ABSTRACT
OBJECTIVE: Despite the increasing prevalence of contact lens (CL) wear, knowledge and compliance with proper care remain suboptimal. This study aims to assess the level of knowledge and compliance with lens care practices in patients attending a third-level institution in Northeast Mexico. METHODS: A cross-sectional study using a self-administered online survey was conducted. Patients at the Instituto Tecnolgico de Monterrey were invited to participate. The questionnaire consisted of three sections: demographic data and CL information, CL practices, and CL care knowledge. Participants responding correctly to 6/7 questions from the second and third sections were classified as having good compliance and good knowledge, respectively. Predictive factors for good compliance and knowledge were calculated using a logistic regression model. RESULTS: A total of 287 users participated in the study. The median age was 25 (14-78) years with a female (n = 221, 77 %) predominance. Good knowledge was observed in 215 (74.9 %), whereas only 42 (14.6 %) presented good compliance. Failing to replace CL as prescribed (n = 199, 69.3 %) and sleeping with the devices (n = 198, 69 %) were the most frequent practices causing non-compliance. Whereas prohibition of swimming with CL was the least known practice (n = 74, 25 %). Users with recent (≤5 years) wearing experience were more likely to present good knowledge (OR 2.19, p = 0.014) and compliance (OR 3.15, p < 00.01). No statistical correlation was established between knowledge and compliance. CONCLUSION: Non-compliance and lack of knowledge of proper CL care were prevalent among in this population. Long-term CL users were at higher risk of non-compliance and lack of knowledge. Moreover, knowledge was not related to compliance; therefore, different strategies must be implemented to reduce CL misconduct.
Subject(s)
Contact Lenses, Hydrophilic , Contact Lenses , Humans , Female , Adult , Cross-Sectional Studies , Mexico/epidemiology , Contact Lens Solutions , Patient ComplianceABSTRACT
BACKGROUND: To report the outcomes of using the combination of oral nicergoline, autologous serum, and contact lens to enhance corneal epithelization in neurotrophic keratitis and to discuss the clinical potential of this management. METHODS: This was a prospective consecutive case series study of eight patients treated for neurotrophic keratitis at the "Conde de Valenciana" Institute of Ophthalmology. Oral nicergoline, autologous serum, and bandage contact lens were initiated at the same time, immediately after stage 3 diagnosis keratitis was confirmed clinically, and until corneal epithelialization was achieved or eminent corneal perforation was seen. In patients where diabetes was a cause, glycosylate hemoglobin was measured to asses metabolic control. Corneal esthesiometry and corrected distance visual acuity were assessed before and after treatment. RESULTS: This study included eight eyes of eight patients (5 men [62.5%], average age 57±17.9 years). All patients completed at least 1 month of follow-up after nicergoline and contact lens suspension. Of the eight eyes, no one had positive culture growth and complete epithelial healing was achieved in all cases. Half of patients had diabetes and had a poor metabolic control. Corneal sensitivity improved in all eyes almost 2 centimeters in Cochet-Bonnet esthesiometry ( P= 0.01). In addition, final visual acuity gains were obtained ( P= 0.100). CONCLUSIONS: The combination of oral nicergoline, autologous serum, and bandage contact lens simultaneously could be an alternative in the management of stage 3 neurotrophic keratitis when conventional medical treatment has no improvement of corneal epithelization.
Subject(s)
Contact Lenses, Hydrophilic , Corneal Dystrophies, Hereditary , Keratitis , Nicergoline , Trigeminal Nerve Diseases , Male , Humans , Adult , Middle Aged , Aged , Nicergoline/therapeutic use , Prospective Studies , Keratitis/diagnosis , Contact Lenses, Hydrophilic/adverse effects , Trigeminal Nerve Diseases/etiology , Bandages , Corneal Dystrophies, Hereditary/etiologyABSTRACT
PURPOSE: Contact lenses (CL) remain a popular mode of refractive error correction globally and in the Caribbean, mostly among young people. However, no data on the characteristics of the CL population wearers in the Caribbean is available. This study reported on the characteristics of CL wearers and the associated factors in Trinidad and Tobago (T&T). METHODS: This retrospective study reviewed the clinical records of 243 CL wearers who attended the University of the West Indies (UWI) optometry clinic between 2017 and 2018. Data on their demographic profiles, CL wearing characteristics including lens type, material, purpose of wear, replacement schedule and lens care systems were extracted and analyzed. The associations between the demographic characteristics and CL wearing characteristics were also determined. RESULTS: About half of the CL wearers used them for fashion (more among those aged 18 to 30 years, 61.0%), therapeutic (more among those <18 years, 43.8%, P = 0.001) and refractive error correction purposes (more in those >40 years, P = 0.001). Females were more likely to use CLs for fashion compared with males (67.0% versus 40.7%). Age (P<0.0005) and gender (P = 0.030) were associated with the lens materials. Those aged 18-30 years were more likely use hydrogels compared with the younger ones (64.1% versus 25.0%). Rigid gas permeable (RGP) CL use was more common in males than females (21.8% versus 10.9%, P = 0.031). Daily disposables were predominantly used by younger respondents (18-30 years old, 31.3%, P < 0.001) and more in females than males (66.7% vs 49.4%, P = 0.040). CONCLUSION: The study found that the CL appears to be more commonly worn for fashion in younger females and for refractive error correction in older males. Age, gender, and employment status were the main determinants of lens wear among respondents attending the university clinic in T&T.
Subject(s)
Contact Lenses, Hydrophilic , Contact Lenses , Refractive Errors , Adolescent , Adult , Aged , Demography , Female , Humans , Male , Refractive Errors/epidemiology , Refractive Errors/therapy , Retrospective Studies , Trinidad and Tobago/epidemiology , Young AdultABSTRACT
PURPOSE: This study aimed to describe a case of keratitis secondary to Metarhizium robertsii, a soil-dwelling fungus with typical insect pathogenicity. METHODS: A Case report. RESULTS: A 58-year-old man with a ocular history of soft contact lens overwear, poor contact lens hygiene, and ocular exposure to ground well water supplying his house was referred to our university practice for a central corneal ulcer with 40% thinning. Same-day rapid microscopic detection with Giemsa stain identified the presence of many hyphae elements, and he was ultimately diagnosed with M. robertsii keratitis. The patient's course involved severe and progressive corneal thinning that stabilized over a 3-month course of antifungal therapy. CONCLUSIONS: Metarhizium robertsii seems more aggressive than other forms of fungal keratitis; therefore, this infection may be watched more closely with the risk for quick progressive corneal thinning, even while on antifungal management.
Subject(s)
Contact Lenses, Hydrophilic/adverse effects , Eye Infections, Fungal/microbiology , Insecta/microbiology , Keratitis/microbiology , Metarhizium/pathogenicity , Rare Diseases , Animals , Contact Lenses, Hydrophilic/microbiology , Eye Infections, Fungal/diagnosis , Humans , Keratitis/diagnosis , Male , Middle Aged , Slit Lamp MicroscopyABSTRACT
OBJECTIVE: To evaluate the Candida krusei and Candida albicans biofilm formation abilities on 5 different types of contact lenses and compare their metabolic activities and biomass. METHODS: After biofilm formation by both the test species, their metabolic activity was assessed by the 2,3-bis (2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide reduction assay with menadione, while the biomass was determined by staining with 0.4% crystal violet dye for further statistical analysis. RESULTS: Both the Candida species could form biofilms on different types of contact lenses, with greater metabolic activities and lower biomass formation in rigid gas permeable lenses. CONCLUSION: Biofilm formation with greater metabolic activity and greater biomass were expected on soft contact lenses considering their surface hydrophobicity. However, the results demonstrated a greater metabolic activity on rigid contact lenses. This result has a great significance with regards to the increasing risk of microbial keratitis, although further studies are warranted to better elucidate the formation of biofilms on different types of contact lens materials in the future.
Subject(s)
Candida albicans , Contact Lenses, Hydrophilic , Antifungal Agents , Biofilms , Candida , Humans , PichiaABSTRACT
PURPOSE: To translate and validate the Contact Lens Dry Eyes Questionnaire (CLDEQ-8) to Portuguese language and to describe the impact of soft contact lenses on the ocular surface. METHODS: We conducted a descriptive transversal study with the aim to: (1) translate and validate the CLDEQ-8 questionnaire to Portuguese language and (2) apply the CLDEQ-8 to a group of contact lens wearers along with a broad evaluation of the impact of soft contact lens on the ocular surface. The evaluation of the impact of soft contact lens was performed for a study population of 81 subjects, categorized in two groups: Group A: 61 contact lens wearers and Group B (control): 20 noncontact lens wearers. The study exclusion criteria were rigid contact lens wear, systemic or ocular diseases, the use of medications predisposing to ocular surface damage, and previous ocular surgeries. RESULTS: For the CLDEQ-8 questionnaire translation and validation, Kappa agreement values were ³0.7 in all questions, implying a good agreement between the Portuguese and English language versions. Considering the ocular surface evaluation of the subjects, all parameters differed in Soft contact lens wearers when compared with the controls (p<0.05), except in those related to tear volume, such as the tear meniscus height and Schirmer test. CONCLUSIONS: This study provided a translated and validated Portuguese version of CLDEQ-8 questionnaire, which represents an important tool for the evolution of contact lens wearers. The broad evaluation of the ocular surface revealed an association between soft contact lens wearing and ocular surface disturbances.
Subject(s)
Contact Lenses, Hydrophilic , Dry Eye Syndromes , Contact Lenses, Hydrophilic/adverse effects , Dry Eye Syndromes/diagnosis , Dry Eye Syndromes/etiology , Eye , Humans , Surveys and Questionnaires , TearsABSTRACT
PURPOSE: To present a case series of non-healing corneal ulcers treated by solid activated platelet-rich plasma (PRP) combined with silicone-hydrogel soft contact lens. METHODS: Three eyes from three patients with unresponsive corneal ulcers were included. A clot of PRP was applied directly onto the corneal ulcer and covered with a soft contact lens. The primary outcome was corneal healing. Changes in corneal ulcer area were measured by analyzing slit-lamp photographs taken using ImageJ software. RESULTS: Successful corneal healing was achieved in all patients within two weeks, with no recurrences or signs of infection through the last follow-up. In two of the three cases, treatment was applied twice. CONCLUSIONS: This novel procedure was easy to perform, economically advantageous, and a possible alternative to surgical approaches for enhancing epithelial wound healing in patients with non-healing corneal ulcers. Further prospective and comparative studies are needed to assess the efficacy of this treatment.
Subject(s)
Contact Lenses, Hydrophilic , Corneal Ulcer , Platelet-Rich Plasma , Corneal Ulcer/diagnosis , Corneal Ulcer/surgery , Humans , Hydrogels , Silicones , UlcerABSTRACT
PURPOSE: Microcornea is a rare condition that frequently resulets in serious cosmetic concerns due to the resultant asymmetrical appearance of the eye, and its cosmetic rehabilitation is possible with the use of colored contact lenses. This paper aims to present our experiences with the use of cosmetic Etafilcon A contact lenses for microcornea. METHODS: Eight patients with unilateral microcornea without any systemic involvement were included in this study, and they underwent routine ophthalmological examination, corneal topography, and optical biometry. We applied the cosmetic Etafilcon A contact lens (1-DAY ACUVUE® DEFINE® with Lacreon®) of the same edge color to the patients. The levels of satisfaction in terms of cosmesis and comfort were evaluated with the use of visual analog scales (VAS). RESULTS: In the patients, the corneal diameter asymmetry was acceptably adjusted, and each of the patients reported extreme satisfaction. The mean VAS score was 8.9 ± 1.0 (range: 7-10) for the cosmetic satisfaction rate and 8.4 ± 1.0 (range: 7-10) for the comfort rate. The patients obtained the best-corrected visual acuity without or with additional eye-glasses. None of the patients complained about vision issues under photopic and scotopic conditions. CONCLUSION: 1-DAY ACUVUE® DEFINE® with Lacreon® lens has promising satisfactory cosmetic outcomes along with visual enhancement in cases of microcornea. This is the first study to report the use of this lens for the cosmetic rehabilitation of patients with microcornea.
Subject(s)
Contact Lenses, Hydrophilic , Contact Lenses , Corneal Topography , Humans , Methacrylates , Ophthalmologic Surgical ProceduresABSTRACT
OBJECTIVE: To report the outcomes and complications of colored soft contact lenses (SCLs) to improve esthetic or eye function in visually impaired (VI) or blind patients. METHODS: This retrospective study enrolled consecutive patients with unilateral or bilateral VI or blindness who had received colored SCLs to improve appearance or ocular function. Data were collected on demographics, complaints, complete ophthalmological examinations, types of SCL, follow-ups, and complications. RESULTS: The study sample was comprised of 109 patients (ages 4-80 years). Eighty-six patients (78.89%) had unilateral blindness, and 14 patients (12.84%) had functional disorder. Most of the patients presenting for improved esthetic had anterior segment pathology (74/67.88%), mainly secondary to trauma (55/50.5%) resulting in leukoma (73/66.97%). Patients with functional VI (19/17.43%) received filtered SCLs for color blindness (7/6.42%), diplopia (7/6.42%), or photophobia (5/4.58%). No serious complications were observed in any cases, and 94.49% of patients were satisfied with the SCLs. CONCLUSION: Colored SCLs can cover ocular surface imperfections in VI or blind eyes of patients who are seeking better cosmesis or improvement functional VI. Soft contact lenses with only one filter can cover imperfections of the ocular surface and improve vision in functional VI. Appropriate follow-up of these patients can reduce complication rates, resulting in good cosmesis and patient satisfaction with a positive impact on the lives of patients suffering from functional VI or blindness.
Subject(s)
Contact Lenses, Hydrophilic , Adolescent , Adult , Aged , Aged, 80 and over , Blindness , Child , Child, Preschool , Esthetics , Humans , Middle Aged , Retrospective Studies , Vision, Ocular , Young AdultABSTRACT
PURPOSE: To report 7 patients (14 eyes) with bilateral Pseudomonas aeruginosa keratitis (PAK). METHODS: Case records of patients with bilateral PAK were reviewed at a single academic medical center from April 2009 to December 2020. RESULTS: Seven patients aged 29 to 94 years presented with bilateral P. aeruginosa corneal ulcers. All patients were soft contact lens wearers except one elderly patient with a complex ocular history. Three patients wore specialty contact lens, including one cosmetic contact lens wearer, one multifocal contact lens wearer, and one extended-wear contact lens wearer. The remaining three patients were not overnight contact lens wearer but regularly showered in contact lens or used tap water for contact lens case cleaning. All patients presented with asymmetric disease, with visual acuity ranging from 20/20 to light perception. Ulcers were located centrally in 5 eyes (35.7%), diffusely over the entire cornea in 5 eyes (35.7%), temporally in 2 eyes (14.2%), and nasally in 1 eye (7.14%), and in 1 eye (8.3%), the ulcer location was not recorded. Corneal thinning was noted in 7 eyes (50%). Hypopyon was also noted in 7 eyes (50%). Two patients required procedures because of progressive stromal necrosis. All other patients were treated nonsurgically, with antibiotic drops, which resulted in ulcer resolution. Final visual acuity on last recorded follow-up ranged from 20/20 to no light perception. CONCLUSIONS: This is the largest case series of bilateral PAK, which occurred primarily in contact lens wearer. This case series reiterates the risk of contact lens infection related to poor hygiene.
Subject(s)
Contact Lenses, Extended-Wear , Contact Lenses, Hydrophilic , Corneal Ulcer , Keratitis , Pseudomonas Infections , Aged , Contact Lenses, Hydrophilic/adverse effects , Corneal Ulcer/diagnosis , Humans , Pseudomonas Infections/diagnosis , Pseudomonas aeruginosaABSTRACT
Abstract Introduction: Multipurpose solutions (MPS) for soft contact lenses (SCL) play an essential role in inhibiting potentially pathogenic agents. Their antimicrobial effectiveness is assessed in vitro and their safety in vivo, with clinical trials that include a combination of different solutions and lens materials. The objective is to assess the biocompatibility of a new SCL MPS produced in Colombia that contains polyhexamethylene biguanide (PHMB) and to determine its antimicrobial activity. Materials and Methods: This was a crossover study with 25 subjects who did not wear lens and who were fitted with different combinations of five SCL materials with either MPS or control physiological saline solution (CS). Corneal thickness, conjunctival hyperemia, corneal staining, and comfort were assessed after two hours of wearing SCL. Antimicrobial effectiveness was measured using ISO 14729 standard assays. Results: When considering SCL material, there was a statistically significant difference between the new MPS and the CS for Comfilcon A (p < 0.05). There was no statistical or clinically significant difference for corneal thickness or corneal staining between the combination of lens material and new MPS with the CS (p > 0.05). After two hours of lens insertion, comfort scores were higher than 7.8. The MPS reduced bacteria colony forming units (CFU) in over 3 log, and fungal CFU in over 1.0 log. Conclusions: The new MPS met the antimicrobial standards of ISO 14729, is considered safe and biocompatible with the ocular surface and retains high comfort levels.
Resumen Introducción: las soluciones multipropósito (SMP) para lentes de contacto blandos (LCB) desempeñan un papel esencial en la inhibición de agentes potencialmente patógenos. Su efectividad antimicrobiana se evalúa in vitro, y su seguridad, in vivo, con ensayos clínicos que incluyen una combinación de diferentes soluciones y materiales para lentes. El objetivo es evaluar la biocompatibilidad de una nueva SMP producida en Colombia que contiene polihexametileno biguanida (PHMB) y determinar su actividad antimicrobiana. Materiales y métodos: estudio cruzado con 25 sujetos no usuarios de lentes, que fueron adaptados con cinco combinaciones diferentes de materiales de LCB con una nueva SMP o solución salina fisiológica de control (CS). El grosor corneal, la hiperemia conjuntival, la tinción corneal y la comodidad se evaluaron después de dos horas de uso del LC. La efectividad antimicrobiana se midió utilizando ensayos estándar ISO 14729. Resultados: considerando el material del LCB, solo hubo una diferencia estadísticamente significativa entre la nueva SMP y el CS para el Comfilcon A (p < 0.05). Tampoco hubo diferencias estadísticamente o clínicamente significativas para el grosor corneal o la tinción corneal, entre la combinación del material del lente y la nueva SMP con el CS (p > 0.05). Después de dos horas de uso del lente, las puntuaciones de confort fueron superiores a 7.8. La SMP redujo las unidades formadoras de colonias (UFC) de bacterias en más de 3 log, y las UFC fúngicas en más de 1.0 log. Conclusiones: la nueva SMP cumplió con los estándares antimicrobianos de ISO 14729, y se considera segura y biocompatible con la superficie ocular, con altos niveles de confort.
Resumo Introdução: as soluções multipropósito (SMP) para lentes de contato macias (LCM) apresentam um papel essencial na inibição de agentes potencialmente patógenos. Sua eficácia como agente antimicrobiano se valia in vitro, e sua segurança, in vivo, como ensaios clínicos que incluem uma combinação de diferentes soluções e materiais para lentes. O objetivo é avaliar a biocompatibilidade de uma nova SMP produzida na Colômbia a base de polihexametileno biguanida (PHMB) e determinar seu potencial antimicrobiano. Materiais e métodos: estudo cruzado com 25 indivíduos não usuários de lentes, que foram adaptados com cinco combinações diferentes de LCM como uma nova SMP ou solução salina fisiológica como controle (CS). A espessura da córnea, a hiperemia conjuntival, a coloração da córnea e a comodidade, foram avaliadas após duas horas de uso da LCB. A eficácia antimicrobiana foi medida com ensaios padrão ISO 14729. Resultados: considerando o material da LCB, houve apenas uma diferença estatisticamente significativa entre a nova SMP e o CS, paro o Comfilcon A (p <0.05). Não houve diferença estatisticamente ou clinicamente significativa para a espessura da córnea ou a coloração da córnea, entre a combinação do material da lente e a nova SMP com o controle CS (p > 0.05). Após duas horas de uso, as pontuações de conforto foram superiores a 7,8. A SMP reduziu as unidades formadoras de colônias (UFC) de bactérias em mais de 3 log, e as UFC fúngicas em mais de 1.0 log. Conclusões: a nova SMP cumpriu com os padrões antimicrobianos ISO 14729, é considerada segura e biocompatível com a superfície ocular, com altos níveis de conforto.
Subject(s)
Humans , Contact Lenses, Hydrophilic , Hyperemia , Stem CellsABSTRACT
Resumo A adaptação de lentes de contato após o transplante de córnea tem sido considerada um desafio na reabilitação visual. Atualmente existe a possibilidade de adaptação de lentes de contato de vários tamanhos, diversos desenhos e com diferentes espessuras e materiais, como por exemplo lentes gelatinosas, lentes corneanas rígidas gás-permeáveis, lentes córneo-esclerais, mini esclerais e esclerais. O objetivo deste estudo foi apresentar uma revisão da literatura atual que possa exemplificar a utilização de alguns dos diferentes tipos de lentes de contato que possam ser usadas após o transplante de córnea. Foi realizada uma revisão integrativa da literatura médica na língua inglesa, utilizando como base de dados para a pesquisa, Pubmed e Mendeley. Como critério de inclusão, foi estabelecido a relevância do artigo de acordo com a experiência da equipe. Foram selecionados 26 artigos, com ano de publicação entre 2001 e 2018. Dentre os artigos selecionados, cinco possuem como principal assunto o transplante de córnea, nove artigos sobre lentes de contato em geral, e 12 artigos sobre lentes de contato esclerais ou mini esclerais. Devido a maior transmissibilidade de oxigênio para a córnea, o uso das lentes corneanas rígidas gás-permeáveis mostrou-se mais seguro e com probabilidade de uso por um período maior de tempo.
Abstract Contact lens fitting after corneal transplantation has been considered a challenge in visual rehabilitation. There is currently the possibility of adapting contact lenses of various sizes, various designs and with different thicknesses and materials, such as gelatinous lenses, gas-permeable rigid corneal lenses, corneal-scleral lenses, mini-scleral and scleral lenses. The objective of this study was to present a review of current literature that may exemplify the use of some of the different types of contact lenses that can be used after corneal transplantation. An integrative review of the medical literature in the English language, using as a database for the research, Pubmed and Mendeley. Twenty six articles were selected, with year of publication between 2001 and 2018, as inclusion criterion, the relevance of articles according to the authors' experience was used. Five articles were selected that have as main subject corneal transplantation, nine articles on contact lenses in general, and 12 articles on scleral or mini scleral contact lenses. Due to the greater transmissibility of oxygen to the cornea, the use of rigid gas-permeable corneal lenses was shown to be safer and more likely to be used for a longer period of time.
Subject(s)
Corneal Transplantation/rehabilitation , Contact Lenses , Contact Lenses, Hydrophilic , Adaptation to DisastersABSTRACT
PURPOSE: To report a case of Nocardia farcinica keratitis in a pediatric contact lens wearer. METHODS: Case report and literature review. RESULTS: A pediatric contact lens wearer was initially misdiagnosed with a poorly healing corneal abrasion after swimming with his contact lenses. On examination at our center, he was found to have a 2.5 by 2.5 mm corneal infiltrate with feathery margins. Microbiology revealed N. farcinica keratitis, which was treated with topical amikacin. The patient returned to his baseline visual acuity after treatment. CONCLUSIONS: Nocardia keratitis can be misdiagnosed because of its low prevalence, especially in young patients. Prompt diagnosis is important for proper management in these cases. The infection resolved in our patient with prompt diagnosis and treatment with topical amikacin eye drops.
Subject(s)
Contact Lenses, Hydrophilic/microbiology , Corneal Ulcer/microbiology , Eye Infections, Bacterial/microbiology , Nocardia Infections/microbiology , Nocardia/isolation & purification , Adolescent , Anti-Bacterial Agents/therapeutic use , Corneal Ulcer/diagnosis , Corneal Ulcer/drug therapy , DNA, Bacterial/genetics , Eye Infections, Bacterial/diagnosis , Eye Infections, Bacterial/drug therapy , Humans , Male , Microbial Sensitivity Tests , Moxifloxacin/therapeutic use , Nocardia/genetics , Nocardia Infections/diagnosis , Nocardia Infections/drug therapy , RNA, Ribosomal, 16S/genetics , Visual Acuity/physiologyABSTRACT
The purpose is to estimate the oxygen diffusion coefficient and the relaxation time of the cornea with respect to the oxygen tension at the cornea-tears interface. Both findings are discussed. From the experimental data provided by Bonanno et al., the oxygen tension measurements in vivo for human cornea-tears-contact lens (CL), the relaxation time of the cornea, and their oxygen diffusion coefficient were obtained by numerical calculation using the Monod-kinetic model. Our results, considering the relaxation time of the cornea, observe a different behavior. At the time less than 8 s, the oxygen diffusivity process is upper-diffusive, and for the relaxation time greater than 8 s, the oxygen diffusivity process is lower-diffusive. Both cases depend on the partial pressure of oxygen at the entrance of the cornea. The oxygen tension distribution in the cornea-tears interface is separated into two different zones: one for conventional hydrogels, which is located between 6 and 75 mmHg, with a relaxation time included between 8 and 19 s, and the other zone for silicone hydrogel CLs, which is located at high oxygen tension, between 95 and 140 mmHg, with a relaxation time in the interval of 1.5-8 s. It is found that in each zone, the diffusion coefficient varies linearly with the oxygen concentration, presenting a discontinuity in the transition of 8 s. This could be interpreted as an aerobic-to-anaerobic transition. We attribute this behavior to the coupling formalism between oxygen diffusion and biochemical reactions to produce adenosine triphosphate. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:14-21, 2020.
Subject(s)
Contact Lenses, Hydrophilic , Cornea/metabolism , Hydrogel, Polyethylene Glycol Dimethacrylate/pharmacology , Models, Biological , Oxygen/metabolism , Cornea/pathology , Diffusion , Humans , TearsABSTRACT
Abstract Objective: To investigate the effects of two types of contact lenses made of two different types of silicone hydrogel material on ocular physiological parameters and tear function tests. Methods: The contact lenses with the appropriate diopters were supplied to the volunteering patients. The patients were evaluated before wearing the contact lenses (visit0:V0), at the first month(visit1:V1) and at the thirth month(visit2:V2) following their wear. At all visits a detailed biomicroscopic examination was done, ocular physiological variables were collected, the tear function tests were performed and the tear meniscus area (TMA) was visualized and measured with anterior segment optical coherence tomography (AS-OCT). Results: The results of Schirmer 1 test were 12.07 ± 1.51 [9-16] mm for the right eyes (samfilcon A group) and 12.09 ± 1.5 [9-16] mm for the left eyes (senofilcon A group) at V0. (p=0.950) At V2, the mean Schirmer 1 test results were 11.92±1.34 [9-15] mm in the samfilcon A group and 12.2±1.41 [9-16] mm in the senofilcon A group (p=0.239). The mean TMA dimensions in the AS-OCT images were 338.42±47.1 [241-401] microns in the samfilcon A group and 338.42±47.1 [241-401]microns in the senofilcon A group at V0. (p>0.05). At V2, the mean TMA dimensions were 337.2±45.53 [241-402] microns in thesamfilcon A group and 340.31±48.22 [240-411] microns in the senofilcon A group (p=0.728). Conclusions: Our study has demonstrated that contact lenses containing samfilcon A and senofilcon A silicone hydrogel material do not cause meaningful ocular surface problems.
Resumo Objetivo: Investigar os efeitos de dois tipos de lentes de contacto feitas de dois tipos diferentes de material de hidrogel de silicone nos parâmetros fisiológicos oculares e testes de função lacrimal. Métodos: As lentes de contacto com as dioptrias apropriadas foram fornecidas aos pacientes voluntários. Os pacientes foram avaliados antes do uso das lentes de contacto (visita0: V0), no primeiro mês (visita1: V1) e no terceiro mês (visita2: V2), após o uso destas. Em todas as visitas, foi realizado um exame biomicroscópico detalhado, as variáveis fisiológicas oculares foram recolhidas, os testes de função lacrimal foram realizados e a área do menisco lacrimal (TMA) foi visualizada e medida com tomografia de coerência óptica do segmento anterior (AS-OCT). Resultados: Os resultados do teste de Schirmer 1 foram 12,07 ± 1,51 [9-16] mm para os olhos direitos (grupo samfilcon A) e 12,09 ± 1,5 [9-16] mm para os olhos esquerdos (grupo senofilcon A) em V0. (p = 0,950) Em V2, os resultados médios do teste de Schirmer 1 foram 11,92 ± 1,34 [9-15] mm no grupo samfilcon A e 12,2 ± 1,41 [9-16] mm no grupo senofilcon A (p = 0,239). As dimensões médias do TMA nas imagens AS-OCT foram 338,42 ± 47,1 [241-401] mícrons no grupo samfilcon A e 338,42 ± 47,1 [241-401] mícrons no grupo senofilcon A em V0. (p> 0,05).> Em V2, as dimensões médias do TMA foram 337,2 ± 45,53 [241-402] mícrons no grupo samfilcon A e 340,31 ± 48,22 [240-411] mícrons no grupo senofilcon A (p = 0,728). Conclusões: O nosso estudo demonstrou que as lentes de contacto que contêm material de hidrogel de silicone de samfilcon A e senofilcon A não causam problemas significativos na superfície ocular.
Subject(s)
Humans , Male , Female , Adolescent , Adult , Silicones/pharmacology , Tears/metabolism , Contact Lenses, Hydrophilic , Hydrogels/pharmacology , Ophthalmoscopy , Visual Acuity , Prospective Studies , Tomography, Optical Coherence , Slit Lamp Microscopy , Anterior Eye Segment/diagnostic imaging , Myopia/therapyABSTRACT
CASE REPORT: A patient with a history of surgical resection of an acoustic neuroma presented with involvement of both the left facial nerve and the left trigeminal nerve. She initially consulted for exposure keratitis, but two weeks later presented with an infectious keratitis. After taking the corneal sample, she presented with persistent epithelial defect, which did not respond to medical management. Topical insulin was indicated, and a decrease in the area of the lesion was seen in the following 5 days. A therapeutic contact lens was also placed at that time and finally, two weeks after the initiation of insulin, the epithelial defect completely closed. DISCUSSION: This was a complex case due to the confluence of facial paralysis, neurotrophic keratitis, and infectious keratitis, which finally had a successful outcome. Topical insulin can be an effective adjuvant therapy in cases of neurotrophic ulcers that do not respond to standard therapy.
Subject(s)
Facial Nerve Injuries/complications , Insulin/therapeutic use , Keratitis/etiology , Neuroma, Acoustic/surgery , Postoperative Complications/etiology , Trigeminal Nerve Injuries/complications , Administration, Ophthalmic , Anti-Bacterial Agents/therapeutic use , Combined Modality Therapy , Contact Lenses, Hydrophilic , Corneal Ulcer/drug therapy , Corneal Ulcer/etiology , Corneal Ulcer/therapy , Facial Paralysis/etiology , Female , Humans , Insulin/administration & dosage , Keratitis/drug therapy , Keratitis/microbiology , Keratitis/therapy , Middle Aged , Moxifloxacin/therapeutic use , Postoperative Complications/drug therapy , Staphylococcal Infections/drug therapy , Staphylococcal Infections/etiology , Vancomycin/therapeutic useABSTRACT
ABSTRACT Purpose: We aimed to describe the outcomes of corneoscleral contact lens fitting with multi-aspherical geometry designs in patients with irregular corneas after laser-assisted in situ keratomileusis (LASIK). Methods: This was a retrospective series of 18 patients (age, 26-38 years) selected from an eye clinic database. Participants were required to have unsatisfactory visual acuity with their current contact lenses or spectacles after LASIK for myopia correction. All patients were fitted with corneoscleral contact lenses designed to correct corneal surface irregularities. A diagnostic trial set was used for fitting, and assessments were performed according to a standardized methodology. Subjective comfort, visual acuity, central corneal thickness, endothelial cell count, and corneal-compensated intraocular pressure were evaluated. The follow-up period was one year. Results: Contact lens use was discontinued in 3 patients, thus leaving 24 eyes from 8 females and 7 males for analysis. The fitting characteristics were optimal in terms of lens position and movement. Statistically significant improvements were found in the best spectacle-corrected vision from before fitting to the visual acuity after fitting (p<0.001). Moreover, the patients reported high subjective comfort ratings and usage times (12.98 ± 2.3 hours/day). After one year of wear, visual acuity, subjective comfort, and usage time were maintained. No statistically significant adverse changes developed in the corneas over this period. Conclusion: Corneoscleral contact lenses with a multi-aspherical geometry design provide optimal visual acuity, improved comfort, and prolonged usage times in patients with irregular corneas after LASIK.
RESUMO Objetivo: Descrever os resultados do ajuste de lentes de contato corneoesclerais com geometria multiasférica em pacientes com córneas irregulares após cirurgia de ceratomileuse in situ assistida por laser (LASIK). Métodos: Esta foi uma série retrospectiva de 18 pacientes (idade, 26-38 anos) selecionados a partir de um banco de dados de uma clínica oftalmológica. Os participantes foram escolhidos ao manifestaram acuidade visual insatisfatória com suas lentes de contato ou óculos atuais depois de terem sido submetidos à LASIK para correção de miopia. Todos os pacientes receberam lentes de contato corneoesclerais projetadas para corrigir irregularidades na superficie da córnea. Um conjunto diagnóstico de prova foi usado para a adaptação e as avaliações foram feitas de acordo com uma metodologia padronizada. O conforto subjetivo, a acuidade visual, a espessura central da córnea, a contagem de células endoteliais e a pressão intraocular compensada da córnea foram avaliados. O período de acompanhamento foi de um ano. Resultados: O uso de lentes de contato foi descontinuado em 3 pacientes, deixando 24 olhos de 8 mulheres e 7 homens para análise. As características de adaptação foram ótimas em termos de posição e movimento da lente. Melhorias estatisticamente significativas foram encontradas na melhoria da visão corrigida por óculos antes de se ajustar a acuidade visual após a adaptação (p<0,001). Além disso, os pacientes relataram altos índices subjetivos de conforto e tempo de uso (12,98 ± 2,3 horas/dia). Após um ano de uso, a acuidade visual, o conforto subjetivo e o tempo de uso foram mantidos. Não houve alterações adversas estatisticamente significativas nas córneas ao longo deste período. Conclusão: As lentes de contato corneoesclerais com projeto geométrico multiasférico proporcionam acuidade visual ideal, maior conforto e tempo de uso prolongado em pacientes com córneas irregulares após o LASIK.
Subject(s)
Humans , Adult , Contact Lenses, Hydrophilic , Keratomileusis, Laser In Situ/adverse effects , Corneal Wavefront Aberration/etiology , Myopia/surgery , Visual Acuity , Retrospective Studies , Follow-Up Studies , Corneal Topography , Corneal Wavefront Aberration/rehabilitation , Corneal PachymetryABSTRACT
PURPOSE: We aimed to describe the outcomes of corneoscleral contact lens fitting with multi-aspherical geometry designs in patients with irregular corneas after laser-assisted in situ keratomileusis (LASIK). METHODS: This was a retrospective series of 18 patients (age, 26-38 years) selected from an eye clinic database. Participants were required to have unsatisfactory visual acuity with their current contact lenses or spectacles after LASIK for myopia correction. All patients were fitted with corneoscleral contact lenses designed to correct corneal surface irregularities. A diagnostic trial set was used for fitting, and assessments were performed according to a standardized methodology. Subjective comfort, visual acuity, central corneal thickness, endothelial cell count, and corneal-compensated intraocular pressure were evaluated. The follow-up period was one year. RESULTS: Contact lens use was discontinued in 3 patients, thus leaving 24 eyes from 8 females and 7 males for analysis. The fitting characteristics were optimal in terms of lens position and movement. Statistically significant improvements were found in the best spectacle-corrected vision from before fitting to the visual acuity after fitting (p<0.001). Moreover, the patients reported high subjective comfort ratings and usage times (12.98 ± 2.3 hours/day). After one year of wear, visual acuity, subjective comfort, and usage time were maintained. No statistically significant adverse changes developed in the corneas over this period. CONCLUSION: Corneoscleral contact lenses with a multi-aspherical geometry design provide optimal visual acuity, improved comfort, and prolonged usage times in patients with irregular corneas after LASIK.
Subject(s)
Contact Lenses, Hydrophilic , Corneal Wavefront Aberration/etiology , Keratomileusis, Laser In Situ/adverse effects , Myopia/surgery , Adult , Corneal Pachymetry , Corneal Topography , Corneal Wavefront Aberration/rehabilitation , Follow-Up Studies , Humans , Retrospective Studies , Visual AcuityABSTRACT
PURPOSE: To report a series of cases of Acanthamoeba keratitis (AK) in scleral lens wearers with keratoconus to determine whether this type of contact lens presents a greater risk for development of infection. METHODS: This study reports three patients who wore scleral contact lenses to correct keratoconus and developed AK. The diagnoses of AK were established based on cultures of the cornea, scleral contact lenses, and contact lens paraphernalia. This study investigated the risk factors for infections. RESULTS: The possible risks for AK in scleral contact lens wearers are hypoxic changes in the corneal epithelium because of the large diameter and minimal tear exchange, use of large amounts of saline solution necessary for scleral lens fitting, storing the scleral lens overnight in saline solution rather than contact lens multipurpose solutions, not rubbing the contact lens during cleaning, and the space between the cornea and the back surface of the scleral lens that might serve as a fluid reservoir and environment for Acanthamoeba multiplication. Two patients responded well to medical treatment of AK; one is still being treated. CONCLUSIONS: The recommendations for use and care of scleral contact lenses should be emphasized, especially regarding use of sterile saline (preferably single use), attention to rubbing the lens during cleaning, cleaning of the plunger, and overnight storage in fresh contact lens multipurpose solutions without topping off the lens solution in the case.