Retinal acuity evaluation with the potential acuity meter in glaucoma patients

The potential acuity meter (PAM) is designed to evaluate retinal acuity in the presence of media opacities. We looked at patients with glaucoma but with clear media, and compared best corrected visual acuity with PAM results to see if they produced comparable results. Sixty eyes in 38 glaucoma patients and 20 eyes in 10 normal ocular patients were evaluated. Our results indicate that PAM visual acuity is a reliable indicator of Snellen visual acuity in normal eyes, in eyes with mild to moderate glaucomatous damage, and when PAM visual acuity measurements were better than 20/60. However, when visual field loss is severe and when PAM visual acuity readings were worse than 20/60, the correspondence between these and Snellen visual acuity was erratic. Poor PAM results will not correlate with postoperative visual acuity in patients with advanced glaucoma and cataracts.     

Pars plana vitrectomy in diabetic macular edema

Purpose: To ascertain the association between the improvement of diabetic macular edema and increased visual acuity after pars plana vitrectomy. Methods: From January 1994 to December 1996 we prospectively studied 18 patients (18 eyes, 7 women and 11 men, mean age 52 years, range 37–68) with type II diabetes and clinically significant macular edema. One group was composed of 9 patients presenting diffuse macular edema (DME); a second group with 9 patients presented cystoid macular edema (CME). All patients underwent pars plana vitrectomy. Results: Preoperative Snellen visual acuity was 20/143 in DME and 20/441 in CME. In both groups vision increased to 20/136 and 20/205, respectively, postoperatively. For the DME this difference was statistically significant (p<0.05) at 1 month after the surgery, but vision decreased again after 10 months reaching preoperative values. Conclusions: Our results suggest that pars plana vitrectomy for diabetic macular edema may increase visual acuity in diffuse macular edema, although this increase is only short lived. This revised version was published online in July 2006 with corrections to the Cover Date.     

First-order Wiener kernel visually evoked potentials obtained from multiple sclerosis patients

Visually evoked potentials (VEP) were measured in multiple sclerosis patients with five sizes of reversing check stimuli. The VEPs were obtained using random binary sequence triggered check reversals. The random binary sequence was cross-correlated with scalp potential responses to obtain the estimates of the linear response of the system.For each evaluation a series of five VEPs, one for each of five check sizes, was done. A correlation coefficient was calculated to evaluate check size versus amplitude of the major negative wave. A tabulation was made to compare Snellen chart visual acuity with these correlation coefficients. For the eyes with a Snellen acuity of 20/20, 63% of the VEP amplitudes increased as the check size was decreased with correlation coefficients of -0.6 to -1. For the eyes with a Snellen acuity of 20/70 or less the amplitude decreased with the check size decrease, showing a correlation coefficient of +0.6 to +1 in 45% of the evaluations. The check size giving the largest amplitude was also tabulated with respect to the visual acuity, but did not appear to have as strong a relationship to visual acuity.     

Potential Acuity Meter Using a Minute Aerial Pinhole Aperture

A new instrument allows accurate measurement of retinal visual acuity behind mild to moderate cataracts. Mounted on a slit lamp, the Potential Acuity Meter projects a Snellen visual acuity chart into the eye via a narrow beam of light converging to a minute aerial aperture only 0.15 mm in diameter. The examiner aims the narrow beam through “windows” in the cataract, avoiding blockage or scattering of the light that would otherwise occur. In 47 cataractous eyes having best preoperative visual acuity of 20/200 and better, the postoperative visual acuity was predicted to within three lines in 100% of cases, and to within two lines in 91%. With a successful result from cataract surgery defined as postoperative vision of 20/40 or better, the prediction of success with the Potential Acuity Meter was correct in 95% of cases.     

Changes in Visual Function over Time in Koreans with Non-arteritic Anterior Ischaemic Optic Neuropathy

Non-arteritic anterior ischaemic optic neuropathy (NAION) causes severe visual loss in elderly patients. However, there are not much data of clinical course of NAION in Asian patients. To evaluate changes in visual acuity and visual field defects associated with non-arteritic anterior ischaemic optic neuropathy (NAION) among Korean patients, the medical records of 50 eyes from 43 patients with NAION patients seen from 1989 to 2011 were reviewed. A significant change in visual acuity was defined as a three-line change in Snellen acuity. Visual field defects were evaluated with Goldmann perimetry. Changes in the visual field were evaluated using the grid method. Thirty-eight percent of eyes showed improvement, 54% showed no change, and 8% showed deterioration of visual acuity at the last follow-up. Thirty-four percent of eyes showed improvement, 54% showed no change, and 12% showed deterioration of the visual field at the last follow-up. Most improvement in visual acuity occurred during the first month after the initial visit and in visual field between the first and third months of follow-up. The prognosis of visual acuity in association with NAION was worse in Korean patients as compared with Western studies. However, improved prognosis of visual field defects might come from the use of different methods for evaluation of the visual field.     

Intereye difference in exudative age-related macular degeneration with minimally classic or occult subfoveal neovascularization after unilateral intravitreal injection of triamcinolone acetonide

PURPOSE: To report on visual outcome after intravitreal injection of triamcinolone acetonide for exudative age-related macular degeneration. DESIGN: Interventional comparative non-randomized clinical trial. METHODS: SETTING: Institutional. PATIENTS: Twenty consecutive patients with bilateral exudative age-related macular degeneration with minimally classic or occult subfoveal neovascularisation. INTERVENTIONS: Unilateral intravitreal injection of about 20 mg triamcinolone acetonide into the eye (study group) more severely affected or showing more pronounced progression of the disease. Mean follow-up was 13.5 +/- 4.1 months. MAIN OUTCOME MEASURES: Visual acuity. RESULTS: In the study group, visual acuity increased significantly (P < 0.001) from 0.96 +/- 0.32 logMar to a mean maximum of 0.76 +/- 0.30 logMar during follow-up. An increase in best visual acuity during follow-up was found in 18 (90%) eyes. In 11 (55%) eyes and 7 (35%) eyes, respectively, best visual acuity increased by at least two Snellen lines and three Snellen lines, respectively. In the control group, visual acuity at baseline and the highest visual acuity measurements during follow-up did not vary significantly (P = 0.90). Comparing study group and control group, visual acuity gain was significantly (P = 0.003) higher in the study group. Correspondingly, the number of eyes with an increase in visual acuity (P = 0.002) and with an increase in visual acuity higher > or = 3 lines compared to a loss of > or = 3 lines was significantly (P = 0.027) higher in the study group. CONCLUSIONS: Intravitreal triamcinolone acetonide may temporarily increase visual acuity in eyes with exudative age-related macular degeneration.     

Lifetime visual prognosis of patients with glaucoma

Background: To investigate the visual outcome of glaucoma patients. Design: This is a retrospective study of case notes of patients who died while under follow up in a glaucoma clinic of a University Hospital in Scotland between 2006 and 2009. Participants: Seventy‐seven patients were identified. Methods: Data collected included type of glaucoma, coexisting pathology and best‐corrected visual acuity in Snellen (converted to decimal values) for the first and final clinic visit. The final visual status was evaluated based on the best‐corrected visual acuity of the better seeing eye at the last glaucoma clinic visit. Patients who had best‐corrected visual acuity of less than Snellen decimal 0.5 were considered not to meet the standards for driving. Main Outcome Measures: Snellen decimal best‐corrected visual acuity, fulfilment of driving standards, and eligibility for partial sight and blind registration at the last clinic visit. Results: The mean ages at presentation and death were 71.8 ± 10.3 years and 82.2 ± 8.7 years respectively. The mean Snellen decimal best‐corrected visual acuity of the better eye at presentation was 0.78, and at the final clinic visit was 0.61. At the final clinic visit, no patients were partial sight registrable, four (5.2%) were blind registrable, and 27 (35.1%) did not fulfil UK driving criteria. Glaucoma patients with other ocular pathologies were more likely to fail UK driving criteria at presentation (P = 0.02) and at last clinic visit (P = 0.03). Conclusion: The majority of glaucoma patients maintained good visual function at the end of their lifetime.     

Changes in Visual Function over Time in Koreans with Non-arteritic Anterior Ischaemic Optic Neuropathy

Abstract

Non-arteritic anterior ischaemic optic neuropathy (NAION) causes severe visual loss in elderly patients. However, there are not much data of clinical course of NAION in Asian patients. To evaluate changes in visual acuity and visual field defects associated with non-arteritic anterior ischaemic optic neuropathy (NAION) among Korean patients, the medical records of 50 eyes from 43 patients with NAION patients seen from 1989 to 2011 were reviewed. A significant change in visual acuity was defined as a three-line change in Snellen acuity. Visual field defects were evaluated with Goldmann perimetry. Changes in the visual field were evaluated using the grid method. Thirty-eight percent of eyes showed improvement, 54% showed no change, and 8% showed deterioration of visual acuity at the last follow-up. Thirty-four percent of eyes showed improvement, 54% showed no change, and 12% showed deterioration of the visual field at the last follow-up. Most improvement in visual acuity occurred during the first month after the initial visit and in visual field between the first and third months of follow-up. The prognosis of visual acuity in association with NAION was worse in Korean patients as compared with Western studies. However, improved prognosis of visual field defects might come from the use of different methods for evaluation of the visual field.     

非动脉炎型前部缺血性视神经病变的临床特点分析

目的　探讨非动脉炎型前部缺血性视神经病变（ｎｏｎ-ａｒｔｅｒｉｔｉｃａｎｔｅｒｉｏｒｉｓｃｈｅｍｉｃｏｐ-ｔｉｃｎｅｕｒｏｐａｔｈｙ,ＮＡＩＯＮ）的临床特点。方法　回顾性分析２０１０年１月至２０１３年１２月首诊于我院的６６例（８３眼）ＮＡＩＯＮ患者的临床资料,包括视力、眼压、视野、荧光素眼底血管造影和ＯＣＴ等检查结果,并对患者全身疾病进行相关分析,观察治疗过程中视力、视野恢复情况及眼底变化。结果　在ＮＡＩＯＮ患者中单眼４９眼,双眼先后发病１３眼,双眼同时发病４眼,其中,７０％双眼先后发病的患者在对侧眼出现ＮＡＩＯＮ时,先发病眼视力得到改善。ＯＣＴ检查发现:ＮＡＩＯＮ患者的视盘水肿主要发生于视盘的上方和下方,形成“双驼峰”状改变。在发病早期２０眼发生黄斑中央凹神经上皮层脱离。发生黄斑渗出的眼中８０％合并糖尿病。结论　颞侧视盘的神经纤维层增厚牵拉所导致的中心凹神经纤维层脱离,可能是早期ＮＡＩＯＮ视力低的因素。双眼发病的ＮＡＩＯＮ患者,可能存在双眼视盘供血代偿机制,来减轻一侧视盘的损害。     

The Pyhäjärvi Cataract Study II. Criteria for cataract surgery

Purpose: It is necessary to develop tools for patient selection to target cataract surgery to patients with the best expected outcomes. We used visual acuity, visual functioning 14 (VF‐14) test, the 15‐dimension health‐related quality‐of‐life questionnaire (15D) and the New Zealand priority criteria to evaluate the criteria for cataract surgery in a post hoc setting. Material and methods: Ninety‐three consecutive patients living in a defined rural area in Finland had cataract surgery as a part of the Pyhäjärvi Cataract Study in 2003. Success of cataract surgery was defined as improvement of visual acuity by at least 2 lines and/or improvement of visual function measured by questionnaires. Results: The patients with a visual acuity of 0.30 logMAR (0.5 Snellen decimal) or worse in the better eye and/or 0.52 logMAR (0.3 Snellen decimal) in the worse eye had successful surgery in 59–83% of cases depending on the definition of success. When subjective judgement was added, the success rates varied between 63% and 91%. Conclusion: Setting indication criteria, it seems sufficient to use two global questions in addition to visual acuity: one on the subjective view on disability, and one on a more neutral view on visual function, such as the 15D item on vision. The VF‐14 did not perform any better than the single item counterparts.     

A comparison of visual function tests in eyes with maculopathy

Several recently developed tests of visual function, including the Potential Acuity Meter (PAM), laser interferometer (LI), white-light interferometer (WLI), blue field entoptic phenomenon, and focal electroretinogram (ERG) were compared in 81 eyes with clear media and known macular disease. The results indicate that the PAM, the LI, and the WLI overread relative to Snellen acuity. Laser interferometric acuity values differed from Snellen acuity by at least 1.5 octaves in approximately 40% of all eyes, regardless of stimulus size (2, 5, or 8 degrees). Similar results were obtained with the WLI. Agreement with Snellen acuity was better for the PAM, with 91% of eyes falling within 1.5 octaves of Snellen acuity. Blue field and focal ERG results were categorized as normal or abnormal. While not producing Snellen equivalents, abnormal results from the blue field and focal ERG corresponded with poor Snellen acuity (less than 20/40) in 65% and 91% of eyes, respectively. Assuming that media opacities do not prevent adequate retinal stimulation, the present results suggest that the PAM and focal ERG are the most reliable for evaluating macular function when maculopathy is present.     

正视眼波前像差与低对比度视力相关性研究

目的 分析正视眼波前像差与低对比度视力的相关性.方法 对95例(95眼)健康正视眼用WASCA(wavefront supported corneal ablation)波阵面像差仪测眼波前像差,对瞳孔6 mm时第2,3,4阶像差的各项Zernike函数(C3-C14)进行分析.用多功能电子视力测量仪检测亮、暗环境中对比度为10﹪和5﹪时的裸眼视力和最佳矫正视力.用多元线性回归分析眼波前像差与各低对比度视力间的相关关系.结果 离焦像差(C4)与亮、暗环境中对比度为10﹪和5﹪时的裸眼视力间的直线相关关系有统计学意义(P＜0.01);水平彗差(C8)与亮、暗环境中对比度为10﹪和5﹪时的最佳矫正视力间的直线相关关系有统计学意义(P＜0.01).其余Zernike 函数与各低对比度视力间的直线相关关系均无统计学意义(P＞0.05).结论 正视眼的波前像差与低对比度视力有关,其中离焦像差与裸眼视力有关,水平彗差与最佳矫正视力有关.     

视网膜脱离复位后视功能研究

目的 研究视网膜脱离（ＲＤ）术后视功能的恢复及其影响因素。方法 选择孔源性ＲＤ痊愈病例２３３例（２３８眼）,采用Ｘ＾２检验进行统计分析。结果 术前３６．７％患者视力≥０．１,而术后为８１．４％（Ｐ〈０．０１）;术前黄斑不脱离和脱离１周内的患者术后视力１００．０％≥０．３,脱离１周后只有２７．１％的患者有相应的视力;术前视力与术后视力明显相关（r＝０．５１７,Ｐ〈０．０１）。结论 ＲＤ术后视力得到不     

特发性黄斑前膜患者内界膜剥除术后视功能的影响因素分析

目的：探讨影响特发性黄斑前膜患者内界膜剥除术后视功能恢复的危险因素。

方法：回顾我院2016-01/2020-04收治的特发性黄斑前膜行视网膜内界膜剥除术的患者118例118眼。术后随访6mo评价手术疗效,观察术前、术后1、3、6mo的视力变化、视物变形程度、黄斑中心凹平均厚度、黄斑区容积。分析术前及术后黄斑中心凹平均厚度、黄斑区容积与术后视力及视物变形评分的相关性,评估术后视功能恢复不良的危险因素。

结果：本组患者96眼视功能恢复良好,手术治疗改善率为81.4%。与术前相比,术后1、3、6mo术眼视力明显提升(P<0.05),水平方向视物变形评分明显缩小(P<0.05),术眼黄斑中心凹平均厚度、黄斑区容积明显减小(P<0.05)。术前与术后6mo黄斑中心凹平均厚度、黄斑区容积与术后6mo视力均呈负相关(P<0.05),与术后6mo水平方向视物变形评分均呈正相关(P<0.05)。IMEM病程、术前矫正视力、术前水平或垂直方向视物变形、术前黄斑水肿是患者术后视功能恢复情况的影响因素(均P<0.05),其中术前矫正视力差(OR=3.062)、术前存在水平方向视物变形(OR=2.438)、术前存在黄斑水肿(OR=2.000)是导致患者术后视功能恢复不良的危险因素。

结论：内界膜剥除术治疗特发性黄斑前膜效果良好,可有效改善术眼视力,减轻视物变形。病程越长、术前矫正视力越差、术前视物变形越严重、术前有黄斑水肿的患者内界膜剥除术后视功能恢复越差。     

The relationship between indoor and outdoor Snellen visual acuity in cataract patients

One hundred six cataractous eyes of 78 patients were evaluated to examine the relationship between indoor and outdoor Snellen visual acuity. While 81 of all cataractous eyes (76.4%) had Snellen visual acuities of 20/40 or better when tested indoors, only 33 eyes (31.2%) had 20/40 or better Snellen visual acuities when tested outdoors facing the sun. When tested indoors, only three eyes (2.8%) had Snellen visual acuities worse than 20/80, while 31 eyes (29.2%) had outdoor Snellen visual acuities worse than 20/80. Ten eyes (9.4%) had outdoor Snellen visual acuities worse than 20/200. Seventy-four eyes (69.8%) had outdoor visual acuities that were at least two Snellen lines worse than those measured indoors and 23 eyes (21.7%) had outdoor visual acuities that were at least five Snellen lines worse. The median difference between indoor and outdoor visual acuity was three Snellen lines. The need for increased precision in the ability to assess outdoor "real world" vision while in the ophthalmologist's examination room is discussed. Clearly, indoor Snellen visual acuity alone is insufficient to evaluate functional visual impairment in cataract patients.     

Fundus autofluorescence imaging of patients with idiopathic macular hole

AIM: To assess the visual outcomes of aspheric multifocal intraocular lenses (IOLs) compared with spherical multifocal IOL after cataract surgery.METHODS:Potential prospective controlled trials that comparing aspheric multifocal IOL implantation with spherical multifocal IOL group were extracted from the computer database. The statistical analysis was carried out using Stata 10 software. Standardized mean differences with 95% confidence intervals (CIs) were calculated for continuous variables. The pooled estimates were computed in the use of a random-effects model.RESULTS:A systematic review identified five prospective nonrandomized controlled trials, including 178 aspheric multifocal IOL and 164 spherical multifocal IOL. There was no significant difference in uncorrected distance visual acuity (95%CI, -0.248 to 0.152;P=0.641) and uncorrected near visual acuity (95%CI, -0.210 to 0.428;P=0.504) between aspheric multifocal IOL and spherical multifocal IOL. Statistically significant differences were detected less spherical aberration in aspheric multifocal IOL (95%CI, -1.111 to -0.472; P＜0.001) when compared to spherical multifocal IOL. Spherical multifocal IOL showed a greater higher order aberration compared to the aspheric multifocal IOL (95%CI, -1.024 to-0.293; P＜0.001). Sensitivity analysis suggested that the results were relatively reliable.CONCLUSION:The overall findings indicated that aspheric multifocal IOL and spherical multifocal IOL provided similar visual acuity at near and distance. Patients implanted with aspheric multifocal IOL had less spherical aberration and higher order aberration than patients with spherical multifocal IOL. Further well-organized, prospective controlled trials involving larger patient numbers are needed.     

Stage III macular hole surgery.

Twelve macular holes in 12 patients underwent a pars plana vitrectomy and epiretinal membrane resection with intravitreal gas tamponade for repair of their macular holes. The patients had stage III macular holes and had previously undergone a normal funduscopic examination within 2 years. The patients have been followed for a mean of 14 months (range 12-18 months) postoperatively. The results show that visual acuity improvements were not seen until at least 6 months after surgery if the hole was closed successfully. Seven holes were closed (58.3%) and all improved their best corrected visual acuity by more than two Snellen lines. In the five eyes that did not demonstrate hole closure (41.6%), one eye improved by two lines as well. The other four eyes remained at their preoperative acuity. One eye developed a dialysis which responded to a fluid air exchange and cryopexy (8.3%). Three eyes developed minimal lenticular opacities during the follow up period (25%). One eye demonstrated an altered perifoveal pigment epithelium perhaps related to intraoperative light toxicity. Macular hole surgery can restore some central acuity even in patients with longstanding holes.     

Birdshot chorioretinopathy

Birdshot chorioretinopathy is a well-known, yet poorly understood, form of posterior uveitis, characterized by multiple, distinctive, hypopigmented choroidal lesions, and strongly associated with human leukocyte antigen (HLA)-A29. We reviewed all English language publications regarding birdshot chorioretinopathy and performed analyses of combined patient data taken from these articles. The mean age at presentation was 53 years, with a slight female predominance (54.1%). At least 95.7% of reported patients have been HLA-A29-positive. Blurring of vision and floaters are the most prevalent presenting complaints, even in patients with visual acuity of 20/20 or better in both eyes. Birdshot chorioretinopathy is a slowly progressive disease with profound dysfunction of vision that may not be reflected in Snellen visual acuity. Two or more lines of Snellen visual acuity were lost in approximately 20% of eyes over a median follow-up of 3.5 years; macular edema was the most common cause of reduced visual acuity. Overall, patients had a slow decline in visual acuity, despite the fact that nearly all were treated with anti-inflammatory therapies. Final visual acuity in the better eye was 20/40 or better in 75.1% of patients and 20/200 or worse in 9.8% of patients. Oral corticosteroids and cyclosporine were the most commonly used medications. Using a regression model, patients in the literature that have been treated with cyclosporine alone had better final visual acuity than patients treated with oral corticosteroids alone. Further study is needed to determine the optimal methods for treating and monitoring patients with birdshot chorioretinopathy.     

Comparison of visual acuity estimates using three different letter charts under two ambient room illuminations

Background:

Visual acuity is an essential estimate to assess ability of the visual system and is used as an indicator of ocular health status.

Aim:

The aim of this study is to investigate the consistency of acuity estimates from three different clinical visual acuity charts under two levels of ambient room illumination.

Materials and Methods:

This study involved thirty Malay university students aged between 19 and 23 years old (7 males, 23 females), with their spherical refractive error ranging between plano and –7.75D, astigmatism ranging from plano to –1.75D, anisometropia less than 1.00D and with no history of ocular injury or pathology. Right eye visual acuity (recorded in logMAR unit) was measured with Snellen letter chart (Snellen), wall mounted letter chart (WM) and projected letter chart (PC) under two ambient room illuminations, room light on and room light off.

Results:

Visual acuity estimates showed no statistically significant difference when measured with the room light on and with the room light off (F_1,372 = 0.26, P = 0.61). Post-hoc analysis with Tukey showed that visual acuity estimates were significantly different between the Snellen and PC (P = 0.009) and between Snellen and WM (P = 0.002).

Conclusions:

Different levels of ambient room illumination had no significant effect on visual acuity estimates. However, the discrepancies in estimates of visual acuity noted in this study were purely due to the type of letter chart used.     

Diabetic macular oedema and visual loss: relationship to location,severity and duration

Purpose: To assess the relationship between visual acuity (VA) and diabetic macular oedema (DMO) in relation to the location of retinal thickening and the severity and duration of central macular thickening. Methods: Data from 584 eyes in 340 placebo‐treated patients in the 3‐years‐long Protein Kinase C Diabetic Retinopathy Study (PKC‐DRS2) trial were used to investigate the relationship between VA and DMO. Eligible eyes had moderately severe to very severe non‐proliferative diabetic retinopathy and VA of at least 45 letters on Early Treatment Diabetic Retinopathy Study (ETDRS) charts (Snellen equivalent = 20/125). Diabetic retinopathy and DMO status were assessed using stereo photographs. Results: Nearly one third of study eyes had foveal centre‐involving DMO at the start of the trial. Sustained moderate visual loss was found in 36 eyes, most commonly associated with DMO at the centre of the fovea in 73% of eyes. There was a strong relationship (p < 0.001) between foveal centre involvement with DMO and mean VA. Mean VA decreased with increasing retinal thickness at the centre (p < 0.001) and increasing duration of centre‐involving DMO (p < 0.001). Conclusion: This study documents the relationship between duration of DMO and progressive vision loss, and the key role of central foveal involvement in patients with diabetic retinopathy. These data will help to develop future strategies to prevent vision loss.