Longitudinal assessment of optical quality and intraocular scattering using the double-pass instrument in normal eyes and eyes with short tear breakup time

Post-Blink Blur Time-A Simple Test to Detect Dry Eye-Related Visual Disturbances

Background: Dry eye disease (DED) stands out as one of the most common eye conditions encountered in clinical settings. This study aimed to determine the diagnostic ability and feasibility of post-blink blur time (PBBT) in detecting patients with DED symptoms. Methods: The study included 200 subjects, 100 with and 100 without DED symptoms defined by the Schein questionnaire, who underwent assessment of DED signs [visual acuity, PBBT, conjunctival hyperemia, lid-parallel conjunctival folds-LIPCOF, tear film break-up time-TBUT, fluorescein corneal staining, and meibum score]. Results: DED subjects had a lower PBBT than controls (p < 0.001), with subjective (6 (1-45) s vs. 8 (1-70) s) and objective (6 (2-33) s vs. 8 (2-50) s) PBBT measurements being similar between repeats. The correlations between subjective and objective PBBT measurements were significantly positive (R = 0.873, p < 0.001). Subjective PBBT was negatively related to the Schein questionnaire (R = -0.217, p = 0.002), conjunctival hyperemia (R = -0.105, p = 0.035), and corneal staining (R = -0.153, p = 0.031), while positively related to the TBUT (R = 0.382, p < 0.001) and meibum score (R = 0.106, p = 0.033). Logistic regression analysis showed DED symptoms were significantly associated with subjective PBBT (AOR 0.91, p = 0.001), TBUT (AOR 0.79, p < 0.001), meibum score (AOR 0.65, p = 0.008), LIPCOF (AOR 1.18, p = 0.002) and corneal staining (AOR 1.14, p = 0.028). Conclusions: Subjective self-reported PBBT is a reliable and non-invasive screening test for evaluating time-wise changes in visual acuity and detecting a tear film dysfunction.

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.

Impact of Dry Eye Disease on the Uncorrected Distance Visual Acuity after Small Incision Lenticule Extraction

The aim of this study was to explore the impact of dry eye disease (DED) on the uncorrected distance visual acuity (UDVA) and refractive status after small incision lenticule extraction (SMILE). This prospective cohort study enrolled 29 patients (DED group, 11 eyes; non-DED group, 18 eyes) who underwent SMILE in our center from July to September 2022. The examinations on DED, refractive status and UDVA were performed before surgery, and on day 7 and 20 after surgery. The results showed that on day 20 after SMILE, subjects in the non-DED group reported greater changes of ocular surface disease index value increase and tear-film breakup time reduction compared to baseline than those in the DED group (p < 0.001 and p = 0.048, respectively). Compared to preoperative status, DED patients had greater improvements of UDVA and better optometric outcomes on day 20 after surgery than non-DED subjects (p = 0.008 and 0.026, respectively). Multiple linear regression analysis showed age, contact lens daily wearing time, and tear meniscus height before surgery were of the highest value to predict UDVA on day 20 after SMILE in contact lens wearers (p = 0.006, 0.010 and 0.043, respectively). In conclusion, preoperative tear function could affect UDVA after SMILE. The impact of DED on UDVA and refraction should be taken into consideration before surgery.

Long-term changes in the ocular surface during orthokeratology lens wear and their correlations with ocular discomfort symptoms

PURPOSE

To evaluate the changes in ocular surface parameters during orthokeratology lens wear and determine their correlations with ocular discomfort symptoms.

METHODS

Fifty individuals were enrolled in this prospective pilot study. Clinical evaluation of the ocular surface included the ocular surface disease index, slit-lamp examination, Keratograph 5M, optical quality analysis system, and corneal staining. After baseline examinations, clinical tests were performed at 1 day, 1 week, 1 month, 3 months, 6 months, and 12 months after orthokeratology lens wear. Correlations between ocular discomfort symptoms and signs of ocular discomfort were evaluated.

RESULTS

Overall ocular surface disease index score and two subscale scores (ocular symptoms and vision-related function) significantly increased at the 3-month visit (P < 0.05), and decreased to levels close to baseline at the12-month visit (P > 0.05). The basic objective scatter index and the mean tear film objective scatter index increased, peaking at 3-month visit (P < 0.05) and gradually decreased thereafter. The modulation transfer function cut-off significantly decreased at the 3-month visit (P < 0.05). During the 12-month study period, the overall ocular surface disease index score and vision-related function score were significantly and positively correlated with the basic objective scatter index and mean tear film objective scatter index (P < 0.05). After 1 week of lens wear, Grade 1 corneal staining increased to 16.4 %, mostly involving the central and inferior cornea.

CONCLUSIONS

Orthokeratology lens wear increased ocular discomfort symptoms and decreased the function of tear film, mainly within 3 months of lens wear. Tear-related visual function parameters were correlated with ocular discomfort. A new parameter, tear film objective scatter index, measured with the optical quality analysis system, was more sensitive in detecting the quality and stability of tear film than traditional indicators.

Evaluation of the effects of vitrectomy with primary epiretinal membrane peel on optical quality using double-pass aberrometry

INTRODUCTION

We performed a prospective, single-center, cohort study in order to evaluate the effects of vitrectomy with epiretinal membrane (ERM) peel on optical quality in patients with primary ERM.

METHODS

Thirty patients treated for primary ERM by vitrectomy with ERM peel were included from our tertiary university hospital ophthalmology department. The main study outcome was variation in optical quality parameters measured using the HD Analyzer™ between pre-operative and two-month post-operative evaluations in operated eyes. Optical quality parameters comprised point spread function (PSF) width at 10% and 50%, objective scatter index (OSI), and modulation transfer function (MTF) cutoff. Contralateral non-operated eyes were used as an internal control for measurement reproducibility.

RESULTS

Mean PSF width at 10% (42.22 vs 27.37 arc/min; p = 0.0002) and mean OSI (3.32 vs 2.32; p = 0.0003) were significantly improved between pre- versus post-operative evaluations. Mean PSF width at 50% and mean MTF cutoff showed no changes. Subgroup analysis according to crystalline lens status gave similar results demonstrating that improvements in mean PSF width at 10% and OSI were not lens-related. Non-operated eyes showed no changes in any of the parameters analyzed.

CONCLUSION

Reduced light scattering measured by OSI indicates improved optical quality following vitrectomy with ERM peel among patients with primary ERM. OSI measurement could thus be a new parameter of interest in the pre-operative assessment of primary ERM and other pre-vitrectomy assessments.

Effect of artificial tears on dynamic optical quality in patients with dry eye disease

BACKGROUND

In clinical practice, fluctuating vision or decreased quality of vision is a common complaint in DED patients. Our study was designed to investigate the change in dynamic optical quality in dry eye patients after the use of artificial tears.

METHODS

Fifty-nine patients with dry eye disease (DED) and 31 control subjects were included in this prospective case-control study. There was no significant difference in age and sex between these two groups (P = 0.342, P = 0.847, respectively). Clinical evaluation of the ocular surface included Ocular Surface Disease Index (OSDI), tear film break-up time (TBUT), lipid layer thickness (LLT), and Schirmer I test. DED patients were divided into two groups, mild (31 patients) and severe (28 patients). The optical quality of the tear film was measured with the Optical Quality Analysis System (OQAS) using the mean objective scatter index (mean OSI), standard deviation of objective scatter index (SD-OSI) and modulation transfer function cut-off (MTF cut-off). After baseline examinations, one drop of artificial tears (ATs, carboxymethylcellulose ophthalmic solution, 0.5%) was instilled in both eyes, and optical quality parameters were measured again at 5 and 30 min following application of ATs.

RESULTS

At baseline, the mean OSI was higher in the DED group (0.95 ± 0.54) than in controls (0.54 ± 0.23, P < 0.001). The SD-OSI was also significantly increased in DED patients (0.44 ± 0.71) compared to control subjects (0.12 ± 0.06, P = 0.003). Five minutes after AT instillation, mean OSI and SD-OSI decreased significantly in severe DED patients (P = 0.044; P = 0.018), remained unchanged in mild DED patients, and increased in the control group (P = 0.019; P < 0.001). Thirty minutes after AT instillation, no significant difference in optical quality parameters was observed among the three groups.

CONCLUSION

The effect of ATs on optical quality in patients with DED may differ according to the severity of the disease. Measurement of optical quality might be a promising tool to evaluate the effects of various ATs and possibly individualize treatment in DED patients.

Objective assessment of optical quality in dry eye disease using a double-pass imaging system

PURPOSE

To assess optical quality dynamics using a double-pass (DP) system in patients with dry eye disease (DED).

METHODS

Seventy-six eyes with DED and 44 control subjects were enrolled in this study. Each patient underwent ocular surface evaluation including fluorescein corneal staining and Schirmer's II test. Ocular Surface Disease Index (OSDI) questionnaire was used to assess subjective symptoms. Optical quality dynamics and tear film instability was analyzed using a DP system (HD AnalyzerTM, Visiometrics, Spain). Mean objective scatter index (OSI), maximum and minimum OSI, difference between maximum and minimum OSI (ΔOSI) were recorded with 40 consecutive scans over 20 s.

RESULTS

The DED group had pronounced impairment of optical quality compared to the control group. Mean OSI (4.29±4.07), minimum (3.22±3.51) and maximum (5.72±4.52) OSI, ΔOSI (2.50±1.96), OSDI score (36.94±16.55), and fluorescein corneal staining (0.79±0.96) were statistically significantly higher than controls (p<0.05). Schirmer's II test was statistically significantly lower in the DED group compared to controls (10.08±7.85, 26.41±6.75, respectively; p<0.001). Three patterns of dynamic changes of OSI were proposed: ladder (continuous increase of OSI), seesaw (instability of OSI without improvement after blinking), and plateau (steady-high OSI). The ladder group showed the highest value of maximum OSI (6.93±4.13; p=0.03) and ΔOSI (3.76±2.08; p<0.001).

CONCLUSION

DP imaging system provides an objective measurement of the visual quality in DED. Tear film instability may be assessed by dynamic changes of OSI over 20 s. In particular, the highest OSI values were observed in the ladder pattern group.

Functional Visual Acuity

Dry eye (DE) causes irregularity of the ocular surface and reduces the quality of vision. An intact, regular tear film is essential for high-quality retinal images; however, visual tasks requiring sustained gazing can disrupt the tear film, eventually degrading visual function. A functional visual acuity (FVA) measurement system has been uniquely developed in Japan to evaluate visual function related to tear stability in patients with DE. FVA has been shown to correlate with optical quality. The system measures the change in visual acuity (VA) over time automatically in aqueous-deficient DE and short tear breakup tear film DE characterized by decreased tear stability and minimal epithelial damage. It is also useful to detect minimal visual deterioration correlated with minimal ocular surface abnormality and vision-related quality of life otherwise undetectable by conventional VA testing, to assess and quantify vision-related symptomatology, and to determine the efficacy of treatments for DE disease. Recently, its use has been expanded, such as for the analysis of visual function accompanying refractive surgery, contact lens, cataract and cataract-related disease, retinal disease, glaucoma, amblyopia, presbyopia, and vehicle driving. Its use has revealed that FVA reflects not only visual function related to tear dynamics, but also visual function related to quick recognition of the target. This simple, noninvasive, and sensitive FVA measurement system may be expected to be used worldwide.

Short Tear Film Breakup Time-Type Dry Eye

Measurement of tear film breakup time (TBUT) has become a standard diagnostic procedure in the dry eye clinic. Short TBUT-type dry eye is characterized by TBUT of less than 5 seconds and dry eye symptoms such as ocular fatigue or dryness; the importance of this type has recently been gaining prominence. Patients with this condition show no reduction in tear production and no staining of the ocular surface. The severity of symptoms is almost the same as in dry eye in which the ocular surface is stained with rose bengal or fluorescein. In addition to discomfort, patients suffer from decreased vision due to the unstable tear film, which can be attributed to the relative abnormality of the lipid layer, aqueous layer, and/or mucin layer. The diagnosis should be performed carefully on the basis of the patient's symptoms and the TBUT test, because the ocular surface appears normal and remains unstained.

Interface healing and its correlation with visual recovery and quality of vision following small incision lenticule extraction

Purpose:

To study the time course of interface healing and its correlation with visual acuity, modulation transfer function (MTF), and aberrations after myopic small-incision lenticule extraction (SMILE) correction.

Methods:

Seventy-eight eyes of 78 patients (1 eye per patient) with a mean age of 25.7 years and mean spherical equivalent (SE) of −3.74D, undergoing bilateral SMILE procedure, were included in this study. On postoperative day 1, 2 weeks, and 3 months, dilated retroillumination photographs were taken and morphology of corneal interface was graded by comparing them with 5 standard templates representing 5 grades of interface roughness (IRG): IRG – 0 (clear), IRG – 1 (mild), IRG – 2 (moderate), IRG – 3 (severe), and IRG – 4 (severe IRG with Bowman's folds in visual axis). Pearson's correlations were computed to study correlation associations, and Wilcoxon signed-rank test was used for intragroup comparison of means. P ≤ 0.05 was considered statistically significant.

Results:

At 3 months, 90.70% eyes were Grade 0 while 9.30% eyes still had Grade 2 interface granularity. Mean IRG significantly improved from 2.47 ± 0.57 at day 1 to 0.62 ± 0.53 at 3 months (P = 0.00). At day 1, pre-SE showed a significant positive correlation with IRG; however, mean postoperative corrected distant visual acuity (CDVA, in decimal), corneal Strehl ratio (SR), and MTF showed weak but significant negative correlation with IRG (r² = 0.28 for SE, −0.052 for CDVA, −0.017 for SR, and −0.39 for MTF, respectively, P < 0.05 for all correlations). At 2 weeks and 3 months, corneal MTF continued to show a significant negative correlation, whereas other parameters did not show any correlation with IRG.

Conclusion:

Visual quality and corneal MTF may be significantly affected by the IRG in the immediate postoperative period after SMILE and may take 3 months or more for complete recovery.

Impact of Forward and Backward Scattering and Corneal Higher-Order Aberrations on Visual Acuity after Penetrating Keratoplasty

PURPOSE

To assess the relationship of forward and backward scattering and corneal higher-order aberrations (HOAs) with corrected distance visual acuity (CDVA) after penetrating keratoplasty (PK).

METHODS

This retrospective study comprised 25 eyes of 25 consecutive patients who underwent PK using the VisuMax femtosecond laser system and age-matched 25 eyes of 25 healthy subjects. We quantitatively assessed objective scattering index (OSI) using the double-pass instrument (OQAS II, Visiometrics), corneal densitometry (CD) and corneal HOAs with the Scheimpflug rotating camera (Pentacam HR, Oculus) 1 year postoperatively.

RESULTS

The OSI, CD, and corneal HOAs were significantly larger in the PK group than those in the control group (p ≤ 0.011). We found significant correlations of logMAR CDVA with the OSI (r = 0.477, p = 0.016), and with the anterior, posterior, and total corneal HOAs of the central 4-mm zone (anterior: r = 0.573, p = 0.003, posterior: r = 0.596, p = 0.002, total: r = 0.472, p = 0.017), but no significant association with the CD of the 0-2 mm zone at any layers (anterior: r = 0.236, p = 0.257, center: r = 0.139, p = 0.506, posterior: r = 0.073, p = 0.728, total: r = 0.212, p = 0.308). Similar results were obtained when the analysis was repeated with corneal HOAs of the central 6-mm zone and CDs in 2-6 mm zone.

CONCLUSIONS

Our pilot study demonstrated that the postoperative CDVA was significantly correlated with OSI and corneal HOAs, but not with backward scattering in post-PK eyes, suggesting that OSI as well as corneal HOAs plays an essential role in postoperative visual performance after PK.

TFOS DEWS II Tear Film Report

The members of the Tear Film Subcommittee reviewed the role of the tear film in dry eye disease (DED). The Subcommittee reviewed biophysical and biochemical aspects of tears and how these change in DED. Clinically, DED is characterized by loss of tear volume, more rapid breakup of the tear film and increased evaporation of tears from the ocular surface. The tear film is composed of many substances including lipids, proteins, mucins and electrolytes. All of these contribute to the integrity of the tear film but exactly how they interact is still an area of active research. Tear film osmolarity increases in DED. Changes to other components such as proteins and mucins can be used as biomarkers for DED. The Subcommittee recommended areas for future research to advance our understanding of the tear film and how this changes with DED. The final report was written after review by all Subcommittee members and the entire TFOS DEWS II membership.

A comparison of mesopic visual acuity and objective visual quality following cataract surgery with hydrophobic acrylic intraocular lenses

PURPOSE

To evaluate mesopic visual acuity and visual quality as measured by objective scatter index (OSI) in pseudophakic eyes with long-term follow-up after implantation of hydrophobic acrylic lenses made from two different lens materials.

SETTING

This study was carried out in a private clinic.

DESIGN

This study was an observational cohort study.

METHODS

This pilot study included 181 eyes of 136 patients who had undergone cataract surgery with implantation of monofocal hydrophobic acrylic intraocular lenses (IOLs), either Alcon AcrySof (82 eyes) or Abbott Medical Optics' Tecnis (99 eyes). The monocular corrected distance visual acuity (CDVA) of the subjects was recorded under mesopic room illumination and OSI was measured by an optical quality analysis system using double-pass wavefront method.

RESULTS

Mean follow-up duration was 60.07±18.82 months. Eyes implanted with Tecnis IOLs had statistically significantly better mesopic CDVA (0.08±0.08) compared to those implanted with AcrySof IOLs (0.11±0.07) (P=0.020). Mesopic CDVA of 20/25 or better was found in 79.8% of eyes in the Tecnis group compared to 62.2% of eyes in AcrySof group. Similarly, OSI was also found to be statistically significantly better for Tecnis IOLs compared to AcrySof IOL group (mean OSI, Tecnis: 1.65±0.92, AcrySof: 2.01±1.36; P=0.033). When glaucomatous eyes were excluded, OSI was still significantly better (P=0.028) in the Tecnis IOL group.

CONCLUSION

The eyes implanted with Tecnis IOLs showed better long-term optical performance in terms of both OSI and mesopic visual acuity in comparison to those with AcrySof IOLs.

Mechanisms of Visual Disturbance in Dry Eye

Dry eye has been believed to be a chronic, symptomatic ocular surface disease that affects vision in a limited manner, because it is difficult to detect visual or optical changes using standard visual acuity testing. In practice, common visual complaints associated with dry eye include fluctuating vision with blinking, blurred vision, glare, and eye fatigue. This review discusses our past and current understanding of visual disturbances in dry eye and the various tools available for assessing visual function or optical quality. Tear film instability and ocular surface damage are key factors in the core mechanism underlying dry eye. The mechanisms of these vision-related subjective symptoms of dry eye based on visual function, particularly wavefront aberrations or light scattering, and the core mechanism of dry eye are described. Tear film instability is associated with decreased stability of postblink higher-order aberrations, leading to "fluctuating vision with blinking" and with increased ocular forward light scattering, leading to "glare." Ocular surface damage in the overlying optical zone (in the central corneal regions), is associated with increased higher-order aberrations and increased corneal backward light scattering that can lead to "blurred vision". "Eye fatigue" occurs when patients with dry eye struggle to see things under such visual symptoms.

Binocular summation and visual function with induced anisocoria and monovision

The advances in new techniques for correcting presbyopia, such as a small aperture combined with monovision, require an in-depth study of binocular aspects. In this work, we have studied binocular visual performance of 12 subjects after inducing different degrees of anisocoria combined with two different add powers in the non-dominant eye. We have analysed visual performance in terms of the visual-discrimination capacity (a function to evaluate the strength of bothersome halos) and the contrast-sensitivity. The results show a deterioration of the binocular vision when inducing anisocoria and with any add power, with a higher perception of halos, a lower contrast sensitivity and poorer binocular summation of these visual functions on increasing anisocoria. This deterioration is clinically acceptable in the case of low add power, since positive binocular summation is maintained in contrast sensitivity, and visual discrimination is not altered.

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

Purpose

To investigate whether suppression of blue light can improve visual function in patients with short tear break up time (BUT) dry eye (DE).

Methods

Twenty-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.

Results

The 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),

Conclusions

Protecting 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.

Intraocular Scattering after Instillation of Diquafosol Ophthalmic Solution

PURPOSE

To assess the changes in intraocular scattering before and after instillation of diquafosol ophthalmic solution in patients with short tear breakup time (TBUT) dry eye.

METHODS

We prospectively examined 20 eyes of 20 short TBUT dry eye patients (study group) and age-matched 20 eyes of 20 healthy subjects (control group). Intraocular scattering was measured as the objective scattering index (OSI) at 0.5-second intervals over 10 seconds without blinking. Patients were instructed to start topical administration of 3% diquafosol ophthalmic solution six times daily for 4 weeks.

RESULTS

The OSI significantly deteriorated after 7.0 seconds compared with the initial value of OSI after the blinking in the study group. The OSI was also significantly higher in the study group than in the control group at 4.5 to 10.0 seconds after the blinking (p < 0.05). We found significant improvements 2 weeks after treatment not only in TBUT (p < 0.001) but also in the mean OSI, the OSI change rate, and the slope of the linear regression line of the OSI within 10 seconds (p < 0.001, p = 0.003, and p = 0.002, respectively). We also found significant improvements 4 weeks after treatment in these variables.

CONCLUSIONS

Intraocular scattering deteriorates significantly with time in patients with short TBUT dry eye. Diquafosol ophthalmic solution exhibits an improvement not only in TBUT but also in intraocular scattering, indicating that diquafosol is also effective for improving the optical quality of the eye.

Intra- and Intersession Repeatability of an Optical Quality and Intraocular Scattering Measurement System in Children

Purpose

To evaluate intra- and intersession repeatability of objective optical quality and intraocular scattering measurements with a double-pass system in children.

Methods

Forty-two eyes of 42 children were included in the study. An optical quality analysis system (OQAS) was used to measure optical quality parameters, including modulation transfer function cutoff frequency (MTF_cutoff), Strehl ratio (SR), OQAS values (OV) at 3 different contrasts and objective scatter index (OSI). Three measurement sessions with 10-min intervals were operated by the same technician, and in each session four consecutive measurements were obtained.

Results

Mean values for MTF_cutoff, SR and OSI were 46.85 ± 7.45cpd, 0.27 ± 0.06 and 0.34 ± 0.22 respectively. 1) The intraclass correlation coefficients were ranged from 0.89 to 0.97 and coefficients of variation from 0.06 to 0.16 for all the parameters in the first session; the relative repeatability were 11.1% (MTF_cutoff), 22.5% (SR), 10.9% (OV100%), 16.6% (OV2%), 22.4% (OV9%) and 56.3% (OSI). Similar results were found in the second and third sessions. 2) Bland-Altman analysis showed that narrow 95% confidence intervals (compared between the first and second sessions) ranged from -5.42 to 5.28 (MTF_cutoff), -0.05 to 0.07 (SR), -0.18 to 0.18 (OV100%), -0.26 to 0.29 (OV20%), -0.33 to 0.39 (OV9%) and -0.11 to 0.09 (OSI); the comparison between any two of the three sessions showed similar results.

Conclusion

Measurements of optical quality and intraocular scattering in children by the double-pass system showed good intra- and intersession repeatability. Retinal image quality is high and intraocular scattering is low in children.