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The files of 40 patients operated on for epimacular membranes were reviewed in order to correlate the functional and anatomical results with the presence or absence of internal limiting membrane on histological specimens. Only the eyes with idiopathic membranes were considered for the study. Visual acuity and fluorescein angiography were obtained preoperatively and at the 6 months postoperative visit. The surface of the posterior pole was measured on fluorescein angiogram pre and postoperatively by computerized image analysis. Light microscopy looked for the presence of significant segments of internal limiting membrane. In 28 cases (group 1) long segments of internal limiting membrane were adherent to the epimacular membrane and in 12 cases (group 2) no internal limiting membrane fragments or only small fragments were present. Mean postoperative visual acuity was the same in the two groups; 64% of eyes from group I and 50% from group 2 had visual acuity superior or equal to 0.5 (NS). Image analysis showed that the posterior pole surface area increased by 25% in group 1 but only by 15% in group 2 (p < 0.025). Internal limiting membrane ablation does not preclude good visual recovery and is correlated with improved unfolding of the posterior pole.

We evaluated the ultrastructural features of seven surgically excised submacular neovascular membranes from seven patients with the ocular histoplasmosis syndrome. Excised neovascular membranes were composed of fibrovascular tissue interposed between Bruch's membrane and the retinal pigment epithelium. Cellular components present in the membranes included, in decreasing order of frequency, retinal pigment epithelium, vascular endothelium, photoreceptor cells, macrophages, erythrocytes, ghost erythrocytes, fibrocytes, myofibroblasts, glial cells, smooth-muscle cells, and lymphocytes. Extracellular constituents of the neovascular membranes included 20 to 25-nm collagen fibrils, fibrin, 10-nm collagen fibrils, and fragments of Bruch's membrane and choroid. Our findings are consistent with the concept that subretinal neovascular membranes in the ocular histoplasmosis syndrome represent a nonspecific healing response to a local stimulus or injury.

Background: The authors studied various cellular and extracellular matrix components of subretinal neovascular membranes (SRNVM) from patients with age-related macular degeneration (ARMD)., Methods: Electron microscopic immunocytochemistry was used on the subfoveal neovascular membranes surgically removed from three patients with disciform lesions due to ARMD., Findings: The SRNVMs always contained large "feeder" vessels along with many new capillaries in different stages of maturation. Capillaries were sparse and embedded in an abundant stroma. The majority of the nonvascular cells were either retinal pigment epithelial (RPE) cells or fibroblast-like cells. The RPE cells formed single or multiple layers on one side of the membranes. The stroma was composed mainly of collagen types I and IV and fibronectin, with small amounts of collagen types III, V, and VI. The absence of Bruch's membrane suggests that a splitting may occur between the RPE cells and Bruch's membrane with the new vessels growing into this cleft. A thickened layer of collagen type IV was often present under the RPE cells. The basement membranes of the newly formed capillaries were morphologically ill-defined, and contained substantial amounts of collagen type IV and fibronectin, but, unlike the basement membranes of normal capillaries, they lacked laminin or heparan sulfate proteoglycan., Conclusion: These results on the ultrastructural components of the SRNVMs may be useful in clarifying the nature of the disciform process in ARMD.

We report a case of evolutive high hyperopia in a child aged 10 years. It is associated with organic amblyopia due to a large papillomacular retinal fold. Ultrasonography and CT scan helped to establish the diagnosis. This is probably a hereditary disease affecting the development of the posterior sclera.

The ultrastructural nature and distribution of basal laminar deposit, considered to be a precursor of age-related macular degeneration, were studied in 42 human maculae. Basal laminar deposit was found from age 19 years on, not only between the retinal pigment epithelial cells and their basement membrane but also more often on the choriocapillary side of Bruch's membrane. No direct relationship was found with other aging changes, such as calcifications in Bruch's membrane, accumulation of lipofuscin granules, or drusen in the macular area. Material similar to basal laminar deposit can be found in the trabecular system, in the cornea, and also in many other organs and tissues. On a structural and morphometrical basis, we think that basal laminar deposit is similar to fibrous long-spacing collagen and thus does not seem to be a purely ocular abnormality.

We performed electron microscopic morphometric analyses on capillaries from macular and peripheral retinas of five adult cynomolgous monkeys and three elderly human subjects. Measurements from the monkey retinal capillaries were compared to those made on capillaries from frontal, temporal, parietal, and occipital cerebral cortex of the same animals. We measured the percent coverage of the endothelial lining of the capillaries by pericyte processes, as well as the ratio of the cytoplasmic areas of pericytes and endothelial cells. In addition, we compared the thickness of the capillary basement membranes in three regions: overlying pericytes; overlying endothelial cells; and interposed between pericytes and endothelial cells. In both monkey and human retinas, pericyte processes covered greater than 85% of the circumference of the capillary endothelial tube, whereas pericyte coverage of monkey cerebral capillaries was highly significantly (P less than 0.001) less than that of capillaries in either the macular or peripheral retina. The ratio of pericyte to endothelial cell cytoplasmic areas also was lower in the monkey cerebral cortex than in the retina, though the statistical significance was less than that of the length measurements. In all tissues measured, both from monkeys and humans, the portions of the capillary basement membranes interposed between pericytes and endothelial cells were highly significantly (P less than 0.0001) thinner than the regions of capillary basement membranes covering pericytes and endothelial cells. Considering functions that have been proposed for pericytes, these measurements suggest that regional control of microcirculatory flow and of blood-tissue barrier integrity, as well as control of endothelial cell proliferation, should be much greater in the retina than in the cerebral cortex. Thinner basement membranes between pericytes and endothelial cells may permit more cell membrane contacts between these cells, thus facilitating such control.

Pathological experimental study of dye laser photocoagulation simulating the confluent treatment of subretinal new vessels in the macular area of a Macacas Cynomolgus monkey. 38 days after treatment the lesions become similar on the choriocapillaris and retinal pigment epithelium whatever the wavelength; the choriocapillaris is always occluded and the pigment epithelium destroyed. The internal limiting membrane is ondulated only with yellow and orange colors. These results are compared to those of similar experimental studies.

The interphotoreceptor matrix in the human retina comprises a highly organised extracellular compartment. Using fluorescent labelled peanut agglutinin and the cationic dyes Cupromeronic and Cuprolinic Blue, unique cylindrical domains surrounding cone photoreceptors can be demonstrated. These cone specific domains are relatively insoluble and are closely adherent to cone photoreceptors and to the pigment epithelium, suggesting that these structures may play a role in retinal attachment.

Five cases of macular pigmentation with peripheral choroidal melanoma are studies. The pigmentation is in relation with accumulation of macrophages under the macula. These macrophages derive from the retinal pigment epithelium over the peripheral malignant melanoma of the choroid.

We show that the entrance aperture of the foveal cone is about 80% of the 3 micron center-to-center spacing. Reduction in contrast caused by averaging of illumination over this aperture prompts us to predict detection with aliasing between the Nyquist limit of 60 c/deg (where contrast reduction is 63%) and 150 c/deg (where contrast is zero) when the eye's optics are bypassed by impressing interference fringes directly on the fovea.

Experimental macular edema of commotio retinae was studied in rhesus monkeys. Clinically, opacification of the retina in these experimental animals closely resembled commotio retinae of man. No pigment epithelial damage was detected by ophthalmoscopy and fluorescein angiography showed no leakage from the retinal and choroidal circulations in the macular region. Histologically, macular swelling was apparent and was due primarily to changes of the outer plexiform layer. In this layer, swelling of the axons of the photoreceptor cells was prominent. Intracellular edema was also detected in the Müller cell processes in the inner retina and in the pigment epithelial cells. Prominent changes also occurred in the inner and outer segments of the photoreceptor cells. Disruption of the blood-retinal barrier was not found using horseradish peroxidase as a tracer. We concluded that retinal opacification was due to disagreement and intracellular edema of the cellular elements of the retina, perhaps a direct result of movement of intracellular fluid in response to mechanical injury.

We studied 41 young and middle-aged adults who developed innumerable, small, round, uniformly sized, yellow, subretinal nodules that were often arranged in clusters throughout the posterior fundus. Angiographically, they fluoresced discretely during the early arteriovenous phase. In middle or later life 17 of these patients developed visual loss caused by vitelliform retinal detachment in the macula of one or both eyes. Spontaneous resolution of the detachment and retention of good visual acuity occurred frequently. We found evidence indicating that the multiple, small, subretinal nodules are probably focal areas of pigment epithelial attenuation overlying nodular thickenings of the basement membrane of the pigment epithelium. The term basal laminar drusen would distinguish these nodules from those of typical drusen, which are caused by focal detachments of attenuated pigment epithelium and its usually normal-thickness basement membrane from the inner collagenous zone of Bruch's membrane.

The cones of the human macula lutea were examined by scanning electron microscopy. It was found that each inner segment had about 15 thread-like processes which projected from the cell surface. They were arranged in a longitudinal straight line along the photoreceptor, and were directed away from or towards the fovea contralis. The villous processes may be analogous with the lateral fins of the inner segments of certain vertebrates. They may perhaps bridge the space between neighbouring photoreceptors and may establish contact and interaction between them.

Light and transmission electron microscopic examinations of two postmortem eyes from an 80-year-old woman with clinically well-documented Best's macular dystrophy disclosed striking abnormalities in the retinal pigment epithelium (RPE), photoreceptors, and sub-RPE area. The RPE cells were flattened, with displacement of the nuclei toward the apex and diffuse deposition of abnormal lipofuscin and pleomorphic melanolipofuscin granules. A PAS-positive, acid-mucopolysaccharide-negative, electron-dense, finely granular material was deposited in the inner segments of the degenerating photoreceptors and the Mueller cells. An abnormal fibrillar material was present underneath and in close association with the RPE cells, just beneath the area of photoreceptor cell loss. The choriocapillaris was normal. Breaks in Bruch's membrane and neovascularization were noted in the foveolar region. There is evidence that the sensory-retinal changes are primary and that the RPE changes are secondary.

Foveomacular vitelliform dystrophy, adult type (FVDAT), is a dystrophy of the retinal pigment epithelium (RPE) characterized in part by autosomal dominant inheritance, midlife onset, mild visual loss, and various patterns of foveal yellow deposits located at the level of the pigment epithelium. Detailed pathologic studies of two postmortem eyes from a 61-year-old woman with documented FVDAT disclosed striking abnormalities involving mainly the foveal RPE and overlying photoreceptors. By light microscopy, marked focal atrophy of the pigment epithelial cells in the foveolar area was bordered by hypertrophic RPE. Interposed between the atrophic RPE and Bruch's membrane were scattered eosinophilic, fusiform collagenous plaques. The sensory retina overlying the deranged RPE displayed marked atrophy of the outer nuclear layer with loss of photoreceptor inner and outer segments. Pigment-laden macrophages containing periodic acid-Schiff-positive material had migrated into the atrophic, outer sensory retina. Ultraviolet fluorescent microscopy demonstrated massive accumulation of lipofuscin pigment within the macular RPE as well as within macrophages in the atrophic outer retina. By scanning electron microscopy, a confluent area of flattened, atrophic retinal pigment epithelial cells was rimmed by taller, hypertrophic RPE cells. By transmission electron microscopy, the pigment epithelial cells contained myriad lipofuscin granules. Bruch's membrane and the intercapillary pillars were slightly thickened and the choriocapillaris was patent. The possible interrelationships between FVDAT and the other pattern dystrophies of the RPE are discussed.

The anterior optic nerve and the macular region of the retina of glaucomatous eyes of five rhesus monkeys (Macaca mulatta) have been examined by light and electron microscopy. The experimental glaucoma had been induced by argon laser treatment of the anterior chamber angle. The eyes were examined 3 to 11 weeks after the onset of sustained elevation of intraocular pressure above 20 mm Hg. Severe degenerative changes were seen in eyes with higher intraocular pressure and longer duration of glaucoma. Eyes with a lesser elevation of intraocular pressure and shorter duration of glaucoma showed changes sharply localized to the axon bundles in the scleral lamina cribrosa. Accumulation of mitochondria and dense bodies occurred anterior and posterior to collagenous septae. The location of these changes is in agreement with the localization of block of axoplasmic transport identified by autoradiographic studies. It is speculated that these cytologic changes reflect blockage of axoplasmic flow in the optic nerve of eyes with glaucoma.

In the center of the fovea centralis of retinas of three cynomolgus monkeys, one baboon and one male human, the external limiting membrane contains circumscribed areas in which zonulae adherentes are lacking between cone inner segments and apices of Müller cells. These discontinuities of the external limiting membrane begin about 300 microns from the foveolar center, involving only a few cones. Towards the center of the fovea the discontinuities become larger.

Clinical and pathological examination was performed on 378 eyes from 216 patients aged 43 to 97 years. This series represented eyes in which the fundi were normal or showed various manifestations of senile macular degeneration. The eyes were divided into six groups according to the histological appearance of a linear deposit at the base of the retinal pigment cells. Groups I and II were considered to represent normal ageing, Groups III and IV the progressive development of senile macular degeneration and Groups V and VI the end-results. Group I showed no basal linear deposit. Thickening and hyalinization of Bruch's membrane was noted as early as the fifth decade. Group II showed patchy development of the basal linear deposit in relation to thickened or basophilic segments of Bruch's membrane, or over intercapillary hyalinization extending to the level of the outer surface of the choriocapillaris. Almost all eyes in these two groups retained a normal fundus appearance but visual acuity declined with age even in the absence of other causes. In Group III the basal deposit formed a thin continuous layer associated with moderate degeneration of the retinal pigment epithelium. More than half the eyes had developed a clinical disturbance of pigmentation and in most vision was reduced. Group IV was characterized by thickening of the deposit and more pronounced disturbance of the pigment epithelium. Clinically most eyes showed coarse pigmentary changes and vision was in the order of 6/24. 14-3 per cent of eyes in this group showed early neovascularization from the choroid. In Group V the pigment epithelium disappeared to produce circumscribed areas of depigmentation. The basal linear deposit could be traced throughout the depigmented area in most eyes. Thin fibrovascular sheets were found beneath the pigment epithelium in 41-7 per cent of eyes. Group VI represented disciform degeneration. The basal linear deposit could often be demonstrated as a disrupted hyalinized layer incorporated into the scar. Disciform degeneration was an alternative end-result to geographical atrophy. In each group the clinical and histological findings may be modified by the presence of drusen or by atrophy of the choroid. The basal linear deposit consisted of banded fibres embedded in granular material lying between the plasma infoldings and the basement membrane of the retinal pigment epithelium. This deposit seems to be a manifestation of gradual failure of the pigment epithelium and proved to be the most suitable criterion by which to study the natural history of senile macular degeneration.

A systematic electron microscopic study was made of the structure of foveal cones of Macaca spp. Transverse sections of inner (IS) and outer segments (OS) were made in sequence, from the pigment epithelial zone (PEZ) to the outer limiting membrane (OLM). The smallest diameters of hundreds of cone sections were measured from electron micrographs with a Zeiss particle-size analyzer, and analyzed statistically. Some details are also included about Cebus photoreceptors. It is claimed in the literature that foveal cones are rod-like (cylindrical) and untapered. Our study shows the foveolar cone to be a tapered structure. There has been some confusion between the foveola, which is rod-free, and the fovea, which has a high concentration of cones, but is not rod-free. Within the fovea, as the ratio of cones to rods falls from infinity to 1, with distance from the central bouquet of cones, the cone center-to-center distances increase, the inner segment diameters increase, and the number of cones/sq mm decreases. The tapered calycal processes are more massive in M. irus than M. mulatta, and the lateral fins are better developed. Lateral fins are not present in the foveola. The cones are arranged in straight lines.

We examined the foveomacular regions from three eyes in which fluorescein angiography had demonstrated the characteristic appearance of cystoid macular edema by light and electron microscopy. Cystoid macular edema was present in two eyes (one of which was from a 63-year-old diabetic man) that contained peripheral choroidal melanomas, and in a third eye from a patient with diabetes only. By light microscopy, cystoid macular degeneration was obvious only in the third eye. The electron microscopic findings common to all three eyes were widespread swelling and necrosis of Müller cell cytoplasm. There was no enlargement of intercellular spaces. There was secondary neuronal degeneration. Retinal vascular changes, consisting mainly of endothelial cell abnormalities, were found in all cases but were far more common in the two eyes from diabetic patients. The retinal vascular changes were probably the cause of the cystoid macular edema.

We used electron microscopy and immunohistochemistry to study the macular regions of nine enucleated elderly human eyes and to document the various abnormalities present in the so-called basal linear deposit. These changes include bush-like strands of electron-dense material, which project from the basement membrane of the retinal pigment epithelium, deposition of wide-banded collagen, vesiculoid elements, membrane-bound structures and occasional melanin granules. Fibronectin was also identified in the basal linear deposit and in Bruch's membrane, but mucopolysaccharides could not be demonstrated. The presence of electron-empty space suggests a disturbance in water permeability. Our studies also showed neovascularisation beneath the retinal pigment epithelium in locations where the basal linear deposit was abundant, as well as erosion of Bruch's membrane by macrophages and endothelial cell processes. Our findings suggest that the basal linear deposit is an important precursor of neovascularisation. Possible pathogenetic mechanisms are discussed.

Detailed light and electron microscopic examination of early idiopathic preretinal fibrosis lesions showed that the fibrosis consisted of a layer of glial cells on the retinal surface. Two cases supported the clinical observation that a glinting retinal reflex preceded the development of retinal folds and traction lines. In both cases there was a break in the inner limiting lamina through which glial cells migrated and, presumably, proliferated on the retinal surface. There was no evidence for vitreoretinal adhesions. The ultrastructural similarity of the lesion to preretinal glial membranes seen in other disease entities suggested the possibility of a common biochemical stimulus for glial cell migration and proliferation on the retinal surface.

Electron microscopic findings in an eye removed from a woman who had biomicroscopic and angiographic signs of cystoid macular edema occurring in association with a peripheral choroidal melanoma disclosed evidence that the anatomic basis for the biomicroscopic and angiographic changes was the polycystic expansion of the extravascular compartment of the retina by serous exudate and not, as previously reported, edema of the Mueller's cells.

The organization of the retinal nerve fiber layer of the cynomolgus monkey was studied by electron microscopy. Nerve fiber size spectra were obtained from measurements of every fiber in enlarged montages of selected bundles. Variation in spectra among nasal, arcuate, and papillomacular bundles was examined, and variation of spectra of a given bundle as it crossed the retina was determined. Among the three types of bundles, the papillomacular contained relatively more small fibers, nasal bundles relatively more large fibers. Systematic variation of fiber spectra was observed as the disc was approached by arcuate and papillomacular but not nasal bundles. Arcuate bundles sampled in the peripapillary area contained relatively more small fibers than when sampled at a greater distance from the disc. In contrast, papillomacular bundles sampled near the disc contained relatively more large fibers than near the fovea.

A case of preretinal macular fibrosis, following long-standing central vein occlusion and hemorrhagic glaucoma, was examined macroscopically and electron-microscopically. Pretreatment with cyclodiathermy puncture was performed twice before enucleation. The following morphologic results were observed: 1. Epiretinal cell layers in the peripapillar and foveolar regions which caused no 'puckering' of the retinal surface. These cell layers were mainly composed of glial cells. Some Müller cell processes and macrophages were also present. The epiretinal glial cells stem from the surface of the papilla and of the retina. They leave the retina through breaks of the basal lamina (especially where the latter is only a thin layer). 2. Folding (puckering) of the retinal surface was exclusively observed under condensed masses of fibrous tissue. The epiretinal fibrous tissue is composed of immature collagen fibrils of various diameters, of acid glycosaminoglycans, and of granular deposits of long-spacing collagen. The fibrillar material is firmly attached to the basal lamina of the retina. Shrinkage of the epiretinal fibrous tissue similar to the shrinkage of scar tissue is assumed to be the reason for the development of traction to the retinal surface. The epiretinal glial cells are assumed to be the sites of synthesis of the preretinal fibrous masses and glycosaminoglycans.

The optical density of human macular pigment was measured for 50 observers ranging in age from 10 to 90 years. The psychophysical method required adjusting the radiance of a 1 degree, monochromatic light (400-550 nm) to minimize flicker (15 Hz) when presented in counterphase with a 460 nm standard. This test stimulus was presented superimposed on a broad-band, short-wave background. Macular pigment density was determined by comparing sensitivity under these conditions for the fovea, where macular pigment is maximal, and 5 degrees temporally. This difference spectrum, measured for 12 observers, matched Wyszecki and Stiles's standard density spectrum for macular pigment. To study variation in macular pigment density for a larger group of observers, measurements were made at only selected spectral points (460, 500 and 550 nm). The mean optical density at 460 nm for the complete sample of 50 subjects was 0.39. Substantial individual differences in density were found (ca. 0.10-0.80), but this variation was not systematically related to age.

Rhesus monkey retina and especially the foveal photoreceptors (PR) were investigated by scanning electron microscopy (SEM). There are a few scattered SEM photomicrographs of the primate retina in the literature but this is the first detailed and comprehensive view by SEM of a primate retina. Some new aspects of surface morphology are displayed and the study also highlights and emphasizes some aspects of photoreceptor structure that have either been overlooked or not clearly displayed in studies using transmission electron microscopy only. For examination by SEM retinas were fixed in glutaraldehyde-formaldehyde, osmicated, immersed in thiocarbohydrazide, dehydrated in alcohols, and gold-coated. The fovea appears as a sharply defined pit with steep slopes, and its vitreal surface looks different from that of the rest of the retina. It appears to have a matted surface. The rest of the vitreal surface is relatively smooth and displays distinct lines which diverge in a radiating pattern from the foveal slopes. The choroid has a spongelike appearance; the sclera appears fibrous with the fibers running parallel to the vitreal surface. Photoreceptor nuclei are sometimes lost during tissue processing. They leave a discrete "nuclear nest" formed from Müller cell processes. Henle fibers turn at a sharp angle from the cones to run parallel to the vitreal surface. The external limiting membrane is seen as a clear line. Immediately vitreal to it, the Müller cell microvilli surround the proximal inner segments. The cone inner segment (CIS) narrows toward the cilium where the cell is markedly constricted. The ciliary connectives are aligned and appear as a shadowy, slightly wavy zone when the retina is viewed in vertical section. The freestanding, tapering calycal processes (CP) arise from and are continuous with longitudinal CIS ridges. CP surround the proximal parts of the outer segments (OS), but there are no CP around the ciliary backbone. Some CP bear small protrusions. OS break off and remain embedded among the pigment epithelium microvilli (PEM) more often than PEM remain attached to OS distal ends. The foveal OS tapers slightly from its proximal to its distal end. The OS may bear knoblike swellings and convolutions in their more distal regions but not at their tips.

An ultrastructural study of the eyes of a six year old girl affected with fucosidosis demonstrated widespread overloading of lysosomes with a fibrillo-granular material of variable density. Conjunctival and corneal epithelial cells, keratocytes, sclérocytes, fibroblasts, corneal endothelial cells, retinal ganglion cells, inner segments of photoreceptors as well as glial cells of the optic nerve were markedly involved by the storage process. On the contrary, the pigment epithelium of the retina, the ciliary body and the iris were unaffected. Membranous cytoplasmic bodies were only disclosed within Schwann cells of conjunctival and ciliary nerves. Particularly striking lesions were observed within the endothelial cells of capillaries and veins of the eyes, as well as in all tissues examined, like the liver, spleen, kidney, lung, brain and skin. On the contrary, artery walls remained intact. These lesions explain the development of retinal vascular tortuosities, conjunctival aneurisms and cutaneous angiomas that characterize the clinical picture of our patient and that are often described in fucosidosis. The massive overloading of retinal ganglion cells contrasts with the absence of a macular cherry-red spot in fucosidosis. The nature of the stored material is probably responsible for this apparent discrepancy. Indeed, ganglion cells contain membranous cytoplasmic bodies in all diseases with cherry-red spots, whereas only a fibrillo-granular material was disclosed in the present case.

Maculae of seven cynomolgus macaque monkeys (Macaca fascicularis) showing abnormalities in color fundus photographs and fluorescein angiograms were studied in serial sections by light and electron microscopy and compared with three eyes without clinically visible defects in the macula. Maculae that showed hyperfluorescent nonleaking window defects showed no drusen or interruptions in the retinal pigment epithelium (RPE). Six of these monkeys had mis-shapen foveal depressions, all showed some degree of photoreceptor degeneration, and one had cells in Bruch's membrane. Bright yellow spots correlated with scattered RPE filled with lipid vacuoles. Shallow RPE elevations correlated with diffuse nonleaking window defects. Patches of RPE deficient in melanin occurred at sites of hyperfluorescence. Quantitative studies showed that maculae with window defects had more lipofuscin and less melanin per RPE cell. Maculae deemed normal by photography showed degenerating photoreceptors.

Cytoplasmic processes on macular rod inner segments are described both in torn, fractured, and sectioned human tissue specimens. Longitudinal rows of villi are present along the inner segment's proximal part in fractured and sectioned tissue. Some villi were obviously abutting neighbouring cells. It is concluded that these processes undoubtedly represent a new type of cell extension different from calycal, pigment-epithelial, and Muller basket processes.

The synaptic pedicles of foveolar cones in the human retina contact each other by means of telodendrial processes. Thus direct lateral coupling of photoreceptor terminals exists even in the area of highest acuity function.

We performed electron microscopic studies on seven specimens removed from the posterior retina at the time of vitrectomy for vitreomacular traction syndrome. Fibrous astrocytes were the predominant cell type in all cases. Fibrocytes were present in two cases and myofibrocytes were seen in three cases. Additional cellular and extracellular features included fragments of internal limiting membrane in six cases, old collagen in all cases, new collagen in one case, occasional macrophages in four cases, and fibrous astrocytes with myofibroblastic differentiation in one case.

18 eyes of 14 pathologic myopia patients with lacker cracks have been studied during a mean follow up of 45 months by initial and final clinical and fluoroangiography evaluation. These lacker cracks happen early in the myopia degeneration evolution in young patients. The evolution is marked by transient coinlike macular hemorrhages without CNM detectable. Prognosis for the retention of central vision after macular hemorrhages resolution is good. It mainly depends of lacker cracks initial location if macular quite wrong, if intramacular, quite right. Development of CNM is an infrequent eventuality but must be systematically research by angio-fluorography after spontaneous macular hemorrhage resolution which usually occurs 4 or 6 weeks later.