The Effect of Ocular Surface Regularity on Contrast Sensitivity and Straylight in Dry Eye

Associations Between Visual Functions and Severity Gradings, Corneal Scatter, or Higher-Order Aberrations in Fuchs Endothelial Corneal Dystrophy

Purpose

The purpose of this study was to investigate the associations between visual function and severity grading, corneal scatter, or higher-order aberrations (HOAs) in patients with Fuchs endothelial corneal dystrophy (FECD).

Methods

This observational case series study included 49 eyes of 27 patients with FECD and 10 eyes of 10 healthy individuals. We evaluated corrected distance visual acuity (CDVA) using Landolt-C and Early Treatment Diabetic Retinopathy Study charts and contrast sensitivity using the CSV-1000E chart and CSV-1000RN letter chart. We analyzed the associations between visual function and explanatory variables, including age, modified Krachmer grade, central corneal thickness (CCT), anterior segment optical coherence tomography (AS-OCT)-based grade, HOAs, intraocular straylight, and corneal densitometry. We additionally conducted receiver operating characteristic (ROC) analysis to identify the corneal densitometry thresholds for decreased visual function.

Results

There were significant associations between visual function and the modified Krachmer grade, CCT, AS-OCT-based grade, HOAs, intraocular straylight, and corneal densitometry. A modified Krachmer grade ≥ 3 was identified as a threshold for decreased visual function. Multivariate analysis showed that corneal densitometry was significantly associated with all visual function parameters, and HOAs were significantly associated with CDVA but not with contrast sensitivity. ROC analysis revealed that corneal densitometry of the posterior layer at 0 to 2 mm ≥ 10 grayscale units (GSU), was identified as a threshold for decreased visual function.

Conclusions

HOAs, forward and backward light scatter affected visual function, with backward light scatter being the most influential. In patients with FECD, modified Krachmer grade ≥ 3 and corneal densitometry ≥ 10 GSU were thresholds for visual disturbance.

Cornea Classic: "Grading of Corneal and Conjunctival Staining in the Context of Other Dry Eye Tests," Bron, Evans, and Smith, 2003

ABSTRACT

Dry eye is an increasingly common ocular condition with significant impact on quality of life due to eye discomfort and blurred vision complaints. In addition, the financial burden of dry eye on both patients and society is substantial. Although there has been a recent explosion of research in the field since 2002 with the approval of the first prescription topical treatment (Restasis, Allergan Inc, Irvine CA), dry eye lags behind other ophthalmic conditions where clinically meaningful outcome measures are closely tied with the metrics by which their therapeutics are evaluated. Unfortunately, current practice is such that physicians largely rely on patient symptoms to evaluate dry eye, and these do not always correlate with objective ocular surface and tear film parameters. In patients with severe dry eye, the patient-reported symptoms are likely dampened because of the neurotrophic state of the ocular surface, which accompanies any long-standing inflammatory ocular condition. Therefore, staining of the corneal and conjunctival surface using vital dyes is an invaluable dry eye test to provide information normally not visible during routine slit-lamp examination. The landmark article by Bron, Evans, and Smith published in Cornea in 2003 provides excellent guidance to clinicians to highlight and quantify ocular surface parameters in patients with dry eye. Validation studies correlating conjunctival or corneal staining with tangible quality-of-life parameters and metrics to measure those are needed to verify ocular surface staining as a clinically meaningful dry eye outcome to be used in clinical practice and clinical trials.

Association between Corneal Higher-Order Aberrations Evaluated with a Videokeratographer and Corneal Surface Abnormalities in Dry Eye

Analysis of higher-order aberrations (HOAs) is one reported method for evaluating dry eye disease (DED)-related loss of visual function. Tear film (TF) instability and corneal epithelial damage (CED) are both reportedly responsible for HOAs in DED, although, to the best of our knowledge, there are no reported methods that allow concurrent evaluation of their effects. In this study, we used a videokeratographer (VK) to continuously measure HOAs in DED after eye opening and investigated factors of ocular surface abnormalities that determine HOAs. This study involved 96 DED cases that underwent DED symptom assessment with a questionnaire and examination of tear volume, TF abnormalities (i.e., TF lipid-layer interference grades and spreading grades, and non-invasive breakup time and fluorescein breakup time), and CED, and their correlation with HOAs evaluated via VK. The results show that HOAs at 1 or 2 s after eye opening can reflect TF instability and CED within the central 4-millimeter-diameter area of the optical zone in DED eyes concurrently. This finding may be useful for the rapid and non-invasive detection and evaluation of degraded visual function in DED cases with a variety of clinical features.

Comparison of the Ocular Surface Disease Index and the Symptom Assessment in Dry Eye Questionnaires for Dry Eye Symptom Assessment

BACKGROUND

Patient-reported dry eye symptoms (DESs), assessed using the Ocular Surface Disease Index (OSDI) and the Symptom Assessment iN Dry Eye (SANDE) questionnaires, were compared in a large sample of patients.

METHODS

The correlation (Spearman coefficient) and agreement (Bland-Altman analysis) between the OSDI and SANDE questionnaire scores (with and without score normalization) were assessed in 1033 patients and classified according to the OSDI score as non-DES and DES in a cross-sectional analysis.

RESULTS

The normalized and non-normalized SANDE results were higher than the OSDI results in all samples (2.83 ± 12.40 (p = 0.063) and 2.85 ± 15.95 (p = 0.016), respectively) and in non-DES (p > 0.063) and DES (p < 0.001) with both OSDI cutoff values. Weak correlations were found (Spearman coefficient <0.53; p < 0.001) in all cases except DES (0.12, p = 0.126). Weak agreement was found with a Bland-Altman analysis of the normalized and non-normalized scores of both questionnaires (mean difference from -7.67 ± 29.17 (DES patients) to -1.33 ± 8.99 (non-DES patients) without score normalization, and from -9.21 ± 26.37 (DES patients) to -0.85 ± 4.01 (non-DES) with data normalization), with a statistically significant linear relationship (R2 > 0.32, p < 0.001). The SANDE questionnaire did not yield the same patient classification as OSDI. The same operative curves (ROC) of the SANDE normalized and non-normalized scores were used to differentiate among patients with DES using OSDI < 12 (0.836 ± 0.015) or OSDI < 22 (0.880 ± 0.015) cutoff values.

CONCLUSIONS

Normalized and non-normalized data collected from the SANDE questionnaire showed relevant differences from those of the OSDI, which suggests that the results of the SANDE visual analog scale-based questionnaire provide different patient classifications than the OSDI score.

TFOS Lifestyle: Impact of elective medications and procedures on the ocular surface

The word "elective" refers to medications and procedures undertaken by choice or with a lower grade of prioritization. Patients usually use elective medications or undergo elective procedures to treat pathologic conditions or for cosmetic enhancement, impacting their lifestyle positively and, thus, improving their quality of life. However, those interventions can affect the homeostasis of the tear film and ocular surface. Consequently, they generate signs and symptoms that could impair the patient's quality of life. This report describes the impact of elective topical and systemic medications and procedures on the ocular surface and the underlying mechanisms. Moreover, elective procedures performed for ocular diseases, cosmetic enhancement, and non-ophthalmic interventions, such as radiotherapy and bariatric surgery, are discussed. The report also evaluates significant anatomical and biological consequences of non-urgent interventions to the ocular surface, such as neuropathic and neurotrophic keratopathies. Besides that, it provides an overview of the prophylaxis and management of pathological conditions resulting from the studied interventions and suggests areas for future research. The report also contains a systematic review investigating the quality of life among people who have undergone small incision lenticule extraction (SMILE). Overall, SMILE refractive surgery seems to cause more vision disturbances than LASIK in the first month post-surgery, but less dry eye symptoms in long-term follow up.

TFOS Lifestyle: Impact of the digital environment on the ocular surface

Eye strain when performing tasks reliant on a digital environment can cause discomfort, affecting productivity and quality of life. Digital eye strain (the preferred terminology) was defined as "the development or exacerbation of recurrent ocular symptoms and/or signs related specifically to digital device screen viewing". Digital eye strain prevalence of up to 97% has been reported, due to no previously agreed definition/diagnostic criteria and limitations of current questionnaires which fail to differentiate such symptoms from those arising from non-digital tasks. Objective signs such as blink rate or critical flicker frequency changes are not 'diagnostic' of digital eye strain nor validated as sensitive. The mechanisms attributed to ocular surface disease exacerbation are mainly reduced blink rate and completeness, partial/uncorrected refractive error and/or underlying binocular vision anomalies, together with the cognitive demand of the task and differences in position, size, brightness and glare compared to an equivalent non-digital task. In general, interventions are not well established; patients experiencing digital eye strain should be provided with a full refractive correction for the appropriate working distances. Improving blinking, optimizing the work environment and encouraging regular breaks may help. Based on current, best evidence, blue-light blocking interventions do not appear to be an effective management strategy. More and larger clinical trials are needed to assess artificial tear effectiveness for relieving digital eye strain, particularly comparing different constituents; a systematic review within the report identified use of secretagogues and warm compress/humidity goggles/ambient humidifiers as promising strategies, along with nutritional supplementation (such as omega-3 fatty acid supplementation and berry extracts).

Abnormal brain function in photophobic patients with dry eye disease: An fMRI study

BACKGROUND AND OBJECTIVES

Photophobia, a frequent and disabling symptom observed in various neurological conditions and eye diseases, is thought to involve maladaptive brain functioning. We assessed this hypothesis, using functional magnetic resonance imaging (fMRI) in photophobic patients with minimal-to-severe dry eye disease (DED), as compared to healthy controls.

METHODS

This prospective, monocentric, comparative, cohort study included eleven photophobic DED patients compared to eight controls. Photophobic patients had a complete evaluation of DED to exclude any other cause of photophobia. All participants were scanned with fMRI under intermittent light stimulation with a LED lamp (27s. ON, 27 s. OFF), and cerebral activations were studied with univariate contrasts between the ON and OFF conditions, and with functional connectivity methods.

RESULTS

Firstly, stimulation activated the occipital cortex more strongly in patients than in controls. Moreover, stimulation deactivated the superior temporal cortex in patients less than in controls. Secondly, functional connectivity analysis showed that light stimulation induced lesser decoupling between the occipital cortex and the salience and visual networks in patients than in controls.

DISCUSSION

The current data shows that DED patients with photophobia have maladaptive brain anomalies. There is hyperactivity in the cortical visual system, associated with abnormal functional interactions, both within the visual cortex, and between visual areas and salience control mechanisms. Such anomalies show similarities with other conditions such as tinnitus, hyperacusis, and neuropathic pain. Those findings support novel neurally oriented methods for the care of patients with photophobia.

Contrast Sensitivity Changes after Phototherapeutic Keratectomy in Heterozygote Granular Corneal Dystrophy Type 2

Purpose: Contrast sensitivity, the ability to distinguish the relative difference in luminance of an object from its surrounding or adjacent objects, is a useful measure of visual function. In granular corneal dystrophy type 2 (GCD2), opacity of the corneal stroma causes deterioration in visual function. We compared the contrast sensitivity of GCD2 patients before and after phototherapeutic keratectomy (PTK) to evaluate the perioperative visual function in these patients.Methods: This study included 22 eyes of heterozygote GCD2 patients. The visual acuity and contrast sensitivity were measured before and after PTK. The contrast sensitivity was measured in mesopic and photopic background luminances, with glare (G) levels of 0-2 (G0, G1, and G2, respectively) and spatial frequencies at 1.5, 3, 6, 12, and 18 cycles per degree (cpd).Results: The contrast sensitivity increased after PTK at 1.5 and 3 cpd in mesopic and photopic conditions with G0-2 glare (p < 0.05). At 6 cpd, the contrast sensitivity increased in the mesopic condition with G1 glare, and in the photopic condition with G0-2 glare (p < 0.05). However, there was no change in contrast sensitivity at any glare level at 12 and 18 cpd after PTK.Conclusions: In GCD2 patients, the contrast sensitivity increased significantly after PTK. The vision of GCD2 patients, which is decreased due to corneal opacity, is improved after PTK.

Impact of Perioperative Dry Eye Treatment with Rebamipide Versus Artificial Tears on Visual Outcomes After Cataract Surgery in Japanese Population

Introduction

The present study aimed to compare the effects of rebamipide and artificial tears during the perioperative period of cataract surgery on the postoperative visual outcomes.

Methods

Seventy-two eyes from 36 patients with a cataract were enrolled. Rebamipide (group R) was administered in one eye and Mytear® artificial tear ophthalmic solution (group A) in the other eye from 4 weeks preoperatively to 3 months postoperatively. Tear breakup time (TBUT), high-order aberrations (HOAs), superficial punctate keratopathy in the central part of the cornea (C-SPK), and corrected distance visual acuity (CDVA) were assessed at baseline, 1 week, 1 month, and 3 months after cataract surgery with trifocal intraocular lens (IOL) implantation. Contrast sensitivity and disability glare with visual angle values compatible with spatial frequencies of 1.1, 1.8, 2.9, 4.5, 7.1, and 10.2 cycles/degree (CPD) were evaluated postoperatively. Between-group differences of all variables were analyzed.

Results

At baseline, no significant differences in the variables were noted between the two groups. Mean TBUT was significantly higher, while mean C-SPK and HOAs were significantly lower in group R than in group A at each assessment. Mean CDVA was significantly higher at 1 week and 1 month postoperatively in group R compared with group A; this value was not significant at 3 months. Between-group differences in contrast sensitivity and disability glare were statistically significant at all spatial frequencies, 1 week and 1 month postoperatively. At 3 months postoperatively, there were significant differences in contrast sensitivity and disability glare at most spatial frequencies.

Conclusion

Dry eye management with rebamipide in the perioperative period of cataract surgery with trifocal IOL implantation was significantly more effective than artificial tears in improving ocular surface condition, contrast sensitivity, and disability glare postoperatively.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40123-022-00523-w.

The Impact of Noncontact Tonometry and Icare Rebound Tonometry on Tear Stability and Dry Eye Clinical Practice

The purpose of this study was to investigate the possible effects of the noncontact air puff tonometry (NCT) and Icare rebound tonometry (ICT) on the tear film stability by using the tear stability analysis system (TSAS) and dry eye parameters. Fifteen eyes from fifteen normal healthy subjects were investigated in this study. All subjects underwent TSAS surface regularity index (SRI) examinations, TBUT, and IOP measurements. The mean IOP results measured with NCT were 13.3 ± 1.86 mm Hg, and the mean IOP results measured with ICT were 15.88 ± 3.09 mm Hg (p > 0.05). The mean values of baseline, 5 min, and 10 min of the NCT-SRI and ICR-SRI were tested. There were statistically significant differences between NCT-Baseline SRI, NCT-5 min SRI, and NCT-10 min SRI values (p < 0.05). SRI values significantly increased after NCT. The mean values of the baseline, 5 min, and 10 min of the ICT-SRI were also assessed. There were no statistically significant differences between ICT-Baseline SRI, ICT-5 min SRI, and ICT-10 min SRI values (p > 0.05). The mean TBUT values exhibited a significant decrease at 1 min, 5 min, and 10 min compared with baseline values for the NCT and ICT (p < 0.01). NCT-TBUT and ICT-TBUT values were also compared with each other in the same time period. There were no statistically significant differences between NCT-Baseline and ICT-Baseline TBUT values (p > 0.05). In conclusion, intraocular pressure measurements in routine ophthalmology clinical practices by either NCT or ICT cause deterioration in the tear film stability which might affect tear stability testing when performed soon after IOP measurements. It is best to wait at least for 20−30 min after the IOP measurement before evaluating the tear film and the corneal surface or perform tonometry after the tear film-ocular surface evaluation tests.

Evaluation of the association between macular damage and disability glare in patients with advanced glaucoma

PURPOSE

This study aimed to investigate the factors associated with disability glare in patients with advanced glaucoma and evaluate the impact of disability glare on the vision-related quality of life.

METHODS

We prospectively studied 225 eyes (225 patients) with advanced glaucoma. The visual function was evaluated using the 10-2 and 24-2 Humphrey visual field (VF) (Dublin, California) and contrast sensitivity test. Structural parameters were obtained using RTVue optical coherence tomography and angiography (Fremont, California). Significant loss of macular vessel density (mVD) was defined as VD < 30%. Each participant completed the National Eye Institute Visual Function Questionnaire 25 (NEI-VFQ-25) and questions regarding subjective symptoms of glare.

RESULTS

Fifty-six patients (24.9%) experienced glare and had a lower NEI-VFQ-25 composite score (P = 0.017). The average retinal nerve fiber layer and ganglion cell complex thickness and mean deviation (MD) in the 24-2 VF test were not associated with glare. Significant superior or inferior mVD loss (P < 0.001; odds ratio [OR], 3.45; and 95% confidence interval [CI], 1.83-6.55), lower logarithmic contrast sensitivity at 0.75 cycles/degree (P < 0.001; OR, 0.27; and 95% CI, 0.13-0.56), and worse MD in the 10-2 VF test (P < 0.001; OR, 0.93; and 95% CI, 0.89-0.97) showed an association with glare.

CONCLUSION

In advanced glaucoma, central VF defect and mVD loss are associated with disability glare, which negatively impacts vision-related quality of life.

Outcome Measures to Assess Dry Eye Severity: A Review

Outcome measures used to assess efficacy of dry eye therapeutics have not been consistently applied in clinical settings, nor have they been shown to correlate with functional outcomes. We propose that corneal staining, a clinically meaningful dry eye parameter, should be used as a standard objective outcome measure across all clinical trials evaluating dry eye treatments. We justify this based on evidence regarding its relationship to vision and vision related quality-of-life. In addition, corneal staining has been shown to correlate with ocular surface inflammation, a well elucidated aspect of dry eye pathophysiology and an active area in therapeutics research. No one outcome measure explored herein correlates perfectly to this heterogenous disease. However, there is mounting evidence showing the correlation between corneal staining and functional visual indices. We hope that future clinical trials will standardize corneal staining as a measure to determine the efficacy of interventions and justify their clinical utility.

Short Tear Breakup Time Could Exacerbate the Progression of Presbyopia in Women

Purpose

The contributory factors and symptoms for presbyopia progression have not been fully determined. The purpose of the study was to compare presbyopia progression in subjects with short and normal tear breakup time and to explore the severity of common ocular symptoms associated with presbyopia progression.

Method

We conducted a clinic-based, retrospective, cross-sectional study. Inclusion criteria were bilateral phakic patients aged 40–69 years with best-corrected distance visual acuity better than 20/30, and exclusion criteria were the use of glaucoma eye drops, any disease affecting vision, or history of ocular surgery. We measured the binocular near add power and compared the results using Kaplan-Meier analysis. Association between near add power and ocular symptoms was explored.

Results

There were 1411 participants (mean age of 50.1 years). There were no significant differences in age, intraocular pressure, spherical equivalent, astigmatism, or anisometropia between the sexes. Kaplan-Meier analysis indicated that women with short tear breakup time reached the endpoint (near add power of +3.00 D) significantly earlier than those with normal tear breakup time (P = 0.043; Cox-Mantel test). Eye fatigue was most severe in the group with an add power of 1.25-2.00 D. Near add power was correlated with hyperopia, astigmatic errors, and anisometropia.

Conclusions

This study suggests an exacerbation of presbyopia progression in women with short tear breakup time. Eye fatigue was most severe in those with an add power of 1.25-2.00 D.

Effects of corneal epithelial superficial keratectomy in patients with focal limbal stem cell disease

Purpose

Irregular corneal epithelium in limbal stem cell disease can cause visual acuity to deteriorate substantially when it reaches the pupil. In this case series, we assessed the effectiveness of simple corneal epithelial superficial keratectomy in improving visual acuity in patients with irregular corneal epithelium in focal limbal stem cell disease covering the visual axis.

Observations

We performed simple corneal epithelial superficial keratectomy in four patients (five eyes) with irregular corneal epithelium covering the visual axis. The main outcome measures were best-corrected visual acuity, slit lamp findings with fluorescein staining, anterior segment optical coherence tomography and histopathology. In all five eyes, slit lamp findings showed uneven fluorescein staining in a spiral pattern, with impaired corneal epithelial smoothness and visual disturbance. We removed the irregular epithelium in all five eyes. Visual acuity in all the eyes was improved immediately after surgery, and good visual acuity and stable epithelium were maintained for the duration of the observation periods. Hematoxylin and eosin staining showed, normal squamous and columnar epithelial cells. Goblet cells were not detected.

Conclusionsand Importance

Corneal epithelial superficial keratectomy can lead to a pathological diagnosis by examining the removed epithelial tissues, and result in excellent therapeutic outcomes in focal limbal stem cell disease reaching the pupil.

Glare and Mobility Performance in Glaucoma: A Pilot Study

PRCIS

Glare disability affects patients with moderate and severe glaucoma. Under glare conditions, mobility performances of glaucoma patients are reduced.

PURPOSE

The aim of this study was to evaluate glare disability and its impact on mobility and orientation in glaucoma patients.

METHODS

Twenty-two glaucoma patients and 12 age-matched control subjects were included. All patients underwent a clinical evaluation of visual function and halo size measurements to determine glare disability with a glare score (GS) of the best eye and worse eye. Mobility was evaluated by 4 mobility courses on an artificial street (StreetLab) under photopic conditions (P) and mesopic conditions with an additional light source in front of the patient to mimic dazzling conditions (M+G). Mobility time, mobility incidents, trajectory segmentation, distance traveled, preferred walking speed on trial (WS) and percentage of preferred walking speed (PPWS) were recorded, and the Nasa task load index (Nasa-TLX) was evaluated.

RESULTS

GS of the worse eye and GS of the best eye were significantly higher in glaucoma patients than in the control group (P=0.001 and 0.003). It was significantly different between moderate glaucoma patients and controls (P=0.001 and 0.010, respectively) and between severe glaucoma patients and controls (P=0.049 and 0.016). In locomotion tasks, comparing performance under M+G and P conditions, mobility performance was significantly different concerning mobility time (P=0.010), distance traveled (P=0.008), WS (P=0.007), PPWS (P=0.006), and Nasa-TLX (P=0.017) in the glaucoma group. Under M+G lighting conditions, mobility performance for glaucoma patients was significantly worse than controls with regard to WS (P=0.038), PPWS (P=0.0498), mobility time (P=0.046), and Nasa-TLX (P=0.006).

CONCLUSION

Glare disability was observed in patients with moderate and severe glaucoma and had an impact on their mobility performance.

The Effect of Diquafosol Ophthalmic Solution on Clinical Parameters and Visual Function in Soft Contact Lens-Related Dry Eye

INTRODUCTION

This study evaluated the efficacy and safety of diquafosol ophthalmic solution (DQS) in soft contact lens (SCL)-related dry eye using artificial tear as a control.

METHODS

This study enrolled 26 patients with SCL-related dry eye. DQS and artificial tears (AT) were instilled into the right and left eyes, respectively, with their SCLs on. Dry eye examinations (including tear film breakup time, tear volume, and staining score) were performed and visual function (including contrast sensitivity) was also evaluated before (at baseline) and after treatment (at 4- and 8-week examinations). Subjective symptoms were assessed separately in each eye using a questionnaire on dry eye in contact lens wearers. The results were compared before and after treatment, and between the right eyes treated with DQS (the DQS eye) and the left eyes treated with AT (the AT eye) using the mixed effect model.

RESULTS

Corneal and conjunctival staining scores at 8-week examination were significantly lower than those at baseline in the DQS eye (p = 0.03; p < 0.001, respectively), but no significant changes were observed in the AT eye. Most subjective symptoms improved significantly in both the DQS and AT eyes. However, major subjective symptoms (dryness and blurry vision) improved significantly only in the DQS eye at 8-week examination. Contrast sensitivity at 8-week examination in the DQS eye improved significantly at 12 cycles/degree compared to baseline (p = 0.001) and was significantly better than that in the AT eye (p = 0.03). There were no adverse events related to DQS or AT.

CONCLUSIONS

DQS was effective and safe for SCL-related dry eye. DQS also improved contrast sensitivity.

TRIAL REGISTRATION

University Hospital Medical Information Network Clinical Trials Registry (UMIN-CTR), Identification No. UMIN000024064.

The vision-related burden of dry eye

PURPOSE

To investigate the relationship between dry eye disease (DED) and vision-related quality of life (VR-QoL) at population level.

METHODS

DED and VR-QoL were assessed in 89,022 participants (18-96 years, 59% female) from the Dutch population-based Lifelines cohort using the Women's Health study (WHS) and Visual function 25 (VFQ25) questionnaires. The relationship between DED and compromised VR-QoL was assessed with logistic regression, corrected for age, sex, BMI, income, education, smoking, and 55 comorbidities.

RESULTS

9.1% of participants had DED. The participants with DED had higher risk of compromised average of ten domains of VR-QoL (OR 3.12 (95% CI 2.98-3.27) corrected for age, sex, BMI, income, smoking, and 55 comorbidities). Increasing symptom frequency was highly associated with decreasing VR-QoL (P < 0.0005). In all VR-QoL domains, including measures of daily visual function and emotional well-being, DED was clearly associated with compromised VR-QoL. Compared to macular degeneration, glaucoma, retinal detachment, and allergic conjunctivitis, DED presented similar or higher risks for compromised score on all VR-QoL domains. The population-attributable fraction of DED for compromised general vision exceeded that of other eye diseases investigated, especially in the younger age groups.

CONCLUSION

DED is associated with reductions in all domains of VR-QoL, also after correction for associated comorbidities. We found that DED imposes an extensive population burden regarding compromised VR-QoL due to its high prevalence and substantial impact on VR-QoL, higher than that for other common vision-affecting eye disorders. Our results emphasize the importance of recognizing DED as a serious disorder from both patient and public health perspectives.

Optical quality in patients with dry eye before and after treatment

CLINICAL RELEVANCE

Dry eye disease could result in vision-related subjective symptoms even in patients with good best-corrected visual acuity. The standard deviation of corneal power and the surface asymmetry index could be indicators of treatment efficacy in dry eye.

BACKGROUND

Few studies have examined changes in optical quality before and after dry eye treatment. Here, we evaluated changes in optical quality in patients with dry eye before and after treatment and identified potential indicators of dry eye-treatment efficacy.

METHODS

Twenty-five right eyes of 25 untreated patients with dry eye were included. The same ocular-surface and optical-quality examinations were performed before and after two-weeks of treatment with hyaluronate in conjunction with fluorometholone eye drops. The Ocular Surface Disease Index, tear film break-up time, and corneal fluorescein staining were measured. Contrast sensitivity was used to measure resolution capability, the double-pass Optical Quality Analysis System to examine the modulation transfer function, Strehl ratio, and objective scattering index, and OPD Scan III to measure anterior corneal aberrations over 4-mm analytical zones including total corneal and high-order aberrations. The standard deviation of corneal power, surface regularity index, and surface asymmetry index were also measured. Paired sample t-tests and Spearman's correlations were used for the analyses.

RESULTS

The Ocular Surface Disease Index, tear film break-up time, and corneal fluorescein staining improved after two weeks of treatment. Contrast sensitivity in photopic, photopic with glare, scotopic, and scotopic with glare conditions all improved (p < 0.05), as did the modulation transfer function, Strehl ratio, and objective scattering index (p = 0.001, p = 0.008, and p = 0.001, respectively). Total corneal aberrations and the surface regularity index did not significantly differ before and after treatment; corneal high-order aberrations, standard deviation of corneal power, and the surface asymmetry index significantly improved after treatment (p = 0.045, p = 0.019, and p = 0.049, respectively). Changes in standard deviation of corneal power and in surface asymmetry index correlated with change in corneal fluorescein staining (p = 0.006 and p = 0.007, respectively).

CONCLUSION

Optical quality in patients with dry eye improved after treatment. The standard deviation of corneal power and surface asymmetry index could be indicators of treatment efficacy in dry eye.

Intraocular Scattering, Blinking Rate, and Tear Film Osmolarity After Exposure to Environmental Stress

Purpose

Dry environments, such as those in offices or aircraft cabins, can potentially generate ocular discomfort and alter the tear film. We compare light scatter, blinking rate, and tear osmolarity in young and older subjects after exposure to low humidity using a controlled environmental chamber.

Methods

Two groups of healthy subjects were recruited; younger (N = 13, 27 ± 6 years) and older (N = 23, 71 ± 7 years). Measurements were carried out before and after 90-minute exposure to low relative humidity (5%) and constant temperature (23 degrees). Ocular light scatter was measured using a double-pass instrument (OQAS, Visiometrics, Spain). Blinking rate was monitored using an infrared video camera. Tear osmolarity was measured using the TearLab system (Escondido, CA, USA).

Results

Ocular light scatter increased by a factor of 10% after exposure to low humidity in the older group (P = 0.03) but did not change significantly in the younger group. Blinking rate increased significantly (40% more blinks) in both groups but there was no difference between the groups. No significant differences in osmolarity were shown between two age groups or as result of environmental stress.

Conclusions

Exposure to dry environment increased light scatter in older subjects. Although more blinks were triggered in both younger and older groups to prevent corneal dehydration, there was no difference between the groups. Blink rate and osmolarity are not associated with the difference in light scatter.

Translational Relevance

Our work approaches a clinical care problem using basic research methods (measuring ocular scatter and blink ratio).

The negative effects of dry eye disease on quality of life and visual function

In recent years, dry eye has become a hot topic within ophthalmology and optometry, especially in regards to new frontiers in treatment modalities which include novel devices, procedures, and medications. However, some of the more understudied areas in dry eye involve its impact on quality of life. Although ocular discomfort symptoms are well known to be associated with dry eye, its negative effects on visual function remain underrecognized. This paper reviews these topics within the currently published literature to heighten awareness among clinicians. Key Words: D ry eye, quality of life, visual function, functional visual acuity, patient questionnaire, OSDI, SPEED, SANDE, IDEEL, NEI VFQ-25

Improvement in Contrast Sensitivity Function after Lacrimal Passage Intubation in Eyes with Epiphora

This prospective case series aimed to investigate the contrast sensitivity function before and after lacrimal passage intubation (LPI) in eyes with epiphora due to lacrimal passage obstruction. We included 58 eyes of 51 patients who underwent LPI for lacrimal passage obstruction. The best-corrected visual acuity (BCVA), contrast sensitivity function, and lower tear meniscus were compared before LPI and one month after lacrimal duct stent removal. The area under the log contrast sensitivity function (AULCSF) was calculated for the analyses. Lower tear meniscus was assessed using anterior segment optical coherence tomography. The BCVA was comparable (p = 0.61) before and after LPI, while AULCSF increased significantly after treatment (before LPI: 1.29 ± 0.17, after LPI: 1.37 ± 0.14, p < 0.0001). Treatment resulted in a significant increase in contrast sensitivity at all spatial frequencies, 3–18 cycles/degree (p < 0.01 for 3, p < 0.01 for 6, p < 0.0005 for 12, p < 0.05 for 18 cycles/degree). The lower tear meniscus parameters improved significantly after treatment (p < 0.005); however, no correlation between the changes in the tear meniscus and those of the AULCSF was found. The contrast sensitivity significantly improved after LPI in eyes with epiphora due to lacrimal passage obstruction.

Deterioration of contrast sensitivity in eyes with epiphora due to lacrimal passage obstruction

Purpose

Epiphora causes deterioration in contrast sensitivity in some eye diseases. This study was conducted to investigate contrast sensitivity in eyes with epiphora caused by lacrimal passage obstruction.

Methods

This single-center, prospective case series enrolled 57 patients with unilateral lacrimal passage obstruction. The best-corrected visual acuity (BCVA), contrast sensitivity function, and lower tear meniscus of the affected and contralateral unaffected eyes were compared. The area under the log contrast sensitivity function (AULCSF) was calculated.

Results

The BCVA did not significantly differ between the affected and contralateral eyes, while the AULCSF was significantly lower in the affected eyes than that in the contralateral eyes (median 1.35, interquartile range 1.22–1.44 vs. median 1.36, interquartile range 1.28–1.46, P = 0.032). Lower tear meniscus parameters were significantly higher in the affected eyes than those in the contralateral eyes (P < 0.005).

Conclusions

The contrast sensitivity function is significantly diminished in eyes with epiphora caused by lacrimal passage obstruction.

Impact of posterior vitreous detachment on contrast sensitivity in patients with multifocal intraocular lens

PURPOSE

To investigate posterior vitreous detachment (PVD) and pars plana vitrectomy (PPV) effects on contrast sensitivity function (CSF) in patients with a multifocal intraocular lens (MfIOL).

METHODS

This single-center prospective case-control study analyzed 27 patients with 43 consecutive eyes. Twenty patients with 36 consecutive eyes received MfIOL implantation with either ZLB00 or ZMB00. CSF was measured as the area under the log contrast sensitivity function (AULCSF) in the presence and absence of PVD (PVD+ group and PVD- group, respectively). Seven eyes associated with a symptomatic PVD and severe visual dissatisfaction after MfIOL implantation underwent PPV (symptomatic PVD+ group). CSF was measured prior to and after PPV.

RESULTS

The mean AULCSF was significantly lower in the PVD+ group (1.5 ± 0.1) versus the PVD- group (1.7 ± 0.1, p < 0.0001). Major complaints in the symptomatic PVD+ group included floaters (n = 2) and blurry vision (n = 5). The preoperative AULCSF (1.4 ± 0.1) was significantly lower in the symptomatic PVD+ group versus the PVD- group (p < 0.0001) and PVD+ group (p = 0.02). The preoperative AULCSF in the symptomatic PVD+ group was significantly improved after PPV (1.4 vs. 1.7, respectively, p = 0.002).

CONCLUSIONS

PVD significantly decreased CSF in patients with MfIOL. Patients with symptomatic PVD exhibited the greatest decrease in CSF, which was significantly improved after PPV. Measurement of CSF and careful assessment of PVD may be useful in determining the appropriateness of surgical intervention for improving visual performance and satisfaction in MfIOL patients with symptomatic PVD.

Protective effect of high-affinity liposomes encapsulating astaxanthin against corneal disorder in the in vivo rat dry eye disease model

Oxidative stress induced by decreases in tear volume and excessive tear evaporation is a key factor in dry eye disease (DED). Previously, we reported that desiccation stress induces reactive oxygen species generation and up-regulated expression of age-related markers such as p53, p21 and p16. We also showed that the antioxidant astaxanthin prepared as a liposomal formulation could suppress these phenomena in the in vitro DED model. In this study, we evaluated the protective effect of liposomes encapsulating astaxanthin against superficial punctate keratopathy (SPK) in the in vivo rat DED model. This model of DED was characterized by decreased tear volume and increased fluorescein score as an indicator of SPK as well as upregulated expression of age-related markers. Repeat-dose of liposomal astaxanthin prevented increases in the fluorescein score and up-regulation of age-related markers. Liposomes bearing a slight positive surface charge had superior effects and higher affinity compared to neutral liposomes. Furthermore, fluorescence intensities in rat corneal epithelium after administration of high-affinity liposomes labeled with fluorescent dye were higher than those for neutral liposomes. In conclusion, we developed the high-affinity liposomal formulation that can prevent DED and promote antioxidative effects of astaxanthin.

Impact of Dry Eye on Visual Acuity and Contrast Sensitivity: Dry Eye Assessment and Management Study

SIGNIFICANCE

Identification of the association of specific signs of dry eye disease with specific visual function deficits may allow for more targeted approaches to treatment.

PURPOSE

The purpose of this study was to explore the association of dry eye signs and symptoms with visual acuity (VA) and contrast sensitivity in the Dry Eye Assessment and Management study.

METHODS

Baseline data from participants in the Dry Eye Assessment and Management study were used in this secondary cross-sectional analysis. Standardized procedures were used to obtain results on the Ocular Surface Disease Index (OSDI), high-contrast logMAR VA, contrast sensitivity, tear film debris, tear breakup time (TBUT), corneal fluorescein staining, meibomian gland evaluation, conjunctival lissamine green staining, and Schirmer test scores. Generalized linear models that included age, refractive error status, and cataract status were used to assess the association between VA and contrast sensitivity with OSDI score and each dry eye sign. The Hochberg procedure was used to account for multiple comparisons.

RESULTS

Among 487 participants (974 eyes), worse VA was associated with worse mean score on the OSDI vision subscale (39.4 for VA 20/32 or worse vs. 32.4 for VA 20/16 or better; adjusted linear trend, P = .02); scores were not associated with contrast sensitivity. Severe meibomian gland plugging and abnormal secretions were associated with worse mean log contrast sensitivity (1.48 for severe vs. 1.54 for not plugged [P = .04] and 1.49 for obstructed vs. 1.57 for clear [P = .002], respectively). Longer TBUT was associated with better mean log contrast sensitivity (1.57 for TBUT >5 seconds and 1.51 for TBUT ≤2 seconds, P < .0001).

CONCLUSIONS

Worse VA rather than worse contrast sensitivity drives vision-related symptoms in dry eye. Greater tear film instability was associated with worse contrast sensitivity.

Quantitative evaluation of visual function in patients with cornea verticillata associated with Fabry disease

PURPOSE

To evaluate the visual function of patients with cornea verticillata associated with Fabry disease through quantitative evaluations of contrast sensitivity function and straylight.

METHODS

We enrolled 28 eyes of 14 patients with Fabry disease (mean age, 37.1 ± 17.2  years) and 20 eyes of 20 age-matched healthy controls. Comprehensive ophthalmological examinations were performed and contrast sensitivity and letter contrast sensitivity were measured for all patients, following which the area under the log contrast sensitivity function (AULCSF) was calculated. Straylight was quantified using a straylight metre. Furthermore, subgroup analysis was performed according to the whorl-like pattern of cornea verticillata (mild and typical groups).

RESULTS

All 28 eyes showed cornea verticillata. Visual acuity and letter contrast sensitivity values were the same for normal eyes and those with Fabry disease. AULCSF differed by 0.15 log[s] between the eyes with Fabry disease and the control eyes (p < 0.001), while straylight differed by 0.45 log[s] between the two groups (p < 0.001). Subgroup analysis based on the whorl-like pattern of cornea verticillata showed that AULCSF and straylight differed by 0.11 log[s] and 0.08 log[s], respectively, between the typical and mild groups (p = 0.036 and p = 0.147, respectively).

CONCLUSION

Although cornea verticillata associated with Fabry disease does not affect the visual acuity and letter contrast sensitivity, more comprehensive testing of visual function by the inclusion of straylight and grating contrast sensitivity measurements shows clear functional deficits in these patients.

New approaches for diagnosis of dry eye disease

We reviewed the literature for different diagnostic approaches for dry eye disease (DED) including the most recent advances, contradictions and promising diagnostic tools and technique. We performed a broad literature search for articles discussing different methods for diagnosis of DED including assessment of tear osmolarity, tear film stability, ocular biomarkers and others. Articles indexed in PubMed and google scholar were included. With the growing cosmetic industry, environmental pollution, and booming of digital screens, DED is becoming more prevalent. Its multifactorial etiology renders the diagnosis challenging and invites the emergence of new diagnostic tools and tests. Diagnostic tools can be classified, based on the parameter they measure, into tear film osmolarity, functional visual acuity, tear volume, tear turnover, tear film stability, tear film composition, ocular biomarkers and others. Although numerous methods exist, the most accurate diagnosis can be reached through combining the results of more than one test. Many reported tests have shown potential as diagnostic/screening tools, however, require more research to prove their diagnostic power, alone or in combination. Future research should focus on identifying and measuring parameters that are the most specific to DED diagnosis.

Assessment of tear film optical quality in a young short tear break-up time dry eye: Case-control study

BACKGROUND

The aim of the study was to evaluate the dynamic changes of tear film optical quality in a short tear break-up time (TBUT) dry eye by using a double-pass system.

METHODS

Thirty-five short TBUT dry eye participants and 43 control subjects without dry eye were included in this study. One eye for each subject was analyzed. The Objective Scatter Index (OSI), modulation transfer function (MTF), and strehl ratio (SR) were recorded within a 20-second period with the participants asked to blink freely, and 10 successive seconds of nonblinking immediately after a blink was recorded to analyze the tear film OSI. The mean tear film OSI in 10 successive seconds, ΔOSI, and ΔOSI/time were evaluated. The correlation between tear film OSI and MTF, and the correlation between tear film OSI and MIT were also analysed.

RESULTS

Short TBUT dry eye participants showed significant deterioration of MTF and SR compared to control subjects. The mean tear film OSI in 10 successive seconds was significantly higher in dry eye participants than in control subjects. The mean OSI of the tear film (0-5 seconds) and the mean OSI of the tear film (6-10 seconds) were significantly higher in dry eye participants than in control participants. Moreover, the ΔOSI was significantly higher in dry eye participants than in control participants. The tear film OSI was significantly correlated with the MTF and the SR.

CONCLUSIONS

The tear film OSI of short TBUT dry eye participants is significantly increased in the early stage. Tear film instability in short TBUT dry eye participants has a significant effect on optical quality.

Fourier Analysis of Corneal Irregular Astigmatism Due to the Anterior Corneal Surface in Dry Eye

OBJECTIVES

To evaluate corneal irregular astigmatism due to the anterior corneal surface using Fourier harmonic analysis with a Placido ring-based corneal topographer (Placido-based topographer) and three-dimensional anterior segment optical coherence tomography (OCT) in dry eyes.

METHODS

Forty-four eyes of 44 subjects with dry eye and 20 eyes of 20 normal control subjects were enrolled. Corneal topographic data were obtained using a Placido-based topographer and OCT. Dioptric data from the central 3-mm zone of the anterior corneal surface were decomposed using Fourier harmonic analysis. Spherical, regular astigmatism, and irregular astigmatism (asymmetry and higher-order irregularity) refractive error components of the cornea from the two imaging modalities were compared.

RESULTS

Both asymmetry and higher-order irregularity values were significantly greater in dry eyes than in control eyes for both the Placido-based topographer and OCT measurements (all P<0.05). In dry eyes, measured values of asymmetry and higher-order irregularities were significantly smaller when obtained with OCT than with the Placido-based topographer (both P<0.001). By contrast, these parameters were not significantly different between the two devices in control eyes. In dry eyes, severity of superficial punctate keratopathy in the central corneal region was correlated with irregular astigmatism.

CONCLUSIONS

The amount of corneal irregular astigmatism, quantified using Fourier harmonic analysis, was significantly higher in dry eyes than in normal eyes. Measurements obtained with OCT and the Placido-based topographer differed in subjects with dry eyes. Therefore, caution should be practiced when trying to use these measurements interchangeably.

Posterior capsular opacification comparison between morphology and objective visual function

BACKGROUND

To compare the influence of posterior capsule opacification (PCO) morphology and severity on intraocular stray light and visual function with different levels of contrast.

METHODS

Forty-five patients diagnosed with PCO were included in this prospective consecutive case series. The Optical Quality Analysis System II (OQAS II) was adopted to assess the objective visual function including objective scatter index (OSI) and optical quality analysis system values (OVs) with 100, 20, and 9% contrast. RTVue-100 OCT was used to evaluate the PCO morphology and severity. Comparisons among visual function, morphology, and severity between pear type and fibrosis PCO were performed. The correlations among the PCO morphology, severity, OSI, and OVs were also determined.

RESULTS

There was a significant correlation between increased OSI and decreased visual acuity in PCO patients before laser capsulotomy. The changes of OSI were also correlated with the PCO area for the 3 mm IOL optic region (r = 0.43, p = 0.02). The OSI was significantly higher in pear type PCO when compared with fibrosis PCO (Z = - 4.06, p ≤ 0.001). In addition, the increased OSI in pear type PCO was significantly correlated with the 100% OVs and the 20% OVs but not with the 9% OVs. In fibrosis PCO, OSI was only correlated with the 100% OVs and the 20% OVs pre-YAG.

CONCLUSIONS

OSI and OVs could objectively indicate the visual function impairment in PCO patients. Effects of PCO on light scattering and on objective visual function might be explained by the variations of morphology and severity.

Association between dry eye symptoms and signs

Purpose

To evaluate the association between subjective dry eye symptoms and the results of the clinical examinations.

Methods

The study was a clinical-based survey involving 215 first-year students selected consecutively during a regular ocular health examination at the University of Cape Coast Optometry Clinic. The data collection process spanned for a period of four months. Out of the 215 students, 212 returned their completed questionnaires and were subsequently included in the study. Dry eye tests including meibomian gland assessment, tear break up time, fluorescein staining, Schirmer test, and blink rate assessment, were performed on each subject after completion of the Ocular Surface Disease Index (OSDI) questionnaire. Shapiro–Wilk test was used to determine the normality of the clinical tests, and Spearman's correlations co-efficient was used to determine the correlations between the clinical test results and dry eye symptoms.

Results

Statistically significant associations were found between OSDI scores and blink rate (r_s = 0.140; P < 0.042), and associations between OSDI scores and contrast sensitivity scores (r_s = 0.263; P < 0001). However, the results of corneal staining (r_s = −0.006; P < 0.926), Schirmer test (r_s = −0.033; P = 0.628), tear break up time (r_s = −0.121; P < 0.078), meibomian gland expressibility (r_s = 0.093; P < 0.180), and meibomian gland quality (r_s = 0.080; P < 0.244) showed no significant association with OSDI. The correlation coefficients range from −0.006 to 0.263 showed low to moderate correlation between dry eye symptoms and the results of clinical test.

Conclusion

Associations between dry eye symptoms and clinical examinations are low and inconsistent, which may have implications for the diagnoses and treatment of dry eye disease.

Effects of tear film dynamics on quality of vision

The precorneal tear film is maintained by blinking and exhibits different phases in the tear cycle. The tear film serves as the most anterior surface of the eye and plays an important role as a first refractive component of the eye. Alterations in tear film dynamics may cause both vision-related and ocular surface-related symptoms. Although the optical quality associated with the tear film dynamics previously received little attention, objective measurements of optical quality using wavefront sensors have enabled us to quantify optical aberrations induced by the tear film. This has provided an objective method for assessing reduced optical quality in dry eye; thus, visual disturbances were included in the definition of dry eye disease in the 2007 Dry Eye Workshop report. In addition, sequential measurements of wavefront aberrations have provided us with valuable insights into the dynamic optical changes associated with tear film dynamics. This review will focus on the current knowledge of the mechanisms of wavefront variations that are caused by different aspects of tear film dynamics: specifically, quality, quantity and properties of the tear film, demonstrating the respective effects of dry eye, epiphora and instillation of eye drops on the quality of vision.

Clinical features and visual function in a patient with Fish-eye disease: Quantitative measurements and optical coherence tomography

Purpose

We describe a case of fish-eye disease (FED) where the clinical features and visual function were investigated using anterior segment optical coherence tomography (OCT) and quantitative measurements.

Observations

A 36-year-old Japanese woman with FED presented with bilateral corneal opacities and visual complaints. Both contrast sensitivity and straylight were measured and OCT imaging was performed. Contrast sensitivity and straylight measurements revealed remarkably decreased visual function, despite good visual acuity. OCT demonstrated homogenously hyper-reflective corneal opacification, and a normal total corneal thickness.

Conclusions and Importance

The findings from this case suggest that OCT is useful for analyzing the clinical features of FED, and that the quantitative measurement of visual function furthers the understanding of vision-related symptoms in FED, despite good visual acuity.