Scleral buckling versus primary vitrectomy in rhegmatogenous retinal detachment study (SPR Study): recruitment list evaluation. Study report no. 2

BACKGROUND: Accompanying the patient recruitment within the "Scleral buckling versus primary vitrectomy in rhegmatogenous retinal detachment multicentre trial (SPR)", all patients with primary rhegmatogenous retinal detachment (RRD) had to be documented in a detailed recruitment list. The main goal of this analysis was to estimate the prevalence of "medium-severe" RRD (SPR Study eligible) as defined by the SPR Study inclusion criteria. In addition, the detailed anatomical situation of medium-severe RRD is investigated. METHODS: SPR Study recruitment was evaluated via a standardised questionnaire, which contained a coloured fundus drawing and information regarding possible reasons for exclusion from the SPR Study in each case. A team of three experienced vitreoretinal surgeons evaluated all fundus drawings from a 1-year period. The review led to a decision on SPR Study eligibility on the pure basis of anatomical assessment. The main outcome measures were assessment of feasible inclusion into the SPR Study by the evaluation team based on the fundus drawing and anatomical details. RESULTS: A total of 1,115 patients with RRD from 13 European centres were prospectively enrolled in the year 2000. The quality of the drawings sufficed for assessment in 1,107 cases (99.3%). Three hundred and twelve fundus drawings (28.2%) met the anatomic inclusion criteria of the SPR Study. RRD of medium severity is characterised by an average number of 2.6 (SD 2.4) retinal breaks, 5.8 (SD 2.8) clock hours of detached retina, unclear hole situation in 15.1% of cases (n=47), attached macula in 42.9% (n=134), bullous detachment in 15.1% (n=47) and vitreous haemorrhage/opacity in 7.7% (n=24). CONCLUSIONS: In the recruitment lists of the SPR Study of the year 2000, RRD of medium severity was present in nearly one third of the patients with primary RRD. These findings emphasise the clinical relevance of the SPR Study.

Treatment of branch retinal vein occlusion induced macular edema with bevacizumab

Branch retinal vein occlusion is a frequent cause of visual loss with currently insufficient treatment options. We evaluate the effect of Bevacizumab (Avastin) treatment in patients with macular edema induced by branch retinal vein occlusion.

Stem cells as tools in regenerative therapy for retinal degeneration

OBJECTIVE: To describe the use of stem cells (SCs) for regeneration of retinal degenerations. Regenerative medicine intends to provide therapies for severe injuries or chronic diseases where endogenous repair does not sufficiently restore the tissue. Pluripotent SCs, with their capacity to give rise to specialized cells, are the most promising candidates for clinical application. Despite encouraging results, a combination with up-to-date tissue engineering might be critical for ultimate success. DESIGN: The focus is on the use of SCs for regeneration of retinal degenerations. Cell populations include embryonic, neural, and bone marrow-derived SCs, and engineered grafts will also be described. RESULTS: Experimental approaches have successfully replaced damaged photoreceptors and retinal pigment epithelium using endogenous and exogenous SCs. CONCLUSIONS: Stem cells have the potential to significantly impact retinal regeneration. A combination with bioengineering may bear even greater promise. However, ethical and scientific issues have yet to be solved.

Comparison between confocal scanning laser tomography, scanning laser polarimetry and optical coherence tomography on the ability to detect localised retinal nerve fibre layer defects in glaucoma patients

BACKGROUND/AIM: To compare the ability of confocal scanning laser tomography (CSLT), scanning laser polarimetry (SLP) and optical coherence tomography (OCT) in recognising localised retinal nerve fibre layer (RNFL) defects. METHODS: 51 eyes from 43 patients with glaucoma were identified by two observers as having RNFL defects visible on optic disc photographs. 51 eyes of 32 normal subjects were used as controls. Three masked observers evaluated CSLT, SLP and OCT images to determine subjectively the presence of localised RNFL defects. RESULTS: Interobserver agreement was highest with OCT, followed by SLP and CSLT (mean kappa: 0.83, 0.69 and 0.64, respectively). RNFL defects were identified in 58.8% of CSLT, 66.7% of SLP and 54.9% of OCT (p = 0.02 between SLP and OCT) by at least two observers. In the controls, 94.1% of CSLT, 84.3% of SLP and 94.1% of OCT scans, respectively, were rated as normal (p = 0.02 between CSLT and SLP, and SLP and OCT). CONCLUSION: Approximately 20-40% of localised RNFL defects identified by colour optic disc photographs are not detected by CSLT, SPL or OCT. SLP showed a higher number of false-positive results than the other techniques, but also had a higher proportion of correctly identified RNFL defects in the glaucoma population.

Decreased visual function after patchy loss of retinal pigment epithelium induced by low-dose sodium iodate

PURPOSE: To correlate damage to the retinal pigment epithelium (RPE) with decreased visual function after the systemic administration of sodium iodate (NaIO(3)). METHODS: Damage was produced in mice by injection of 15, 25, or 35 mg/kg NaIO(3). Visual function was assessed with the cued water maze (WM) behavioral test and the optokinetic reflex (OKR) measurement at different times after injection. Autofluorescence in whole eye flatmounts was quantified, and hematoxylin and eosin staining of paraffin sections was performed to assess changes in the outer retina. RESULTS: After 15 mg/kg NaIO(3), cued WM test results were normal, whereas OKR measurements were significantly decreased at all times. Focal RPE loss began on day 21, but no significant damage to the outer nuclear layer was observed. After 25 mg/kg NaIO(3), the cued WM test was transitionally reduced and the OKR measurement again decreased at all times. Large areas of RPE loss occurred on day 14 with a reduced outer nuclear layer on the same day. With 35 mg/kg NaIO(3), the cued WM test was reduced beginning on day 14 with complete obliteration of the OKR beginning on day 3, large areas of RPE loss on the same day, and a reduced outer nuclear layer on day 7. CONCLUSIONS: Stable, patchy RPE loss was observed with a low concentration of NaIO(3). The OKR measurement showed changes in visual function earlier than the cued WM test and before histologic findings were observed.

Congenital retinal macrovessels: description of three cases and review of the literature

BACKGROUND: Congenital retinal macrovessels are large aberrant branches of retinal arteries or veins that cross the macula. We present three patients with a unilateral congenital retinal macrovessel and we conduct a review of the literature. PATIENTS AND METHODS: A 22-year-old man complaining of chronic headache as well as two other men, 18 and 23 years old, respectively, during a routine ophthalmological examination, were found with a unilateral congenital retinal macrovessel each. A thorough ophthalmological examination was performed, including colour fundus photography in all three patients and fluorescein angiography in two of the patients. We followed them up for five years. THERAPY AND OUTCOME: Investigation revealed a unilateral venous congenital retinal macrovessel in all patients. Clinical findings and visual acuity remained unchanged throughout the entire follow-up period. No complications were recorded. CONCLUSIONS: Congenital retinal macrovessels are rare and they tend to remain stable. Visual acuity is preserved in most cases. Complications occur only occasionally and have been described in the literature. Differential diagnosis from other arteriovenous malformations affecting multiple organs is necessary.

Long-term evaluation of anatomic and functional results after complicated retinal detachment treated with pars plana vitrectomy and heavy silicone oil tamponade

BACKGROUND: Heavier than water tamponades offer the possibility to support the inferior part of the fundus after retinal detachment. The aim of this study was to evaluate the anatomic and functional outcome of complicated retinal detachment treated with vitreous surgery and heavy silicone oil (HSO) tamponade. Surgery was performed in eyes with rhegmatogenous retinal detachment (RD) predominantly in the lower hemisphere or with penetrating injury (either as primary intervention or after development of proliferative vitreoretinopathy [PVR]). MATERIALS AND METHODS: Sixty-one eyes of 61 patients with RD - mostly complicated by PVR - and a minimum follow-up of 12 months were included in this study. Vitreoretinal surgery with HSO (Oxane HD) tamponade was performed in all patients. In 52 patients, heavy silicone oil was used in the management of complicated RD. 9 patients had surgery for complicated RD after penetrating eye injury.The mean follow-up period was 30.3 +/- 10.2 months. RESULTS: The overall final anatomic success rate was 79 %. In 39 % of the cases the retina remained attached during the entire follow-up period. CONCLUSIONS: The anatomic success rate after surgery with HSO (Oxane HD) was relatively low; however, only complex cases bearing a higher risk of retinal re-detachment received HSO in this study. Oxane HD does not appear to have major advantages compared to conventional silicone oil or other new-generation heavy silicone oils in these cases.

Reproducibility of retinal thickness measurements in healthy subjects using spectralis optical coherence tomography

PURPOSE: To test the reproducibility of retinal thickness measurements in healthy volunteers of a new Frequency-domain optical coherence tomography (OCT) device (Spectralis OCT; Heidelberg Engineering, Heidelberg, Germany). DESIGN: Prospective, observational study. METHODS: Forty-one eyes of 41 healthy subjects were included into the study. Intraobserver reproducibility was tested with 20 x 15 degree raster scans consisting of 37 high-resolution line scans that were repeated three times by one examiner (M.N.M.). Mean retinal thickness was calculated for nine areas corresponding to the Early Treatment Diabetic Retinopathy Study (ETDRS) areas. Coefficients of variation (COV) were calculated. RESULTS: Retinal thickness measurements were highly reproducible for all ETDRS areas. Mean total retinal thickness was 342 +/- 15 microm. Mean foveal thickness was 286 +/- 17 microm. COVs ranged from 0.38% to 0.86%. Lowest COV was found for the temporal outer ETDRS area (area 7; COV, 0.38%). Highest COV was found for the temporal inner ETDRS area (area 3; COV, 0.86%). Mean difference between measurement 1 and 2, measurement 1 and 3, and measurement 2 and 3 for all ETDRS areas was 1.01 microm, 0.98 microm, and 0.99 microm, respectively. CONCLUSION: Spectralis OCT retinal thickness measurements in healthy volunteers showed excellent intraobserver reproducibility with virtually identical results between retinal thickness measurements performed by one operator.

Rare retinal haemorrhages in translational accidental head trauma in children

PURPOSE: The characteristic findings in accidental head injury consist of linear skull fracture, epidural haematoma, localized subdural haematoma, or cortical contusion because of a linear or translational impact force. Retinal haemorrhages have been found, although uncommon, in accidental head trauma. METHODS: We performed a retrospective study of 24 consecutive cases of children with severe head injuries caused by falls. Inclusion criteria were skull fractures and/or intracranial haemorrhages documented by computerized tomography. All patients underwent a careful ophthalmic examination including dilated indirect fundoscopy within the first 48 h following admission. RESULTS: No retinal haemorrhages could be found in patients whose accidents were plausible and physical and imaging findings were compatible with reported histories. Excessive bilateral retinal haemorrhages were found in only three children with the typical signs of shaken baby syndrome. In eight children, trauma had led to orbital roof fractures. CONCLUSIONS: Retinal haemorrhages were not found in any of the patients with accidental trauma despite the severity of their head injuries. Hence, we add more evidence that there are strong differences between the ocular involvement in accidental translational trauma and those in victims of non-accidental trauma. Fall-related injuries carry a very low risk of retinal haemorrhages.

Serum Amyloid A, C-reactive Protein and Retinal Microvascular Changes in Hypertensive Diabetic and Non-diabetic Individuals: An ASCOT Substudy

To study the association of the inflammatory markers serum amyloid A (SAA) and C-reactive protein (CRP) with retinal microvascular parameters in hypertensive individuals with and without type 2 diabetes.

Differential effects of anti-hypertensive treatment on the retinal microcirculation: an Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) sub- study

Changes in the retinal microcirculation are associated with hypertension and predict cardiovascular mortality. There are few data describing the impact of antihypertensive therapy on retinal vascular changes. This substudy of the Anglo-Scandinavian Cardiac Outcomes Trial compared the effects of an amlodipine-based regimen (373 patients) with an atenolol-based regimen (347 patients) on retinal microvascular measurements made from fundus photographs. The retinal photographs were taken at a stage in the trial when treatments were stable and blood pressure was well controlled. Amlodipine-based treatment was associated with a smaller arteriolar length:diameter ratio than atenolol-based treatment (13.32 [10.75 to 16.04] versus 14.12 [11.27 to 17.81], median [interquartile range]; P<0.01). The association remained significant after adjustment for age, sex, cholesterol, systolic and diastolic blood pressures, body mass index, smoking, and statin treatment. This effect appeared to be largely attributable to shorter retinal arteriolar segment lengths in the amlodipine-treated group and is best explained by the vasodilator effects of amlodipine causing the visible emergence of branching side vessels. Photographic assessment of the retinal vascular network may be a useful approach to evaluating microvascular structural responses in clinical trials of antihypertensive therapy.

Prevalence of retinal hemorrhages in pediatric patients after in-hospital cardiopulmonary resuscitation: a prospective study

Child abuse occurs in 1% of children in the United States every year; 10% of the traumatic injuries suffered by children under 5 years old are nonaccidental, and 5% to 20% of these nonaccidental injuries are lethal. Rapid characterization of the injury as nonaccidental is of considerable benefit to child protection workers and police investigators seeking to safeguard the child care environment and apprehend and prosecute those who have committed the crime of child abuse. Physically abused children present with a variety of well-described injuries that are usually easily identifiable. In some cases, however, particularly those involving children with the shaken baby syndrome, obvious signs of physical injury may not exist. Although external signs of such an injury are infrequent, the rapid acceleration-deceleration forces involved often cause subdural hematomas and retinal hemorrhages, hallmarks of the syndrome. Frequently, retinal hemorrhages may be the only presenting sign that child abuse has occurred. Complicating the interpretation of the finding of retinal hemorrhages is the belief by some physicians that retinal hemorrhages may be the result of chest compressions given during resuscitative efforts. The objective of this study is to determine the prevalence of retinal hemorrhages after inpatient cardiopulmonary resuscitation (CPR) in pediatric patients hospitalized for nontraumatic illnesses in an intensive care unit.

Characteristics of rod regeneration in a novel zebrafish retinal degeneration model using N-methyl-N-nitrosourea (MNU)

Primary loss of photoreceptors caused by diseases such as retinitis pigmentosa is one of the main causes of blindness worldwide. To study such diseases, rodent models of N-methyl-N-nitrosourea (MNU)-induced retinal degeneration are widely used. As zebrafish (Danio rerio) are a popular model system for visual research that offers persistent retinal neurogenesis throughout the lifetime and retinal regeneration after severe damage, we have established a novel MNU-induced model in this species. Histology with staining for apoptosis (TUNEL), proliferation (PCNA), activated Müller glial cells (GFAP), rods (rhodopsin) and cones (zpr-1) were performed. A characteristic sequence of retinal changes was found. First, apoptosis of rod photoreceptors occurred 3 days after MNU treatment and resulted in a loss of rod cells. Consequently, proliferation started in the inner nuclear layer (INL) with a maximum at day 8, whereas in the outer nuclear layer (ONL) a maximum was observed at day 15. The proliferation in the ONL persisted to the end of the follow-up (3 months), interestingly, without ongoing rod cell death. We demonstrate that rod degeneration is a sufficient trigger for the induction of Müller glial cell activation, even if only a minimal number of rod cells undergo cell death. In conclusion, the use of MNU is a simple and feasible model for rod photoreceptor degeneration in the zebrafish that offers new insights into rod regeneration.