Visual Maintenance Ratio Research Articles

Preliminary Application of a Continuous Functional Contrast Visual Acuity System in the Assessment of Visual Function in Dry Eye Patients.

To investigate the feasibility and efficacy of a continuous functional contrast visual acuity (CFCVA) system in the assessment of visual function in dry eye disease (DED). Twenty patients with DED and 15 normal controls were recruited. Subjective symptoms were evaluated using the Ocular Surface Disease Index (OSDI) questionnaire, and tear film stability was assessed by a noninvasive corneal topographer. Under natural blinking conditions, the custom-built CFCVA system was used to take serial visual acuity measurements at 100%, 25%, 10%, and 5% contrast for 60 seconds. A 5-minute measurement at a 100% contrast level was defined as the stress test (ST). Mean CFCVA was defined, and visual maintenance ratio (VMR) was the ratio of mean CFCVA divided by baseline visual acuity. In both groups, VMR decreased and mean CFCVA (logarithm of the minimum angle of resolution) increased with decreasing optotype contrast (from 100% to 5%). In ST, the ST VMR at the fourth and fifth minutes (VMR54 and VMR55) showed the strongest correlations with OSDI total, ocular symptoms, and vision-related function (-0.646 and -0.598, -0.688 and -0.693, and -0.599 and -0.555, respectively, P < 0.05). VMR54 and VMR55 also demonstrated the best discriminating ability for detecting DED, with areas under the curve of 0.903 and 0.867, respectively. Extending the continuous measuring time was more effective for detecting vision-related functional abnormalities in patients with DED than simply decreasing the optotype contrast level. The proposed CFCVA system and associated parameters offer a potential method for quantifying and interpreting the visual symptoms of DED in clinical care.

Visual function in eyes with diffractive extended depth-of-focus and monofocal intraocular lenses: 2-year comparison.

To compare long-term visual function after implantation of diffractive extended depth-of-focus (EDF) intraocular lenses (IOLs) using echelett optics and monofocal IOLs with the same platform. In this prospective comparative case series, diffractive EDF or monofocal IOLs were implanted binocularly and followed up for 2years. At the last visit, distance-corrected binocular visual acuities were measured at distances of 0.3, 0.5, 0.7, 1, 2, 3, and 5m. Photopic and mesopic contrast sensitivity was also examined. Dynamic visual function was evaluated in terms of functional visual acuity (FVA), standard deviation of visual acuity (SDVA), visual maintenance ratio (VMR), mean response time, and number of blinks. The outcomes were compared between the two IOLs, and the influence of posterior capsule opacification (PCO) on contrast sensitivity and FVA was examined. Binocular visual acuity of eyes with EDF IOLs was better at distances of 0.5 and 0.7m than that of eyes with monofocal IOL (P < 0.026). There were no differences in binocular visual acuity at other distances, contrast sensitivities, or dynamic visual functions. The influence of PCO on the visual functions was not found in eyes with EDF IOLs. Up to 2years postoperatively, eyes with diffractive EDF IOLs sustained superior intermediate visual acuity together with visual function comparable to that of eyes with monofocal IOLs.

Simultaneous real-time analysis of tear film optical quality dynamics and functional visual acuity in dry eye disease

BackgroundTo assess the effect of tear film instability in dry eye disease (DED) by measuring visual performance and tear film optical quality in a simultaneous real-time analysis system.MethodsThirty-seven DED participants and 20 normal controls were recruited. A simultaneous real-time analysis system was developed by adding a functional visual acuity (FVA) channel to a double-pass system. Repeated measurements of FVA and objective scatter index (OSI) were performed simultaneously with this system under blink suppression condition for 20 s. Patient-reported symptoms was evaluated using the Ocular Surface Disease Index (OSDI) questionnaire. Mean FVA, mean OSI, and visual acuity break-up time were defined. The OSI maintenance ratio was calculated as an evaluation index to assess the difference between dynamic OSI changes and baseline OSI. The visual maintenance ratio was also calculated in the same way.ResultsModerate correlations were noted between mean OSI and FVA-related parameters (mean FVA, visual maintenance ratio, visual acuity break-up time: 0.53, − 0.56, − 0.53, respectively, P < 0.01 for all). Moderate to high correlations were noted between OSI maintenance ratio and FVA-related parameters (mean FVA, visual maintenance ratio, visual acuity break-up time: − 0.62, 0.71, 0.64, respectively, all P < 0.01). The metrics derived from the simultaneous real-time analysis system were moderately correlated with the patient-reported symptoms and the visual acuity break-up time possessed the highest correlation coefficients with OSDI total, ocular symptoms, and vision-related function (− 0.64, − 0.63, − 0.62, respectively, P < 0.01). The OSI-maintenance ratio alone appeared to exhibit the best performance of the metrics for the detection of DED with sensitivity of 95.0% and specificity of 83.8% and the combinations of FVA parameters and OSI parameters were valid and can further improve the discriminating abilities.ConclusionsOSI-related metrics were found to be potential indicators for assessing and diagnosing DED which correlated with both subjective visual performance and patient-reported symptoms; the FVA-related metrics were quantifiable indicators for evaluating visual acuity decline in DED.Trial registration number: Chinese Clinical Trial Registry, ChiCTR2100051650. Registered 29 September 2021, https://www.chictr.org.cn/showproj.aspx?proj=134612

Functional visual acuity after implantation of diffractive extended depth-of-focus intraocular lenses using an echelett optics

BackgroundThe prospective comparative case series aimed to evaluate all-distance visual acuity, contrast sensitivity, and functional visual acuity (FVA) of eyes with diffractive extended depth-of-focus (EDOF) intraocular lenses (IOLs) using an echelett optics and monofocal IOLs with the same platform.MethodsDiffractive EDOF and monofocal IOLs were implanted in 27 eyes of 27 patients each. At 3 months after implantation, all-distance visual acuities at distances of 0.3, 0.5, 0.7, 1, 2, 3, and 5 m were measured under distance-corrected. Static visual function was also examined using photopic contrast sensitivity and area under the logarithmic contrast sensitivity function (AULCSF). Dynamic visual function was examined with FVA, and mean FVA value, visual maintenance ratio (VMR), mean response time, and number of blinks were evaluated. These outcomes were compared between the two IOLs.ResultsThe mean distance-corrected visual acuities were better at distances of 0.7 m or nearer in eyes with EDOF IOLs. There was no difference in the contrast sensitivities (P > 0.22). In the FVA results, no difference was found in mean FVA and VMR (P > 0.68).ConclusionThe static and dynamic evaluations of postoperative visual functions demonstrated that the visual function of eyes with EDOF IOLs under photopic and distance-corrected conditions was comparable to eyes with monofocal IOLs.

Ocular and Systemic Effects of Antioxidative Supplement Use in Young and Healthy Adults: Real-World Cross-Sectional Data.

Randomized controlled studies have shown that antioxidative supplements are effective in suppressing the progression of age-related macular degeneration and visual display terminal syndrome. However, effects of their general use in the real-world and by young and healthy individuals have not been well documented. We analyzed 27 participants who were under 35 years of age and had no diagnosed diseases. Mean functional visual acuity (FVA) score and visual maintenance ratio, which represent quick recognition of a target, both measured using FVA system, were better (both p < 0.01) in subjects who had had regular antioxidative supplement intake for more than 2 months (11 participants) compared with those who had not. Systemic data, i.e., total cholesterol, hemoglobin A1c (HbA1c), and high-sensitivity C-reactive protein (hs-CRP) levels, which correspond to chronic low-grade inflammation, were lower (all p < 0.05) in the former. Overall, hs-CRP levels had a correlation with total cholesterol (p < 0.05) and a trend of correlation with HbA1c (p = 0.054) levels. Thus, current real-world data showed that young, healthy participants who had a regular intake of antioxidative supplements had better visual acuity and systemic levels of metabolic and low-grade inflammation markers. This study will help promote future research into the effects of general antioxidative supplement use.

Relationship between visual function and cognitive function in the elderly: A cross-sectional observational study.

It has been suggested that functional visual acuity (VA) testing may be able to measure both the visual performance and cognitive ability needed for driving and help to reduce the number of road traffic accidents. The aim of this study was to investigate the relationship between visual ability and cognitive function in healthy elderly subjects. The study included 34 eyes with a decimal best-corrected visual acuity (VA) ≥1.0 in 34 subjects (16 men, 18 women; mean age 72.7 ± 6.1 [range, 61-83] years) with the same type of monofocal intraocular lens implant. Using the score on the Japanese version of the Mini-Mental State Examination (MMSE) questionnaire, the subjects were divided into a mild cognitive impairment (MCI) group (score <28) and a normal cognition (NC) group (score ≥28). Visual ability was evaluated by functional VA testing. Functional VA was significantly lower in the MCI group (n = 10) than in the NC group (n = 24; P<0.02). There was no significant difference in best-corrected VA between the two groups. High correlations were found between the MMSE score and the logMAR functional VA (r = -0.36, P = 0.04), standard deviation of functional VA (r = -0.39, P = 0.02), and the visual maintenance ratio (r = 0.34, P = 0.048). In summary, despite a good best-corrected VA, deterioration in visual ability was detected in elderly individuals with MCI when measured by the functional VA test. Functional VA could be used to evaluate the integrated visual ability associated with age-related cognitive decline and have applications that help to reduce the disproportionately high rate of road traffic accidents in the elderly.

Improvement of visual function and ocular and systemic symptoms following blepharoptosis surgery

ABSTRACT Purpose: To study the changes of the visual function and ocular and systemic symptoms following blepharoptosis surgery.Methods: Seventy-eight involutional blepharoptosis patients (72.1 ± 6.4 years) underwent levator advancement procedure. Before and at 2 months after the surgery, OPD-Scan III (Nidek) was used to measure corneal astigmatism, total higher order aberrations (HOAs), and area ratio (AR), an index of the objective contrast sensitivity. FVA-100 (Nidek) was used to determine the functional visual acuity (FVA) and visual maintenance ratio (VMR). The ocular and systemic symptoms were also determined by a questionnaire using visual analogue scale (VAS) scores.Results: Before surgery, the corneal astigmatism, HOAs, AR, FVA, and VMR were 1.56 ± 0.52 diopters (D), 0.23 ± 0.24 µm, 14.8 ± 4.2%, 0.68 ± 0.32 logMAR units and 0.76 ± 0.06, respectively. After surgery, these values were 1.29 ± 0.41 D, 0.19 ± 0.21 µm, 18.6 ± 3.4%, 0.31 ± 0.18 logMAR units and 0.88 ± 0.03, respectively. Corneal astigmatism and HOAs were significantly reduced after surgery (P=0.007 and P=0.023, paired t test, respectively), and AR, FVA and VMR were significantly improved after surgery (P=0.033, P=0.012 and P=0.016, respectively). The VAS scores significantly improved after surgery, and this improvement was positively and significantly correlated with the increase of the AR (r=0.421, P=0.003) and the VMR (r=0.497, P =0.005).Conclusions: Blepharoptosis surgery is visual functionally beneficial and can help to reduce the ocular and systemic symptoms.

Shortened Measurement Time of Functional Visual Acuity for Screening Visual Function.

The functional visual acuity test which is the average of the visual acuities measured during a specific time frame (standard, 60 seconds) has been used recently to assess the visual function in various conditions. The availability of a shorter version of the functional visual acuity test promises to be patient friendly in that it is a simple screening test performed in a shorter period of time than the standard test. The results of measurements of the FVA test between the 30-second measurement time (short-version FVA test) and the standard 60-second measurement are compared, and the feasibility of the short-version FVA test instead of the standard FVA test is investigated. Twenty-eight healthy volunteers (25 men and 3 women) were enrolled in this prospective observational study. All subjects underwent measurement of the binocular distance-corrected visual acuity and the binocular distance-corrected FVA with the 60-second and 30-second measurement times. The interchangeability of the corrected-distance FVA, maximal VA, visual maintenance ratio, and average response time in the short-version and the standard FVA tests was evaluated using the Bland–Altman method, and the results showed agreements of the two tests except for the minimal VA. The short-version FVA test is equivalent to the standard method except for evaluating the visual acuity fluctuations and promises to be a simple visual screening test that can be performed in a shorter time.

Reduction in Ocular Hypotensive Eyedrops by Ab Interno Trabeculotomy Improves Not Only Ocular Surface Condition But Also Quality of Vision.

Purpose To investigate the effect of ab interno trabeculotomy using the Trabectome surgical system on tear film stability and functional visual acuity (FVA). Patients and Methods Adult glaucoma patients who underwent Trabectome surgery alone or Trabectome surgery combined with phacoemulsification with intraocular lens insertion were included in this study. Corneal epithelial defects, tear film breakup time (TBUT), tear meniscus height, tear film spreading grade, tear interferometry grade, and FVA were assessed before and after surgery in addition to routine ophthalmic examinations. Changes in ocular surface conditions and visual acuity as a result of the Trabectome surgery were investigated. Results Thirty eyes of 22 patients with a mean age of 72.2 ± 7.9 years, including 8 males and 14 females, were enrolled. The Trabectome surgery significantly reduced the intraocular pressure (IOP) from 20.3 ± 5.2 to 15.0 ± 3.3 mmHg (P < 0.001) and the number of different types of ocular hypotensive eyedrops used from 3.2 ± 0.7 to 1.1 ± 0.7 types (P < 0.001). The surgery significantly improved corneal epithelial defects, the tear spreading grade, the tear interferometry grade, and FVA. The surgery also improved the visual maintenance ratio among all enrolled patients, including those who underwent Trabectome surgery only. Conclusion Trabectome surgery may be beneficial not only for IOP reduction but also for improving ocular surface conditions and FVA.

Relation of accommodative microfluctuation with dry eye symptoms in short tear break-up time dry eye.

PurposeTo investigate accommodative microfluctuations (AMFs) and visual function in short tear break-up time (BUT)-type dry eye (DE) and non-DE subjects.MethodsThis prospective comparative study included 48 volunteers with DE symptoms (mean age 34.8 ± 5.5 years, age range 25–42 years) and 73 without DE symptoms (mean age 30.6 ± 4.7 years, age range 25–42 years). The eyes were divided into two groups: (1) DE group with DE symptoms and BUT ≤ 5 s and (2) non-DE group without DE symptoms and BUT > 5 s. We excluded eyes with Schirmer score ≤ 5 mm and positive keratoconjunctival epithelial damage. Tear evaluation, AMF, and functional visual acuity (VA) examinations were performed. AMF parameters included total high-frequency component (HFC), HFC with low accommodation for the task of staring into the distance (HFC1), and HFC with high accommodation for deskwork (HFC2). Functional VA parameters included starting VA, functional VA, visual maintenance ratio, and blink frequency.ResultsA total of 33 and 34 eyes were categorized in the DE and non-DE groups, respectively. Mean blink frequency and HFC1 values were significantly higher in the DE group than they were in the non-DE group.ConclusionsDEs with symptoms showed abnormal AMF and visual function, which may be associated with DE symptoms.

Quality of Vision in Eyes With Epiphora Undergoing Lacrimal Passage Intubation

To investigate visual function and optical quality in eyes with epiphora undergoing lacrimal passage intubation. Prospective case series. Thirty-four eyes of 30 patients with lacrimal passage obstruction were enrolled. Before and 1month after lacrimal passage intubation, functional visual acuity (FVA), higher-order aberrations (HOAs), lower tear meniscus, and tear clearance were assessed. An FVA measurement system was used to examine changes in continuous visual acuity (VA) over time, and visual function parameters such as FVA, visual maintenance ratio, and blink frequency were obtained. Sequential ocular HOAs were measured for 10 seconds after the blink using a wavefront sensor. Aberration data were analyzed in the central 4mm for coma-like, spherical-like, and total HOAs. Fluctuation and stability indices of the total HOAs over time were calculated. Lower tear meniscus was assessed by anterior segment optical coherence tomography. After lacrimal passage intubation, visual function significantly improved, as indicated by improved FVA (P= .003) and visual maintenance ratio (P < .001). Blink frequency decreased significantly after treatment (P= .01). Optical quality significantly improved, as indicated by a decrease in coma-like aberrations (P= .003), spherical-like aberrations (P= .018), and total HOAs (P= .001). Stability index increased (P< .001) and fluctuation index decreased (P= .019), and tear meniscus dimension decreased (P < .001). Lacrimal passage intubation for eyes with epiphora significantly improved visual function andoptical quality via patency of the lacrimal passage.

Influence of intraocular lens subsurface nanoglistenings on functional visual acuity

To investigate the influence of intraocular lens subsurface nanoglistenings (SSNGs) on functional visual acuity (FVA), thirty-nine eyes of 29 patients were examined in this study. The SSNG group comprised 19 eyes of 14 patients (75.7± 5.4 years, mean ± standard deviation), and the control group comprised 20 eyes of 15 patients (73.6 ± 6.5 years). The SSNGs were diagnosed on the basis of the typical whitish IOL appearance upon slit-lamp examination and results of densitometry regarding surface light scattering using Scheimpflug images. The FVA measurement system (AS-28; Kowa, Aichi, Japan) was used to examine changes in continuous visual acuity (VA) over time, and visual function parameters such as FVA, visual maintenance ratio (VMR), maximum VA, minimum VA, standard deviation of VA, and number of blinks were assessed. The results were compared between the SSNG and control groups, and correlations of FVA parameters with the intensity of surface light scattering, time after surgery, and age were also evaluated. There were significant differences in VMR (P = 0.035) and standard deviation of VAs (P = 0.031) between the two groups, although no significant differences were found in baseline VA, FVA, maximum VA, minimum VA, and number of blinks. None of the FVA parameters showed any significant correlations with the intensity of surface light scattering, time after surgery, or age. There is a possibility that VA is unstable during a continuous gazing task in patients with SSNGs.

Evaluation of Functional Visual Acuity in Glaucoma Patients

We evaluated the association between functional visual acuity (FVA) and visual fields in glaucoma patients. Forty-seven patients with glaucoma were enrolled (28 men, 19 women; mean age: 65.2±7.3 y; range: 38 to 82 y), and their 94 eyes were studied. Inclusion criteria were having glaucomatous optic disc abnormalities, visual field loss with glaucoma, and a best-corrected visual acuity in each eye of 1.0 (equivalent to Snellen 20/20) or better. FVA and visual maintenance ratio evaluations were made with an AS-28 FVA measurement system. To assess FVA, Landolt optotypes were displayed sequentially for 2 seconds each, and the size was reduced when the patient gave the correct answer. Humphrey automated perimetry was performed to determine mean deviation (MD) and foveal threshold, and these values were used to evaluate associations between FVA and visual field. Mean and SD was calculated for all parameters for statistical comparisons. The MD values were -10.1±7.3 (range: -29.87 to 1.05) dB, and foveal thresholds were 34.8±2.8 (mean±SD, range: 25 to 41) dB. The logMAR FVA values were 0.14±0.17 (range: -0.14 to 0.73), and the visual maintenance ratios were 0.92±0.06 (range: 0.73 to 1.02). Linear regression analysis of the logMAR FVA values and visual field gave a MD of R=0.26 (P=0.01), and a foveal threshold of R=0.51 (P<0.001). The corresponding figures for the visual maintenance ratio and visual field were MD: R=0.25 (P=0.01) and foveal threshold: R=0.48 (P<0.001). The results of the current study showed that the logMAR FVA and visual maintenance ratio correlated moderately with foveal threshold.

Functional visual acuity in patients with successfully treated amblyopia: a pilot study.

The aim of this study was to use conventional visual acuity measurements to quantify the functional visual acuity (FVA) in eyes with successfully treated amblyopia, and to compare the findings with those for contralateral normal eyes. Nineteen patients (7 boys, 12 girls; age 7.5 ± 2.2years) with successfully treated unilateral amblyopia and the same conventional decimal visual acuity in both eyes (better than 1.0) were enrolled. FVA, the visual maintenance ratio (VMR), maximum and minimum visual acuity, and the average response time were recorded for both eyes of all patients using an FVA measurement system. The differences in FVA values between eyes were analyzed. The mean LogMAR FVA scores, VMR (p < 0.001 for both), and the LogMAR maximum (p < 0.005) and minimum visual acuity (p < 0.001) were significantly poorer for the eyes with treated amblyopia than for the contralateral normal eyes. There was no significant difference in the average response time. Our results indicate that FVA and VMR were poorer for eyes with treated amblyopia than for normal eyes, even though the treatment for amblyopia was considered successful on the basis of conventional visual acuity measurements. These results suggest that visual function is impaired in eyes with amblyopia, regardless of treatment success, and that FVA measurements can provide highly valuable diagnosis and treatment information that is not readily provided by conventional visual acuity measurements.

Reducing Short-Wavelength Blue Light in Dry Eye Patients with Unstable Tear Film Improves Performance on Tests of Visual Acuity.

PurposeTo investigate whether suppression of blue light can improve visual function in patients with short tear break up time (BUT) dry eye (DE).MethodsTwenty-two patients with short BUT DE (10 men, 12 women; mean age, 32.4 ± 6.4 years; age range, 23–43 years) and 18 healthy controls (10 men, 8 women; mean age, 30.1 ± 7.4 years; age range, 20–49 years) underwent functional visual acuity (VA) examinations with and without wearing eyeglasses with 50% blue light blocked lenses. The functional VA parameters were starting VA, functional VA, and visual maintenance ratio.ResultsThe baseline mean values (logarithm of the minimum angle of resolution, logMAR) of functional VA and the visual maintenance ratio were significantly worse in the DE patients than in the controls (P < 0.05), while no significant difference was observed in the baseline starting VA (P > 0.05). The DE patients had significant improvement in mean functional VA and visual maintenance ratio while wearing the glasses (P < 0.05), while there were no significant changes with and without the glasses in the control group (P > 0.05),ConclusionsProtecting the eyes from short-wavelength blue light may help to ameliorate visual impairment associated with tear instability in patients with DE. This finding represents a new concept, which is that the blue light exposure might be harmful to visual function in patients with short BUT DE.

Functional Visual Acuity in Age-Related Macular Degeneration.

ABSTRACTPurposeWe evaluated whether a functional visual acuity (FVA) system can detect subtle changes in central visual acuity that reflect pathological findings associated with age-related macular degeneration (AMD).MethodsTwenty-eight patients with unilateral AMD and logMAR monocular best corrected VA better than 0 in both eyes, as measured by conventional chart examination, were analyzed between November 2012 and April 2013. After measuring conventional VA, FVA, and contrast VA with best correction, routine eye examinations including spectral domain–optical coherence tomography were performed. Standard Schirmer test was performed, and corneal and lens densities were measured.ResultsThe FVA score (p < 0.001) and visual maintenance ratio (p < 0.001) measured by the FVA system, contrast VA (p < 0. 01), and conventional VA (p < 0.01) were significantly worse in the AMD-affected eyes than in the fellow eyes. No significant differences were observed in the anterior segment conditions. Forward stepwise regression analysis demonstrated that the length of interdigitation zone disruption, as visualized by optical coherence tomography imaging, correlated with the FVA score (p < 0.01) but not with any other parameters investigated.ConclusionsThe FVA system detects subtle changes in best corrected VA in AMD-affected eyes and reflects interdigitation zone disruption, an anatomical change in the retina recorded by optical coherence tomography. Further studies are required to understand the value of the FVA system in detecting subtle changes in AMD.

Mesopic Functional Visual Acuity in Normal Subjects.

To evaluate mesopic functional visual acuity (FVA) with a newly developed system in normal subjects and to compare the results with photopic FVA, sixty-eight healthy volunteers (24.03 ± 4.42 [mean ± standard deviation] years) were enrolled in this study. A commercially available FVA measurement system (AS-28; Kowa, Aichi, Japan) was modified to measure FVA under mesopic conditions as well as photopic conditions. Measurements were performed monocularly in photopic conditions during 60 seconds. After dark adaptation for 15 minutes, the same measurements were repeated in mesopic conditions. Outcomes included starting visual acuity (VA), FVA (the average of VAs), visual maintenance ratio (VMR), maximum VA, minimum VA, and numbers of blinks during the 60-second measurement session, and were compared between mesopic and photopic conditions. Starting VA was –0.11 ± 0.08 and 0.39 ± 0.12 logarithm of the minimum angle of resolution (logMAR) in photopic and mesopic conditions, respectively. FVA was –0.06 ± 0.09 and 0.52 ± 0.14 logMAR, VMR was 0.98 ± 0.02 and 0.94 ± 0.04, maximum VA was –0.15 ± 0.06 and 0.33 ± 0.12 logMAR, the minimum VA was 0.05 ± 0.12 and 0.78 ± 0.20 logMAR, and the number of blinks was 8.23 ± 7.54 and 7.23 ± 6.20, respectively. All these parameters except the number of blinks were significantly different between the two conditions (P < 0.001). Besides, the difference between maximum and minimum VAs and standard deviation of VA were significantly larger in mesopic than in photopic conditions (P < 0.001). This study revealed that not only overall visual function decline but also instability of vision under mesopic conditions even in healthy subjects.

Dry-eye screening by using a functional visual acuity measurement system: the Osaka Study.

We determined whether functional visual acuity (VA) parameters and a dry eyes (DEs) symptoms questionnaire could predict DEs in a population of visual terminal display (VDT) users. This prospective study included 491 VDT users from the Osaka Study. Subjects with definite DE, diagnosed with the presence of DE symptoms, tear abnormality (Schirmer test ≤ 5 mm or tear breakup time [TBUT] ≤ 5 seconds), and conjunctivocorneal epithelial damage (total staining score of ≥3 points), or probable DE, diagnosed with the presence of two of them, were assigned to a DE group, and the remainder to a non-DE group. Functional VA was assessed, and DE questionnaires were administered. We assessed whether univariate and discriminant analyses could determine to which group a subject belonged. Sensitivity and specificity were assessed. Of 491 subjects, 320 and 171 were assigned to the DE and non-DE groups, respectively. No significant differences were observed between DE and non-DE groups in Schirmer test value and epithelial damage, but TBUT value (3.1 ± 1.5 vs. 5.9 ± 3.0 seconds). The sensitivity and specificity of single test using functional VA parameters were 59% and 49% in functional VA, 60% and 50% in visual maintenance ratio, and 83% and 30% in frequency of blinking, respectively. According to a discriminant analysis using a combination of functional VA parameters and a DE questionnaire, six variables were selected for the discriminant equation, of which area under the curve (AUC) was 0.735. Sensitivity and specificity of diagnoses predicted by the discriminant equation were 85.9% and 45.6%, respectively. The discriminant equation obtained using functional VA measurement combined with a symptoms questionnaire may suggest the possibility for the first step screening of DE with unstable tear film. Since the questionnaire has an overall poor sensitivity and specificity, further amelioration may be necessary for the actual utilization of this screening tool.

Detection of early visual impairment in patients with epiretinal membrane

Patients with epiretinal membrane sometimes complain of impaired central visual function, despite good best corrected visual acuity (BCVA), as measured by visual acuity (VA) charts. Here, we evaluate early epiretinal membrane-induced changes in central VA. Subjects were 72 eyes of 36 patients with epiretinal membrane in only one eye and a BCVA in each eye better than 1.0, as measured by conventional Landolt C chart, at the Retina Division Clinic of the Department of Ophthalmology, Keio University Hospital, between December 2010 and November 2011. The conventional Landolt VA, functional VA (FVA) and contrast VA measurements were taken after a general eye examination. For the FVA, Landolt optotypes were sequentially displayed every 2 seconds, which size was changed according to the correctness of the answer. To exclude the influence of other diseases, a standard Schirmer test was performed to diagnose dry eye, and corneal and lens densities were evaluated. Average BCVA measured by Landolt C chart was not changed between affected and unaffected fellow eyes. However, the affected eyes showed a poorer FVA score (0.21 ± 0.12, affected; 0.09 ± 0.12, fellow) and visual maintenance ratio (VMR) (0.90 ± 0.04, affected; 0.94 ± 0.04, fellow), measured by the FVA system, and contrast VA score (0.35 ± 0.11, affected; 0.25 ± 0.14, fellow) than fellow eyes. The FVA and contrast VA values were correlated with the presence of epiretinal membrane, but not with the presence of dry eye, cataract and corneal densities. FVA and contrast VA results reflected early changes in central visual function caused by epiretinal membrane, which were not detected by conventional Landolt BCVA.

Corneal Fluorescein Staining Correlates with Visual Function in Dry Eye Patients

To investigate the changes in functional visual acuity (VA) and higher order aberrations in dry eye patients. In this prospective comparative case series, 22 right eyes were classified into those with or without superficial punctate keratopathy (SPK) in the central cornea of 22 patients with Sjögren syndrome; 10 right eyes of 10 normal subjects served as the control. Serial measurements of VAs using a functional VA measurement system and higher order aberrations using a wavefront sensor were performed under blink-free conditions without topical anesthesia over a 10-second period. The parameters for each measurement were compared among the SPK-positive and -negative and normal groups. The correlation between those parameters was also analyzed. Dry eye with SPK showed significant deterioration of visual function and optical quality compared with dry eye without SPK and in normal eyes, as detected by both the visual maintenance ratio (VMR; P < 0.05) and the variation of VA (P < 0.05) and by comalike and total higher order aberrations (P < 0.05). Moreover, the severity of epithelial damage at the central cornea correlated significantly with VMR (P < 0.01) and variation of VA (P < 0.01) as well as comalike (P < 0.05) and total higher order aberrations (P < 0.05). The dry eye group without SPK showed minor visual deterioration compared with normal eyes, as detected only by VMR (P < 0.05). Optical disturbances at the central optical zone of the cornea in dry eye disease may affect visual performance. Functional VA measurement may be an applicable method of evaluating visual performance in dry eyes that is as efficient as wavefront aberration measurements.