Poor illumination, VDTs, and desiccated eyes

A survey on the degree of eye discomfort caused by video terminal use among college students in different altitudes

OBJECTIVE

To analyze the risk factors associated with different levels of eye discomfort due to video terminal use among college students at different altitudes.

METHODS

This cross-sectional study was conducted to assess the prevalence and extent of eye discomfort by distributing an questionnaire to university students via the Internet. To analyze the causes and risk factors of eye discomfort among college students at different altitudes after using video terminals.

RESULTS

A total of 647 participants who met the criteria were included in this survey, of whom 292 (45.1%) were males and 355 (54.9%) were females. The results of the survey showed 194 (30.0%) participants without eye discomfort and 453 (70.0%) participants with eye discomfort. The results of the univariate comparison of the degree of eye discomfort in the study subjects with different characteristics showed that the differences in the degree of eye discomfort were statistically significant (P < 0.05) for the 7 groups of indicators: gender, region, wearing corneal contact lenses for more than 2 h per day, frequent use of eye drops, sleep time, total time of VDT use per day, and total time per VDT use, while the remaining indicators, including age, profession, and whether refractive surgery or other eye surgery was performed, whether frame glasses were worn for a long time, and duration of daily mask wear were not statistically significant. The results of multi-factor logistic analysis of the degree of eye discomfort in the study subjects with different characteristics showed that gender, region, frequent use of eye drops, sleep time, and total time of VDT use per day were the risk factors affecting the degree of eye discomfort.

CONCLUSIONS

Female, high altitude, frequent use of eye drops, shorter daily sleep duration and longer daily VDT use were associated risk factors for the development of severe eye discomfort, where the severity of eye discomfort was significantly negatively correlated with increased sleep duration and significantly positively correlated with increased total time of VDT use.

Review on the possible pathophysiological mechanisms underlying visual display terminal-associated dry eye disease

BACKGROUND

Visual display terminal (VDT) use is a key risk factor for dry eye disease (DED). Visual display terminal (VDT) use reduces the blink rate and increases the number of incomplete blinks. However, the exact mechanisms causing DED development from VDT use have yet to be clearly described.

PURPOSE

The purpose of the study was to conduct a review on pathophysiological mechanisms promoting VDT-associated DED.

METHODS

A PubMed search of the literature investigating the relationship between dry eye and VDT was performed, and relevance to pathophysiology of DED was evaluated.

FINDINGS

Fifty-five articles met the inclusion criteria. Several pathophysiological mechanisms were examined, and multiple hypotheses were extracted from the articles. Visual display terminal (VDT) use causes DED mainly through impaired blinking patterns. Changes in parasympathetic signalling and increased exposure to blue light, which could disrupt ocular homeostasis, were proposed in some studies but lack sufficient scientific support. Together, these changes may lead to a reduced function of the tear film, lacrimal gland, goblet cells and meibomian glands, all contributing to DED development.

CONCLUSION

Visual display terminal (VDT) use appears to induce DED through both direct and indirect routes. Decreased blink rates and increased incomplete blinks increase the exposed ocular evaporative area and inhibit lipid distribution from meibomian glands. Although not adequately investigated, changes in parasympathetic signalling may impair lacrimal gland and goblet cell function, promoting tear film instability. More studies are needed to better target and improve the treatment and prevention of VDT-associated DED.

A New Perspective on Dry Eye Classification: Proposal by the Asia Dry Eye Society

The 2017 consensus report of the Asia Dry Eye Society (ADES) on the definition and diagnosis of dry eyes described dry eye disease as "Dry eye is a multifactorial disease characterized by unstable tear film causing a variety of symptoms and/or visual impairment, potentially accompanied by ocular surface damage." The report emphasized the instability of tear film and the importance of visual dysfunction in association with dry eyes, highlighting the importance of the evaluation of tear film stability. This report also discussed the concept of tear film-oriented therapy, which stemmed from the definition, and which is centered on provision of insufficient components in each tear film layer and ocular surface epithelium. The current ADES report proposes a simple classification of dry eyes based on the concept of tear film-oriented diagnosis and suggests that there are three types of dry eye: aqueous-deficient, decreased wettability, and increased evaporation. It is suggested that these three types respectively coincide with the problems of each layer: aqueous, membrane-associated mucins, and lipid/secretory mucin. Although each component cannot be quantitatively evaluated with the current technology, a practical diagnosis based on the patterns of fluorescein breakup is recommended. The Asia Dry Eye Society classification report suggests that for a practical use of the definition, diagnostic criteria and classification system should be integrated and be simple to use. The classification system proposed by ADES is a straightforward tool and simple to use, only through use of fluorescein, which is available even to non-dry eye specialists, and which is believed to contribute to an effective diagnosis and treatment of dry eyes.

Effects of MaquiBright® on improving eye dryness and fatigue in humans: A randomized, double-blind, placebo-controlled trial

This study aims to investigate the effects of MaquiBright^®, also known as BrightSight^®, a standardized maqui berry extract, on improving eye dryness and fatigue in Japanese subjects (aged 30–60 years) experiencing eye dryness, eye fatigue, and ≥4 h of visual display terminal (VDT) work daily. Seventy-four participants were equally but randomly assigned to either a MaquiBright^® (MB) or a placebo (P) group, wherein each participant consumed one capsule daily for 4 weeks of the appropriate treatment (MaquiBright^® 60 or 0 mg). Eye dryness and fatigue were measured using the Schirmer's test, tear break-up time (BUT) test, pupillary response, and flicker test before intake and 4 weeks after intake. Furthermore, subjective symptoms were assessed using the Visual Analogue Scale (VAS) method and the Dry Eye–related Quality of Life Score (DEQS) questionnaire. The MB group demonstrated a significantly higher lacrimal fluid production in both eyes (increased 6.4 ± 8.1 mm, P = 0.005) in Schirmer's test compared to the P group before VDT load (playing a video game) at 4 weeks after intake. In the VAS method after VDT load, the reduction of subjective symptoms in eye fatigue (P = 0.047) and stiff shoulders (P = 0.035) were significantly higher in the MB group than in the P group as well as bothersome ocular symptoms (P = 0.037) by the DEQS. No adverse events were reported. Thus, the consumption of 60 mg of MaquiBright^® per day for 4 weeks reduced eye dryness and seemed to alleviate eye fatigue.

Accumulation of secretory vesicles in the lacrimal gland epithelia is related to non-Sjögren's type dry eye in visual display terminal users

Previous observations in a rat model of a non-Sjögren's syndrome (non-SS) type of dry eye seen in users of visual display terminals (VDT) indicated that secretory vesicle (SV) accumulation in the lacrimal gland epithelia contributes to the condition. Here, to examine this possibility in humans, we compared the lacrimal gland histology and percent SV area in the cytoplasm of acinar epithelial cells using light microscopy and transmission electron microscopy, in patients with VDT work-related non-SS dry-eye (VDT group), SS-induced dry-eye, and autopsied normal controls. In addition, the VAMP8 (vesicle-associated membrane protein 8, an exocrine-pathway molecule) and Rab3D (mature vesicle marker) were histochemically examined in lacrimal gland tissue sections. The lacrimal gland acini were larger in the VDT group than in the SS group, and the percent SV area was significantly higher in the VDT group than in the normal controls (P = 0.021) or SS group (P = 0.004). Immunostaining revealed abnormal distributions of VAMP8 in the VDT and SS groups. Rab3D was more strongly expressed in the cytoplasm of acinar epithelial cells in the VDT group than in that of normal controls. The duration of VDT use was significantly longer in the VDT group than in the other groups. These findings suggest that excessive SV accumulation in the acinar epithelia may contribute to the reduced tear secretion in VDT users.

Antioxidative and aldose reductase-inhibitory effects of a fermentation filtrate of Rubus coreanus

Antioxidative and aldose reductase (AR)-inhibitory effects of a fermentation filtrate of Rubus coreanus (FRC) were investigated using corneal/retinal homogenate and lens cytosol, respectively. Rat corneal/retinal homogenate was treated with 50 µM FeCl₃ in the presence of FRC (3.2-100 µg/mL) for 30 min at 37℃, and thiobarbituric acid-reactive substances (TBARS) was quantified as a lipid peroxidation parameter. FRC markedly suppressed the TBARS production in a concentration-dependent manner, leading to 50% (IC₅₀) and 100% (IC₁₀₀) inhibitory concentrations of 20 and 95 µg/mL, respectively, which was similar to the effect of butylated hydroxyanisole. Activity of AR from rat lens was assayed in the presence of FRC (1-31.6 µg/mL) at 25℃ using glyceraldehyde as a substrate. FRC inhibited lens AR by 50% (IC₅₀) and 90% (IC₉₀) at approximately 2 and 31.6 µg/mL, respectively, comparable to the effect of quercetin. The results indicate that ERC could be a promising candidate for the improvement of eye injury and visual dysfunction of dry eye and diabetic patients.

Lacrimal hypofunction as a new mechanism of dry eye in visual display terminal users

Background

Dry eye has shown a marked increase due to visual display terminal (VDT) use. It remains unclear whether reduced blinking while focusing can have a direct deleterious impact on the lacrimal gland function. To address this issue that potentially affects the life quality, we conducted a large-scale epidemiological study of VDT users and an animal study.

Methodology/Principal Findings

Cross sectional survey carried out in Japan. A total of 1025 office workers who use VDT were enrolled. The association between VDT work duration and changes in tear film status, precorneal tear stability, lipid layer status and tear secretion were analyzed. For the animal model study, the rat VDT user model, placing rats onto a balance swing in combination with exposure to an evaporative environment was used to analyze lacrimal gland function. There was no positive relationship between VDT working duration and change in tear film stability and lipid layer status. The odds ratio for decrease in Schirmer score, index of tear secretion, were significantly increased with VDT working year (P = 0.012) and time (P = 0.005). The rat VDT user model, showed chronic reduction of tear secretion and was accompanied by an impairment of the lacrimal gland function and morphology. This dysfunction was recovered when rats were moved to resting conditions without the swing.

Conclusions/Significance

These data suggest that lacrimal gland hypofunction is associated with VDT use and may be a critical mechanism for VDT-associated dry eye. We believe this to be the first mechanistic link to the pathogenesis of dry eye in office workers.

"Healthy" eye in office-like environments

Eye irritation symptoms, e.g. dry eyes, are common and abundant symptoms reported in office-like environments, e.g. aircraft cabins. To improve the understanding of indoor related eye symptomatology, relevant knowledge from the ophthalmological and indoor environmental science literature has been merged. A number of environmental (relative humidity, temperature, draft), occupational (e.g. visual display unit work), and individual (e.g. gender, use of cosmetics, and medication) risk factors have been identified, which are associated with alteration of the precorneal tear film (PTF); these factors may subsequently exacerbate development of eye irritation symptoms by desiccation. Low relative humidity including reduced atmospheric pressure further increases the water evaporation from an altered PTF; in addition, work with visual display units may destabilize the PTF by lower eye blink frequency and larger ocular surface. Results from epidemiological and clinical studies support that relative humidity >40% is beneficial for the PTF. Only few pollutants reach high enough indoor concentrations to cause sensory irritation of the eyes, while an altered PTF may exacerbate their sensory effect. Sustained low relative humidity causes impairment of the PTF, while its stability, including work performance, is retained by low gaze and intermittent breaks.

The dichotomy of relative humidity on indoor air quality

Dry and irritated mucous membranes of the eyes and airways are common symptoms reported in office-like environments. Earlier studies suggested that indoor pollutants were responsible. We have re-evaluated, by review of the literature, how low relative humidity (RH) may influence the immediately perceived indoor air quality (IAQ), including odour, and cause irritation symptoms (i.e. longer-term perceived IAQ). "Relative humidity" were searched in major databases, and combined with: air quality, cabin air, dry eyes, formaldehyde, inflammation, mucous membranes, offices, ozone, pungency, sensory irritation, particles, precorneal tear film, sick building syndrome, stuffy air, and VOCs. The impact of RH on the immediately and longer-term perceived IAQ by VOCs, ozone, and particles is complex, because both the thermodynamic condition and the emission characteristics of building materials are influenced. Epidemiological, clinical, and human exposure studies indicate that low RH plays a role in the increase of reporting eye irritation symptoms and alteration of the precorneal tear film. These effects may be exacerbated during visual display unit work. The recommendation that IAQ should be "dry and cool" may be useful for evaluation of the immediately perceived IAQ in material emission testing, but should be considered cautiously about the development of irritation symptoms in eyes and upper airways during a workday. Studies indicate that RH about 40% is better for the eyes and upper airways than levels below 30%. The optimal RH may differ for the eyes and the airways regarding desiccation of the mucous membranes.

Successful tear lipid layer treatment for refractory dry eye in office workers by low-dose lipid application on the full-length eyelid margin

PURPOSE

To test tear lipid layer treatment by low-dose lipid application on the full-length eyelid margin for the treatment of office workers with dry eyes refractory to conventional treatments.

DESIGN

Prospective interventional case series.

METHODS

Thirty eyes of 30 office workers with dry eyes with dark tear interference images, which did not respond to conventional treatments, were included. To supply lipid using a commercially available nonpreserved topical medication having both polar and nonpolar lipid base, ofloxacin eye ointment (Santen Pharmaceutical, Osaka, Japan) was selected. Low-dose ofloxacin ointment application on the full-length eyelid margin was carried out three times a day for two weeks. The symptom of ocular dryness using a visual analog scale, tear interferometry to assess lipid layer thickness (LLT), corneal fluorescein staining, tear-film breakup time (BUT), and meibum expressibility gradings were compared.

RESULTS

After the treatment, the symptom score of ocular dryness decreased from 91.4 +/- 11.9 to 33.6 +/- 21.0 (P < .0001), LLT increased from 39 +/- 4 nm to 161 +/- 91 nm (P < .0001), BUT was prolonged from 2.6 +/- 1.6 seconds to 4.8 +/- 2.1 seconds (P = .01), and meibum expressibility gradings decreased from 2.8 +/- 1.3 to 1.6 +/- 1.3 (P = .0005).

CONCLUSION

For office workers with refractory dry eyes, tear lipid layer treatment by low-dose ointment applied on the full-length eyelid margin was shown to be an effective approach. The applied lipid formed a uniform lipid layer, which contributed to tear stability, leading to the improvement of the symptom.

The Effect of Antireflection Film Use on Blink Rate and Asthenopic Symptoms during Visual Display Terminal Work

PURPOSE

To investigate the effect of visual display terminal antireflection (AR) films on blink rate and subjective symptoms of asthenopia.

METHODS

This was a nonrandomized, prospective clinical trial in which 7 healthy volunteers underwent blink rate measurements with a blink rate recording system while viewing a DVD on a computer display for 10 minutes. The measurements were carried out without an AR film on terminal displays initially. The same tasks were performed on the next day with an AR film on the displays. The subjects were also required to score their symptoms of asthenopia on a visual analog scale before and just after DVD viewing. The changes in blink rate and asthenopia scores with AR film use were assessed by the Student t test.

RESULTS

The mean baseline blink rate was 15.7 +/- 5.9 blinks /min, which decreased significantly to 9.6 +/- 4.3 blinks/min after DVD viewing without an AR film (P < 0.05). The mean baseline and final blink rates for DVD viewing with an AR film were 14.6 +/- 9.2 and 14.3 +/- 9.2 blinks/min, respectively. There were no significant differences between baseline and final blink rates after DVD viewing with an AR film (P > 0.05). The mean cumulative visual analog asthenopic symptom score after DVD viewing without an AR film was 72 +/- 18% compared with the mean cumulative symptom score of 52 +/- 11% after DVD viewing with an AR film. The difference was statistically significant (P < 0.05).

CONCLUSIONS

Visual display terminal work appears to be associated with asthenopic symptoms and decreased blink rates. The use of AR films on computer displays may prevent both reflections of light from screen surfaces and reduction in blink rates resulting in fewer asthenopic symptoms.

Quantification of Tear Interference Image

PURPOSE

To review the literature on lipid supplementation therapy for dry eye and on image analysis using tear interference images from the specific tear lipid layer interference camera DR-1.

METHODS

Systematic literature review of lipid supplementation therapy for lipid tear deficiency dry eye, kinetic analysis of tear interference images using DR-1 camera, and computer-synthesized interference color chart for DR-1 camera.

CONCLUSION

To establish lipid supplementation therapy, a quantification system of tear lipid layer is required. Tear lipid thickness could be quantified using a computer-synthesized interference color chart system.

Visual protective sheet can increase blink rate while playing a hand-held video game

PURPOSE

To evaluate the effectiveness of a protective sheet in reducing eye strain caused by unnecessary light reflection on portable liquid crystal display panels while playing Game Boy (Nintendo, Kyoto, Japan).

DESIGN

Nonrandomized clinical trial.

METHODS

The blink rates of 24 normal volunteers were measured under relaxed conditions while viewing a portable liquid crystal display panel and playing Game Boy with and without the protective sheet of polyethylene terephthalate with antiglare coating for a total of 10 minutes each.

RESULTS

The results showed a dramatic increase (from 5.6 +/- 3 to 9.1 +/- 4.9 [P <.0001]) in blinks/minute with use of the protective sheet.

CONCLUSION

The protective sheet has shown the possibility of increasing the blink rate by making the screen easier to see.

Treatment of dry eye by autologous serum application in Sjögren's syndrome

AIM

To evaluate the efficacy of autologous serum application for the treatment of dry eye in Sjögren's syndrome.

METHODS

The stability of essential components (EGF, vitamin A, and TGF-beta) in preserved serum were examined following preservation at 4 degrees C and -20 degrees C. In a primary clinical trial, 12 patients with Sjögren's syndrome were treated with autologous serum (diluted to 20% with sterile saline) for 4 weeks, and vital staining of the ocular surface was compared before and after treatment. The effects of serum on mucin (MUC-1) expression were observed in cultured conjunctival epithelial cells in vitro.

RESULTS

EGF, vitamin A, and TGF-beta were well preserved for up to 1 month in the refrigerator at 4 degrees C and up to 3 months in the freezer at -20 degrees C. Rose bengal and fluorescein scores improved significantly from the initial scores of 5.3 and 5.6 to 1.7 and 2.5 after 4 weeks, respectively. The additive effect of human serum for cultured conjunctival epithelial cells showed significant MUC-1 upregulation on the cell surface.

CONCLUSION

Autologous serum application is a safe and efficient way to provide essential components to the ocular surface in the treatment of dry eye associated with Sjögren's syndrome.

Tear dynamics and dry eye

Tears undergo four processes: production by the lacrimal gland, distribution by blinking, evaporation from the ocular surface and drainage through the nasolacrimal duct. Abnormalities in any of these steps can cause dry eye. There are two kinds of tear production, basic and reflex, which can be distinguished from each other by the Schirmer test with nasal stimulation. Reflex tearing is important because it supplies such essential components as EGF and vitamin A, whose deficiency may cause squamous metaplasia. There is no reflex tearing in Sjogren's syndrome because of destruction of the lacrimal gland. In cases of diminished or absent reflex tearing, topical autologous serum is the treatment of choice. Even when there is adequate tear production, insufficient distribution, such as occurs with the decreased blinking associated with the use of video display terminals (VDT), may cause dry eye. Any process or activity that suppresses blinking interferes with tear distribution. Tear evaporation increases under certain conditions and in some diseases. When the exposed ocular surface area is increased, such as in VDT work, tear evaporation increases. Meibomian gland dysfunction (MGD) also causes increased tear evaporation by altering the quality of the oily layer in tears. Tear evaporation can be suppressed by using a warm compresser or a humidifier, narrowing the palpebral fissure, or wearing protective eyeglasses. The tear clearance rate is measured by fluorescein dye dilution in the conjunctiva. When the tear clearance is low, inflammatory cytokines or preservatives accumulate in the conjunctival sac, resulting in ocular surface diseases. Frequent use of artificial tears without preservative is the key treatment. A differential diagnosis of the abnormalities of tear dynamics can give us a proper understanding of the pathogenesis of dry eye. With this knowledge, we can formulate an efficient therapeutic approach.

Blinking is controlled primarily by ocular surface conditions

PURPOSE

To investigate the relation between blinking and ocular surface conditions and to introduce and examine a new index, the maximum blink interval.

METHODS

In a prospective study, the blink rate of subjects under relaxed conditions was determined from a video recording taken by a hidden observer. The maximum blink interval was defined as the longest time subjects can avoid blinking without feeling uncomfortable.

RESULTS

Significant changes in the blink rate and maximum blink interval were induced by factors that directly or indirectly affect the ocular surface: topical anesthesia, changing exposed ocular surface area, and wind. Moreover, the blink rate and maximum blink interval were significantly different in dry eye patients compared with healthy volunteers, with the values of the former approaching the values of the latter after use of artificial tears. The maximum blink interval was decreased by the same factors that increased the blink rate, and there was a significant inverse correlation between blink rate and maximum blink interval. Use of video display terminals was associated with decreased maximum blink interval and, hence, the development of dry eye symptoms.

CONCLUSIONS

There was an important association among blink rate, maximum blink interval, and ocular surface conditions. The blink rate and our newly introduced measurement, the maximum blink interval, should prove useful in assessing factors that cause dry eye. This prospective study should contribute to the understanding and treatment of dry eyes.