Changes in Ocular Physiology, Tear Film Characteristics, and Symptomatology With 18 Months Silicone Hydrogel Contact Lens Wear

2022 Glenn A. Fry Award lecture: Enhancing clinical assessment for improved ophthalmic management

ABSTRACT

Detailed clinical assessment is critical to allow sensitive evaluation of the eye and its management. As technology advances, these assessment techniques can be adapted and refined to improve the detection of pathological changes of ocular tissue and their impact on visual function. Enhancements in optical medical devices including spectacle, contact, and intraocular lenses have allowed for a better understanding of the mechanism and amelioration of presbyopia and myopia control. Advancements in imaging technology have enabled improved quantification of the tear film and ocular surface, informing diagnosis and treatment strategies. Miniaturized electronics, large processing power, and in-built sensors in smartphones and tablets capacitate more portable assessment tools for clinicians, facilitate self-monitoring and treatment compliance, and aid communication with patients. This article gives an overview of how technology has been used in many areas of eye care to improve assessments and treatment and provides a snapshot of some of my studies validating and using technology to inform better evidence-based patient management.

Assessment of condition-induced changes on the ocular surface using novel methods to assess the tear film dynamics and the lipid layer

OBJECTIVES

To assess the effects of different condition-induced changes on current and novel ocular surface metrics.

METHODS

Eighty-four healthy volunteers (22.4 ± 2.6 years) participated in this study. The ocular surface and tear film response to (1) computer use, (2) contact lens insertion and (3) tear film instillation during computer use with contact lenses were assessed. Current metrics included the ocular surface disease (OSDI) questionnaire, 5-item dry eye questionnaire (DEQ-5), bulbar redness, tear meniscus height (TMH) and non-invasive keratograph break-up time (NIKBUT). Novel metrics included the lipid layer thickness obtained from the intensity of the reflected Placido disk and the speed of tear film particles post-blink.

RESULTS

Higher dry eye symptoms, TMH and bulbar redness, and lower values in metrics related to the intensity of the Placido disk pattern and to particle speed were found after the computer reading task (p < 0.036). When a contact lens was fitted, lower TMH, NIKBUT and particle speed metrics were obtained (p < 0.044). Mixed ANOVA revealed that artificial tears significantly ameliorated the effect of computer reading on OSDI, DEQ-5, NIKBUT, metrics related to the intensity of the Placido disk pattern and metrics related to particle speed (p < 0.033).

CONCLUSIONS

Computer use and contact lens wear worsened dry eye signs and symptoms, but artificial tears ameliorated this effect. Newly developed methods can serve as a tool to detect changes in the tear film triggered by different ocular surface-disturbing conditions.

The Effects of Soft Contact Lens Wear on The Tear Film and Meibomian Gland Drop-Out and Visibility

As contact lens (CL) wear affects the ocular surface, this cross-sectional study aims to assess the effects of soft CL wear and its duration on the tear film and meibomian gland (MG) drop-out and visibility. Thirty non-CL wearers (22.5 ± 2.3 years) and twenty-four soft CL wearers (23.8 ± 2.2 years) participated in this study. The Keratograph 5M was used to assess the ocular surface. CL users were surveyed on years of CL wear and hours per week. MG visibility was assessed using a previously developed method based on analysing pixel intensity of meibographies. The CL group showed higher gland drop-out (p < 0.001) and lower gland visibility (p < 0.022). Gland drop-out was independently associated with CL wear (p = 0.006). When gland drop-out was excluded, the relative energy of pixel intensity values showed an independent association with CL wear (p = 0.005). Prolonged hours of CL wear were associated with higher dry eye symptoms and entropy of MGs (p < 0.029). A reduction in non-invasive keratograph break-up time was associated with using CLs for ≥8 years (p = 0.030). Overall, gland drop-out was higher and gland visibility lower in soft CL wearers. New gland visibility metrics might help to assess MGs in soft CL wearers quickly and objectively.

Digital display use and contact lens wear: Effects on dry eye signs and symptoms

PURPOSE

To assess the potential additive effects of short-term display use and contact lens (CL) wear on the ocular surface and tear film.

METHODS

Thirty-four healthy volunteers (20.87 ± 2.33 years old) participated in this study. Participants' dry eye symptoms, ocular surface, tear film and pupil size were assessed before and after executing a 20-min reading task on a computer and a smartphone with and without CL wear, or with CL wear and artificial tear instillation. Measurements included the Ocular Surface Disease Index (OSDI) questionnaire; 5-item Dry Eye Questionnaire (DEQ-5); tear meniscus height (TMH); noninvasive keratograph break-up time (NIKBUT); bulbar conjunctival redness (BR) and pupil size.

RESULTS

Higher symptoms were reported after reading on both displays with and without CLs (p ≤ 0.001) for short periods. BR was higher and NIKBUT shorter after reading on the computer regardless of wearing CLs (p ≤ 0.02 and p ≤ 0.02, respectively), while TMH increased for all conditions (p ≤ 0.02) except for CL computer reading (p = 0.23). Reading with CLs did not lead to greater signs of dry eye (BR, NIKBUT) and symptoms compared with reading unaided (p > 0.05), although a smaller increase in TMH was observed when reading on the computer with CLs (p = 0.005). Artificial tear instillation during CL wear led to a smaller increase in symptoms (p ≤ 0.02), a smaller increase in BR (p ≤ 0.04) and a decrease in NIKBUT (p = 0.02) compared to reading without correction.

CONCLUSIONS

Disposable CL wear had no additive effects on signs and symptoms of dry eye when using digital devices for short periods. The instillation of artificial tears is an effective strategy for reducing the impact of display use in CL wearers.

Dynamic Changes of Ocular Surface in First-Time Contact Lens Wearers and the Effective Factors of Contact Lens Discomfort

Purpose

The purpose of the study is to investigate the dynamic changes in ocular surface indicators in first-time contact lens (CL) wearers and identify the most influential factors in CL discomfort (CLD).

Methods

A total of 26 healthy non-CL wearers (26 eyes) were recruited and fitted monthly with disposable hydrogel CLs. Each participant underwent a full ocular surface evaluation, which include Efron grading, tear film breakup time, Schirmer's I test, corneal dendritic cell (DCs) imaging by in vivo confocal microscopy (IVCM), and conjunctival microvasculature evaluation by functional slit-lamp biomicroscopy. CLD was assessed using the Ocular Surface Disease Index questionnaire at baseline, 1 week, 1, 3, and 6 months after wearing it and another 6 months after discontinuing it.

Results

Clinical signs and CLD were significantly increased in the first week (p < 0.05). The microvascular response and DC activation peaked at the 1-month interval (p < 0.05). During CL wear, CLD is positively correlated with corneal staining (B = 0.238, p = 0.002), papillary conjunctivitis (B = 0.245, p < 0.001), and microvascular blood flow velocity (B = 0.353, p < 0.001). After discontinuation, only DC activation remained elevated at 6 months, whereas the other signs recovered.

Conclusions

The first week of CL wear was the main period for the appearance of ocular surface clinical signs, and the first month was the main period for the activation of subclinical inflammation. Corneal staining and conjunctival microvascular response are the main factors affecting CLD. Even if the clinical signs recover after discontinuing wear, subclinical inflammation may persist.

Long-term effect of contact lens wear: A citation network study

BACKGROUND

Contact lenses can cause complications in 2/3 of the total population, but in most cases, they are mild and easy to manage. However, most of the studies are short-term. The aim of the study was to analyze the publications on the long-term effects of contact lens wear to understand the current research landscape through the analysis of dating networks as well as determining the different research areas and the most cited publications.

METHODS

The Web of Science database was used to perform the publication search, looking for the terms "Long-term" AND "contact lens wear" within the period between 1977 and January 2021. The CitNetExplorer and CiteSpace software were then used to conduct the publication analysis. To obtain the graphics, the VOSviewer software was used.

RESULTS

A total of 721 publications were found with 2999 citations generated within the network. The year 2010 was singled out as a "key year", considering the number of publications that emerged in that year and increase in adaptations of contact lens worldwide. The most widely cited publication was "Effects of long-term extended contact lens wear on the human cornea", an article by Holden et al., which was published in 1985. By using the clustering function, we were able to establish three clusters that encompassed the different research areas within this field: morphological changes, the loss of corneal sensitivity, tear film characteristics and longitudinal changes in ocular physiology.

CONCLUSIONS

The main research topic in this field focuses on the morphological changes that take place in the corneal endothelial cell layer.

Use of digital displays and ocular surface alterations: A review

Digital display use has been accepted to be implicated as a contributing factor for dry eye disease (DED). Abnormal blinking during computer operation, including a reduced blink rate and an incomplete eyelid closure, increased palpebral fissure as consequence of high visualization angles, and meibomian gland dysfunction associated to long-term display use, are behind the increased prevalence of dry eye signs and symptoms found in digital display users. Previous research reveals significant reductions in tear volume and stability, alterations in tear film composition, including increased osmolarity, inflammatory cytokines, oxidative stress markers and reduced mucin secretion, eyelid abnormalities and ocular surface damage, encompassing corneal and conjunctival staining and bulbar redness, as a direct consequence of digital display use. In this regard, individual differences in the way that the various digital displays are typically set up and used may account for differences in their effects on induced dryness signs and symptoms. Furthermore, factors such as the use of contact lenses or inappropriate working environments, usually accompanying the use of displays, may significantly increase the prevalence and the severity of induced dry eye. Other factors, such as old age and female gender are also relevant in the appearance of associated alterations. Finally, clinicians should adopt a treatment strategy based on a multidirectional approach, with various treatments being applied in conjunction.

The Role of Soft Contact Lens Wear on Meibomian Gland Morphology and Function

PURPOSE

To evaluate the impact of soft contact lens (CL) wear on the morphology and function of the meibomian glands (MG).

METHODS

One hundred seventy-three eyes of 87 soft CL wearers and 103 eyes of 55 age-matched healthy volunteers were included into this study. The patients were divided into 3 groups according to the total duration of lens wear: less than 3 years, 3 to 7 years, and more than 7 years. Ocular Surface Disease Index (OSDI) scores, slitlamp biomicroscopy findings, fluorescein staining of the ocular surface, tear film break-up time (BUT), Schirmer I test, and meibography findings were recorded in all patient eyes and were compared with controls.

RESULTS

The mean meiboscores of the upper and lower eyelids were significantly higher in CL wearers compared with controls (P<0.05). The mean BUT and the mean MG expressibility were significantly lower, whereas the mean OSDI score, corneal staining scores, percentage of partial/complete gland loss, and percentage of thickened and curled MG in upper/lower lids were statistically significantly higher in CL wearers (P<0.05). Meiboscores were significantly higher in patients with a total lens wear duration of more than 3 years compared to those with less than 3 years of lens wear for both upper/lower lids (P<0.05). The earliest morphological change in the MG of CL wearers was MG thickening, and this parameter was the only meibography finding that had the highest diagnostic ability for MG dysfunction.

CONCLUSION

Soft CL wear causes significant morphological and functional changes in MG with thickening of MG presenting an early diagnostic finding of MG dysfunction on meibography.

Predictive Potential of Eyelids and Tear Film in Determining Symptoms in Contact Lens Wearers

SIGNIFICANCE

Early diagnosis of clinical markers of contact lens discomfort can help clinicians set realistic expectations and monitor and provide prophylactic management for contact lens wearers.

PURPOSE

The purpose of this study was to evaluate the potential of eyelid- and tear film-related clinical markers to be used as predictive factors for diagnosing discomfort in contact lens wearers.

METHODS

A cross-sectional study was performed on 30 contact lens wearers (6 male, 24 female) with median age of 23 years (range, 18 to 41 years). Eyelid signs and tear film characteristics were evaluated during a single visit, and subjects completed the Contact Lens Dry Eye Questionnaire to evaluate ocular discomfort. Area under the curve (AUC) statistics and sensitivity and specificity values from receiver operating characteristic curves were analyzed to evaluate the predictive potential of clinical signs in discriminating symptoms of contact lens discomfort.

RESULTS

The presence of foam at meibomian gland orifices (AUC, 0.944; P < .05; sensitivity >0.7), meibomian gland secretion volume (AUC, 0.935; P < .05; sensitivity >0.7), quality (AUC, 0.969; P < .05; sensitivity >0.7), and expressibility (AUC, 0.933; P < .05; sensitivity >0.7) were significant and strong predictors of discomfort in lens wear. Tear evaporation rates with (AUC, 0.779; P < .05; sensitivity >0.7) or without contact lenses (AUC, 0.788; P < .05; sensitivity >0.7), palpebral conjunctival roughness (AUC, 0.859; P < .05; sensitivity >0.7), palpebral conjunctival staining (AUC, 0.817; P < .05; sensitivity >0.7), palpebral conjunctival hyperemia (AUC, 0.746; P < .05; sensitivity >0.7), meibomian gland orifice capping (AUC, 0.873; P < .05; sensitivity >0.7), pouting (AUC, 0.891; P < .05; sensitivity >0.7), and lid-parallel conjunctival folds (AUC, 0.770; P < .05; sensitivity >0.7) were other acceptable discriminators of symptoms of discomfort during contact lens wear. An equation was developed to identify symptomatic from asymptomatic lens wearers based on the significant predictors: Symptom discriminant function score = 3.378 (meibomian gland secretion grade) + 0.224 (meibomian gland morphology grade) + 0.61 (tear evaporation rate without contact lenses) + 0.439 (lid-parallel conjunctival folds grade) - 0.346 (palpebral conjunctival health grade) - 4.625.

CONCLUSIONS

This study demonstrated that clinical signs related to meibomian gland secretions and morphology, tear evaporation, lid-parallel conjunctival folds, and palpebral conjunctival health may successfully predict symptoms of discomfort in contact lens wearers.

Effects of Blink Rate on Tear Film Optical Quality Dynamics with Different Soft Contact Lenses

Objective

The aim of this study was to investigate tear film optical quality dynamics for four types of silicone hydrogel contact lenses (SHCLs) for daily wear over a 15-day period and for different blink rate (BR) patterns.

Methods

A prospective randomized, double-blind, cross-over pilot study including four SHCLs (A: lotrafilcon B (Air Optix plus HydraGlyde, Alcon Laboratories); B: samfilcon A (Ultra, Bausch & Lomb); C: comfilcon A (Biofinity, CooperVision); and D: filcom V3 (Blu:gen, Mark'Ennovy)). Serial measurements of Objective Scatter Index (OSI) using the HD Analyzer (Visiometrics S.L., Terrassa, Spain) were taken at different blinking patterns: blinking every 2.5 seconds (high BRs) and every 9 seconds (low BRs). They were performed during the first visit before CL insertion (baseline), after 20 minutes of CL wear (Day 1), and during the last visit after 8 hours of CL wear on day 15 of use (Day 15).

Results

Normal young healthy subjects were recruited and fitted with the four lenses. For low BRs, the mean OSI value increased over time for all CLs and the slope of the curve also increased for all CLs, except for CL D. However, for high BRs, the mean OSI value increased only for CLs B and C and the slope of the curve did not change over time for any of them.

Conclusions

These results suggest that the tear film optical quality dynamics after wearing SCHLs for 15 days seems to undergo a slight deterioration only for lowest BR.

Differences between tears of contact lens wearers studied by photon correlation spectroscopy

PURPOSE

The purpose was to evaluate if there are differences between tears of contact lens (CL) wearers of different materials detectable by measuring the hydrodynamic diameter of tear components through photon correlation spectroscopy (PCS).

METHODS

Tears of 59 CL wearers and tears of 39 non-wearers were collected by glass capillary. Wearers were divided into groups depending on the CL material: (i) hydrogels of II FDA group (H-II, 15 subjects), (ii) hydrogels of IV FDA group (H-IV, 13 subjects), (iii) silicone hydrogels (SH, 31 subjects). PCS analyses were performed at 25 °C on samples diluted with deionized water with tear concentration (10 ± 2)% ^V/_W to obtain, for each subject, the average hydrodynamic diameter (d_H,avg) of tear components by analyzing intensity fluctuations in time of scattered light.

RESULTS

Means of d_H,avg calculated on each group were found, on increasing order, to be 256 nm (std dev 18 nm) for non-wearers, 297 nm (std dev 45 nm) for H-II, 360 nm (std dev 76 nm) for SH, and 391 nm (std dev 85 nm) for H-IV with statistical differences between each group of wearers compared to non-wearers and between groups of wearers except between SH and H-IV.

CONCLUSIONS

PCS reveals the differences between tears of CL wearers of different materials, not only between tears of wearers and non-wearers.

Tear film inflammatory cytokine upregulation in contact lens discomfort

PURPOSE

To investigate the ocular inflammatory response, using clinical and immunological techniques, in people experiencing contact lens (CL) discomfort.

METHODS

This study involved 38 adults who were full-time, silicone-hydrogel CL wearers. Participants were categorized into groups based upon a validated CL dry-eye questionnaire (CLDEQ-8) (n = 17 'asymptomatic', CLDEQ-8 score <9; n = 21 'symptomatic', CLDEQ-8 score ≥13). Examinations were performed at two visits (one with, and one without, CL wear), separated by one-week. Testing included: tear osmolarity, ocular redness, tear stability, ocular surface staining, meibography, tear production and tear collection. Tear osmolarity was taken from the inferior-lateral and superior-lateral menisci. The 'Inferior-Superior Osmotic Difference', I-SOD, was the absolute osmolarity difference between these menisci. Concentrations of seven cytokines (IL-2, IL-4, IL-6, IL-10, IL-17A, IFN-gamma, TNF-alpha) were assayed from basal tears using multiplex cytometric bead array.

RESULTS

At baseline, there was no significant difference in key clinical signs between asymptomatic and symptomatic CL wearers (p > 0.05). The I-SOD was greater in symptomatic than asymptomatic CL wearers (23.1 ± 2.6 versus 11.3 ± 1.4 mOsmol/L, p = 0.001). People experiencing CL discomfort had higher tear IL-17A (122.6 ± 23.7 versus 44.0 ± 10.0 pg/mL, p = 0.02) and reduced tear stability (6.3 ± 1.1 versus 10.4 ± 1.6 s, p = 0.03) after several hours of CL wear. Tear IL-17A levels correlated with both the I-SOD (r = 0.43, p = 0.01) and CLDEQ-8 score (r = 0.40, p = 0.01).

CONCLUSIONS

CL discomfort occurs in individuals having no clinical dry eye signs, and is associated with higher tear levels of the pro-inflammatory cytokine IL-17A. These findings support an association between the discomfort response and low-grade, ocular surface inflammation.

Evaluation of Long-Term Silicone Hydrogel Use on Ocular Surface Inflammation and Tear Function in Patients With and Without Meibomian Gland Dysfunction

OBJECTIVES

To determine whether silicone hydrogel (SH) contact lens (CL) use, with or without meibomian gland dysfunction (MGD), promotes ocular surface inflammation.

METHODS

Subjects wearing SH-CL for at least 6 months who also had coexisting MGD (group 1, n=20), SH-CL users who did not have MGD (group 2, n=20), patients who had MGD but did not use CL (group 3, n=20), and healthy CL-naive individuals with no known systemic or ocular diseases (group 4, n=20) were included in this cross-sectional, single-center study. All subjects underwent tear function tests consisting of tear break-up time (tBUT), ocular surface staining, Schirmer test, and the Ocular Surface Disease Index (OSDI) questionnaire, as well as determination of tear IL-1RA, IL-1β, IL-2, IL-2R, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, IL-13, IL-15, IL-17, IFN-α, IFN-γ, TNF-α, granulocyte-macrophage colony-stimulating factor, IP-10, monokine induced by gamma interferon, RANTES, eotaxin, MIP-1α, MIP-1β, and MCP-1 levels using Luminex multicytokine immunobead assay. Intergroup comparisons were made using one-way analysis of variance or Kruskal-Wallis test.

RESULTS

The tBUT was lower (P=0.048) and ocular surface staining (P=0.032) as well as OSDI scores (P=0.001) were higher in group 1 but not in groups 2 or 3 when compared with those in the control group. Tear cytokine levels were similar across all groups. None of the tear cytokine levels were elevated in CL wearers (groups 1 and 2) or those with MGD (groups 1 and 3) as compared to those in control subjects.

CONCLUSION

Silicone hydrogel contact lens use with concomitant MGD is not associated with cytokine-driven ocular surface inflammation but may impact tear function leading to dry eye symptoms.

Tear film evaluation and management in soft contact lens wear: a systematic approach

The human tear film is a highly ordered structure consisting of a thin layer of lipid on the surface and a thicker aqueous-mucin phase, which increases in mucin concentration toward the corneal epithelial cell layer. The health of the tear film and ocular surface influences the likelihood of being able to achieve successful contact lens wear. Contact lens discomfort and dryness are the most frequent reasons why contact lens wearers experience reduced wearing times, which can eventually lead to contact lens discontinuation. Comprehensive clinical assessment of tear film integrity and ocular surface health is therefore essential prior to commencing contact lens wear, to enable the ocular surface environment to be optimised to support lens wear. These parameters should also be evaluated over the course of contact lens wear, in order to identify any aspects requiring clinical management and ensure maintenance of optimal lens-wearing conditions. This review summarises current knowledge relating to the effects of soft contact lens wear on the tear film and ocular surface. It also provides a systematic approach to evaluating tear film and ocular surface integrity, in order to guide the clinical management of tear film anomalies with respect to contact lens wear.

TFOS DEWS II iatrogenic report

Dry eye can be caused by a variety of iatrogenic interventions. The increasing number of patients looking for eye care or cosmetic procedures involving the eyes, together with a better understanding of the pathophysiological mechanisms of dry eye disease (DED), have led to the need for a specific report about iatrogenic dry eye within the TFOS DEWS II. Topical medications can cause DED due to their allergic, toxic and immuno-inflammatory effects on the ocular surface. Preservatives, such as benzalkonium chloride, may further aggravate DED. A variety of systemic drugs can also induce DED secondary to multiple mechanisms. Moreover, the use of contact lens induces or is associated with DED. However, one of the most emblematic situations is DED caused by surgical procedures such as corneal refractive surgery as in laser-assisted in situ keratomileusis (LASIK) and keratoplasty due to mechanisms intrinsic to the procedure (i.e. corneal nerve cutting) or even by the use of postoperative topical drugs. Cataract surgery, lid surgeries, botulinum toxin application and cosmetic procedures are also considered risk factors to iatrogenic DED, which can cause patient dissatisfaction, visual disturbance and poor surgical outcomes. This report also presents future directions to address iatrogenic DED, including the need for more in-depth epidemiological studies about the risk factors, development of less toxic medications and preservatives, as well as new techniques for less invasive eye surgeries. Novel research into detection of early dry eye prior to surgeries, efforts to establish appropriate therapeutics and a greater attempt to regulate and oversee medications, preservatives and procedures should be considered.

[Contact lens associated dry eye. Current study results and practical implementation]

Contact lens-associated dry eye symptoms have mostly been therapeutically addressed using artificial tears containing hyaluronic acid to supplement tear film volume with often unsatisfactory results. However, the main reason for contact lens-associated dry eye is not the lack of tear fluid but the lack of tear film stability due to meibomian gland dysfunction leading to reduction of the lipid film of tears. This is associated with increased evaporation of the aqueous phase of tear fluid and a measurable hyperosmolarity of the residual "denatured" tear film. A subsequent inflammatory reaction of the ocular surface then leads to the vicious circle of dry eye. The aim of this review is to summarize current study results on this topic and to give practical advice on how to address dry eye symptoms in contact lens wearers more accurately. For most contact lens-associated dry eye symptoms a combined therapy with unpreserved artificial tears plus phospholipid-liposome eye spray yields the best results. In cases of additional signs of blepharitis the regular use of phospholipid-liposome solution for lid margin hygiene is beneficial.

Computational methods for objective assessment of conjunctival vascularity

Assessment of vascularity of conjunctiva has many diagnostic and prognostic applications, thus creation of computational methods for its fast and objective assessment is of importance. Here we provide two different methods for estimation of conjunctiva's vascularity from color digital images, with our best results showing a correlation coefficient of 0.89 between the predicted and ground truth values using a committee of artificial neural networks.

Ethnic differences in dry eye symptoms: effects of corneal staining and length of contact lens wear

PURPOSE

To explore the relationships among length of contact lens (CL) wear, degree of corneal staining and severity of dryness symptoms, and to determine whether these relationships differ between Asians and non-Asians.

METHODS

Adapted soft CL wearers (n=395; 180 Asian, 215 non-Asian) were required to discontinue CL wear for at least 24h and report to the University of California, Berkeley Clinical Research Center (UCB-CRC). Fluorescein corneal staining was graded according to Brien Holden Vision Institute scales. Length of CL wear was reported by subjects and subjective dryness ratings were collected using the UCB-CRC Dry Eye Flow Chart (DEFC).

RESULTS

More Asian CL wearers exhibited corneal staining compared to non-Asians, and Asian CL wearers had a higher mean grade of corneal staining (p<0.001), as well as a higher mean DEFC classification (p<0.001). The difference between Asians and non-Asians in grades of corneal staining extent and depth were significant (p<0.001). Among non-Asian CL wearers, dryness symptoms decreased with more years of CL wear and increased in the presence of corneal staining, which was not the case for Asian CL wearers.

CONCLUSIONS

Asian soft CL wearers reported more severe dryness symptoms and demonstrated more severe corneal staining overall compared to non-Asians. Among non-Asians, dryness symptoms were less severe on average with increased years of CL wear and more severe in the presence of corneal staining. Dryness severity does not appear to be related to years of CL wear or corneal staining among Asians.

Predicting success with silicone-hydrogel contact lenses in new wearers

PURPOSE

to evaluate changes in tear metrics and ocular signs induced by six months of silicone-hydrogel contact lens wear and the difference in baseline characteristics between those who successfully continued in contact lens wear compared to those that did not.

METHODS

Non-invasive Keratograph, Tearscope and fluorescein tear break-up times (TBUTs), tear meniscus height, bulbar and limbal hyperaemia, lid-parallel conjunctival folds (LIPCOF), phenol red thread, fluorescein and lissamine-green staining, and lid wiper epitheliopathy were measured on 60 new contact lens wearers fitted with monthly silicone-hydrogels (average age 36±14 years, 40 females). Symptoms were evaluated by the Ocular Surface Disease Index (OSDI). After six months full time contact lens wear the above metrics were re-measured on those patients still in contact lens wear (n=33). The initial measurements were also compared between the group still wearing lenses after six months and those who had ceased lens wear (n=27).

RESULTS

There were significant changes in tear meniscus height (p=0.031), bulbar hyperaemia (p=0.011), fluorescein TBUT (p=0.027), corneal (p=0.007) and conjunctival (p=0.009) staining, LIPCOF (p=0.011) and lid wiper epitheliopathy (p=0.002) after six months of silicone-hydrogel wear. Successful wearers had a higher non-invasive (17.0±8.2s vs 12.0±5.6s; p=0.001) and fluorescein (10.7±6.4s vs 7.5±4.7s; p=0.001) TBUT than drop-outs, although OSDI (cut-off 4.2) was also a strong predictor of success.

CONCLUSION

Silicone-hydrogel lenses induced significant changes in the tear film and ocular surface as well as lid margin staining. Wettability of the ocular surface is the main factor affecting contact lens drop-out.

Lidrandhygiene bei Kontaktlinsenträgern mit Blepharitis

Hintergrund

Blepharitis als Folge der Dysfunktion der Meibom-Drüsen („Meibom gland dysfunction“, MGD) wird als weltweit häufigste Ursache des trockenen Auges angesehen. Wahrscheinlich ist die MGD auch eine wichtige Ursache der Symptome des trockenen Auges bei Kontaktlinsenträgern. Von den Beschwerden und Symptomen des trockenen Auges sind 50–75% der Kontaktlinsenträger betroffen. In der hier vorgestellten prospektiven, randomisierten und verblindeten Beobachtungsstudie soll die Wirksamkeit bekannter Therapieoptionen zur Behandlung der MGD bei Kontaktlinsenträgern anhand objektiver und subjektiver Methoden verglichen und ihre Wirksamkeit hinsichtlich der Beschwerdelinderung bei Kontaktlinsenträgern überprüft werden.

Methoden

An der Untersuchung nahmen 53 symptomatische Kontaktlinsenträger teil, die per Los auf die beiden Behandlungsgruppen „Lidrandhygiene mit verdünntem Babyshampoo“ oder „Lidrandhygiene mit liposomaler Lidrandreinigungslösung“ verteilt wurden. Der Behandlungszeitraum betrug 4 Wochen.

Die vergleichenden Untersuchungen zu Studienbeginn und nach 4 Wochen umfassten die verblindete Bewertung von Spaltlampenfotografien zur Beurteilung der Lidränder, die Bewertung der lidkantenparallelen konjunktivalen Falten (LIPCOF), die Messung der Tränenfilmaufreißzeit (NiBUT) und die subjektive Bewertung durch die Studienteilnehmer anhand des standardisierten Ocular-Surface-Disease-Index(OSDI)-Fragebogens.

Ergebnisse

Von den an der Studie beteiligten 53 Kontaktlinsenträger wurden 32 (60,4%) mit der Phospholipidlösung und 21 (39,6%) mit dem Babyshampoo behandelt. Beide Gruppen zeigten Befund- und Symptomverbesserungen. Die Verbesserungen waren sowohl objektiv als auch subjektiv signifikant stärker in der Phospholipidlösung- als in der Babyshampoo-Behandlungsgruppe ausgeprägt.

Schlussfolgerung

Die gängige klinische Praxis der zumeist einseitig auf die Substitution der wässrigen Tränenfilmphase abzielenden Therapie wird infrage gestellt. Vielmehr ist für Kontaktlinsenträger mit Siccabeschwerden auf evidenzbasierter Grundlage zu empfehlen, die Restitution der Lipidphase des Tränenfilms in den Vordergrund zu stellen. Im Falle einer assoziierten Blepharitis sollte die gängige klinische Praxis, einfach Babyshampoo für die Lidrandhygiene zu empfehlen, überdacht werden, denn die regelmäßige Lidrandhygiene mit einer phospholiposomalen Reinigungslösung, hier Blepha Cura, ist therapeutisch am wirksamsten.

Comparison of the tear film clinical parameters at two different times of the day

PURPOSE

The aim of the present study was to analyse the quality and quantity of the tear film in a young, healthy and non-contact lens-wearing population with measurements taken in the morning and in the afternoon to establish if changes exist in these parameters.

METHODS

In a controlled laboratory setting, morning and afternoon clinical parameters of tear film were assessed. Schirmer test, tear meniscus height, break-up time and non-invasive break-up time were measured in 51 normal subjects on the same day for each individual.

RESULTS

Tear volume showed no significant changes during the day but tear film stability was significantly reduced at the end of the day (p < 0.001), demonstrating that tear film stability is affected by the time of day.

CONCLUSION

Researchers and clinicians might wish to consider these differences when comparisons are made between studies and populations and also when the same patient is observed over periods. Fluorescein instillation can affect the measurements of tear stability in subjects with poor quality tear film.

The Stability of Dryness Symptoms After Refitting With Silicone Hydrogel Contact Lenses Over 3 Years

PURPOSE

To assess the stability of dryness symptoms after refitting patients wearing low-Dk/t hydrogel contact lenses with high-Dk/t silicone hydrogel contact lenses and to determine whether early dryness symptoms were predictive of discontinuation in the 3-year study.

METHODS

Two hundred seventy-eight hydrogel lens wearers were refitted with lotrafilcon A silicone hydrogel contact lenses for continuous wear of up to 30 nights. Self-administered questionnaires at baseline, 1 week, and 3 years captured the frequency and intensity of dryness symptoms during the day and at the end of the day. One-week and 3-year responses were compared to baseline by a Bowker test of symmetry and median change in response with Wilcoxon signed rank test.

RESULTS

Frequency of during-the-day and end-of-day dryness decreased from baseline to 1 week and 3 years (during the day, frequency > or = "sometimes" 57.1% vs. 33.1% after 1 week and 58.5% vs. 28.8% after 3 years; end of day, 61.1% vs. 41.0% after 1 week and 64.0% vs. 35.9% after 3 years [P<0.0001 for all comparisons]). After refitting, the proportion of subjects with dryness symptoms was stable. After 1 week, the presence of frequency of at least "sometimes" and severity of at least "moderate" during-the-day and end-of-day dryness were significantly associated with study discontinuation (during-the-day frequency [P=0.007] and severity [P=0.017]; end-of-day frequency [P=0.002] and severity [P=0.003]).

CONCLUSIONS

Dryness symptoms improved after 1 week of refitting with lotrafilcon A and remained stable through 3 years. The presence of dryness after 1 week was associated with discontinuation from contact lens wear. Refitting with silicone hydrogel lenses reduced the frequency and severity of dryness symptoms seen with hydrogel lens wear for many subjects.

A 12-month prospective clinical trial of comfilcon A silicone-hydrogel contact lenses worn on a 30-day continuous wear basis

PURPOSE

To evaluate the clinical performance of comfilcon A (Biofinity) during 12 months of continuous wear compared to other silicone-hydrogel lenses.

METHOD

Forty-five subjects were fitted in one eye with the comfilcon A (test) lens. For 22 subjects, the other eye was fitted with lotrafilcon A (group A) and for the remaining 23 subjects the other eye was fitted with balafilcon A (group B). Twelve-month data are presented on 48 measured variables.

RESULTS

There were no serious adverse events during the course of the study. A total of 33 subjects completed the study, with only 4 discontinuations for lens-related reasons, spread proportionately between the lenses. On preference scales, the test lens was superior to both control lenses for comfort (p<0.05) and overall preference (p<0.05) and in group A for vision (p<0.05). On grading scales, the test lens scored better than both control lenses for overall comfort (p<0.1 for group A, p<0.05 for group B), comfort during the day (p<0.05), end-of-day comfort (p<0.05) and overall preference (p<0.05), and better in group A for general vision quality (p<0.01), night vision quality (p<0.01) and handling (p<0.05). All lenses performed to a comparable degree on the basis of microcysts and corneal staining. There were significant differences between lenses in producing limbal redness (p<0.05), bulbar conjunctival hyperemia (p<0.1) and conjunctival NaFl staining (p<0.01) with the control lens in group A showing the greatest effect and the control lens in group B the least.

CONCLUSION

Comfilcon A offers performance advantages over first generation silicone-hydrogel materials for continuous wear.

The comparative clinical performance of a new polyhexamethylene biguanide- vs a polyquad-based contact lens care regime with two silicone hydrogel contact lenses

PURPOSE

To compare the clinical performance of a new polyhexamethylene-biguanide (PHMB)- vs a polyquad-based contact lens care regime with two silicone hydrogel contact lenses.

METHODS

This study was a randomised, controlled and investigator-masked (to the lens regimen) clinical study where the clinical performance of two multipurpose contact lens solutions was compared at a single site. Forty-one existing contact lens wearers were recruited and fitted randomly with either galyfilcon A or lotrafilcon A contact lenses. Subjects wore the same lens type for a period of 2 months but used a different care regime (PHMB- and polyquad-based) in a crossover manner, each for a period of 1 month. The primary outcome measure was the difference in corneal staining. Corneal staining was graded in five different locations: central, superior, inferior, temporal and nasal. Measurements of conjunctival redness, limbal redness, conjunctival staining and papillary conjunctivitis were also carried out throughout the study. Biomicroscopic measures were graded using the Efron grading scales. A variety of symptoms were also measured using a visual analogue scale.

RESULTS

There was no statistically significant difference in overall corneal staining between lens types (p = 0.16) or care regimens (p = 0.60). Central corneal staining was significantly greater for the polyquad-based care regimen when compared with the PHMB-based care regimen (p = 0.04). Lotrafilcon A lenses showed greater superior corneal staining (p = 0.0004) and papillary conjunctivitis (p = 0.02), and lower comfort on insertion (p = 0.03) when compared with galyfilcon A lenses regardless of the care regime used. There were no statistically significant differences in the other biomicrosopic signs and symptoms between the lens types and the care regimes.

CONCLUSIONS

Both care regimes performed in a similar clinical manner and are valid for use with the two silicone hydrogel contact lenses used in this study.

Initial comfort of lotrafilcon A silicone hydrogel contact lenses versus etafilcon A contact lenses for extended wear

PURPOSE

To compare the initial comfort afforded by silicone hydrogel lenses (lotrafilcon A) versus the comfort afforded by conventional hydrogel lenses (etafilcon A) in extended wear (EW).

DESIGN

Prospective, double-masked and randomized controlled trial.

METHODS

Lotrafilcon A and etafilcon A contact lenses were eye randomly fitted on an EW basis for 7 days and nights in 20 subjects. A forced-choice subject preference questionnaire was made. Subjects were comfort, dryness, red eye and visual quality after night wear and at the end of the day. Subjective scored satisfaction (scale: 1-5) and lens preference were assessed.

RESULTS

Lotrafilcon A proved more comfortable after night wear (60%, CI95% 38-82%) and at the end of the day (70%, CI95% 49-90%) than etafilcon A after night wear (10%, CI95% 0-23%, P<0.05) and at the end of the day (20%, CI95% 2-38%, P<0.05). The feeling of dryness was more marked with etafilcon A after night wear (50%, CI95% 27-72%) and at the end of the day (50%, CI95% 27-72%) than it was with lotrafilcon A (15%, CI95% 0%-31%) after night wear (P>0.05) and at the end of the day (25%, CI95% 5%-44%, P<0.05). General satisfaction with the lotrafilcon A lens was 3.65 points (CI95% 3-4.2) and with etafilcon A 2.95 points (CI95% 2.5-3.3, P<0.05). Eighty percent (CI95% 62%-98%) of subjects preferred lotrafilcon A (P<0.05) for EW.

CONCLUSIONS

In EW, lotrafilcon A contact lenses were more comfortable and led to less dryness after night wear and at the end of the day than etafilcon A contact lenses.