The efficacy of a device-based approach to microorganism disinfection and protein removal for orthokeratology lenses in varied clinical circumstances.

PURPOSE: RigidCare is an electrolysis-based device that recently obtained approval from the US's FDA to sterilise microorganisms and remove proteins for orthokeratology (O-K) lenses. The study was conducted to investigate the device's performance in varied clinical circumstances. METHODS: Trial lenses and private lenses were employed by O-K lens wearers from five hospitals for an evaluation of disinfection and sterilisation and an assessment of protein removal, respectively. Menicon multipurpose solution and protein remover were selected for use with the control group. Following the instructions, pre-cleaning lens samples, post-cleaning lens samples and residual solution samples of trial lenses of the experimental and control groups were collected for microorganism examinations by an experienced third-party testing organisation. The levels of protein deposition for these two approaches were rated by senior O-K experts. Categorical variables were analysed using statistical tests, such as the chi-squared test and Fisher's exact test. RESULTS: The microbial positive rate detected from the pre-cleaning and post-cleaning lens samples and the residual solution of the trial lenses for the experimental and control group was 4/76 vs 1/74 (P = 0.37), 1/76 vs 0/74 (P = 1.00) and 0/76 vs 8/74 (P = 0.006), respectively. Following protein removal, the experimental group exhibited a significantly higher overall proportion of lenses rated as 'clean' or with a 'mild deposit' (96.4 %, 79/82) compared to the control group (85.7 %, 66/77), with a significant difference (P < 0.05). CONCLUSION: This multi-center study demonstrated that RigidCare exhibited superior efficacy in disinfection, sterilisation and protein removal as compared to Menicon multipurpose solution and protein remover.

High myopia control is comparable between multifocal rigid gas-permeable lenses and spectacles.

Purpose: Ocular pathology may be reduced by slowing myopia progression. The purpose of this study was to evaluate the potential of a novel custom-designed rigid gas permeable (RGP) contact lens to control high myopia by comparing the efficacy of multifocal RGP lenses and single-vision spectacles for high myopia control. Methods: The medical records of children fitted with spectacles or multifocal rigid gas-permeable lenses between January 2018 and May 2020 were retrospectively reviewed. Children (5-17 years) with non-cycloplegic spherical equivalent refraction of ≤ -6.00 D or spherical equivalent refraction > - 6.00 D with baseline axial length ≥ 26.5 mm, and astigmatism of ≥ -2.00 D were included. Axial length and refraction were measured at baseline, before fitting the participants with multifocal rigid gas-permeable lenses or spectacles, and at 1- and 2-year follow-up visits. Changes in axial length were compared between the groups. Results: Among the 77 children with 1-year follow-up data, the mean axial elongation was 0.20 ± 0.17 mm and 0.21 ± 0.14 mm in the multifocal rigid gas-permeable and control groups, respectively, without significant differences between groups (F = 0.004, p = 0.835). Among the 41 patients who completed 2 years of follow-up, the mean axial elongation values in the multifocal rigid gas-permeable and control groups were 0.21 ± 0.15 mm and 0.24 ± 0.13 mm, respectively, at the 1-year follow-up, and 0.37 ± 0.27 mm and 0.43 ± 0.23 mm, respectively, at the 2-year follow-up, without significant between-group differences at either time point (p = 0.224). Conclusion: Axial length increased at a similar rate in both the control (spectacles) and multifocal rigid gas-permeable lens groups, suggesting that multifocal rigid gas-permeable lenses have no significant impact on controlling high myopia progression compared with spectacles.

The correlation between modifications to corneal topography and changes in retinal vascular density and retinal thickness in myopic children after undergoing orthokeratology.

Purpose: This study aimed to investigate the relationship among changes in corneal topography, retinal vascular density, and retinal thickness in myopic children who underwent orthokeratology for 3 months. Method: Thirty children with myopia wore orthokeratology lenses for 3 months. Using optical coherence tomography angiography (OCTA), the retina was imaged as 6 × 6 mm en-face images at baseline and 3 months after orthokeratology. Cornea data was acquired by topography and analyzed by customer MATLAB software. The cornea was divided into 3 zones and 9 sectors. The relative corneal refractive power shift (RCRPS) was used in this study. Changes in retinal vascular density (RVDC) and retinal thickness change (RTC) were associated with RCRPS by using spearman test. Statistical significance was set at p < 0.05. Result: A significant correlation was observed between the RVDC and the RCRPS in many regions (the r was 0.375 ~ 0.548, all p value <0.05). Significant positive correlations were found between RVDC in inner and outer temple regions with RCRPS at inner and outer nasal sectors. There were no significant correlations between RTC and RCRPS in other sectors except in the central cornea and the outer nasal retina (r:0.501, p:0.006). At baseline and 3 months after wearing the orthokeratology lens, no significant differences in the retinal microvasculature or thickness (p > 0.05) were observed at any regions. Conclusion: The correlation between the cornea and the retina was observed after orthokeratology. Cornea changes may affect regional retinal responses accordingly，which may explain how orthokeratology delays myopia progression partially.

The effect of orthokeratology lenses on optical quality and visual function in children.

Purpose: To assess changes in optical quality and visual function in children after 3 months of wearing orthokeratology (OK) lenses. Methods: A total of 25 myopic children aged 8-12 years were recruited and completed the follow-up study. Optical quality, visual function and corneal morphology were assessed at baseline and at follow-ups 1 and 3 months after wearing OK lenses. Optical quality parameters mainly included the modulation transfer function (MTF) cutoff, objective scattering index (OSI), Strehl ratio (SR) and the predicted visual acuities (PVAs). Visual function was assessed by visual acuity, monocular contrast sensitivity function (CSF) across five spatial frequencies and the area under the log contrast sensitivity function (AULCSF) that was also computed as an index for overall CSF. Results: The MTF cutoff and SR values both increased after 1 month of wearing the OK lenses (baseline vs. 1 month: P MTF = 0.008 and P SR = 0.049); this improvement plateaued after 3 months of lens wear (1 month vs. 3 months: P MTF = 0.626, P SR = 0.428). The corneal morphology also showed the similar change trend. The OSI showed the opposite change trend (baseline vs. 1 month: P OSI < 0.001; 1 month vs. 3 months: P OSI = 0.720). The mean CSF at 1.5 cpd decreased significantly after 1 month of wearing the lenses (baseline vs. 1 month: p = 0.001) and recovered after 3 months of lens wear (baseline vs. 3 months: p = 0.076). CSF at spatial frequencies of 3, 6, 12 and 18 cpd as well as the AULCSF did not significantly differ between any two timepoints (all Ps > 0.05). Conclusion: After 3 months of wearing OK lenses, the subjects exhibited a decrease in optical quality, similar to corneal morphology, whereas their visual function remained largely unchanged. Thus, the optical quality was more susceptible to OK lenses than visual function in children. The initial month of OK treatment of children is a key period to be paid close attention to deterioration of optical quality and visual function.

The Long-Term Effect of Blue-Light Blocking Spectacle Lenses on Adults' Contrast Perception.

Purpose: To evaluate the long-term effect of two different degrees of blue-light blocking (BB) spectacle lenses on adults' contrast perception under various lighting conditions. Methods: In total, 144 healthy adults aged 24.70 (±4.32 years) were recruited to this randomized controlled trial. The participants were randomly divided into three groups and used three different spectacle lenses (15% BB: 15% blue-blocking spectacle lenses; 30% BB: 30% blue-blocking spectacle lenses; RC: regular clear lenses serving as control). Contrast sensitivity under four light conditions (scotopic and photopic, both with/without glare) was measured using standard clinical tests at baseline, 1 month, 3 months and 6 months of use. The area under the log contrast sensitivity function (AULCSF) was also computed as an index for their overall contrast sensitivity across spatial frequencies. Results: There was no significant difference in AULCSFs among the three types of spectacle lenses under any light condition (all P > 0.81). No statistical difference was found in the AULSCF among the four time points (all P > 0.39), with no interaction between the effects of group and time (all P > 0.42). Conclusion: Wearing blue-light blocking lens had no clinically significant effect on adults' long-term contrast perception under scotopic or photopic conditions, or with glare.

Comparison of Two Main Orthokeratology Lens Designs in Efficacy and Safety for Myopia Control.

Purpose: This study aimed to compare the efficacy and safety of corneal refractive therapy (CRT) lenses and vision shaping treatment (VST) lenses for myopia control in children. Methods: Medical records of 1,001 children (2,002 eyes) who had been fitted with orthokeratology lenses for over 1.5 years were retrospectively reviewed. We collected the clinical data of four types of orthokeratology (OK) lenses available: one CRT lens (brand: CRT) and three VST lenses (brands: Euclid, Alpha, and Hiline) over 1.5 years. Results were compared and analyzed using a one-way ANOVA and Pearson's chi-square test. Results: Axial length elongation in the CRT lens group was 0.13 ± 0.02 mm faster than that in the Euclid lens, 0.1 ± 0.02 mm faster in the Alpha lens, and 0.08 ± 0.02 mm faster in the Hiline lens over the 1.5-year period (all P < 0.05). Among the subjects, 37.3% of them using the CRT lens experienced more than 1 D of refractive growth, compared with 20.2-30.8% of subjects wearing the three groups of VST lenses (all P < 0.05). A lower incidence of total adverse events was found with the CRT lenses compared with the VST lenses (P < 0.05), especially corneal staining. No difference was found in axial length elongation, refraction growth, and incidence of adverse events among the three types of VST lenses (all P > 0.05). Conclusions: Compared with the VST lenses, CRT lenses demonstrated a weaker effect on myopia control but with a better safety profile. Different types of VST lenses had similar efficacy and safety in the context of controlling myopia progression.

Effect of orthokeratology on axial length elongation in moderate myopic and fellow high myopic eyes of children.

CLINICAL RELEVANCE: The effects of orthokeratology (Ortho-K) on myopic eyes was examined, providing confidence to optometrists applying Ortho-K to high myopic and anisometropic children. BACKGROUND: Ortho-K slows the progression of low to moderate myopia. The effectiveness of Ortho-K in Chinese children with fellow moderate and high myopic eyes was determined. METHODS: This retrospective study included female (n = 35) and male (n = 30) children with moderate myopia in one eye (spherical equivalent refractive (SER) error ≤ -3.00 D, but > -6.00 D) and high myopia in the contralateral eye (SER error ≤ -6.00 D). Three age groups were included: 7-10-years (n = 18), 11-12-years (n = 21), and 13-15-years (n = 26). Baseline refraction and axial lengths were measured before fitting Ortho-K lenses worn nightly for at least eight-hours, and after one-year. RESULTS: Axial length increased 0.14 ± 0.13-mm (mean ± standard deviation) and 0.13 ± 0.16-mm in the moderate and high myopic groups respectively (p = 0.78). For females, axial elongation in the moderate and high myopic groups was 0.10 and 0.08-mm respectively. For males, it was 0.19-mm in both groups. Axial elongation in 7-10-year-old children with moderate and high myopic eyes was 0.24 ± 0.14 and 0.21 ± 0.15-mm respectively. In 11-12-year-old children, it was 0.12-mm in both myopic groups. In 13-15-year-old children, it was 0.09-mm in both groups. In moderate myopic eyes, axial elongation in the youngest group was greater than the other two age groups (p < 0.01). In high myopic eyes, there were no differences among the age groups (p = 0.06). CONCLUSIONS: Ortho-K was equally effective in reducing myopic progression in moderate and in contralateral high myopic eyes. Axial elongation was greater for males than females. For both sexes, it decreased at the same rate with increasing age, regardless of difference in myopia.

Clinical observations of the effect of orthokeratology in children with myopic anisometropia.

PURPOSE: To evaluate the clinical effect of orthokeratology in controlling myopia and treating anisometropia among children with myopic anisometropia. METHODS: A total of 108 myopic anisometropic children aged 8-16 years old who wore orthokeratology lenses in both eyes were enrolled in this study and followed up for over 1 year. The more severely myopic eye of each patient was assigned to the more myopic group (108 eyes), with a mean spherical equivalent refraction of -4.25 (-5.00, -3.38) D; the opposite eye of each patient was assigned to the less myopic group (108 eyes), with a refraction of -2.75 (-3.63, -1.88) D. This study observed and analyzed changes in ocular parameters after orthokeratology (Wilcoxon signed-rank test). RESULTS: In children who wore orthokeratology lenses for approximately 1 year, the level of anisometropia significantly dropped from 1.38 (1.13, 1.75) D to 1.25 (1.13, 1.75) D (P = .005). The difference between the axial lengths of the two eyes significantly dropped from 0.54 (0.37, 0.74) mm to 0.46 (0.28, 0.67) mm (P< .0001). CONCLUSIONS: Orthokeratology seemed to be more effective at delaying the progression of myopia in the more myopic eyes than in the less myopic eyes of myopic anisometropic children. Orthokeratology lenses are suitable for anisometropic children, although the effectiveness of orthokeratology against anisometropia requires additional follow-up time for further observation and study.

Changes and Diurnal Variation of Visual Quality after Orthokeratology in Myopic Children.

PURPOSE: To assess the changes and the diurnal variation of visual quality after orthokeratology in myopic children. METHODS: Forty-four eyes of 22 subjects with a mean age of 10.55 ± 1.53 years (8 to 14 years) were enrolled in this prospective study. Their spherical equivalent ranged from -1.25 to -4.25 diopters (D) and astigmatism was less than 1.00 D. Parameters including corneal curvature, ocular objective scatter index (OSI), the modulation transfer function (MTF), root mean square of ocular and corneal wavefront aberrations, and contrast sensitivity function (CSF) were measured before and at two time points during the same day after 1 month of orthokeratology. RESULTS: After orthokeratology, uncorrected visual acuity (UCVA) and spherical equivalent were significantly improved from baseline (P < 0.001), and their diurnal variation was not significant (P=0.083, 0.568). OSI increased from 0.29 ± 0.15 to 0.65 ± 0.31 (P < 0.001). MTF decreased significantly (P < 0.01). Corneal curvature and ocular total aberration decreased (P < 0.001), while the ocular and corneal higher-order aberration increased significantly (P < 0.01). The CSF under photopic condition decreased at 3 cpd (P=0.006) and increased at 18 cpd (P=0.012). The diurnal variation of CSF at 18 cpd under mesopic and high glare conditions and at 12 cpd under photopic condition was significant (P=0.002, 0.01, 0.017). CONCLUSIONS: Orthokeratology can effectively improve UCVA and high spatial frequency CSF by decreasing the low-order aberrations. However, MTF and CSF at low spatial frequency decreased because of the increase of intraocular scattering and high-order aberrations. Meanwhile, CSF at high spatial frequency fluctuates significantly at two times during the same day after 1 month orthokeratology.

Short term effect of choroid thickness in the horizontal meridian detected by spectral domain optical coherence tomography in myopic children after orthokeratology.

AIM: To investigate choroidal thickness changes in the horizontal meridian after orthokeratology. METHODS: This is a prospective cross-sectional observed study. Subjects (n=30; 11.3±1.7y) with low-to-moderate myopia (-1.0 to -6.0 diopters), wore orthokeratology (Ortho-K) lenses for 3mo. Before and after Ortho-K, OCT scans were made through the fovea in the horizontal meridian. Choroid thickness around the fovea was acquired by custom software. The analyzed regions along the horizontal meridian were divided into 7 equal zones. Ocular parameters were measured by Lenstar LS 900 non-contact biometry. RESULTS: Only the right eye ocular parameters were analyzed in this study. Before Ortho-K, choroidal thickness along the horizontal meridian was 273.7±31.8 µm in the temporal zone, 253.1±38.6 µm in the macula zone, and 194.8±52.2 µm in the nasal zone. After Ortho-K, the choroid was thicker in each horizontal zone (P<0.05). The increased thickness was greatest in the temporal zone (13.5±22.5 µm) and least in the nasal zone (8.4±14.2 µm). The axial length (AL) increased 0.02 mm (P>0.05). The choroid thickness change in each horizontal zone was negatively correlated with AL (r, -0.3 to -0.4; P<0.05) except one of the nasal zones. CONCLUSION: In myopic children, the thickness of the choroid is greatest in the temporal zone and thinnest in the nasal zone. After nightly Ortho-K for 3mo, the thickness increase along the horizontal meridian. The choroid thickness changes are negatively correlated with the change of AL.

Short-Term Effects of Overnight Orthokeratology on Corneal Sensitivity in Chinese Children and Adolescents.

PURPOSE: To assess the effects of the 3-month period of orthokeratology (OK) treatment on corneal sensitivity in Chinese children and adolescents. METHODS: Thirty subjects wore overnight OK lenses in both eyes for 3 months and were assessed at baseline, 1 day, 1 week, 1 month, and 3 months after the treatment. Changes in corneal sensitivity were measured by the Cochet-Bonnet (COBO) esthesiometer at the corneal apex and approximately 2 mm from the temporal limbus. Changes in refraction and corneal topography were also measured. RESULTS: Central corneal sensitivity suffered a significant reduction within the first month of the OK treatment period but returned to the baseline level at three months (F = 3.009, P=0.039), while no statistically significant difference occurred in temporal sensitivity (F = 2.462, P=0.074). The baseline of central corneal sensitivity correlated with age (r = -0.369, P=0.045). A marked change in refraction (uncorrected visual acuity, P < 0.001; spherical equivalent, P < 0.001) and corneal topographical condition (mean keratometry reading, P < 0.001; eccentricity value, P < 0.001; Surface Regularity Index, P < 0.001) occurred, but none of these measurements were correlated with corneal sensitivity. CONCLUSIONS: A 3-month period OK treatment causes a reduction in central corneal sensitivity in Chinese children and adolescents but with a final recovery to the baseline level, which might be because neuronal adaptation occurred earlier in children and adolescents than in adults.

Comparison of three monocular methods for measuring accommodative stimulus-response curves.

PURPOSE: The aim was to evaluate the repeatability of dynamic measurement of the accommodative stimulus-response curve (ASRC) at three different dioptric speeds using a modified instrument and its agreement with two other methods. METHODS: Twenty-nine adults (23.5 ± 2.0 years) were enrolled in the study. ASRC was measured monocularly using three methods: dynamic and static measurement using a motorised Badal system mounted on an open-field auto-refractor (WAM-5500, Grand Seiko Co., Ltd, Japan) and the minus lens technique. Dynamic measurements were conducted at three dioptric stimulus speeds to simulate continuous stimuli for ASRC (0.25, 0.40 and 0.55 D/s), with three repetitions for each speed. All three types of ASRCs were fitted with third-degree polynomial equations. The slope and objective accommodative amplitude of the ASRC were analysed. RESULTS: The repeatability of objective accommodative amplitude worsened as the speed of the stimuli increased. The repeatability of the slope was best at a speed of 0.40 D/s and worst at 0.55 D/s. The measurement method significantly influenced the objective accommodative amplitude values and slope (both, p < 0.001). The minus lens technique yielded the highest amplitude of accommodation (6.21 ± 0.84 D) and steepest slope (1.11 ± 0.14), followed by the static Badal method (5.60 ± 0.83 D and 0.89 ± 0.09 D). The objective accommodative amplitude decreased with increasing speed during dynamic measurements. There was no difference between the slopes at 0.25 D and 0.40 D/s (p > 0.05) and the slope was lowest at 0.55 D/s. CONCLUSION: The accommodative stimulus-response curve values are method-dependent and the significant differences between three methods used to determine the ASRC based on slope and accommodative amplitude indicate that these methods are non-interchangeable. Using dynamic measurements, accommodative behaviour varies with the speed of dioptric-change of the stimulus. A speed of 0.40 D/s appears to be the best compromise in terms of time, results and repeatability for dynamic ASRC measurement.

Effects of Near Addition Lenses and Prisms on Accommodative Microfluctuations in Chinese Children.

PURPOSE: To investigate the effects of different near addition lenses and prisms on accommodative microfluctuations (AMFs) in Chinese early-onset myopic (EOM) and emmetropic (EMM) children. METHODS: Twenty-one EMM and 27 EOM children aged between 9 and 14years participated in the study. At near, 23 children were exophoric (exo, <0 Δ), and 25 were esophoric (eso, ≥0 Δ). The AMFs and phoria through multiple addition lenses (-1.00, 0, +1.00, +2.00, and +3.00D on each eye) and prisms (base-in prism power: 3 Δ, 2 Δ, 1 Δ; and base-out prism power: 1 Δ and 2 Δ on each eye) were measured at 25cm under binocular viewing conditions with a Grand Seiko WAM-5500 auto-refractor and a modified Thorington card. RESULTS: Higher AMFs were found in EOM than in EMM (EOM, 0.19±0.06D; EMM, 0.16±0.03D; p=0.035). Plus additions from +1.00 to +3.00D reduced the AMFs in both EMM and EOM, except +3.00D for EMM. In both refractive groups, -1.00D additions increased AMFs. Esophores showed greater AMFs compared with exophores (esophores, 0.20±0.01D; exophores, 0.16±0.01D; p=0.012). Prisms increased the AMFs in EMM and did not alter the AMFs in EOM. CONCLUSIONS: Microfluctuations of accommodation decreased with plus addition lenses and increased with negative addition lenses. Plus addition lenses of +2.00 to +3.00D for EOM and +2.00D for EMM decreased AMFs the least at a 25-cm working distance. Esophores had higher AMFs than exophores, indicating that phoria status influences AMFs.

The impact of eyelid and eye contour factors on a toric soft contact lens fitting in Chinese subjects.

PURPOSE: To evaluate eyelid and eye contour factors that can influence the fitting of toric soft contact lenses (TSCLs). METHODS: Thirty-two subjects (64 eyes) were enrolled and fitted with Lo-Torque design TSCLs. One eye of each subject was randomly selected. High-resolution digital images were acquired after the subjects had worn the lens for 20 minutes, and the images were then processed with Adobe Photoshop. The palpebral aperture (PA), various angles of the eyelid, horizontal visible iris diameter (HVID), and lens parameters were obtained. Finally, lens fitting was evaluated. RESULTS: During the assessment of the correlations between the eyelid and eye contour factors and the lens fitting, there were four pairs of significant correlations: (1) the PA and rotational direction of the lens: larger eye PA was associated with a greater possibility of nasal rotation of the corresponding lens (P=0.03); (2) the angle of the central lower lid (θ3) and the rotational stability of the lens: the larger the angle was, the worse the rotational stability was (P=0.02); (3) the lower lid angle of the medial canthus (θ5) and temporal rotational recovery: the smaller the angle was, the more quickly the lens recovered (P=0.05); and (4) HVID and routine fitting assessments: the larger the HVID was, the looser the lens fitting (P=0.00). Finally, when assessing correlations between some lens parameters and the orientation of the lens, we found that lower sphere values were associated with quicker lens recovery (P=0.04). CONCLUSION: Several eye factors, as well as lens characteristics, had impacts on the TSCLs fitting, including the PA, the angle of the central lower lid (θ3), the lower lid angle of the medial canthus (θ5), and the sphere of the lens. These factors should receive particular attention when fitting TSCLs.

Repeatability, reproducibility, and agreement of central anterior chamber depth measurements in pseudophakic and phakic eyes: optical coherence tomography versus ultrasound biomicroscopy.

PURPOSE: To evaluate the intraexaminer repeatability, interexaminer reproducibility, and agreement of central anterior chamber depth (ACD) measurements obtained by anterior segment optical coherence tomography (AS-OCT) and ultrasound biomicroscopy (UBM) in pseudophakic eyes and phakic eyes. SETTING: Eye Hospital, Wenzhou Medical College, Wenzhou, Zhejiang, China. METHODS: In this prospective study, the central ACD in right pseudophakic eyes and right phakic eyes was measured with the Visante AS-OCT system and the OTI-Scan HF 35-50 UBM system. Intraexaminer repeatability and interexaminer reproducibility were evaluated in a subgroup of eyes from each group. The repeatability and reproducibility of the measurements were evaluated using intraclass correlation coefficients (ICCs) and the Bland-Altman method. RESULTS: The mean ACD in the 70 pseudophakic eyes was 3.91 mm +/- 0.29 (SD) by AS-OCT and 3.76 +/- 0.33 mm by UBM and in the 70 phakic eyes, 2.97 +/- 0.31 mm and 2.90 +/- 0.32 mm, respectively. The 95% limits of agreement between the 2 methods were -0.32 to 0.62 mm in pseudophakic eyes and -0.11 to 0.25 mm in phakic eyes. The ICC for the repeatability and reproducibility of AS-OCT and UBM measurements was high (range 0.985 to 0.996). CONCLUSIONS: Both AS-OCT and UBM ACD measurements showed good repeatability and reproducibility. However, the agreement was better in phakic eyes than in pseudophakic eyes. Thus, the measurements should not be used interchangeably in pseudophakic eyes.

[Enhanced near stereopsis after phacoemulsification and implantation of posterior chamber intraocular lens by prescribing addition properly].

OBJECTIVE: To improve near stereopsis in pseudophakic eyes after phacoemulsification and implantation of posterior chamber intraocular lens (IOL). METHODS: This prospective case-series study comprised 92 eyes of 46 patients aged 50 to 70 years [mean age (61.33 +/- 5.54) years] who had phacoemulsification and implantation of posterior chamber IOL, including 24 unilateral pseudophakia (Group A) and 22 bilateral pseudophakia (Group B). The accommodative amplitude, relative accommodation, reading addition, near stereoacuity, etc. were measured. All data were analyzed with the SPSS11.0 for Windows. RESULTS: (1) The mean value of monocular accommodative amplitude in the group A and group B was (2.05 +/- 1.12) and (2.35 +/- 1.30) D, respectively. (2) In the group A and group B, the binocular add was (2.08 +/- 0.37) and (2.13 +/- 0.46) D, respectively, and the monocular add was (2.20 +/- 0.42) and (2.01 +/- 0.39) D, respectively. There was a significant difference between the binocular add and the monocular add (t = 2.33, 2.20, P<0.05) , and between left monocular add and right one (t =3.70, 5.02, P<0.01) in each group. (3) The near stereopsis with monocular add was better than that with binocular add in each group, the difference was significant (X2 = 6.46, 7.02, P = 0.04, 0.03). CONCLUSION: Monocular add is beneficial to a pseudophakia with posterior chamber IOL implantation to improve near stereopsis.