. A random telephone survey of 32,000 households in Australia and 7,500 in New Zealand accurately determined the level of use of various contact lenses in the community. The impact of new contact lens types: silicone hydrogels and daily disposables were investigated. Increased risk persisted in overnight wear with silicone hydrogel materials. Microbial keratitis associated with silicone hydrogel materials had slightly shorter disease duration however other factors had a stronger influence on severity. Rigid gas permeable and frequent replacement soft lenses when used for daily wear constitute the lowest risk. Cost analysis was developed in a hospital case series of microbial keratitis. This analysis was applied in the surveillance study including cases managed in the private health care sector. Disease duration and associated costs are novel indices of severity for contact lens-related disease. The most dramatic effects on disease severity were seen with the type of organism involved. Keratitis attributed to environmental organisms (Gram-negative bacteria, Acanthamoeba, fungi and Nocardia species) were 10x more likely to cause loss of visual acuity, had longer duration of symptoms and incurred higher costs. Importantly, delays in receiving treatment increased disease duration and associated costs. Greater awareness of the need for specialist healthcare is indicated amongst health care providers and contact lens wearers. The hypothesis that overnight wear in silicone hydrogel lenses would not increase the risk of infection has been disproven. This information is of value to practitioners who are responsible for informing contact lens wearers about the risk of contact lens-related infections and should be weighed against the benefits of continuous wear. The identification of factors which contribute to the outcomes of disease will be used in education campaigns amongst health care providers and contact lens wearers to minimise the impact of disease.

Fusarium solani is a soil-borne pathogen devastating agricultural crops throughout the world. While most pathogens are host specific, the fusaria are able to infect both plants and animals. In 2004, an outbreak of Fusarium occurred in association with contact lens wear. Several species of Fusarium were involved but F. solani and F. oxysporum were most prominent. In this work, we have identified a MAP kinase (MAPK), highly similar to fmk1 in F. oxysporum, belonging to the YERK1 subfamily of extracellular regulated kinases. Directed disruption of fmk1 in F. solani AFR4 (FSSC 1) affected several aspects of fungal growth and pathogenicity. Colonies of AFR4„½fmk1 displayed pigmented colony-like formation as opposed to the cottony-white diffuse growth observed with the wild-type strain. Mutants displayed changes in morphology and conidiation patterns with AFR4„½fmk1 mutants producing increased amounts of macroconidia vs. microconidia. AFR4„½fmk1 germ tube emergence was similar to that of wild-type AFR4 and wet weight growth was equivalent but germinules were not able to sense nutrient in chemotropic assays. The disruption of fmk1 increased spore surface hydrophobicity leading to a decrease in association with commercially available hydrogel contact lenses. FMK1 did not affect unworn lens penetration in phosphate buffered saline as both wild-type and mutant strains were able to penetrate commercially available silicone hydrogel contact lenses. AFR4 displayed increased penetration of silicone lenses and this is likely due to: increased spore/lens association, and the inability of AFR4„½fmk1 macroconidia to germinate in phosphate buffered saline. Diminished invasive growth was also noted with disruption of fmk1. Wild-type AFR4 was detected throughout the eye after conidial microinjection while AFR4„½fmk1 was limited to the vitreous fluid. The reduced invasive growth seen is attributed to the loss of chemotropism. The ability to sense and respond to the environment is essential for pathogenicity. MAPK has been deemed essential for plant pathogenicity and now, with its affect on chemotropism, appears to be necessary for animal pathogenicity. FMK1 plays a conserved role in the pathogenicity of Fusarium.

Trečdalis gyventojų kenčia dėl pavargusių ir sausų akių sindromo (Pečeliūnienė, 2006). Juos vargina jausmas, lyg į akis būtų pripilta smėlio ar žvyro, akis gali parausti arba atsiranda būdingas svetimkūnio bei diegimo, raižymo pojūtis, šviesos baimė. Rytais, tik atsimerkus, gali būti jaučiamas neilgalaikis aštrus skausmas ar padidėjęs ašarojimas bei akių nuovargis, matymo pablogėjimas, kontaktinių lęšių netoleravimas. Pusė patiriančiųjų pavargusių akių simptomus jų visai negydo. Nesiėmus reikiamų priemonių, tokiems žmonėms vėliau diagnozuojamas sausų akių sindromas (SAS). Ypač dažnai sausumas vargina pacientus, dėvinčius kontaktinius lęšius – ašarų turi pakakti dar ir lęšiui sudrėkinti. / One third of people suffer from tired and dry eye syndrome (Pečeliūnienė, 2006). They weary a feeling of eye full of sand or gravel, ache and cutting, fair of light, an eye can get red. In the mornings when eyes are just opened, there can be a short period of sharp ache or increased tearing and also eye tiredness, vision deterioration, intolerance of contact lenses. A half of people who suffer from eye tiredness, do not treat them at all. When taking no measures, a dry eye syndrome is later diagnosed (SAS). This very often appear to people with contact lenses - tear drops must be also enough for irrigating the lenses.

Myopia is a major cause of vision loss throughout the world. High myopia is associated with severe eye diseases like maculopathy, retinal detachment and glaucoma. The prevalence of myopia is increasing, and varies by country and by ethnic group. In some Asian populations the prevalence is 70%-80%.  This thesis includes five experiments. In experiment I we investigated the effects of added positive and negative spherical aberration on accommodative response accuracy. We found that the accommodative response can be altered by modulating the spherical aberration of the eye with soft contact lenses. There was an improvement in the accommodative response slopes and a decrease in the lag of accommodation with the negative spherical aberration lenses compared to positive spherical aberration lenses.  In experiment II we investigated whether the negative spherical aberration in contact lenses could be tolerated visually in terms of wearability and comfort. We found that all the subjects were satisfied with the contact lens comfort, distance and near vision and the stability of the vision with the lenses. The accommodative response was stable through out the treatment period. In experiment III we investigated the efficacy of a novel dual treatment for the improvement of accommodative accuracy and dynamics in myopes. The spherical aberration of the eye was effectively altered to negative in the treatment group as predicted. In the control group as expected there was no significant change in the spherical aberration of the eye with and without contact lenses. The treatment lenses decreased the lag of accommodation and increased the accommodative response slope at 3 months. In the experiment IV we investigated the effect of the treatment lenses used in the previous experiment on high and low contrast visual acuities after a one year treatment period. The results showed a significant improvement in both high and low contrast visual acuities after the one year period in the treatment group compared to the control group, even though it was not clinically significant. In experiment V we investigated the intrasession repeatability of peripheral aberrations using COAS-HD VR aberrometer and also reported the distribution of higher order aberrations in a group of young emmetropes. There was no significant difference in the variance of total higher-order RMS between on- and off-axis measurements. There was a significant change in the horizontal coma, spherical aberration and higher-order RMS with off-axis angle along the horizontal visual field. We demonstrated that fast, repeatable and valid peripheral aberration measurements can be obtained with this instrument. This thesis contributes new results in this field of myopia, aberration and accommodation.