Factors influencing stereoacuity outcomes in adults with acquired strabismus

PURPOSE: Functional improvements of binocular vision after strabismus surgery in adults are common but not well understood. In a prospective study, factors associated with stereoacuity outcome in patients with strabismus acquired following binocular vision maturation were investigated. DESIGN: Prospective data collection. METHODS: Twenty-three patients aged 14 to 85 years with acquired strabismus were enrolled. Random dot stereoacuity was quantified using a battery of tests including the Randot Preschool Stereoacuity test, the Randot (version 2) shapes test, and the Randot Butterfly test. RESULTS: Ninety-six percent of patients achieved measurable stereoacuity following successful eye realignment. Better median stereoacuity is achieved in patients with the following characteristics: < or =12 months of constant strabismus (60 vs 400 seconds of arc with >12 months' strabismus, P < .001); a presurgical capacity for fine to moderate stereopsis (60 vs 400 seconds of arc with coarse or no measurable stereopsis, P < .005); a presurgical capacity for macular fusion (60 vs 400 seconds of arc with no measurable macular fusion capacity, P < .001); and postsurgical orthotropia (100 seconds of arc) or intermittent orthotropia (100 seconds of arc vs 2000 seconds of arc with 5 to 8 prism diopters (PD) of postsurgical residual strabismus, P < .05). CONCLUSION: Surgical correction of acquired strabismus is associated with recovery of stereopsis. Factors associated with stereoacuity outcomes include duration of strabismus and presurgical binocular vision capacity. A postsurgical correction of orthotropia or intermittent orthotropia supports better stereoacuity than a larger residual angle of strabismus subtending up to 8 PD of deviation.     

Stereopsis in refractive surgery

PURPOSE: To examine stereopsis in myopic refractive surgery patients undergoing sequential bilateral and unilateral treatment. DESIGN: Prospective, observational, cohort study. METHODS: Setting: Clinical practice. Patients: Eighty-three patients were studied; 55 had sequential bilateral and 28 had unilateral treatment. Mean age was 32 years. Stereopsis was measured using a multitarget red-green anaglyph stereo vision test. Only patients with fine preoperative stereopsis were included in the study. Repeat measurements were taken one week laser-assisted in situ keratomileusis (LASIK) or three weeks laser epithelial keratomileusis (LASEK) after treatment of one eye in all patients. Further measurements were taken at six and 12 weeks in unilaterally treated patients and after treatment of the fellow eye in bilaterally treated patients. RESULTS: A total of 38.6% of patients retained fine stereopsis (28 to 41 seconds of arc) over a range of anisometropia from 0.625 to 4.375. Moderate stereopsis (66 to 526 seconds of arc) was recorded 28.9% in the presence of 1.375 to 5.525 diopters of anisometropia. Poor/absent stereopsis (< or =2000 seconds of arc) was found in 32.5% in the presence of 2.1 to 8.0 diopters of anisometropia. A strong correlation was found between stereopsis and anisometropia, but interpatient variability was found. Uncorrected visual acuity (UCVA) in the untreated eye of > or =20/200 was associated with retention of fine stereopsis. Unilaterally treated patients showed improvement in stereopsis at six weeks after surgery. Sequential bilateral treatment had no deleterious effect on stereopsis. CONCLUSIONS: Loss of stereopsis was strongly correlated with anisometropia. UCVA in the untreated eye was a good indicator of postoperative stereopsis. Stereopsis improved during the postoperative adaptation period in unilateral treatments. Bilateral sequential treatment has no long-term effect on stereopsis.     

Predictive factors underlying the restoration of macular binocular vision in adults with acquired strabismus.

PURPOSE: To investigate whether macular binocular vision can be permanently lost following acquired strabismus and to identify predictive factors underlying its restoration. SUBJECTS AND METHODS: Twenty-three patients with strabismus acquired after binocular vision maturation were enrolled. Factors studied included duration of eye misalignment, age at treatment, pre-surgical strabismus type, pre-surgical diplopia, and pre-surgical capacity for binocularity. The restoration of macular binocular vision was evaluated between 1 and 3 years following successful eye re-alignment and was defined as 60 seconds of arc stereopsis or better on the Titmus circles and/or the Preschool Randot Stereoacuity test. RESULTS: Sixteen of 23 (70%) or 7/23 (30%) of patients achieved macular binocular vision following successful surgical eye realignment using the Titmus circles versus the Preschool Randot Stereoacuity test. Patients with < or =12 months constant eye misalignment were more likely to achieve macular binocular vision following treatment than patients with >12 months constant eye misalignment. CONCLUSIONS: Macular binocular vision continues to be susceptible to permanent loss in adult patients. Factors that are predictive of the restoration of macular binocular vision include duration of constant eye misalignment and the pre-surgical capacity for binocularity.     

Stereoacuity and foveal fusion in adults with long-standing surgical monovision

PURPOSE: Although binocular vision deficits occur in children who have a constant esotropia onset following significant maturation of stereopsis, it is uncertain whether adults are susceptible to changes to binocular vision. We examined binocular vision in adults with longstanding surgical monovision (> or =6 month's duration) to determine whether the binocular visual system remains susceptible to change. METHODS: Participants included 32 adults with longstanding monovision through laser-assisted in situ keratectomy or photorefractive keratectomy and 20 age-matched control subjects. After full binocular correction, binocular function was measured by using the Randot Stereoacuity Test, the Randot Preschool Stereoacuity Test, and the Worth 4-dot test at near and distance. Monovision patients were grouped as having low anisometropia (<1.5 spherical D) or moderate anisometropia (> or =1.5 spherical D). RESULTS: Non-parametric analysis of variance revealed a significant difference between group median stereoacuity (H = 16.062; P <.001). Pairwise multiple comparisons indicated both groups with monovision had significantly worse stereoacuity compared with control subjects (P <.05). Median stereoacuity values were 100 seconds of arc for patients with low anisometropia, 150 seconds of arc for patients with moderate anisometropia, and 40 seconds of arc for control subjects. A larger proportion of patients with moderate anisometropia failed the Worth-4 dot test at distance than control subjects (z = 2.619; P =.009). CONCLUSIONS: Reduced stereoacuity and an absence of foveal fusion in adults with longstanding surgical monovision suggest continued susceptibility of the binocular visual system to anomalous binocular experience.     

Aniseikonia and stereoacuity in pseudophakic patients. Unilateral and bilateral cases.

PURPOSE: To evaluate the efficacy of intraocular lens (IOL) implant procedures, analyzing visual function of the operated eyes and the resulting binocular vision. METHOD: The authors measured aniseikonia and stereoacuity in patients with both bilateral and unilateral posterior chamber intraocular lenses (PC IOLs). The aniseikonia was measured with the New Aniseikonia Test; the stereoacuity was evaluated with the Titmus Stereotest. RESULTS: In 41 patients with bilateral PC IOLs, aniseikonia measured with the New Aniseikonia Test ranged from 0% to 4% (mean, 0.76%; standard deviation = 1.04%). The average stereoacuity evaluated with the Titmus test was 7.68 circles (less than 60 seconds; range, greater than 800 to 40 seconds of arc), with 36 of 41 patients (87.8%) showing a stereoacuity less than or equal to 100 seconds of arc. In 37 patients with unilateral PC IOLs, the aniseikonia ranged from 0% to 6% (mean, 0.97%; standard deviation = 1.13%). Their stereoacuity also ranged from greater than 800 to 40 seconds (mean, 7.67 circles) (less than 60 seconds). In this group, 34 of 37 (91.8%) patients showed a stereoacuity less than or equal to 100 seconds of arc. CONCLUSION: Although the problem of aniseikonia still remains, a significant number of patients attain good binocular function after unilateral and bilateral PC IOL implantation.     

Binocular function and patient satisfactionafter monovision induced by myopic photorefractive keratectomy

Purpose:To measure binocular function and patient satisfaction with monovisioninduced by photorefract ve keratectomy (PRK) in myopic presbyopic patients.Setting:Refractive Department; Cleveland Clinic; Cleveland, Ohio, USA.Methods:This study comprised 21 myopic presbyopic patients with monovisioninduced by PRK. Sixteen emmetropic patients who had PRK served as a control group. Monovision was induced by undercorrecting the nondominant eye by 1.25 diopters for near vision and correcting, the dominant eye with emmetropia for distance vision. Monocular and binocular uncorrected Snellen visual acuities at 20 feet and 13 inches, manifest refraction, ocular dominance, stereopsis at 20 feet and 13 inches, Monocular and binocular contrast sensitivities, Worth-4-Dot test at 20 feet and ⅓ of a meter, and fusional convergence amplitudes were examined in each patient.Results:In the monovision group at near and distance, 20 patients (95.3%) had binocular visual acuity of 20/25 or better. No patient in the monovision group used reading glasses postoperatively; 4 of 16 patients (25.0%) in the control group used such glasses. All patients maintained binocular fusion and stereo acuity ranging from 40 to 800 seconds of arc. Mean patient satisfaction was 86% (range 40% to 100%). In the control group, 12 patients (75.0%) had binocular distance visual acuity of 20/25 or better and 11 (68.8%) had binocular near visual, acuity of 20/25 or better.Conclusion:Monovision PRK patients had better near vision than control PRKpatients, with minimal compromise in stereo acuity and overall high patient satisfaction.     

Visual outcomes after surgery for unilateral cataract in children more than two years old: posterior chamber intraocular lens implantation versus contact lens correction of aphakia.

PURPOSE: We sought to determine whether posterior chamber intraocular lens implantation yields better visual acuity and binocular vision than does conventional contact lens correction of aphakia in similar groups of pediatric cataract patients. METHODS: We reviewed the medical records of children aged 2 to 16 years who had unilateral cataract surgery by a single pediatric ophthalmologist between 1986 and 1996. Before 1992 all patients underwent standard lensectomy with vitrectomy. Beginning in 1992 posterior chamber intraocular lens (IOL) implantation was offered as a choice to families and was performed on most patients. RESULTS: Monocular vision outcomes were not significantly different in 20 IOL and 31 lensectomy-vitrectomy patients, with 85% of the IOL group and 77% of the lensectomy-vitrectomy group showing better than 20/100 final acuity. Binocularity, however, was much better in the IOL group, with 90% demonstrating at least 400 seconds of arc stereopsis, as opposed to 39% in the lensectomy-vitrectomy group (p = 0.003). Subgroups of patients with traumatic or nontraumatic cataract origin, age at surgery less than 7 years, and preoperative visual acuity less than 20/100 compared very similarly. CONCLUSION: Posterior chamber IOL implantation appears to provide significantly better binocular function than conventional management of unilateral cataract in childhood but does not substantially improve visual acuity results.     

Validity of the Titmus and Randot circles tasks in children with known binocular vision disorders.

PURPOSE: The Titmus and Randot (version 2) circles tests contain monocular form cues that may enable patients with binocular vision disorders to pass without any measurable stereopsis. The purpose of this study was to evaluate the validity of the Randot and Titmus circles tests for quantifying stereoacuity in children with known binocular vision disorders. METHODS: Participants included 170 consecutive children with diverse binocular sensory function ranging from fine to no measurable stereopsis. Stereoacuity was measured using the Randot circles, the Titmus circles, and the Randot Preschool Stereoacuity tests. RESULTS: Discrepancies between stereoacuity scores derived using either the Titmus or Randot circles tests and the Randot Preschool Stereoacuity test increased as a function of random-dot stereoacuity. Stereoacuity scores derived using the circles tests showed good agreement with random-dot stereoacuity when stereoacuity was 2.2 log seconds of arc (160 seconds of arc) or better, but they progressively overestimated stereoacuity for poorer random-dot stereoacuity scores. CONCLUSION: When measuring stereoacuity using either the Titmus or Randot circles tests in patients with known binocular vision disorders, stereoacuity scores > 2.2 log seconds of arc should be interpreted with caution because it is above this level of stereoacuity that the monocular form cues of each of the tests may invalidate the results.     

Combination of Toric and multifocal intraocular lens implantation in bilateral cataract patients with unilateral astigmatism

AIM: To assess the binocular visual function in bilateral cataract patients with unilateral astigmatism after combined implantations of Toric with multifocal intraocular lens (IOL), and to compare with that of Toric and monofocal IOL implantation. METHODS: All the 30 patients with unilateral astigmatism suffered bilateral cataract were randomly divided into two groups: Toric plus multifocal IOL group and Toric plus monofocal IOL group. Uncorrected and corrected visual acuity at distance (5.0 m), intermediate distance (0.6 m), and near (0.33 m), contrast sensitivity, and stereopsis were assessed 6mo after surgery. Patients were also surveyed for visual disturbances and spectacle dependence. RESULTS: Binocular uncorrected visual acuity (LogMAR) of Toric/multifocal IOL eyes at distance, intermediate, near were 0.05±0.05, 0.24±0.10, and 0.14±0.06 respectively. The values of Toric plus monofocal IOL eyes were 0.06±0.07, 0.26±0.08, and 0.37±0.10 respectively. These values did not indicate significant differences between two groups with exception of near visual acuity. In the photopic condition (with or without glare), the contrast sensitivity of multifocal IOL eyes was significant lower than the monofocal IOL eyes in 18 cpd. In the mesopic condition, the contrast sensitivity of multifocal group was significant lower than monofocal group in 12 cpd, and in mesopic glare condition, this significant difference was found both in 6 cpd and 12 cpd. The stereopsis of Toric/multifocal IOL eyes decreased slightly (100±80 seconds of arc, t=2.222, P=0.136). Mean near vision for patient satisfaction was statistically significantly higher in Toric/multifocal IOL group patients versus than that in Toric/monofocal IOL group (80% vs 25.5%, P=0.000). Visual disturbance was not noticed in either group. CONCLUSION: Although the combination of Toric and multifocal IOL implantation results in compromising stereoacuity, it can still provide patients with high levels of spectacle freedom and good overall binocular visual acuity.     

白内障手术相关的不等像及其对术后双眼视觉的影响

目的：探讨双眼白内障术后不等像的变化,并分析不等像对术后双眼视觉状态的影响。方法：前瞻性临床研究。2019年1—11月于萨鲁斯大学宾夕法尼亚视光学院和LewisLASIK眼科诊所招募拟接受双眼白内障手术的患者（≥50岁）73例。所有受检者在第1眼手术前接受不等像检查,第2眼手术后接受不等像检查和综合双眼视检查。综合双眼视检查方案包括立体视、眼位、融像性聚散、聚散灵活度及集合近点检查等。根据双眼视检查结果确定受检者的双眼视觉状态（正常双眼视或双眼视异常）。采用McNemar卡方检验比较手术前、后有临床意义的不等像比例（≥3%）;Spearman检验分析不等像与屈光参差、双眼人工晶状体（IOL）度数差值及立体视之间的相关性;Logistic回归分析不等像对术后双眼视觉状态的影响;受试者工作特征（ROC）曲线确定能预测术后是否存在双眼视异常的不等像临界值。结果：术后平均随访时间为2个月。最终纳入51例受检者,其中13例（25%）在术后被诊断为非斜视性双眼视异常,主要为集合不足11例（22%）。术后有临床意义的不等像比例较术前差异无统计学意义（χ2=1.14,P=0.286）。术前、术后及术源性不等像与屈光参差、双眼IOL度数差值及立体视均无相关性。Logistic回归分析显示,术后的双眼视异常与术前（OR=1.46,P=0.047）、术后（OR=1.67,P=0.031）及术源性（OR=1.48,P=0.021）不等像之间均存在相关性。ROC曲线分析显示,术源性不等像显示出最佳的曲线下面积（AUC）,其AUC值为0.74,术源性不等像>2.4%时,其预测术后双眼视异常的敏感性和特异性最佳,分别为80.6%和65.0%。术前和术后的不等像AUC值分别为0.68、0.66,分别取临界值3.3%和2.9%时,预测的敏感性和特异性最佳。结论：双眼白内障手术并不明显改变不等像。然而,双眼白内障手术群体的不等像可作为预测因子,用来预测术后发生双眼视异常的风险。     

Reduced binocular beat visual evoked responses and stereoacuity in patients with Duane syndrome.

PURPOSE: To study the effects that the abnormal eye movements of patients with Duane retraction syndrome have on the development of binocular function. METHODS: Pattern reversal visual evoked responses (VEPs) to 15-minutes-of-arc and 60-minutes-of-arc checks and binocular beat VEPs to diffuse sinusoidally modulated 18- and 20-Hz stimuli were recorded in 10 patients with Duane retraction syndrome who maintain binocular function by using an abnormal head posture. Visual acuity, stereoacuity, and eye movements were measured. The results have been compared to those from 10 normal subjects. RESULTS: The patients with Duane retraction syndrome had reduced stereoacuity compared to the normal control group (TNO mean, 82.5 seconds of arc compared to 37.5 seconds of arc; Titmus mean, 143 seconds of arc compared to 44 seconds of arc). The binocular beat VEPs showed a significantly reduced difference beat response at 2 Hz in the patients with Duane syndrome compared to normal subjects (mean signal-to-noise ratio 2.40 +/- 1.05 compared to 4.30 +/- 2.66; t = 2.21, df = 18, P < 0.05). Binocular enhancement of the P100 pattern reversal amplitude to 15-minute checks was increased in these patients, because of a reduction of the monocular P100 amplitudes compared to the normal group. CONCLUSIONS: Patients with Duane syndrome who maintain binocular function using an abnormal head posture have reduced stereoacuity and show electrophysiological evidence of reduced cortical binocular interaction.     

影响弱视儿童双眼视觉功能重建的多因素分析

目的对影响弱视患儿双眼视觉功能重建的多个因素进行分析。方法对192例就诊于我院斜弱视专科门诊，坚持治疗且视力恢复正常的弱视患儿进行双眼视觉检查，并记录其性别、初诊时年龄、视力正常时年龄、治疗时间、弱视程度及弱视类型,通过logistic回归分析这些因素与患儿双眼视觉功能重建的关系，结果在192例临床治愈的弱视患儿中，初诊时具有立体视功能者7例（400”者1例，占0．52％；800”者6例，占3．13％；共计3．65％），融合功能者22例（11．46％），同时视功能者76例（39．58％），无功能者87例（45.31％）。视力正常时具有立体视功能者61例（≤60”者27例，占14．06％;100”～200”者21例,占10．94％：400”～800”者13例，占6．77％；共计31．77％），融合功能者104例（54．17％），同时视功能者16例（8．33％），无功能者11例（5．73％）。对同时视有影响的因素为弱视类型（屈光不正性弱视）、治疗时间和弱视程度；对融合有影响的因素为治疗时间、初诊年龄、弱视类型（斜视性弱视）和弱视程度；对立体视有影响的因素为视力正常时年龄、初诊年龄、弱视类型（斜视性弱视）和弱视程度。结论弱视类型、弱视程度、初诊年龄、视力正常时年龄和治疗时间是影响双眼视觉功能重建的有关因素，其中对同时视、融合和立体视形成影响最大的因素分别为弱视类型、治疗时间和视力正常时年龄。     

Duane's retraction syndrome: a retrospective review from Kathmandu, Nepal

Purpose: The aim was to study the clinical characteristics of Duane's retraction syndrome (DRS) in Nepalese patients. Method: Medical records from 52 cases of DRS from May 2003 to April 2010 were retrospectively reviewed for age, gender, laterality and clinical characteristics. Forty‐one case records (78.8 per cent) that had complete clinical findings were considered for further evaluation. Examination included visual acuity by Snellen chart, refraction, associated horizontal and vertical strabismus in primary gaze, upshoot and downshoot on attempted adduction, binocular vision assessed with the Worth four‐dot test on adopted gaze and stereopsis examined with the Titmus stereo test. Results: DRS type I was the most common type observed in 73.2 per cent of cases, followed by DRS type II (14.6 per cent) and DRS type III (12.2 per cent). It was more common in female patients (58.5 per cent) than male patients (χ²= 4.6, df = 1, p = 0.03). DRS was more common in the left eye (68.3 per cent) than the right eye and unilaterally present in 95.1 per cent of subjects. In primary gaze, orthotropia (41.5 per cent) was more common than exotropia (34.1 per cent) and esotropia (24.4 per cent) and vertical strabismus was present in 24.4 per cent of subjects. Upshoot and downshoot on attempted adduction was seen in 14.6 and 9.8 per cent, respectively. Binocular single vision was present in 68.3 per cent of subjects by Worth four‐dot test at near. Stereopsis of 3,000 seconds of arc was present in 9.8 per cent, 100 to 200 seconds of arc in 14.6 per cent and 40 to 60 seconds of arc in 43.9 per cent with the Titmus stereo test. Conclusion: DRS is more common in female patients and the left eye. DRS type I is the most common type.     

Effects of Duane's retraction syndrome on sensory visual development

PURPOSE: To study the effects of Duane's retraction syndrome on sensory visual development. METHODS: Monocular and binocular visual function and ocular motility have been studied and pattern reversal visual evoked potentials recorded from 22 patients with Duane's syndrome aged from 4 to 55 years. RESULTS: Sixteen of the patients maintained binocular single vision using an abnormal head posture. All had normal visual acuities in both eyes. The 12 adults in this group had a mean stereoacuity of 78 seconds of arc with the mus stereotest and 101 seconds of arc with the TNO test. Both these values were significantly worse than for normal adults with a similar age range. The binocular VEPs from these patients showed enhancement of the binocular P100 VEP amplitude compared to the mean monocular P100 amplitude when they used their head posture but, unlike in normal subjects, this binocular enhancement was not reduced significantly after the age of 5. Six patients had lost binocular function and had a manifest convergent squint. Of these, 4 were anisometropic. VEPs in this group showed mildly delayed P100 latencies in the affected eye with asymmetric amplitudes even though their amblyopia had been successfully treated by patching and only one patient had a substantially reduced acuity. In neither group was there any relationship between the degree of restriction of ocular motility and the sensory changes. CONCLUSION: Patients with Duane's syndrome who retain binocular single vision show abnormal binocular visual maturation after the age of 5 years. This results in reduced stereoacuity in the absence of amblyopia.     

Binocular status after surgery for constant and intermittent exotropia

PURPOSE: To investigate whether constant exotropia patients with a previous history of intermittent exotropia X(T), like X(T) patients, can achieve postoperative bifixation, and whether they have a better postoperative sensory outcome than those without previous history of X(T). DESIGN: Prospective comparative clinical study. METHODS: Sixty-three consecutive patients with intermittent or constant exotropia were divided into three groups: X(T) (group 1), constant exotropia with a previous history of X(T) (group 2), and constant exotropia without previous history of X(T) (group 3). The surgical outcomes were assessed and compared in motor and sensory terms separately between the three groups. Successful motor alignment was defined as within 8 prism diopters (PD) (exo or eso). A stereoacuity < or =60 seconds of arc was considered as bifixation, and a stereoacuity < or =800 seconds of arc was considered as gross stereopsis. RESULTS: The successful motor alignment rates of group 1, group 2, and group 3 were 79%, 71%, and 67%, respectively (group 1 vs group 2, P = .826; group 1 vs group 3, P = .551; group 2 vs group 3, P = 1.000). Twenty-five (74%) patients in group 1 achieved bifixation and none achieved in group 2 or group 3 (group 1 vs group 2, P = .001; group 1 vs group 3, P = .001). Meanwhile, 34 patients (100%) in group 1, 11 (79%) in group 2, and 5 (33%) in group 3 achieved gross stereopsis (group 1 vs group 2, P = .021; group 2 vs group 3, P = .025; group 1 vs group 3, P = .001). Compared with patients in the two constant exotropia groups, patients in X(T) group had a significantly better sensory outcome in both bifixation and gross stereopsis. Patients in group 2 had a better sensory outcome than those in group 3 in gross stereopsis. CONCLUSIONS: Constant exotropia patients with a previous history of X(T) have a better postoperative sensory outcome in gross stereopsis than those without previous history of X(T), but a worse surgical sensory outcome when compared with X(T) patients in both bifixation and gross stereopsis. Constant exotropia patients decompensated from X(T) may have missed the best time for treatment.     

Current concepts and techniques in corneal transplantation

The corneal endothelium is the most important single layer in corneal transplantation. In his Castroviejo Lecture, William Bourne, MD, summarizes his work on the corneal endothelium and its importance to corneal transplantation. Almost half the corneal transplants performed in the United States are done so because of malfunctioning, diseased, or absent endothelial cells. If just this layer could be transplanted, the long wait for better vision after keratoplasty (up to two years in some countries) can be eliminated, as well as the problems of epithelial and subepithelial graft rejection. The significant astigmatism after keratoplasty could also be reduced. Transplantation of the endothelium in deep lamellar keratoplasty is being done in limited fashion throughout the world and the first patients have now been done in the United States. In many countries where corneal tissue is difficult to obtain, keratoplasty is only performed on one eye, even though both eyes may need it. One article this year discusses binocular vision recovery in bilateral keratoplasty and the objective and subjective improvements after bilateral keratoplasty. Patients who are bilaterally blind from diseases such as Stevens-Johnson syndrome, and ocular pemphigoid have little hope of visual recovery from conventional corneal transplants. The use of a keratoprosthesis to bypass the totally abnormal conjunctival surface has helped many people in the past. The preoperative prognostic categories of patients who may benefit from keratoprosthesis has been carefully reviewed in a large number of keratoprosthesis patients and this information will help ophthalmologists decide who will benefit the most benefit from keratoprosthesis. This year, articles on corneal transplantation after conjunctival flaps, suture-related complications in keratoplasty, the implantation of an intraocular lens after penetrating keratoplasty, and long-term results of penetrating keratoplasty with glaucoma drainage tube implants are subjects that warrant in depth discussion and evaluation. Finally, eye bank considerations will be discussed concerning the long-term question of transmission of cancer through corneal transplantation.     

Limbal autograft and allograft transplantations in patients with corneal burns

AIM: To investigate and compare the surgical outcomes of limbal autograft and limbal allograft transplantations in patients with corneal burns. METHODS: In total, 20 patients (n=22 eyes) with chemical burn and two patients (n=2 eyes) with thermal burn were included in this study. Limbal autograft or limbal allograft transplantation surgery was performed in all patients. HLA-typing was tested before allograft surgeries. Limbal allografting was performed in all eyes using donor tissue from live relatives. Systemic cyclosporine A was administered for immunosuppression. RESULTS: The corneal surface was successfully reconstructed in all eyes (100%) after limbal autografting, two eyes required additional amniotic membrane transplantation and one eye required allografting. The mean follow-up period for limbal autografts was 13.9 +/- 7.0 months. Limbal allografting failed to reduce corneal vascularity and opacification in five (55.6%) eyes and was successful only in four (44.4%) eyes (mean follow-up 16.2 +/- 11.2 months) (P=0.002). In all, 15 eyes undergoing limbal autografting completed re-epithelialization of the cornea at a mean of 35.6 +/- 60.2 days. The mean epithelial healing time in nine eyes undergoing limbal allografting was 13.0 +/- 7.3 days (P=0.525). After limbal autografting, functional vision (> or =1/10) was attained in 12 (80%) eyes. Only one eye (11.1%) achieved functional vision after limbal allografting (P=0.036). Penetrating keratoplasty was performed in three patients following limbal allografting. No cyclosporine-associated side effects were observed. CONCLUSIONS: Limbal autograft transplantation is an effective and safe procedure for unilateral corneal burns. It seems that limbal allograft transplantation is better combined with penetrating keratoplasty for a better visual outcome and higher graft survival rate. Systemic immunosuppression seems to be necessary for limbal allografts even in the presence of HLA-matched donor tissues.     

Amniotic membrane transplantation for severe neurotrophic corneal ulcers

AIMS: To evaluate whether amniotic membrane transplantation can be an effective alternative treatment for neurotrophic corneal ulcers. METHODS: Amniotic membrane transplantation was performed in 16 eyes of 15 patients with neurotrophic corneal ulcers and vision equal to or worse than 20/200. The neurotrophic state was developed following keratoplasty (four eyes), herpes zoster ophthalmicus (four eyes), diabetes mellitus (four eyes), radiation (two eyes), removal of acoustic neuroma with neuroparalysis (one eye), and herpes simplex keratitis (one eye). RESULTS: During a mean follow up period of 18.8 (SD 13.0) months, one to three layers of amniotic membrane with or without additional membrane as a patch were used for 17 procedures in 16 eyes for persistent neurotrophic corneal ulcers. All but four (76.4%) instances of amniotic membrane transplantation achieved rapid epithelialisation in 16.6 (9.0) days. Of the four eyes showing delayed healing, three eyes healed by tarsorrhaphy, and the remaining one eye with corneal perforation required penetrating keratoplasty and tarsorrhaphy. Two eyes gained vision better than 20/200. The healed corneal surface was accompanied by reduced inflammation. CONCLUSION: Amniotic membrane transplantation can be considered an effective alternative for treating severe neurotrophic corneal ulcers.     

间歇性外斜视手术时机探讨

目的 通过观察不同年龄、双眼视功能状态手术前后变化,探讨间歇性外斜视的手术时机.方法 将56例间歇性外斜视患者根据手术时年龄≤5岁、5～9岁和≥9岁分为A、B、C三组,再根据术前有无融合功能及远或近立体视分组,统计分析不同年龄组手术前后眼位、双眼视功能变化,以及手术前后融合功能变化、远或近立体视功能变化.结果 术后眼位正位率A组77.8%、B组91.7%、C组85.7%,差异无统计学意义.双眼视觉功能的恢复率A组88.9%、B组87.5%、C组50.0%,差异显著有统计学意义.结论 B组术后正位率优于A组,但双眼视觉功能的恢复却A组优于B组.术前具有融合点及融合范围者,术后双眼视功能恢复率高.近立体视丧失、远立体视保存者术后远立体视锐度恢复好,术后立体视的恢复由远立体视开始.间歇性外斜视的手术时机应根据病人眼位、年龄、融合状态及立体视功能多方面综合考虑.     

Binocular function of the patient with the refractive multifocal intraocular lens

PURPOSE: To investigate binocular function in bilateral and unilateral implantation of the refractive multifocal intraocular lens (IOL). SETTING: Department of Ophthalmology, Musashino Red Cross Hospital, Tokyo, Japan. METHODS: Sixty-six eyes of 40 patients were enrolled in this retrospective study. Twenty-six were implanted bilaterally and 14 were implanted unilaterally with the 3-zone refractive multifocal IOL. Distance visual acuity, near visual acuity, and contrast sensitivity were measured monocularly and binocularly. Stereopsis, aniseikonia, and the use of spectacles were also evaluated. RESULTS: There were no significant between-group differences in monocular and binocular visual acuity. In the bilateral group, 85% had 60 seconds or more of stereopsis; in the unilateral group, 43% had the same level of stereopsis (P =.009). Ninety-two percent and 21%, respectively, had no aniseikonia (P =.001), and 89% and 50%, respectively, did not use spectacles (P =.012). In the unilateral group, in 4 of 5 cases in which surgery was performed in the dominant eye, spectacles were not required; in 9 cases in which surgery was performed in the nondominant eye, 78% used spectacles for reading (P =.063). CONCLUSIONS: Bilateral implantation of the multifocal IOL appeared to lead to better results than unilateral implantation. However, our results suggest that the patient may be satisfied with unilateral implantation when it is performed in the dominant eye.