Stereopsis Acuity Research Articles

Stereopsis after bilateral implantation of Toric intraocular lenses in high myopic cataract patients with astigmatism

PurposeTo evaluate near, intermediate, distance visual acuity and stereopsis after bilateral implantation of Toric intraocular lenses (IOLs) in high myopic patients with astigmatism. MethodsBilateral Toric or non-Toric IOL implantation (n ​= ​40 eyes each) was performed on high myopic cataract eyes with astigmatism. Best-corrected distance visual acuity (BCDVA), uncorrected intermediate visual acuity (UCIVA), uncorrected near visual acuity (UCNVA), residual refractive astigmatism (RRA), and near, intermediate, and distance stereoacuity were measured postoperatively at 7 days, 1 month, and 3 months. ResultsThe three-month postoperative BCDVA, UCIVA, and UCNVA of the Toric group were 0.08 ​± ​0.07, 0.30 ​± ​0.11, and 0.23 ​± ​0.14 LogMAR. All improved over the preoperative assessments (P ​< ​0.05). The RRA, UCIVA, and UCNVA were significantly better in the Toric group than the non-Toric group at all follow-up examinations (all P ​< ​0.05). At 3 months, the median near and intermediate stereoacuity of the Toric group were 100 (range 40 – 400) and 120 (range 50 – 400) arcsec, which were better than the non-Toric group (both P ​< ​0.05). Fine near stereopsis ≥100 arcsec was present in 65% of the Toric patients, and 50% had good intermediate stereopsis of ≥100 arcsec. However among non-Toric patients, only 15% and 5% achieved fine near and intermediate stereopsis. The postoperative BCDVA and best-corrected distance stereoacuity were similar in the two groups (P ​> ​0.05). ConclusionsIn bilateral high myopic cataract patients with astigmatism, Toric IOLs not only improved UCIVA, UCNVA, and RRA, but also enhanced near and intermediate stereopsis acuity.

Do monocular myopia children need to wear glasses? Effects of monocular myopia on visual function and binocular balance.

This study aims to compare the binocular visual functions and balance among monocular myopic adolescents and adults and binocular low myopic adolescents and explore whether monocular myopia requires glasses. A total of 106 patients participated in this study. All patients were divided into three groups: the monocular myopia children group (Group 1 = 41 patients), the monocular myopia adult group (Group 2 = 26 patients) and the binocular low myopia children group (Group 3 = 39 patients). The refractive parameters, accommodation, stereopsis, and binocular balance were compared. The binocular refractive difference in Group 1, Group 2, and Group 3 was -1.37 ± 0.93, -1.94 ± 0.91, and -0.32 ± 0.27 D, respectively. Moreover, uncorrected visual acuity (UCVA), spherical equivalent (SE) and monocular accommodative amplitude (AA) between myopic and emmetropic eyes in Group 1 and Group 2 were significantly different (all P < 0.05). There was a significant difference in the accommodative facility (AF) between myopic and emmetropic eyes in Group 2 (t = 2.131, P = 0.043). Furthermore, significant differences were found in monocular AA (t = 6.879, P < 0.001), binocular AA (t = 5.043, P < 0.001) and binocular AF (t = -3.074, P = 0.003) between Group 1 and Group 2. The normal ratio of stereopsis according to the random dots test in Group 1 was higher than in Group 2 (χ2 = 14.596, P < 0.001). The normal ratio of dynamic stereopsis in Group 1 was lower than in Group 3 (χ2 = 13.281, P < 0.001). The normal signal-to-noise ratio of the binocular balance point in Group 1 was lower than Group 3 (χ2 = 4.755, P = 0.029). First, monocular myopia could lead to accommodative dysfunction and unbalanced input of binocular visual signals, resulting in myopia progression. Second, monocular myopia may also be accompanied by stereopsis dysfunction, and long-term uncorrected monocular myopia may worsen stereopsis acuity in adulthood. In addition, patients with monocular myopia could exhibit stereopsis dysfunction at an early stage. Therefore, children with monocular myopia must wear glasses to restore binocular balance and visual functions, thereby delaying myopia progression.

A comparative study on visual acuity and stereopsis outcomes between perceptual learning based on cloud services and conventional therapy for amblyopia

Background Amblyopia is a developmental disorder of spatial vision that results in both monocular and binocular deficits.Conventional therapy for amblyopia which focuses on monocular training can improve visual acuity.However, how to improve the binocular function, especially stereopsis is rarely studied. Objective This study was to evaluate the outcome of perceptual learning based on cloud services of improving stereopsis and visual acuity for amblyopia. Methods A randomized-controlled clinical study was performed.One hundred and seven amblyopic patients (178 eyes) with the age of 5—18 years old were recruited in The Second Affiliated Hospital of Anhui Medical University from July 2013 to March 2014.The patients were randomized into the perceptual learning group and the conventional therapy group.A perceptual learning based on cloud services with computer under the best corrected visual acuity was carried out in the perceptual learning group with 30-day duration as a course for 5—6 cycles, and training feedback data was obtained after each cycle for the regulation of following treatment.The dominant eye was covered during the training process.In the conventional therapy group, a training regimen of health eye covering that combined with eyesight training of amblyopic eye was performed.The stereopsis and visual acuity of the patients were estimated after training.Written informed consent was obtained from the parents or custodians of the children before entering the cohort. Results The total effective rate of visual acuity improvement is significantly higher in the perceptual learning group than that in the conventional therapy group after training (Z=6.368, P=0.012). The mean stereopsis value of the amblyopic eyes in the perceptual learning group and the conventional therapy group was (127±53)″ and (174±67)″ after training, which was significantly higher than (273±95)″ and (311±103)″ before training, respectively, and the increasing range of the mean stereopsis was considerably larger in the perceptual learning group than that in the conventional therapy group(t=12.329, 9.557, 15.649; all at P<0.05). In the perceptual learning group, the improving range of mean stereopsis was larger in the severe or moderate amblyopic eyes than that in the mild amblyopic eyes, and the improving range of mean stereopsis in ametropic amblyopia was larger than that in anisometropic amblyopia (all at P<0.05). Conclusions Both perceptual learning based on cloud services and conventional therapy can improve stereopsis and visual acuity in amblyopic eyes.However, perceptual learning based on cloud services can improve the treating compliance of children. Key words: Amblyopia/physiopathology; Vision, binocular/physiology; Visual acuity/physiology; Amblyopia/therapy; Children; Randomized controlled trials; Cloud services; Perceptual learning

Post LASIK progressive astigmatism in a child with partially accommodative esotropia

Refractive surgery is considered a safe and effective method for correction of refractive errors in adults. To report an unusual case of a young child with partially accommodative esotropia presenting with deterioration of vision and worsening of esotropia following refractive surgery. Unanticipated and progressive irregular corneal astigmatism along with deterioration of visual acuity and loss of stereopsis developed post- LASIK in a seven-year-old Indian child with partially accommodative esotropia. Keratorefractive surgery in young children has to be undertaken with caution, especially in such cases where there is no medical indication for refractive surgery and waiting beyond teenage years is a viable option.

Development of stereopsis among children

To study the development of stereopsis in children from 30 to 50 months of age. It was a prospective study.We examined the visual acuity and stereopsis of 152 normal children from 30 to 50 months of age. The stereopsis was examined with Titmus, RPS and TNO. In 152 children, a complete examination was performed in 119 children had visual acuity of >or= 0.6; 12 children had visual acuity of < 0.6; 21 children could not complete the examination. The mean age of these 21 children was significantly lower than the others. Using Titmus 60'', Titmus 100'' and RPS 60'' as the normal criteria, the normal ratio of near stereopsis acuity in the 119 children was correlated to the age by chi(2) test. They were divided into four groups by 5 month-age groups. The normal ratio in the 46 to 50 month group was significantly greater than that in the other three groups. The normal ratios was 89.9%, 94.1% and 95.0% for the criteria of Titmus 100'', RPS 200'' and TNO 240'', respectively. The stereopsis in children from 30 to 50 months of age is still in developing status. We suggest using 100'' for Titmus, 200'' for RPS and 240'' for TNO as normal stereopsis criteria in 3 to 4 year old children. RPS provides a reliable procedure for the measurement of stereopsis acuity in preschool children.

Study of binocular function in early stage after implantation of multifocal intraocular lens

To evaluate binocular function in the early stage after implantation of multifocal intraocular lens. Three weeks postoperatively, simultaneous perception, fusion, near and far-distance stereoacuity, visual acuity and visual symptoms were observed in 31 cases (46 eyes) with multifocal intraocular lens implantation (MIOL) [MIOL group, in which 16 cases with unilateral implantation (Ms) and 15 cases with bilateral implantation (Md)] and 32 cases (47 eyes) with single-focal intraocular lens implantation (SIOL) [SIOL group, in which 17 cases with unilateral implantation (Ss) and 15 cases with bilateral implantation (Sd)]. All patients obtained simultaneous perception and fusion sense, there was no significantly statistical difference between these two group (P > 0.05). Foveal far-distance stereoacuity was established in 38.7% cases among MIOL group (12/31) and 40.6% in SIOL group (13/32), with no statistically significant difference between these two groups (P > 0.05). Foveal near-distance stereoacuity was established in 41.9% MIOL cases (13/31) and in 15.6% SIOL group (5/32), the difference was statistically significant (P < 0.05). Foveal near and far-distance stereoacuity of either Ms and Md or Ss and Sd revealed no significantly statistical difference (P > 0.05). Two patients (6.5%) with MIOL in only one eye complained glare at night, others were satisfied. The stereopsis visual performance such as the quality of vision during eating, up-and-down stairs was improved in MIOL group [80.6% (25/31)] and in SIOL group [56.2% (18/32)], the difference was statistically significant (P < 0.05). There is a complete recovery of binocular vision in the early post-operative stage of MIOL implantation as compared with the normal value of aged people. Foveal near and far-distance stereoacuity after bilateral and unilateral implantation of either MIOL or SIOL revealed no statistically significant difference. Foveal near-distance stereopsis acuity of MIOL group was improved more quickly than that of SIOL group. MIOL has distinct advantage in providing whole-distance visual acuity and stereoacuity.

A study on stereopsis acuity of multifocal intraocular lens

目的 比较多焦点人工晶状体(MIOL)眼与单焦点人工晶状体(SIOL)植入术后患者的立体视锐度有无改变以评价多焦点人工晶状体植入的有效性及安全性.方法 2000年9月～2001年12月我院住院的老年性白内障患者中选择合适的44例(60眼),随机分为两组,每组30眼,行晶状体超声乳化吸出术,MIOL组植入AMO Array SA40N,SIOL组植人Allergan S140NB.术后1天查远、近视力,术后3月进行远、近视力及立体视锐度等视功能的检查,问卷调查视物情况及视觉症状.结果 MIOL眼具有与SIOL眼一样良好的非矫正远视力(分别为1.00±0.27,0.89±0.23,P＞0.05),MIOL眼非矫正近视力明显优于SIOL眼(分别为0.86±0.27,0.45±0.14,P＜0.05);双眼植入MIOL者近立体视觉优于双眼植入SIOL者.结论 MIOL植入安全而有效,可以提供与SIOL一样良好的远视力,而近视力及立体视觉更好。

ＢＲＡＤＤＩＣＫ ＲＡＮＤＯＭ‐ＤＯＴ ＧＲＡＤＥＤ ＳＴＥＲＥＯ ＳＬＩＤＥＳを用いた遠見立体視と視力の検討

ＢＲＡＤＤＩＣＫ ＲＡＮＤＯＭ‐ＤＯＴ ＧＲＡＤＥＤ ＳＴＥＲＥＯ ＳＬＩＤＥＳを用いた遠見立体視と視力の検討

X linked ocular albinism in Japanese patients.

Thirteen affected Japanese male patients and 13 female carriers with X linked ocular albinism from seven families were examined to assess their clinical findings and to compare them with those of white and black patients. Affected Japanese patients had poor visual acuity, horizontal nystagmus, macular hypoplasia, and loss of stereopsis. Some affected patients had non-albinotic fundus with moderate pigmentation. The amount of pigment in the fundus varied among affected patients and appeared to be between that of the white and black patients. All affected patients had brown irides that show no translucency. Interestingly, two affected patients had megalocornea and a third affected patient had posterior embryotoxon. All female carriers exhibited good visual acuity, normal eye position, stereopsis, brown irides without translucency, and the typical mosaic pattern in the fundus. The pigmented iris and fundus made the correct diagnosis of these affected patients difficult. Nine affected patients (70%) had been diagnosed initially as having congenital nystagmus, with or without macular hypoplasia, until they were reviewed for this study.

Binocular vision regained after monocular traumatic aphakia by wearing contact lenses.

In this study 35 patients with monocular traumatic aphakia were enrolled to document the degree of binocular vision gained by optical correction with contact lenses. The most important factors in achieving binocular vision were the interval between formation of the traumatic cataract and surgery and between the operation and starting wearing contact lenses. There was a statistically significant correlation between these two intervals and the achievement of near stereopsis and normal visual acuity.

Faulty depth perception caused by cyclotorsion.

IN A RECENT paper, Nicholls1reviewed the literature dealing with the relation of heterophorias to depth perception. This author concludes that, within fairly wide limits, heterophoria seems to have little influence on the acuity of stereopsis. This is certainly true, inasmuch as cyclotorsional movements of the eyes are not involved. In this paper an attempt is made to show that, under certain circumstances, misinterpretations of space frequently occur owing to cyclotorsion, i. e., wheel-like rotations of the eyes about their lines of fixation (Ogle2). Cyclotorsion is normally performed in the interest of proper alignment of the eyes to provide binocular single vision and reliable distance discrimination of vertically located objects. Cyclomotions of the eyes for this purpose are called movements. According to Ogle,2the most evident characteristics of the cyclofusional mechanisms can be described as follows: 1. Both eyes perform essentially equal, but opposite, cyclotorsional movements

Some Data Concerning Verhoeff’s Quantitative Test for Measuring the Acuity of Binocular Stereopsis

Some Data Concerning Verhoeff’s Quantitative Test for Measuring the Acuity of Binocular Stereopsis

EVALUATION OF STEREOPSIS

Increasing use of visual tests in the field of personnel selection, 1 special military needs and the rapid expansion of aviation have stimulated interest in technics which measure stereopsis. For several years the Howard-Dolman test of stereopsis 2 (not to be confused with the original Howard test 3 ) has been used extensively, and more recently Verhoeff 4 has described another method. Verhoeff's test evaluates the acuity of stereopsis by means of a simple device which causes the estimate of relative depth to be based on binocular parallax, eliminates eye-hand coordination and difference in image size as aids in forming judgments and permits little opportunity (1 chance in 65,000) for passing the test by guessing. 4 The results obtained when a group of adolescents was given both these tests are discussed in this report. METHOD The entire student population of a boys' preparatory school was given a thorough ophthalmic examination, 5