Evolution Of Visual Acuity Research Articles

High Altitude as a Risk Factor for the Development of Nonarteritic Anterior Ischemic Optic Neuropathy.

Episodic high-altitude exposure leads to optic disc edema and retinopathy. It is uncertain whether high-altitude exposure is a risk factor for nonarteritic anterior ischemic optic neuropathy (NAION). We performed a single-center, retrospective, cross-sectional case study of 5 patients with high-altitude-associated NAION (HA-NAION) from April 2014 to April 2019. Main study parameters included known vascular risk factors for NAION, evolution of visual acuity, visual field, optic disc, and macula measurements. We studied 5 eyes of 5 patients with HA-NAION that occurred at 7,000-9,000 ft above sea level, 28 patients with classic NAION that developed at sea level (normal altitude NAION or NA-NAION), and 40 controls. All 5 patients with HA-NAION had clinically confirmed NAION by a neuro-ophthalmologist within 3-21 days of onset and comprehensive follow-up evaluations (average follow-up of 23 months). Other than high-altitude exposure, 4 of 5 patients had undiagnosed obstructive sleep apnea (OSA, apnea-hypopnea index 5.4-22.2) and 1 had systemic vascular risk factors. All patients had disc-at-risk in the contralateral eye. The best-corrected distance visual acuity was 20/20 to 20/70 (median logMAR 0) at presentation and 20/70 to counting finger (median logMAR 0) at ≥6 months. Automated static perimetry revealed average mean deviation of -18.6 dB at presentation and -22.1 dB at ≥6 months. The average retinal nerve fiber layer was 244 µm (80-348 µm) at onset and 59 µm (55-80 µm) at ≥6 months. The average ganglion cell complex thickness was 50 µm (43-54 µm) at onset and 52 µm (50-55 µm) at ≥6 months. The patients with OSA were started on home continuous positive airway pressure treatment. Visual outcomes were similar in patients with HA-NAION and NA-NAION. - After addressing all NAION risk factors, no new events occurred in the HA-NAION group within 2-8 years with or without repeat high-altitude exposure. NAION can occur under high-altitude conditions. HA-NAION is associated with relatively younger age at onset, disc-at-risk, and OSA. These patients exhibit a relatively progressive course of vision loss after initial onset and severe thinning of optic nerves on optical coherence tomography. Treatment for OSA is recommended, especially with repeated high-altitude exposure.

"Treat-and-Extend" Regimen for Exudative Age-Related Macular Degeneration: A Two-Year Retrospective Follow-up Study.

After the introduction of a "treat-and-extend" regimen (T&E) with aflibercept for exudative age-related macular degeneration, naive eyes were compared with eyes pretreated with a "pro re nata" scheme (PRN). The Ethics Committee of Eastern Switzerland approved the retrospective single-centre study (EKOS20/084, project ID: 2020-01193). The study included 342 eyes of 303 patients newly treated with or switched to T&E between January 2018 and March 2018 at the Eye Clinic of the Cantonal Hospital St.Gallen. The gender distribution of the treated eyes was 63.5% (n = 217) female and 36.5% (n = 125) male. The mean age was 81.6 years (SD = 8.6 years). The collective was divided into three groups: 1) naive, untreated eyes (n = 92), 2) eyes with ≤ 6 previous treatments with PRN (n = 37), 3) eyes with > 6 previous treatments with PRN (n = 213). The following parameters were analysed up to December 2019: the evolution of visual acuity, the number of intravitreal injections, the number of recurrences, the duration of the follow-up, the dropout rate, and the duration of the last treatment interval. During the observation period, group 1 showed a statistically significant improvement in visual acuity of + 1.5 ETDRS, while groups 2 and 3 showed a decrease in visual acuity of - 2.9 and - 3.7 ETDRS, respectively. Group 1 had better development of visual acuity than groups 2 and 3 (p = 0.005), while groups 2 and 3 were not significantly different (p = 0.92). The other parameters examined in the three groups did not differ significantly between groups. Treatment with aflibercept in T&E shows significantly better visual acuity in naive eyes than in eyes pretreated with PRN.

Clinical characteristics and functional outcome of pediatric ocular trauma in a third level reference hospital in Guadalajara, Mexico.

Ocular trauma is one of the leading causes of decreased visual acuity and monocular blindness in the pediatric population. Since its occurrence is potentially preventable, it is essential to understand its demographic characteristics and risk factors to alert and implement prevention and health promotion programs. We conducted a retrospective study in which we reviewed 187 clinical records of patients ≤ 15 years old with the diagnosis of severe ocular trauma admitted in 2017 to the Hospital Civil de Guadalajara. We analyzed demographic variables, circumstances of the event, type of treatment, and the evolution of visual acuity and complications. In total, 187 patients and 188 eyes were included; the average age was 6.99 ± 4.1 years. Children of 2 to 5 years of age (41%) were the most affected, and a higher occurrence was observed in males (73%). Open ocular trauma was the most common type of injury (72.7%) caused by sharp objects (45.4%). Most injuries occurred at home (78.1%), without adult supervision (48.1%), and during leisure time (74.9%). Most events were accidental (80.4%), although 12.3% were direct aggression. Surgery was required in 179 patients, in whom corneal injury repair (43.2%) was the most commonly used procedure. Final visual acuity was quantified in 132 eyes, and visual acuity < 20/200 was found in 18.1%. Loss of 4.2% of the eyeballs was recorded. The highest proportion of cases was identified in male patients ≤5 years old, unsupervised by an adult. Many eye injuries are preventable, so it is necessary to implement socio-educational programs in alliance with pediatric organizations that alert the severity of the problem and promote safe environments.

Intravitreal Gene Therapy vs. Natural History in Patients With Leber Hereditary Optic Neuropathy Carrying the m.11778G>A ND4 Mutation: Systematic Review and Indirect Comparison.

Objective: This work aimed to compare the evolution of visual outcomes in Leber hereditary optic neuropathy (LHON) patients treated with intravitreal gene therapy to the spontaneous evolution in prior natural history (NH) studies.Design: A combined analysis of two phase three randomized, double-masked, sham-controlled studies (REVERSE and RESCUE) and their joint long-term extension trial (CLIN06) evaluated the efficacy of rAAV2/2-ND4 vs. 11 pooled NH studies used as an external control.Subjects: The LHON subjects carried the m.11778G>A ND4 mutation and were aged ≥15 years at onset of vision loss.Methods: A total of 76 subjects received a single intravitreal rAAV2/2-ND4 injection in one eye and sham injection in the fellow eye within 1 year after vision loss in REVERSE and RESCUE. Both eyes were considered as treated due to the rAAV2/2-ND4 treatment efficacy observed in the contralateral eyes. Best corrected visual acuity (BCVA) from REVERSE, RESCUE, and CLIN06 up to 4.3 years after vision loss was compared to the visual acuity of 208 NH subjects matched for age and ND4 genotype. The NH subjects were from a LHON registry (REALITY) and from 10 NH studies. A locally estimated scatterplot smoothing (LOESS), non-parametric, local regression model was used to modelize visual acuity curves over time, and linear mixed model was used for statistical inferences.Main Outcome Measures: The main outcome measure was evolution of visual acuity from 12 months after vision loss, when REVERSE and RESCUE patients had been treated with rAAV2/2-ND4.Results: The LOESS curves showed that the BCVA of the treated patients progressively improved from month 12 to 52 after vision loss. At month 48, there was a statistically and clinically relevant difference in visual acuity of −0.33 logarithm of the minimal angle of resolution (LogMAR) (16.5 ETDRS letters equivalent) in favor of treated eyes vs. NH eyes (p < 0.01). Most treated eyes (88.7%) were on-chart at month 48 as compared to 48.1% of the NH eyes (p < 0.01). The treatment effect at last observation remained statistically and clinically significant when adjusted for age and duration of follow-up (−0.32 LogMAR, p < 0.0001).Conclusions: The m.11778G>A LHON patients treated with rAAV2/2-ND4 exhibited an improvement of visual acuity over more than 4 years after vision loss to a degree not demonstrated in NH studies.Clinical Trial Registration: NCT02652767, NCT02652780, NCT03406104, and NCT03295071.

Comparative study of combined vitrectomy with phacoemulsification versus vitrectomy alone for primary full-thickness macular hole repair

BackgroundTo assess the effectiveness and safety of 23-gauge pars plana vitrectomy combined with phacoemulsification versus vitrectomy alone in patients over 50 years with primary full-thickness macular holes (FTMH).MethodsWe retrospectively reviewed the medical records related to 406 consecutive vitrectomies performed for primary FTMH. Phacovitrectomy was performed in 294 phakic eyes whereas vitrectomy alone in 112 pseudophakic eyes. The cases were divided into three groups according to the stage of the FTMH: stage 2 (n = 93), stage 3 (n = 270), or stage 4 (n = 43). The primary outcome measure was the closure of the FTMH. The secondary outcome measures were the evolution of visual acuity as well as intraoperative and postoperative complications.ResultsNeither the primary nor the secondary outcomes differed between phacovitrectomy and vitrectomy alone for all three stages. The FTMH were closed in 375 eyes (92.4 %) after a first operation. The closure rate was higher for stage 2 (96.8 %) than for stages 3 (91.1 %) or 4 (90.75 %), but not significantly (P = 0.189). The mean visual acuity increased significantly from preoperatively LogMAR 0.68 (± SD 0.2) to LogMAR 0.43 (± SD 0.24) at the end of the follow-up (p < 0.001).ConclusionsCombined 23-gauge pars plana vitrectomy with phacoemulsification for primary FTMH repair in patients over 50 years is as efficient and safe when compared with vitrectomy only.Trial registrationThe study was approved on 30th April 2020 by the local ethics committee (Ethikkommission Ostschweiz, EKOS 20/074; BASEC Nr. 2020-01033).

Fornix-Based Trabeculectomy Conjunctival Closure: Winged Sutures versus Modified Wise Closure

To compare the midterm safety and efficacy profile of winged sutures versus modified Wise closure for fornix-based trabeculectomy. Retrospective comparative study. Consecutive cases that underwent fornix-based trabeculectomy by a single surgeon between January 5, 2015, and May 8,2017. Potential cases were identified using the Current Procedural Terminology code, and their charts were reviewed thoroughly. Only 1 eye per patient was included. Demographic and clinical data were collected. Primary outcomes were bleb leak and subsequent surgical revision rates. Secondary outcomes included intraocular pressure (IOP), number of glaucoma medications (NGM), visual acuity (VA), and other complications. A total of 313 patients were identified, 157 with winged sutures and 156 with modified Wise closure. Baseline demographic and clinical characteristics were similar between the 2 groups. Twenty-six cases (16.6%) of winged sutures and 10 cases (6.4%) of modified Wise group developed bleb leak (P= 0.007), but only a total of 10 eyes needed bleb revision (P= 0.336). Other complications were similar in rates between the groups (P > 0.05). At 6 months, the modified Wise group had significantly greater IOP reduction (-3.10±1.29 [standard error], P= 0.016). Number of glaucoma medications reduction and VA evolution were similar between the 2 groups (P > 0.05). Fornix-based trabeculectomy with either closure technique was effective in lowering IOP and NGM with comparable safety profile at 6 months. Furthermore, modified Wise closure provided larger IOP reduction and lower bleb leak rate, suggesting a potential superiority to winged sutures. Our study was limited by mitomycin C (MMC) delivery method change near the time of conjunctival closure change, although MMC delivery methods did not show significance in any outcome model.

Visual outcome after posterior uveal melanoma episcleral brachytherapy including radiobiological doses.

PurposeTo assess the long-term influence of radiobiological doses in the evolution of visual acuity (VA) in patients with uveal melanoma treated by episcleral brachytherapy.Material and methodsVisual acuity was evaluated prospectively from a case series of 243 patients in 2016 treated with 125I. Data analysis was applied to trend VA outcome and find the accurate best-fit line. Biologically effective dose (BED) was included in survival analysis with the use of Kaplan-Meier and Cox regressions. Hazard ratio (HR) and confidence interval at 95% (CI) were determined. Variables statistically significant were analyzed and compared by log-rank tests.ResultsThe median follow-up was 74.2 months (range, 3-223). Exponential regression shows a 25% reduction and 50% in visual acuity score (VAS) scale for 5 and 27.8 months, respectively. Cumulative probabilities of survival analysis were 57%, 42%, 27%, and 23% at 3, 5, 10, and 15 years, respectively. Multivariable analysis found tumor height (HR = 1.18, 95% CI: 1.07-1.29), applicator size (HR = 1.22, 95% CI: 1.08-1.36), juxtapapillary localization (HR = 1.70, 95% CI: 1.01-2.84), and dose to foveola (HR = 1.01, 95% CI: 1.00-1.01) significantly associated with VA loss. Log-rank tests were significant for all those variables. BED has a strong influence in univariate model, but not statistically significant in the multivariate one.ConclusionsVisual acuity changes can be modeled by an exponential function for the first 5 years after treatment. No relation between VA loss and BED has been found; nevertheless, apical height, plaque size, juxtapapillary localization, and dose to fovea were found as statistical significant variables.

Optical Coherence Tomography Examination of the Retinal Pigment Epithelium in Best Vitelliform Macular Dystrophy

To describe the anatomic changes and natural history of vitelliform lesions in Best vitelliform macular dystrophy (BVMD) using spectral-domain optical coherence tomography (OCT). Prospective comparative case series. Twenty patients (40 eyes) with molecular confirmation of mutation in the BEST1 gene and 20 age-matched controls were included. Color fundus photographs, fundus autofluorescence, and spectral-domain OCT were obtained, and these findings were compared between the 2 groups. Fifteen of the 20 patients with Best disease had more than 1 visit, and the imaging studies from each visit were compared with each other over time. Evolution of visual acuity and clinical stage of BVMD correlated to OCT measurement parameters, including retinal pigment epithelium (RPE) thickness, central macular thickness, and integrity of the ellipsoid zone. Patients with BVMD demonstrated progressive disorganization and thinning of the submacular RPE on OCT when compared with normal controls. Concurrent with the appearance of "egg-yolk lesions," the OCT showed a cleft in the outer retina, creating an apical and basal separation of retinal layers. The apical complex of the vitelliform lesion eventually degenerated and flattened. Patients with such lesions nevertheless maintained reasonable visual acuity into the advanced vitelleruptive stages despite the disruption of normal anatomic changes. Our study suggests that in BVMD, subretinal vitelliform material accumulation leads to a clear separation of the outer retinal layers. The level at which this cleft forms is a topic of discussion andinterest, with the most likely levels of least resistance being the interdigitation zone or between the RPE and the Bruch's membrane. It is possible that RPE may continue to form a preserved photoreceptor-RPE complex that provides essential nutrients to the photoreceptors and in turn helps patients maintain better than expected visual acuity for years.

Responses to ranibizumab in wet age-related macular degeneration patients with vitreomacular traction

PurposeThe purpose of the present study is to compare the responses to ranibizumab between wet age-related macular degeneration patients, with and without accompanying vitreomacular traction syndrome. MethodsOur database of optical coherence tomography files was searched for eyes of age-related macular degeneration patients that had been treated with ranibizumab, and that had evidence of vitreomacular traction. A control group was selected from the same database for comparison.The case history of each selected individual was reviewed for data regarding the evolution of visual acuity in that patient, and the number of intravitreal injections that had been required to date. ResultsFrom a database of 373 eyes, clear images of vitreomacular traction were obtained for a total of 18 eyes.The mean follow-up period was 20.6 months (SD=10.6, range=10.4–31.7).Patients in the vitreomacular traction group had been given an average of 5.1 injections versus an average of 4.2 injections in patients in the control group.The mean changes in visual acuity (which was measured using ETDRS charts) were −15 letters and −4 letters in the vitreomacular traction and control groups (p=0.07), respectively. ConclusionsAfter ranibizumab treatment, age-related macular degeneration patients with accompanying vitreomacular traction showed a tendency to have a poorer prognosis in terms of visual acuity than patients without this finding. In addition, higher numbers of intravitreal injections were required to obtain clinical responses in patients with vitreomacular traction.

Respuesta a ranibizumab en pacientes con degeneración macular húmeda con tracción vitreomacular

PurposeThe purpose of the present study is to compare the responses to ranibizumab between wet age-related macular degeneration patients, with and without accompanying vitreomacular traction syndrome. MethodsOur database of optical coherence tomography files was searched for eyes of age-related macular degeneration patients that had been treated with ranibizumab, and that had evidence of vitreomacular traction. A control group was selected from the same database for comparison.The case history of each selected individual was reviewed for data regarding the evolution of visual acuity in that patient, and the number of intravitreal injections that had been required to date. ResultsFrom a database of 373 eyes, clear images of vitreomacular traction were obtained for a total of 18 eyes.The mean follow-up period was 20.6 months (SD=10.6, range=10.4-31.7).Patients in the vitreomacular traction group had been given an average of 5.1 injections versus an average of 4.2 injections in patients in the control group.The mean changes in visual acuity (which was measured using ETDRS charts) were -15 letters and -4 letters in the vitreomacular traction and control groups (P=.07), respectively. ConclusionsAfter ranibizumab treatment, age-related macular degeneration patients with accompanying vitreomacular traction showed a tendency to have a poorer prognosis in terms of visual acuity than patients without this finding. In addition, higher numbers of intravitreal injections were required to obtain clinical responses in patients with vitreomacular traction.

Chorioretinitis as the First Sign of Acquired Toxoplasmosis Transmitted from Donor following Kidney Transplantation: Case Report and Review of the Literature

Purpose: To report a case of chorioretinitis as the earliest manifestation of Toxoplasma gondii infection acquired through donor after kidney transplantation.Design/Methods: Three months after kidney transplantation thepatient referred for visual acuity loss in her left eye and was diagnosed withtoxoplasmicchorioretinitis. Systemic treatment was started.Results: The evolution of visual acuity was satisfactory. Laboratory studies confirmed that the patient was seronegative for Toxoplasma gondiiprior to the surgery.Conclusions: The literature reports toxoplasmosis as an uncommon but dangerous source of morbidity and mortality after transplantation. This case highlights the value of the ophthalmologic examination when taking care of these patients.

Evolution of visual acuity in patients with wet type of AMD and good initial visual aquity

Abstract Purpose The evaluation of wet type of AMD after intravitreal injections with anti‐angiogenic factors in patients with good initial visual aquity. Correlation between final and initial visual acuity, as well as with the number of injections Methods 101 patients of average age 76 participated in the study. All of them suffered from wet type of AMD. Study group included 24 of them with good initial visual acuity, defined as visual acuity of 6/10 of the decimal scale or higher. The remaining 77 patients served as control group. The initial evaluation included full ophthalmologic examination, OCT imaging and fluorescein angiography. The decision for the treatment was based on the findings of the first examination and of the monthly reevaluation thereafter. Results In the 24 patients of the study group, visual acuity increased significantly from 0,61 (+/‐0,2) to 0,82 (+/‐0,2) in decimal scale or from 0,27 (+/‐0,22) to 0,14 (+/‐0,2) in LOGMAR scale (p&lt;0,001). The average number of intravitreal injections was 4,9 in a mean monitoring time of 9 months. In this team the final visual acuity depends on the initial one (p= 0,013), but not on the number of intravitreal injections (p&gt; 0,05). Conclusion the final visual acuity in the group with good initial visual acuity correlates well with the initial visual acuity and does not correlate with the number of injections. This finding shows the significance of early diagnosis of subretinal neovascularisation in AMD, when the vision is still high.

SPONTANEOUS RESOLUTION OF MACULAR EDEMA AFTER PANRETINAL PHOTOCOAGULATION IN FLORID PROLIFERATIVE DIABETIC RETINOPATHY

To report the evolution of diabetic macular edema (DME) after extensive panretinal photocoagulation in patients with Type 1 diabetes exhibiting florid proliferative diabetic retinopathy (FPDR). This retrospective observational case series comprised 17 eyes of 10 consecutive patients (8 women and 2 men). All patients exhibited FPDR combined with severe DME, and all underwent panretinal photocoagulation. The evolution of visual acuity and progression of FPDR were evaluated. The evolution of DME during follow-up was assessed by fluorescein angiography and repeated optical coherence tomography examinations. At baseline, all eyes had diffuse DME. Mean logMAR visual acuity was 0.402 +/- 0.46. Mean central macular thickness was 468.23 +/- 113.63 microm. After panretinal photocoagulation, DME regressed spontaneously in all eyes after a mean follow-up of 7.1 +/- 2.68 months. Mean central macular thickness decreased to 268.12 +/-54.67 microm (t-test, P < 0.0001). Mean visual acuity improved significantly to 0.184 +/- 0.12 (t-test, P = 0.048). Diabetic macular edema only recurred in two eyes. In DME combined with FPDR, extensive panretinal photocoagulation and glycemic control seem effective in reducing DME and improving vision. In FPDR, DME may be caused by excessive production of vascular endothelial growth factor by the unperfused retina.

Corneal changes induced by laser ablation: study of the visual-quality evolution by a customized eye model

This study focuses on the changes induced in both the asphericity and homogeneity of the cornea for a group of myopic eyes undergoing LASIK surgery. Eyes were characterized by a Kooijman-based customized eye model in which changes were introduced in the form of Gaussian-distributed refractive-index variations of given correlation length for the inhomogeneities and in the form of an expression, based on the modified Munnerlyn's paraxial formula, for the post-LASIK asphericity. Visual quality was evaluated in terms of the Modulation Transfer Function and the Point-Spread Function. The results show that, on average, the evolution of visual acuity is consistent with the change in corneal asphericity, while the evolution of contrast sensitivity requires a loss in corneal homogeneity in order to be explained. By including both effects in the model, the overall model performance in predicting visual quality is improved.

Occurrence and predictors of retinopathy and visual acuity in Type 2 diabetic patients and control subjects: 10-year follow-up from the diagnosis

The evolution of visual acuity and retinopathy and their risk factors in patients with newly diagnosed type 2 diabetes and in control subjects. A 10-year prospective study consisting of a representative group of 133 (70 men, 63 women) newly diagnosed type 2 diabetic patients diagnosed at health centers between 1979 and 1981 and 144 (62 men, 82 women) non-diabetic control subjects recruited from the population register. The frequency of retinopathy was determined by grading of 45° fundus photographs at baseline and after 5 and 10 years. By the 10-year follow-up the diabetic patients had lower visual acuity than the control subjects. The impairment of the visual acuity correlated inversely to HbA 1C value of the 5-year examination. The frequency of retinopathy in type 2 diabetic patients increased sharply after 5 years and at 10-year 55% of diabetic patients had signs of retinopathy. The frequency of retinopathy in the control subjects was low, but detectable. In the diabetic patients poor glycemic control was the most important predictive factor for the development of retinopathy. In the control subjects blood pressure levels were higher and microalbuminuria more common in those with than in those without retinopathy. The visual acuity deteriorated and the frequency of retinopathy increased in newly diagnosed type 2 diabetic patients with duration of disease and poor glycemic control. Interestingly, higher blood pressure levels and microalbuminuria predicted retinopathy in control subjects.

Place de l'hémodilution aiguë normovolémique dans le traitement des occlusions veineuses rétiniennes

The supposed state of retinal venous occlusions by a thrombus has led to the use of diverse antithrombotic treatments (heparin, fibrinolytic agents). This theory being considered at the moment as controversial, haemorheological theories being more particularly favoured, other treatments are proposed in an attempt to better retinal microcirculation, and this by changing the blood viscosity parameters. The study reported here compared the effects on recovery of visual acuity of retinal venous occlusion patients of anticoagulant treatment alone, haemodilution alone, or borth together. After initial ophtalmic assessment, twenty-five patients were randomly assigned to one of three groups : groupe I (n = 5; mean age 62±14 yr) received heparin for 21 days, followed by antivitamin K drugs for a further 30 days; group II (n = 10; mean age 54±16 yr) were acutely haemodiluted with 40,000 daltons molecular weight dextran, bringing the haematocrit to between 0.25 and 0.30; on day 2, the same anticoagulant treatment as in group I was associated; group III (n = 10; mean age 58±18 yr) were only haemodiluted. The haemodiluted state was maintained for 21 days. A biological assessment was carried out for the three groups on days 1, 2, 7, 14, 21 and 30 (haematocrit, fibrinogen level, platelet count, kaolin-kephalin time, heparin level). The evolution of visual acuity was assessed on days 7, 14, 21, 30, 60 and 90. Mean visual acuity was assessed on days 7, 14, 21, 30, 60 and 90. Mean visual acuity was virtually the same for the three groups on day 0. In group I, there was an initial worsening of this until day 30, followed by a return to initial values on days 60 and 90. In group II, visual acuity was bettered from day 7 on, this increase being statistically significant on days 60 (p <0.05) and 90 (p <0.02). In group III, the improvement in visual acuity became significant on day 14 (p <0.02) and highly significant on days 60 and 90 (p <0.01). There was no significant difference between the two haemodiluted groups; but there was a significant difference with the « anticoagulant onlygroup from day 14 on (p <0.05), this difference increasing for group III on day 90 (p <0.01). Acute isovolaemic haemodilution alone therefore seemed a useful treatment for the improvement of visual acuity in retinal venous occlusion patients. An added anticoagulant treatment did not appear justified.