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To determine the role of ultrasound biomicroscopy (UBM) in the management of children affected with retinoblastoma. A review of clinical records of children with the diagnosis of retinoblastoma at the Hospital for Sick Children from January 1995 to December 2007, for whom UBM was used to determine the extent of intraocular tumor. Clinical characteristics were compared with UBM. Pathological correlation was performed for enucleated eyes. In total, 101 eyes of 75 patients were included in the final analysis. Only 11 eyes were diagnosed on UBM to have extension of the tumor anterior to the ora serrata, and were enucleated. Histopathological examination confirmed the anterior extension in all the 11 eyes. In total, 50 eyes were enucleated because of various reasons, such as poor visual prognosis (12 eyes), unilateral group D or E (23 eyes), recurrences (8 eyes), and treatment failure (7 eyes). None of those patients were found to have anterior extension of the disease on histopathological examination. UBM did not yield any false negative (0/50) or any false positives (0/11). The UBM provided a sensitive and reproducible visualization of the anterior retina, ciliary region, and anterior segment allowing a better staging of the advanced disease process. Primary assessment of the true extent of retinoblastoma is critical for the selection of an optimal management approach.

PURPOSE: To report a case of vitreous hemorrhage from ciliary granuloma in Wegener granulomatosis. METHODS: Interventional case report. An 18-year-old woman with Wegener granulomatosis and episcleral granuloma in her LE had ultrasound biomicroscopy findings of a mass in the pars plana of the ciliary body in the meridian corresponding to the episcleral granuloma. RESULTS: The patient underwent vitrectomy in the LE for subsequent vitreous hemorrhage. Intraoperatively, the mass was diagnosed as a ciliary granuloma at the pars plana. Dense blood clotting around the ciliary granuloma and subretinal exudation at the ora serrata were observed, with no other changes causative for the vitreous hemorrhage. CONCLUSIONS: We report a case of vitreous hemorrhage associated with a ciliary granuloma that was revealed by ultrasound biomicroscopy. Careful observation is necessary in eyes with persistent inflammation in Wegener granulomatosis.

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Pan-American Association of Ophthalmology/Pan-American Ophthalmologic Foundation Deutsche Ophthalmologische Gesellschaft (DOG) Fehr Foundation, Marburg Purpose: To determine the incidence of rhegmatogenous retinal detachments (RD) after intravitreal injection in six high-volume centres.Methods: A consecutive, interventional, multicenter case series measured the incidence of RD in patients receiving intravitreal anti-VEGF. A total of 35 942 intravitreal anti-VEGF injections (the number of the injections determined by review of injection log books over a 3 year period) were performed under sterile conditions with the patient in a supine position. Injections were given 3.5-4.0 mm behind the limbus in a tunnelled fashion.Results: During 36 consecutive months, five RD were reported, between 2 and 6 days after the injection. of the affected eyes, four were myopic) 1.75 to) -5.5 dpt. the incidence rate of rhegmatogenous RD was 0.013% (5/35 942) per injection.Conclusions: the incidence of RD in our community setting was very low (1 per 7188 injections). All RD occurred during the early postoperative period. the risks of RD can be minimized by a careful injection technique. Univ Bonn, Dept Ophthalmol, D-53127 Bonn, Germany Univ Marburg, Dept Ophthalmol, Marburg, Germany Avastin Data Base Bonn, Bonn, Germany Triemli Hosp, Dept Ophthalmol, Zurich, Switzerland Universidade Federal de São Paulo, Vis Inst IPEPO, São Paulo, Brazil Asklepios Clin, Dept Ophthalmol, Hamburg, Germany Eye Clin, Duisburg, Germany Universidade Federal de São Paulo, Vis Inst IPEPO, São Paulo, Brazil Web of Science

The authors describe a technique for the gross examination of postmortem eyes of children who are suspected to have been the victims of deliberate trauma. By removing the anterior segment (cornea, iris, lens and pars plicata of the ciliary body) en bloc by a coronal incision through the pars plana just anterior to the ora serrata, the pathologist may view and photograph the fundus exactly as it would have been seen clinically. The photographs obtained with this technique correlate more closely with antemortem clinical examinations and photographs than conventional gross examination procedures and have been introduced as evidence in trials concerning the issue of retinal hemorrhages in injured children. The anterior segment and optic nerve are also examined to facilitate a comprehensive description of ocular findings.

The age-related loss of accommodation (presbyopia) in human and nonhuman primates clearly involves loss of deformability of the crystalline lens. In addition, ciliary muscle mobility, as measured by both histologic1,2 and ultrasonographic (monkey)3 and magnetic resonance (human)4 imaging techniques, also diminishes with age. However, the isolated ciliary muscle in nonhuman primates maintains its full ability to contract in response to appropriate pharmacologic stimulation throughout life,1,2,5 and its contractile machinery and receptor biology also remain normal.6,7 Therefore, posterior restriction of muscle movement in the aging eye has been hypothesized to play a role in the pathophysiology of presbyopia as well, at least in monkeys.8 In addition, there are zonular attachments to the vitreous membrane in both species that have not yet been fully investigated. Earlier studies were focused mainly on the anterior hyaloid membrane. Wieger9 was among the first to describe attachments of the zonules to the anterior vitreous membrane. They were later termed Wieger's ligament.10–12 Streeten and Pulaski13 doubted the strength of Wieger's ligament, because, after lens extraction, it is not uncommon for a superficial flap of either the capsule or anterior hyaloid to be torn from Wieger's area.13 Bernal et al.,14 using a combination of environmental scanning electron microscopy (ESEM) combined with a custom-made manual lens stretcher to facilitate inside microscopy, were able to further analyze the complex connection between the anterior vitreous membrane and zonule.14 Attachments between the posterior pars plana zonule and the vitreous membrane have been observed in histologic sections and by SEM.15–17 Improved in vivo imaging by ultrasound biomicroscopy (UBM) allows visualization of zonular fibers in the living eye.18 Using UBM, we observed a straight line parallel to but separated from the pars plana by a cleft approximately 2 mm wide, extending from the region of the ciliary processes to the region of the ora serrata (see Fig. 1). There has been debate as to whether the structure observed by UBM was (1) the pars plana zonule, which in the living eye is normally separated from the pars plana ciliary epithelium, but after fixation for histology or air drying for scanning electron microscopy (SEM) becomes apposed to the pars plana ciliary epithelium (CE)19; (2) the vitreous membrane20; or (3) another component of the vitreozonular system that has not been well described or characterized. Figure 1. UBM overview image in a live rhesus monkey shows a prominent straight line (arrow) extending from the pars plicata region of the ciliary body to the ora serrata region and separated from the pars plana epithelium by a cleft. CP, ciliary processes, CB, ... We investigated the zonule, the posterior vitreous, and their attachments by novel scanning SEM and UBM techniques, and we now can hypothesize about how this system may affect ciliary muscle movement. In addition, we provide preliminary physiological evidence that ciliary muscle movement may be increased by perturbing the system.

The Na+,K+-ATPase α1, α2, and α3 subunit isoforms have been shown to be differentially expressed in the nonpigmented (NPE) and pigmented (PE) cells of the ocular ciliary epithelium (CE)(Martin-Vasallo et al., J. Cell. Physiol., 141: 243-252, 1989; Ghosh et al., J. Biol. Chem., 265:2935-2940, 1990). In this study we analyzed and compared the pattern of expression of the multiple Na+,K+-ATPase α (α1, α2, α3) subunit genes with the pattern of expression of the Na+,K+-ATPase β (β1, β2) subunit genes along the bovine CE. We have selected three regions in the CE, referred to as (1) the anterior region of the pars plicata, near the iris; (2) the middle region of the pars plicata; and (3) the posterior region of the pars plana, near the ora serrata. Using isoform-specific cDNA probes and antibodies for the Na+,K+-ATPase α1, α2, α3, β1, and β2 subunits on Northern and Western blot analysis, we found that mRNA and polypeptides are expressed in all three CE regions with different abundance. The pattern of expression of α and β isoforms detected along the NPE cell layer suggests a gradient of α1, α2, α3, β1, and β2 mRNAs and polypeptides that correlates with decreasing Na+,K+-ATPase activity from the most anterior region at the pars plicata towards the posterior region at the ora serrata. We also found marked differences in the pattern of immunolocalization of Na+,K+-ATPase α1, α2, α3, β1, and β2 subunit isoforms in different regions of the CE. In the anterior region, NPE cells stained intensely at the basal lateral membrane with specific monoclonal and polyclonal antibodies for each of the α (α1, α2, α3) and β (β1, β2) Na,K-ATPase isoforms. In the middle and posterior regions of the CE, NPE cells showed lower or absent levels of staining with α1, α2, α3, and β1 antibodies, although staining with β2 was abundant. In contrast, PE cells throughout the CE were stained at the basal lateral membrane by antibodies to α1 and β1, while no staining signals were detected with the rest of the antibodies (i.e. α2, α3, and β2). Our results support the conclusion that the three α and two β isoforms of the Na+,K+-ATPase are differentially expressed in the two cell layers that make up the CE. These results also suggest that the expression of the Na+,K+-ATPase α and β subunit isoforms may underlie subtle differences along the NPE cell layer in ion transport.

Video-enhanced imaging of retinal wholemounts reveals an abrupt change in the composition of the photoreceptor mosaic at the edge of the human retina. Cone densities rise threefold and rod densities fall tenfold in a 1-mm-wide peripheral band. Antibodies directed against cones confirm the identification of the major subtypes of photoreceptors within this peripheral band. The cone-enriched rim is most highly developed along the nasal retinal margin, an area where the extreme lateral periphery of the visual field is imaged. This rim of cones may function as part of a rapid-acting alert mechanism under conditions of moderate and bright illumination.

Seventy-seven patients developed retinal breaks following an episode of ocular contusion, and 65 (84.4%) of these developed rhegmatogenous retinal detachment. Surgical treatment successfully restored or maintained retinal apposition in 74 (96.1%) of the eyes. Thirty-six (46.8%) eyes recovered visual acuity of 6/9 or better. Of the retinal breaks recognised dialysis at the ora serrata was observed in 49 eyes, of which 28 were situated at the lower temporal quadrant. Seventeen eyes had irregular breaks arising within necrotic retina at the site of scleral impact. Twenty-four (31.2%) patients had retinal break or retinal detachment diagnosed within 24 hours of injury and 49 (63.6%) within six weeks. Immediate retinal detachment was a feature of necrotic retinal breaks, while inferior oral dialyses led to a slow accumulation of subretinal fluid. Delayed diagnosis of retinal detachment was due either to opaque media or to failure to examine the retina after injury. Visual prognosis was good when retinal break or detachment were diagnosed within six weeks of injury. However, those patients who escaped initial retinal examination and were lost to follow-up had a less favourable visual outcome.

An unusual peripheral depigmented streak lesion of the retina is described in three patients. This depigmented line is located in the equatorial region running parallel to the ora serrata and seems to result from a focal reduction or loss of pigmentation in the retinal pigment epithelium. Similar lesions have been reported as a symptom of the presumed ocular histoplasmosis syndrome (POHS) called linear streaks of the equator. As we did not find any additional symptoms of POHS in our patients, the aetiology of this peripheral depigmented streaks remains unclear.

t i F t v d f o F t v v OR THE PAST CENTURY, THE PATHOGENESIS OF AGErelated macular degeneration (AMD) has remained unclear. Treatments developed over the past two ecades focus on late-stage disease, where our knowledge is ost comprehensive. Understanding the first stages of MD may allow us to develop interventions earlier in the isease and save vision. The etiology of AMD, I believe, is largely attributable to mpairment of choroidal perfusion. Atherosclerosis inreases scleral rigidity. Scleral rigidity, in turn, interferes ith choroidal venous drainage of retinal lipoproteins; nd, finally, the accumulation of these lipoproteins is esponsible for the retinal damage seen in early AMD. rogression to the neovascular form results from angioenic factors such as vascular endothelial growth factor VEGF). Photoreceptor loss occurs in geographic atrophy nd neovascular AMD secondary to apoptosis and necrois. For centuries, we have known that the coat of the eye ardens with age. Hardening can be attributable to age, ietary lipid, or atherosclerosis. Venous choroidal blood raverses the sclera tangentially through its four vortex eins rather than in a perpendicular manner characteristic f arterial flow. This tangential passage is not a problem hile the sclera is healthy and pliable, but with increased cleral rigidity, flow can become impaired. As a result, the learance of retinal lipoproteins (from photoreceptor turnver by the retinal pigment epithelium [RPE]) can derease. In 1937, Friedenwald stressed the role of elevated cleral rigidity in the aging eye and Verhoeff, in the same ear, attributed the pathogenesis of AMD to impairment of horoidal blood flow and the development of drusen. In 963, we showed that drusen are manifestations of an xudative process involving the choriocapillaries of chooidal veins (Figure 1). In 1970, using choroidal flatounts, we demonstrated that indeed drusen tend to ppear in those parts of the vortex system farthest from the eart, where the venous pressure is the greatest, anteriorly region of the ora serrata) as well as posteriorly (near the acula), confirming venous involvement in the pathology Figure 2). Recent research by Dashti and associates has hown that the lipoproteins are not of dietary or systemic rigin but are most likely waste products of retinal metablism that are usually excreted by the choroidal circula

This review will focus on the molecular organisation of the adult vitreous and how it undergoes ageing changes throughout life that result in vitreous liquefaction and a predisposition towards posterior vitreous detachment and retinal break formation. At birth, the vitreous humour is in a gel state due to the presence of a network of fine collagen fibrils. With ageing, these collagen fibrils progressively aggregate due to a loss of type IX collagen from their surfaces. The aggregation of collagen fibrils may cause vitreous liquefaction which, when combined with an age-related weakening of postbasal vitreoretinal adhesion, predisposes to posterior vitreous detachment. Throughout postnatal life, the posterior border of the vitreous base migrates posteriorly from the ora serrata into the peripheral retina. This is due to new collagen synthesis by the peripheral retina. This new collagen intertwines with pre-existing cortical vitreous collagen to create new adhesions and thereby extends the vitreous base posteriorly. If irregularities in the posterior border of the vitreous base arise from this process, there is a predisposition towards retinal break formation during posterior vitreous detachment and subsequent rhegmatogenous retinal detachment.

Specific antisera, raised in rabbits, against somatostatin 1-14, somatostatin 1-28, the fragment 1-12 of somatostatin 1-28, and prosomatostatin 20-36 were used for immunohistochemistry and gel filtration of the rat retina.With all antisera, immunoreactive perikarya could be located in the inner nuclear and ganglion cell layers. In the inner nuclear layer, amacrine cells with processes extending predominantly into the first sublayer of the inner plexiform layer were observed. Some processes extended also to the ganglion cell layer. In addition, somatostatin-immunoreactive interplexiform cells were present in the inner nuclear layer.In the ganglion cell layer, perikarya were found located in the midperiphery and in the far periphery of the retina. The neurons located in the midperiphery of the retina possessed a round perikaryon from which processes could be followed going into the inner plexiform layer, where they dichotomized in the third and first sublayers. The perikarya in the far periphery of the retina near the ora serrata exhibited an ovoid-shaped cell body from which processes extended horizontally in a bipolar manner in the layer itself.By use of an [35S]-labeled antisense oligonucleotide probe,in situhybridization of the rat retina showed the presence of perikarya in the inner nuclear layer and ganglion cell layer containing mRNA encoding for prosomatostatin.Gel filtration of the retinal extracts followed by radioimmunoassay showed the presence of somatostatin 1-14, the fragment 1-12 of somatostatin 1-28, and prosomatostatin 1-64. However, somatostatin 1-28 was not detected.The results obtained in this study verify the presence of somatostatin 1-14 in the rat retina located in perikarya and processes in the inner nuclear and ganglion cell layers. The positivein-situhybridization signals show that the intraneuronal somatostatin immunoreactivity is due to synthesis of the peptide and not uptake in the neurons. The presence of the somatostatin propeptide and fragments of this propeptide, in both intraretinal perikarya and fibers, indicate a posttranslational modification of this neuropeptide in the perikarya and the processes as well.

We report the results of a nonrandomized, matchedgroup, survival and visual preservation study of patients with a choroidal or ciliary body melanoma managed by microsurgical resection of the tumor versus cobalt-60 episcleral plaque radiotherapy. Each treatment group consisted of 30 patients. All patients were matched on a case-by-case basis in terms of tumor size (largest linear tumor dimension), location of the anterior tumor margin relative to the ora serrata, location of the posterior tumor margin relative to the equator, and age at the time of treatment. Although the estimated actuarial 5-year survival probability was slightly greater in the resection group (85.2%) than in the cobalt plaque group (81.8%), this difference was neither clinically impressive nor statistically significant. In contrast, there was a substantially higher rate of early posttreatment severe visual loss in the resection group (P = .0008, MantelHaenszel test).

We report the results of a nonrandomized, matched group survival study comparing 29 patients with a choroidal or ciliary body melanoma managed by enucleation alone to 29 patients managed by enucleation following external beam ocular irradiation (20 Gy in five fractions over 5-7 days just prior to enucleation). Variables on which the patients in the two groups were matched included age at time of enucleation, largest linear tumor dimension, location of the anterior tumor margin relative to the equator and ora serrata, melanoma cell type, and extrascleral tumor extension. The cumulative 5-year survival in the enucleation alone group was 57.9% (SE = 9.9%), whereas that in the preenucleation radiation therapy group was 63.9% (SE = 12.2%). This difference is not statistically significant (p greater than 0.5, Mantel-Haenszel test). The authors discuss the strengths and limitations of their study and the implications of their results.

The binding of RPE-1, a mouse monoclonal antibody selective for newt retinal pigment epithelium, was followed in eyes undergoing embryonic development and retinal regeneration. Using the indirect immunofluorescence technique on frozen sections, we observed bright and continuous labelling exclusively in the retinal pigment epithelium (RPE) of normal adult newts, but labelling became diminished near the ora serrata region and stopped abruptly at the ciliary margin. During development, labelling was not detected in the retinal pigment epithelium (RPE) until the formation of photoreceptor outer segments and was not observed in any other ocular tissue. There was no correlation between the appearance of pigment in retinal pigment epithelial cells and their labelling with the RPE-1 antibody. Furthermore, albino salamander embryos showed the same pattern of labelling with RPE-1 as that seen in age-matched pigmented animals. During retinal regeneration, RPE cells were labelled less intensely, but heavy labelling was observed in the newly formed retinal cells. With time, labelling in regenerated retina receded, so that by the end of regeneration, labelling by RPE-1 was once more restricted to the RPE cells. The identification of RPE-1 as a marker for postmitotic retinal neurons about to undergo differentiation provides a promising approach for further studies of regeneration with the help of molecular tools.

The uveal tract of rabbit eyes was examined using transmission electron microscopy of thin sections and freeze-fracture replicas. Emphasis was placed on the organization of pigmented and fibroblastic cells near the ora serrata and more generally in the lamina fusca, since these regions were previously found to restrict ingress of tracer molecules to the choroid in hamster eyes. There were significant differences between rabbit and hamster in the disposition of the pigmented cells and fibroblastic layers, the extent and patterns of tight junctions adjoining fibroblastic cells, and the presence of vesicles or fenestrations in the attenuated fibroblastic cell processes.

We report here that similar to E6-chicken retinal cells, dissociated cells from 5.5-day-old (E5.5) quail retinae reaggregate in rotary culture, multiply about tenfold and reestablish histotypical areas. These cellular aggregates include all nuclear layers either with inversed or correct laminar polarity, depending on the local origin of the cells (called “rosetted” and “laminar” in-vitro-retinae (IVR), respectively; Layer and Willbold 1989). In combined cultures, chick and quail cells are evenly mixed only during the first two days of culture. Along with the assembly of single cells into rosettes and then into discrete laminae, sectors of chick and quail cells begin to segregate. They are delineated by borders running radially through all three nuclear layers. Thus, interspecies migration of cells at this advanced stage of differentiation is strongly inhibited. Concomitant with this segregation, coherent radial columns spanning all three layers but containing cells from either species only, can be traced histologically. We conclude that a weak segregation of chick and quail retinal cells takes place already at the single cell level, but that the permanent segregation of entire tissue parts must be due to clonal cellular proliferation within the IVR in conjunction with some developmental-structural mechanism retaining clonal progenies within a columnar order.

The uveal tract of the eyes of monkeys was examined by electron microscopy using both thin sections and freeze-fracture replicas. The ultrastructural features of the lamina fusca in the monkey resembled those previously described for rabbit. The lamina fusca was composed of numerous interleaved processes of fibroblastic and pigmented cells and contained tight junctions between fibroblastic cell processes that were predominantly discontinuous, as well as numerous fenestrations through the attenuated cell processes. There was no regional compaction of cellular processes traversing the entire uvea at the level of the ora serrata as reported previously in hamster eyes.

PURPOSE To describe the autofluorescence features of CHRPE. DESIGN Noncomparative case series. PARTICIPANTS Thirteen consecutive eyes with CHRPE. METHODS : CHRPE was studied with fundus photography and autofluorescence. Autofluorescence was judged relative to the surrounding retinal pigment epithelium. MAIN OUTCOME MEASURE Autofluorescence features of CHRPE. RESULTS The mean CHRPE basal dimension was 4.75 mm and the tumor location was between the macular and equator (n = 10) or equator and ora serrata (n = 3). Overall, CHRPE show hypoautofluorescence in every case and was classified as trace (n = 1), moderate (n = 6), or marked (n = 6) hypoautofluorescence. Compared to the central portion of CHRPE, the margin showed isoautofluorescence (n = 8) or trace hyperautofluorescence (n = 5). There were eight lesions with lacunae and this feature generally showed trace to moderate hyperautofluorescence (n = 6). A nonpigmented halo was present surrounding six lesions, generally showing trace hyperautofluorescence (n = 3). A pigmented halo was present surrounding eight lesions, usually showing isoautofluorescence (n = 6). CONCLUSIONS CHRPE shows striking hypoautofluorescence and this correlates with known histopathologic evidence of lack of lipofuscin in the retinal pigment epithelium of CHRPE. The lacunae showed general mild hyperautofluorescence that might correlate with scleral autofluorescence.

A 31-YEAR-OLD AUStralian resident presented with a 2-week history of painless visual loss in her right eye. Her only overseas travel had been a holiday in Thailand 4 years earlier. Her visual acuity was 20/200 OD and fundoscopy revealed a curvilinear chorioretinal scar that extended from the temporal ora serrata to the right macula where it terminated in a gray, edematous subfoveal lesion (Figure 1). There was no anterior uveitis or vitritis. Fluorescein angiography revealed a classic subfoveal choroidal neovascular membrane (CNVM) (Figure 2). The patient consented to a single treatment of photodynamic therapy with verteporfin in combination with a 4-mg intravitreal injection of triamcinolone acetonide. Three months later, her visual acuity improved to 20/30 with no evidence of extension in the chorioretinal scar. Repeat fluorescein angiography and optical coherence tomography confirmed complete cessation of leakage from the CNVM and resolution of the intraretinal edema and subretinal fluid (Figure 2).

Summary The aim of this study was to describe and localize the intercellular junctions in the ora serrata region of albino and pigmented rabbit eyes. Eyes of albino and pigmented rabbits were fixed and processed for transmission electron microscopy. Light and electron microscope examination was carried out on semithin and ultrathin sections. The ora serrata region showed adherens, gap and tight junctions in the retinal and ciliary margins of albino and pigmented rabbit eyes. In the retinal margin, zonulae adherens between Muller cells and photoreceptors are associated with tight junctions. In the ciliary margin, epithelial cells are joined by adherens, gap and tight junctions localized between apical and apicolateral cell membranes. Tight junctions appear as zonulae occludens in the non-pigmented apicolateral cell membranes and as tight focal junctions between pigmented and non-pigmented apical cell membranes. Between the ciliary and retinal margins there are adherens and tight focal junctions which attach pigmented apical cell membranes to adjacent cells. There were no differences in the distribution of intercellular junctions between albino and pigmented rabbits.

The neural retinal degeneration in the aging Fischer 344 (F344) rat has been previously characterized. Here we describe the ultrastructural changes that occur in the retinal pigment epithelium (RPE), Bruch's membrane, and choriocapillaris in the periphery of the aged Fischer 344 rat.F344 eyes from 24-month-old animals (n = 4 animals, 8 eyes) were fixed and embedded for ultrastructural study. Serial mid-sagittal sections were taken from the superior peripheral retinas within 300 microm of the ora serrata. Pathology within the RPE, Bruch's membrane, and choriocapillaris was described.Progressive changes were seen in the RPE/Bruch's/choriocapillaris complex, increasing anteriorly as the ora serrata was approached. Early pathology of the RPE included increased number of basal infoldings, increased number of phagolysosomes and lipofuscin deposits, attenuation, inclusion of vasculature, vesicle formation, and whirling extensions of the basement membrane into the cytoplasm. Bruch's membrane showed spots of considerable thinning, but most prominent was the nodular thickening. The choriocapillaris was found to have severe endothelial degeneration and transformation to fibrous tissue in the most severely affected regions. Lipofuscin was also found in areas of degenerated choriocapillaris.Prior work focused on the neural retina, documented photoreceptor cell loss, and showed that Müller cell changes preceded that loss in the periphery of the F344 rat. It is now evident that the pathology in the RPE/Bruch's membrane/choriocapillaris complex may also be a critical component of the overall degenerative process. A possible mechanism for the extensive peripheral retinal degeneration in the F344 is presented.

The term “giant retinal tear” (GRT) should be restricted to very large tears at the ora serrata associated with an abnormally anterior separation of the posterior hyaloid membrane. Under the influence of gravity and freed from the mechanical restraints of a more limited gel separation, they are often characterised by an independent mobility of their posterior flap and occasionally if this is excessive, by radial posterior extensions at their apices. Although popular in public perception only a minority of giant retinal tears occur secondary to trauma and even with successful repair in these circumstances the visual prognosis may be limited by associated collateral ocular damage [1]. Retinal perforation or incarceration from penetrating trauma rarely causes acute rhegmatogenous retinal detachment, but the associated corneoscleral wound provides access for extrinsic fibroblasts so that the more common sequel is a pathologically anterior separation of the posterior hyloid membrane (PHM) and late giant tear complicated by combined tractional and rhegmatogenous components [1]. Retinal detachment due to blunt trauma is more commonly associated with a disinsertion at the ora serrata rather than true giant tear. The sudden anteroposterior compression is associated with a corresponding coronal expansion and retinal avulsion injury characterised by an accompanying festoon of non-pigmented pars plana epithelium. There is a greater preponderance for superior quadrant involvement in contrast to the usual lower temporal quadrant involvement in non-traumatic dialysis [3, 6]. Although the disinsertion may exceed 90 degrees of the circumference and superficially resemble a giant retinal tear, the vitreous gel characteristically remains attached to the posterior flap so that independent mobility is not a feature (Fig. 6.1a). They respond well to conventional scleral buckling techniques. Subretinal fluid recruitment is slow so that unless the ora serrata is routinely inspected after blunt trauGiant Retinal Tear

Objective To evaluate the effect of a near confluent pattern of indirect laser photocoagulation in reducing the rate of progression and re-treatment of threshold retinopathy of prematurity. Methods This study examined a noncomparative interventional case series. We performed a retrospective review of the medical records of patients who underwent peripheral laser ablation by 1 surgeon for threshold retinopathy of prematurity from 1997 to 2002. A total of 58 eyes from 31 patients were treated, and 44 eyes of 23 patients were included in the study. Ten eyes of 5 infants had zone 1 disease, and 34 eyes of 18 infants had zone 2 disease. Laser spots were placed in a near confluent pattern in the peripheral avascular retina between the ridge of extraretinal proliferation and the ora serrata. The mean ± SD number of laser spots was 2534 ± 455 for zone 1 (range, 2100-3378) and 1850 ± 487 for zone 2 (range, 1030-2689). Results In 7 eyes of 4 infants with zone 1 disease, the retinopathy regressed and did not require any further treatment. Three eyes of 2 infants, however, progressed after laser treatment and required vitrectomy surgery. Progression was defined as the development of stage 4 or 5 disease. None of the patients with zone 2 disease had progression of retinopathy, and none of them needed more than 1 treatment. Patients tolerated the procedure well, and there were no complications at the time of the procedure or at follow-up visits. Conclusions A near confluent pattern of laser photocoagulation may reduce the rate of progression of threshold retinopathy of prematurity in zone 2 (0%). The near confluent pattern of treatment may also reduce the re-treatment rate of the disease (0%). Larger studies are needed to confirm our findings.

The retinal pigment epithelium (RPE) is a monolayer of cuboidal epithelial cells intercalated between the photoreceptors and the choriocapillaries. The human RPE incorporates some 3.5 million epithelial cells arranged in a regular hexagonal pattern. The density of RPE cells is relatively uniform throughout the retina, approximately 4000 cells/mm 2 . With age, the cell density decreases particularly in the periphery, where it is reduced to approximately 2000 cells/mm 2 in individuals over 40 years. The peripheral RPE cells are larger and more pleomorphic than central cells (Harman et al., 1997; del Priore et al., 2002). In the primate retina, each RPE cell faces 30–40 photoreceptors, a number that is rather constant throughout the retina, although perhaps somewhat lower in the fovea (Robinson and Hendrickson, 1995). In fully developed primate retinas, no mitoses are seen in the RPE, and the epithelium is currently believed to consist of a stable, nondividing, pool of cells (Tso and Friedman, 1967). The retinal membrane of the RPE faces the subretinal space, which is the extracellular space surrounding the photoreceptor outer segments (Figure 1). Between the optic disc and the ora serrata, there are no anatomical contacts between the photoreceptors and the RPE. The RPE forms numerous long microvilli that interdigitate with the rod outer segments. In mammals, the cone outer segments are ensheathed by multilamellar specializations of the RPE, the so‐called cone sheaths. The epithelial cells are bound together by junctional complexes with tight junctions that separate the cells into an apical half that faces the retina and a basal half that faces the choroid. The nucleus and mitochondriae are located in the basal half of the cell. Numerous pigment granules, located predominantly in the apical cytoplasm, give the epithelium its macroscopic black appearance, from which it derives its name. The choroidal side of the RPE directly apposes Bruch's membrane, a pentalaminar, approximately 2 μm thick, elastic membrane. The innermost part of Bruch's membrane is the basement membrane of the RPE. The outer part of Bruch's membrane is the basement membrane of the choriocapillaries. In between are two collagenous layers and a central elastic layer.

Purpose We report the immunopathology of progressive subretinal fibrosis, a variant of sympathetic ophthalmia. Design Brief case report. Method Review of medical record and immunopathology of a chorioretinal biopsy of a 40-year-old man who presented with left total retinal detachment (RD) following multiple vitrectomies in the right eye for RD. Small peripherally retinal holes, snow banks, and inflammatory nodules along the ora serrata were observed during left vitrectomy. Both eyes deteriorated rapidly to blindness with progressive subretinal fibrosis and inflammation over 3 months, and the patient was unresponsive to systemic prednisolone and azathioprine. Result Immunopathology of the chorioretinal biopsy of the right eye revealed aggregates of CD20+ B cells, surrounded by CD3+ T cells. CD68+ macrophages were scattered throughout. Conclusion The rapid clinical course described in this case may be related to the unique immunopathology of rapidly forming peudogerminal centers in the choroids and retina.

Objective To evaluate and compare the relationships between the posterior surface of the crystalline lens and peripheral retina with the use of curved vitrectomy instruments. Materials and methods Specially designed curved endolaser and vitrectomy probes were compared with conventional straight probes through sclerotomy sites at 3.0 mm and 4.0 mm, in 12 fresh cadaver phakic eyes. For the safety profile, the perpendicular distance between the probe oriented toward a reference point on the retina and the midpoint of the posterior surface of the lens was measured. For access to the retinal periphery, the distance between the ora serrata and the most peripheral accessible point on the retina without touching the crystalline lens with the probes was measured. Results The perpendicular distance between the probe and posterior surface of the lens increased, and the ability of the probe to reach the most peripheral accessible point on the retina improved with the curved probes as compared with straight probes. Conclusions Curved probes can access the peripheral retina and ora serrata with lesser possibility to injure the crystalline lens during vitreous surgery than the standard straight probes.

PURPOSE To evaluate the efficacy of pars plana vitrectomy in conjunction with intraoperative perfluoro-n-octane (PFO) use as initial treatment of retinal detachment (RD) with multiple breaks located at various distances from the ora serrata. METHODS Twenty-two consecutive eyes (15 phakic, 2 aphakic, and 5 pseudophakic) presenting with RD with multiple breaks and tears underwent primary pars plana vitrectomy, PFO retinal reattachment, transcleral cryopexy or endolaser treatment of breaks, PFO/air exchange, and final injection of 18% perfluoropropane (C3F8). Scleral buckles were not used. The mean follow-up period was 29 months. RESULTS Temporary PFO utilization attached the posterior retina and facilitated the safe removal of vitreous at its base and around the retinal tears. Intraoperative complications included new breaks (3 eyes), enlargement of breaks (2 eyes), and a small bubble of subretinal PFO (1 eye). Postoperatively, the retina remained attached during follow-up in 19 eyes. Cataract developed or progressed in 13 phakic eyes. CONCLUSIONS Pars plana vitrectomy in conjunction with intraoperative PFO utilization is effective as initial treatment of RDs with multiple breaks. The main limitation of this technique is the postoperative progressive cataract formation in phakic eyes.

Aims: To report a case of an unusual retinal vascular morphology in connection with a novel AIPL1 mutation in a patient with Leber’s congenital amaurosis (LCA). Methods: A patient with LCA and no light perception from birth had both eyes enucleated at the age of 22 years because of excruciating pain. Mutation analysis was performed on known LCA genes. The eyes were processed for casts of the vascular tree, routine histopathology, and electron microscopy. Results: A novel H82Y (244C→T) mutation and a H90D (286G→C) polymorphism were detected in exon 2 of the AIPL1 gene. Both the cast and the histopathological examination showed dilated retinal vessels, mainly venules, primarily localised in the posterior pole. In the mid-peripheral retina the density of capillaries on the arteriolar side of the microcirculatory units was significantly decreased. The vascular system was seen to gradually attenuate towards the retinal periphery, and to stop at a zone located approximately 4 mm from the ora serrata along the whole circumference. In this zone pigmented aggregates characteristic of retinitis pigmentosa were seen to ensheath the retinal vessels. The photoreceptors were almost totally absent and retinal gliosis was present. A decreased number of ganglion cells and an increased vacuolisation of the nerve fibre layer were observed. The retinal pigment cells and Bruch’s membrane appeared normal in all regions. Conclusion: An unusual retinal vascular morphology in an LCA patient is presented and possible pathogenic mechanisms of the findings are discussed.

PURPOSE: To determine the width of the posterior vitreous base in human eyes of different ages and to clarify the nature of the postoral retinovitreous adhesion that underlies the development of juxtabasal retinal tears and retinal detachment after posterior vitreous detachment (PVD). METHODS: The posterior limit of the vitreous base was delineated with indocyanine green after mechanical peeling of the postbasal vitreous cortex from the retina in 58 pairs of donor eyes. The area of residual retinovitreous adhesion was measured by image analysis. Scanning electron microscopy was performed on the undersurface (or retinal aspect) of the inner limiting lamina (ILL) after trypsin digestion of the peripheral retina. RESULTS: An age-dependent increase in the anteroposterior dimension of the posterior vitreous base was revealed that became progressively wider in eyes of male donors than in those of female donors and in the nasal half compared with the temporal half of the globe. Ultrastructural studies showed progressive invasion of the innermost peripheral retina by bundles of collagen fibrils, initially in the form of characteristic braids splaying out beneath the ILL and eventually as a dense sublaminar mat in the elderly. The collagen fibrils penetrated the ILL through localized defects and intertwined with those in the basal gel. CONCLUSIONS: With aging, the posterior border of the vitreous base migrates posteriorly so that an annular band of firm adhesion eventually straddles the ora serrata eccentrically. Intraretinal synthesis of collagen fibrils, their penetration of the ILL, and their splicing with cortical vitreous fibrils, underlie the slowly evolving retinovitreous adhesion.

Changes in retinal neuron distribution may reflect normal or pathological changes in retinal function. The quantitative study of retinal neurons provides a better understanding of anomalous mechanisms, such as those controlling ocular growth and refractive error development in experimental animals. We developed a method to facilitate the quantitative analysis of amacrine neuron populations in wholemount chick retinae, since the domestic chicken is used extensively as an animal model in myopia studies. This method involved automated cell counting from confocal microscopic images and mathematical estimation of total cell numbers based on image cell density and retinal surface areas. Cell densities and cell counts were obtained from immunohistochemically-labeled amacrine neuron populations, using derived formulae to calculate retinal surface area based on vitreous chamber depth, equatorial width, ora serrata diameter and scleral thickness. Normalized total cell counts in each eye were compared, rather than cell densities, since changes in eye growth can affect cell densities. We also compared neuron distribution in central versus peripheral portions of the retina. This is an alternative technique for retinal analysis that supplements traditional anatomical cell counting methods, allowing higher numbers of specimens to be rapidly analyzed.

Background/aims: To evaluate the potential of ultrasound biomicroscopy (UBM) as a tool to study the precise location and changes of sclerotomy sites of the eye with an intraocular drug delivery device. Methods: Eight eyes of six patients (13 sites) who received ganciclovir implants were examined by UBM. Examinations were performed 1–26 months (mean 12.8 months) postoperatively. Serial transverse and radial sections of the anterior ciliary body around the sclerotomy sites were obtained. Results: The ganciclovir implant contour was successfully viewed using an UBM with high reflectivity. Three implants were deviated anteriorly and they were very close to the ciliary body and the lens (anterior deviation), while four implants were deviated posteriorly and away from the lens (posterior deviation). The other six implants were located at the appropriate position as intended. A solitary homogeneous mass with a medium reflectivity around the suture tab was observed at 12 out of 13 sites in seven eyes. Thick membranes extending from sclerotomy sites to the ora serrata were found at two sites in two eyes. Conclusion: UBM is helpful in detecting abnormal manifestations around ganciclovir implants and is a valuable tool to assess the changes of the sclerotomy sites of the sustained released intraocular devices.

Aim: To determine the frequency of ciliary body or retinal breaks and retinal detachment in eyes with atopic cataract. Methods: The records of 106 eyes (74 patients) with atopic cataract that underwent cataract extraction were reviewed. The frequency of ciliary body or retinal breaks and retinal detachment was classified by their presence preoperatively and postoperatively, and by cataract type. Results: Breaks were detected preoperatively in 27 eyes (25.5%) of 17 patients in the ciliary body (20 eyes, 18.9%), near the ora serrata (five eyes, 4.7%), and in undefined locations (two eyes, 1.9%). Among these, 16 eyes (15.1%) had already developed retinal detachment. After surgery, a ciliary body break occurred in one eye (0.9%) and retinal detachment in four eyes (3.8%) of three patients. The breaks that caused postoperative retinal detachment were in the ciliary body. When classified by cataract type, the highest frequency of breaks was associated with mature cataracts (35.0%), and all eyes with breaks developed retinal detachment. Conclusions: One fourth of eyes with atopic cataract had breaks in the ciliary body or ora serrata, or retinal detachment preoperatively. The highest frequency of either breaks or retinal detachment was associated with mature cataract. The frequency of breaks or detachment that occurred postoperatively (approximately 5%) was lower than that present preoperatively.

We describe our use of an indirect ophthalmoscope argon laser for the treatment of selected retinoblastomas. The essential aspect of the technique is the creation, using the "continuous" exposure setting, of a confluent white laser burn completely around the tumor base. This procedure results in the prompt regression of most tumors, although several sessions, 1 to 4 weeks apart, are usually necessary for all but the smallest lesions. This method of laser treatment is applicable to retinoblastoma tumors located anywhere in the ocular fund us, including ones adjacent to the ora serrata.

Ciliary body location is an established prognostic factor for metastasis-related death from uveal melanoma. We evaluated alternative approaches for classifying this covariate when constructing predictive models of patient survival.The analyses were based on a consecutive series of 1848 primary choroidal and/or ciliary body melanoma patients treated with proton beam irradiation (70 cobalt gray equivalent in 5 fractions) at the Harvard Cyclotron Laboratory, Boston, Mass, between July 1975 and December 1995. For each patient, the anatomic site of the tumor was classified according to an estimate of the proportion of the tumor base lying anterior to the ora serrata. Using proportional hazards regression, we estimated relative risk ratios and death rates from melanoma metastasis according to the extent of ciliary body involvement. All estimates were adjusted for other established prognostic factors.Patients were followed up through April 30, 1998; none were lost to follow-up. Of 1848 patients analyzed, 378 died of melanoma metastasis. The median follow-up period among survivors was 9.5 years. Ciliary body origin (50% of tumor base anterior to the ora serrata) was positively associated with tumor pigmentation (P.001), tumor height (P.001), and extrascleral extension of the tumor (P.001). Compared with tumors involving only the choroid, melanoma-associated death rates increased with the proportion of the tumor base lying within the ciliary body (P =. 006); the multivariate-adjusted relative risk ratio for greater than 75% involvement was 2.30 (95% confidence interval [CI], 1.26-4.23). The covariate-adjusted 5-year death rates for ciliary body origin and choroidal origin were 15.9% (95% CI, 11.3%-21.2%) and 9.8% (95% CI, 8.3%-11.7%), respectively.Patients with melanomas of presumed ciliary body origin seem to be subject to a higher risk of death resulting from melanoma metastasis. Arch Ophthalmol. 2000;118:1066-1070

The number and topographical distribution of photoreceptors was studied in whole-mounted retinas of Cebus apella. It was estimated a total of 48 million rods and 3.8 million cones. The average peak foveal cone density and the Nyquist Limit at the foveola were estimated as 169, 127 cells/mm(2) and 46.77+/-7.98 cyc/deg, respectively. A cone-enriched rim was found near the ora serrata, more noticeable in the nasal retina. Rod distribution was asymmetrical along horizontal and vertical meridians with a higher density in the dorsal retina. The rod/cone ratio was variable and asymmetrical along both meridians.

Cryotherapy has been shown to be an effective treatment for retinopathy of prematurity stage 3. It is said to reduce the unfavourable outcome of the disease by 50%. The accepted method of therapy includes ablation of the whole avascular retina from the ridge to the ora serrata. This is achieved by two to three rows of cryoapplications. When 360 degrees cryo treatment is performed, it requires 52 cryo applications. We present our method of cryotherapy which involves only one row of cryoapplications in the avascular retina anterior to the fibrovascular ridge. An average of 25-30 cryoapplications was required for a 360 degrees treatment. The anatomical results in 23 babies are presented. Complete regression of active retinopathy was found in all.

Objective To report on frequency, time of occurrence, treatment, and final outcome of rhegmatogenous retinal detachment after block excision, combined with corneoscleral tectonic grafts, of intraocular epithelial implantation cysts and tumors of the anterior uvea involving the anterior chamber angle. Design Noncomparative case series. Participants The study included 144 patients who had consecutively undergone scleral full-thickness block excision of tumors of the anterior uvea (n = 87) or intraocular epithelial implantation cysts (n = 57). Diameter of the block excision ranged between 5.5 and 20 mm. In 39 patients, the tumor extended posterior to the ora serrata. Interventions Retinal detachment surgery. Main outcome measures Retinal detachment rate, visual acuity, risk factors. Results Retinal detachment occurred in 10 (6.9%) of 144 patients (2 of 57, or 3.5% of patients with cysts; 8 of 87 or 9.2% of patients with tumors) 3 to 12 months after block excision. Six patients underwent primary pars plana vitrectomy with temporary endotamponade by silicone oil, which was removed 3 to 9 months later. In four patients, a scleral buckling procedure only was performed. After a mean follow-up of 31 months after silicone oil removal or the buckling procedure (median, 30 months; range, 13–42 months), the retina has remained attached in all patients operated on. Visual acuity increased from 2/20 (median; range, light perception-6/20) to 8/20 (median; range, 2/20–12/20). In the eyes with retinal detachment compared to the eyes without retinal detachment, the block excision was significantly larger (13.75 ± 4.86 mm vs. 9.41 ± 3.02; P = 0.01) and was located significantly more posteriorly (limbus distance of posterior excision margin: 6.75 ± 2.87 vs. 4.35 ± 3.24 mm; P = 0.01). Conclusions Scleral buckling procedures and primary pars plana vitrectomy with temporary ocular endotamponade can give acceptable results in eyes with rhegmatogenous retinal detachment occurring after block excision of epithelial implantation cysts or tumors of the anterior uvea. Despite intraoperative vitreous prolapse or tumor extension posterior to the ciliary body, rhegmatogenous retinal detachment occurs in fewer than 10% of patients undergoing block excision of cysts or tumors of the anterior uvea. Size and posterior location of the block excision are the main risk factors for rhegmatogenous retinal detachment, which becomes unlikely later than 12 months after surgery.

Central-to-peripheral migration of QH1-positive microglial precursors occurs in the vitrealmost part of the developing quail retina. This study shows that some QH1-positive ameboid cells with morphological features of migrating cells are already present in the margin of the retina before microglial precursors migrating centrally to peripherally arrive in this zone. Because the earlier cells are oriented parallel to the ora serrata, we deduce that some microglial cells migrate circumferentially in the margin of the retina, whereas other microglial precursors migrate from central to peripheral zones. Microglial cells that migrate circumferentially are first seen on embryonic day 6 (E6) and advance in a temporal-to-dorsal-to-nasal direction from the temporoventral quadrant of the retina. When cells migrating centrally to peripherally reach the retinal margin, they meet those migrating circumferentially. From E6 on, some QH1-positive dendritic cells in the ciliary body bear processes that penetrate the retina, where they are oriented circumferentially. These observations suggest that microglial cells that migrate circumferentially in the retinal margin share a common origin with dendritic cells of the ciliary body. Therefore, microglial cells of the quail retina appear to make up a heterogeneous population, with some cells originating from the pecten/optic nerve head area and others from the ciliary body.

Purpose: To evaluate the utility of ultrasound biomicroscopy (UBM) in the diagnosis of anterior proliferative vitreoretinopathy (APVR). Methods: Ultrasound biomicroscopy (frequency, 50 MHz; depth of penetration, 5 mm; resolution, 40 μm) was used to examine 53 eyes of 52 subjects with rhegmatogenous or traumatic retinal detachment (RD). The results were compared with findings during vitrectomy. Results: In 43 eyes (42 patients), RD was detected using UBM, attaining 81 % consistency with observations during operation. Among 36 eyes with surgically proved APVR, 33 (92%) had APVR detected by UBM. The UBM images showed shallow RD, circumferential contraction, or anterior displacement around the ora serrata. The anterior displacement could be classified into C-shaped anterior displacement, ciliary body adhesion, and pupil adhesion. Ultrasound biomicroscopy showed that a retinal step was formed on the surface of the ora serrata and the ciliary body. Failure to detect APVR by UBM may be due to severe choroidal detachment or a narrow palpebral fissure that hampers exposure of the ora serrata and the part of the eyeball posterior to it. Conclusion: Ultrasound biomicroscopy is a useful tool for the evaluation of APVR, which is difficult by ordinary methods. Ultrasound biomicroscopic images of APVR have typical features that may be used to help guide surgery and estimate prognosis.

Verification of the position of an episcleral iodine-125 gold plaque in relation to underlying choroidal melanoma is essential during early radiation therapy to ensure accurate plaque placement and thus optimum dose delivery. The authors used magnetic resonance (MR) imaging to examine 15 patients with choroidal melanoma after plaque placement to assess tumor coverage. The relationship of the plaque to the tumor was well defined in all cases, including two tumors anterior to the ora serrata. MR imaging measurements of the plaques were within 1 mm of the actual plaque sizes, while tumor measurements were within 2 mm of the preoperative ultrasound estimations of tumor dimensions. Tumors as small as 3 mm thick were readily visualized with MR imaging. Associated subretinal effusion was demonstrated in seven cases.

Retinal and subdural haemorrhages with or without occult bone fractures in children aged

This article evaluated the effect of myopia on the position of the ora serrata relative to the extraocular muscle insertions. In this prospective case series, 11 patients were evaluated during scleral buckling procedures. Intraoperative measurements of the distance from the ora serrata to the muscle insertion in each quadrant were compared to baseline refractive error. The distance between the ora serrata and the muscle insertion increased with increasing myopia superonasally and inferonasally. The surgeon must be aware of the need to position a scleral buckle more posteriorly with increasing myopia to avoid improper scleral buckling position and consequent surgical failure. [Ophthalmic Surg Lasers Imaging 2007;38:518-519.] AUTHORS From the Bascom Palmer Eye Institute, University of Miami, Miami, Florida. Accepted for publication May 10, 2007. Address correspondence to William E. Smiddy, MD, Bascom Palmer Eye Institute, 900 NW 17th Street, Miami, FL 33136.

Purpose: The present study compares morphological changes associated with optical defocus-induced myopia (ODM) with those from form deprivation myopia (FDM), as it is yet to be determined whether the latter is a consequence of visual deprivation or active myopic eye growth. Methods: Hatchling chicks were reared for 2 weeks wearing a monocular translucent occluder or -10.00 D lens, with the other eye used as a control. After enucleation, eyes were processed for scanning electron microscopy. Results: Anatomical profiles of control eyes revealed significant variations in tissue thickness as a function of nasotemporal location. Both FDM and ODM eyes demonstrated similar morphological profiles of retinal thinning, cartilaginous scleral thickening, enlarged photoreceptor inner segments and decreased photoreceptor cell density towards the ora serrata. A graded differential orientation of photoreceptors existed in all eyes. Conclusion: The comparable morphological changes in FDM and ODM suggest that the response to altered visual experience is similar in both paradigms.

There are many regional differences in cell morphology and neurochemistry in the retina. This study examined a specialized population of neuropeptide Y- and glucagon-like immunoreactive amacrine cells in the peripheral retina of the turtle. Some of the dendritic processes from these peptidergic amacrine cells formed a dense circumferentially oriented nerve fiber plexus which ran parallel to the ora serrata. Collaterals from this plexus projected into and innervated the nonpigmented ciliary epithelium in the pars plana region of the ciliary body. Electron microscopy revealed that the neuropeptide Y- and glucagon-like immunoreactive processes in the ciliary epithelium contained many labeled, large dense-cored vesicles. Small crystals of lipid-soluble fluorescent dye were implanted in the retina near the ora serrata in fixed retinal tissue to search for other peripheral retinal specializations. Numerous thick and thin cell processes oriented parallel to the ora serrata were labeled in the retina by the dye. In addition, many dye-labeled somata with circumferentially oriented dendritic arborizations were seen in the extreme periphery of the retina. Many of these dye-labeled cells and processes were clearly not associated with the neuropeptide Y- and glucagon-like immunoreactive cells described above. This study has shown that some peptidergic neurons in the peripheral retina have a unique morphology in comparison to more centrally located cells. The function of these specialized peripheral cells is not established, but the innervation of the ciliary epithelium by peptidergic amacrine cells suggests that they may be involved in control of aqueous inflow.

Purpose: The ideal lens-sparing radiotherapy technique for retinoblastoma calls for 100% dose to the entire retina including the ora serrata and zero dose to the lens, Published techniques, most of which use photons, have not accomplished this ideal treatment. We describe here a technique that approaches this ideal configuration using electron beam therapy, Methods and Materials: Dose-modeling calculations were made using a computer program built around a proprietary algorithm, This program calculates 3D dose distribution for electrons and photons and uses the Cimmino feasibility method for the inverse problem of beam weighting to achieve the prescribed dose, The algorithm has been verified in the ocular region by measurements in a RANDO phantom, To search for an ideal lens-sparing beam setup, a stylized phantom of an 8-month-old infant was generated with built-in inhomogeneities, and a phantom of a 5-year-old child was generated from a patient CT series, Results: Of more than 100 different beam setups tested, two 9 MeV electron beams at gantry angles plus and minus 26 degrees from the optic nerve axis achieved the best distribution. Both fields have a lens block and an isocenter between the globe and origin of the optic nerve. When equal doses are given to both fields, the entire extent of the retina (including ora serrata) received 100%, while the lens received 10% or less, Conclusion: The two-oblique-electron-beam technique here described appears to meet most of the stringent dosimetry needed to treat retinoblastoma, It is suitable for a range of ages, from infancy to early childhood years, (C) 1997 Elsevier Science Inc.

Editor,—Schwartz–Matsuo syndrome describes a condition characterised by rhegmatogenous retinal detachment, with ‘cells’ in the anterior chamber and elevated intraocular pressure, often in the evening.1 The detachment is typically caused by a dialysis at the ora serrata or a break in the non-pigmented epithelium of the pars plana or pars plicata of the ciliary body.23 The elevated intraocular pressure is usually discovered incidentally at the time of diagnosis of the retinal detachment, and resolves without specific treatment when the retina is reattached. We present a case in which the reverse was found. The patient presented with acute open angle glaucoma and the retinal detachment was found incidentally. ### CASE REPORT A 24-year-old man presented with a 1 day history of pain in the right eye and blurred vision, following 6 months of intermittent episodes of blurring of vision in that eye. He reported being kicked in this eye by his 2-year-old son 6 months previously. Corrected visual acuity was 6/12 right eye and 6/5 left …

This study was undertaken to investigate the potential of basic fibroblast growth factor (bFGF) to delay photoreceptor cell loss in retinas of Fischer 344 rats which exhibit an age-related peripheral retinopathy. Eight male 16-month-old Fischer 344 rats were injected intravitreally with 2.0 micrograms bFGF in the right eye, while the vehicle was injected into the left eye and all rats were killed at two months post-injection. Eight other Fischer rats were injected with either bFGF or vehicle at 16 and again at 18 months, then killed two months later. After enucleation, eyes were processed for light and electron microscopic and morphometric analyses. The distance from the ora serrata to the point where the outer nuclear layer (ONL) in the superior retina was two cells in thickness, called the die-back zone, that represents the extent of the peripheral retinopathy, was compared in bFGF- and vehicle-injected Fischer rats. These measurements revealed that the die-back zone in retinas of eyes injected twice with bFGF was significantly reduced (P0.01) when compared to this zone in retinas of age-matched rats that received vehicle injections. However, there was no significant difference (P0.05) in this degeneration zone in retinas of 18-month-old rats that received a single-bFGF injection when compared to retinas of respective vehicle-injected rats. In addition, the ONL at 2 and 3 mm from the ora serrata in the superior retina of bFGF-injected 20-month-old Fischer rats was significantly thicker than corresponding regions in retinas of vehicle-control rats. Furthermore, the photoreceptor cells in the superior retina of 20-month-old rats which received two injections of bFGF had normal-appearing inner and outer segments, while the few photoreceptors had short inner and outer segments in vehicle-injected retinas of Fisher rats. These findings reveal that injections of bFGF into eyes of Fischer 344 rats significantly delays the progress of photoreceptor cell degeneration suggesting that exogenous bFGF may act as a survival-promoting factor in these aged retinas.

Data for densities and sizes of human cones were analyzed as a function of retinal eccentricity. Density of cones followed a decreasing power of about -2/3 over much of the eccentricity range. This decrease, and the subsequent increase in cone density toward the ora serrata, were predictable on the basis of a hypothetical density-control mechanism to equate the integrated luminous flux at the photoreceptors per unit retinal area, together with the empirical rule that cone diameter increases with a power of about 1/3 with eccentricity beyond the foveola. The analysis implies that cones aggregate in inverse proportion to the light impinging on them, and provides an explanation for the pronounced increase to 100% cone density at the ora serrata.