Juxtapapillary Retina Research Articles

Acute Syphilitic Posterior Placoid Chorioretinitis: A Narrative Literature Review

Acute syphilitic posterior placoid chorioretinitis (ASPPC) is defined by the presence of a placoid, yellowish, often solitary lesion, typically involving the areas of the temporal vascular arcades, the juxtapapillary retina, and/or the macular region, with the lesions being present at the level of the outer retina and retinal pigment epithelium (RPE). The visual acuity may range from no light perception to 20/20. There may be associated anterior chamber inflammation and vitritis. Therapy should include antibiotics for neurosyphilis. The role of corticosteroids is controversial. HIV coinfection should always be tested for. With appropriate therapy, the prognosis seems to be good.

Hemangiomas of the optic nerve head

The article presents five cases of various forms of hemangiomas of the optic nerve head (ONH) and juxtapapillary retina that were monitored and analyzed using ocular visualization methods. The obtained data allowed a conclusion that capillary hemangioma of the ONH features clearly-seen boundaries of the lesion both on ophthalmoscopy and optical coherence tomography (OCT) images; on the other hand, juxtapapillary granuloma can be characterized by blurred outlines on ophthalmoscopy and a gradual transition of the altered retina on OCT images with secondary changes seen in the macular area. When comorbid, capillary hemangioma of the ONH and retina feature a combination of these visualization signs.

Differentiation between optic disc drusen and optic disc oedema using fundus photography.

To describe a funduscopic sign that can be used to differentiate between optic disc drusen (ODD) and optic disc oedema (ODE). A total of 73 eyes from 73 consecutive subjects with disc margin blurring who had been evaluated using spectral-domain optical coherence tomography (SD-OCT) were included. Final diagnosis was made by SD-OCT; ODD was defined by direct visualization of ODD, while ODE was defined by documentation of retinal nerve fibre layer oedema (nasal retinal nerve fibre layer thickness >78.0μm). Peripapillary retina was selected as a two-disc-diameter-sized square image from the fundus photograph. Using MATLAB software, colour photographs were converted to indexed image of eight colours. Presence of a smooth contour strip between the nasal disc margin and juxtapapillary retina was defined as a halo. Whether the halo could predict the ODD was analysed retrospectively. The halo sign was detected in 45 eyes (100%) with ODD including one eye with both ODD and ODE. No eyes with ODE alone showed the halo sign. The halo sign implied the presence of ODD (Cohen's kappa=1.000, p<0.001) and the absence of ODE (Cohen's kappa=0.971, p<0.001). The halo sign showed a good interobserver reliability [ICC (2, 1)=0.944, 95% confidence interval 0.912-0.964]. SD-OCT images showed that halos represented retinal elevations above ODD. In the patients with blurred disc margin, the presence of a halo strongly suggested underlying ODD rather than ODE.

Combined Hamartoma (CHR-RPE) A Case Study

Combined Hamartoma also known as CHR-RPE, is a rare benign lesion located on the macula, juxtapapillary or peripheral retina. They commonly present in children usually between 1–15 years of age.Com...

Age-Related Choroidal Atrophy

To report the clinical characteristics of a newly defined entity, age-related choroidal atrophy. Retrospective, observational case series. The choroidal thickness was measured in images obtained by positioning a spectral-domain optical coherence tomography device close enough to the eye to acquire an inverted image. Seven sections each comprised of 100 averaged scans were obtained within a 5 x 15-degree or larger rectangle to encompass the macula and temporal juxtapapillary retina. The choroidal thickness of patients less than 125 microm in thickness were included, whereas eyes with myopia of 6 diopters or more, a history of uveitis, trauma, ionizing radiation, photodynamic therapy, intravitreal corticosteroid injection, or tapetoretinal dystrophy were excluded. The patients were evaluated for visual acuity, macular appearance, and the presence of glaucoma. There were 28 eligible eyes of 17 patients with a mean age 80.6 years (standard deviation, +/- 7.3 years). All eyes had a tessellated fundus appearance. The mean subfoveal choroidal thickness was 69.8 microm and became even more attenuated nasally. Of the 18 eyes that had no evidence of late age-related macular degeneration (AMD), the mean visual acuity was 20/40, there were pigmentary changes in the macula that arose in part from the choroid potentially mimicking early AMD, and a rarefaction of the choroidal vessels under the macula. Concurrent late AMD was found in the 10 remaining eyes. Glaucoma was present in 6 patients (35.3%), all of whom had peripapillary atrophy. The choroid was seen to become nearly obliterated before the demarcation of the beta-zone of peripapillary atrophy. Age-related choroidal atrophy affects older individuals in whom posterior pole abnormalities develop that may mimic and also be associated with findings typical for AMD. Patients with age-related choroidal atrophy may be at higher risk for glaucoma.

Oxygen saturation levels in the juxta-papillary retina in eyes with glaucoma

Oxygen saturation (OS) levels in the juxta-papillary retina particularly inferotemporal retina were investigated in open-angle glaucoma (OAG) patients as well as normal subjects. Fifty-six eyes of 56 OAG Japanese patients and 20 eyes of 20 age-matched normal subjects were recruited for the study. OAG eyes (56) were subdivided into two groups: 15 eyes of low-tension (LT) subgroup and 41 eyes of high-tension (HT) subgroup. The average of age of the LT, HT subgroup and normal group were 60.5, 55.9 and 52.6 years, respectively. OS levels in the retina were measured using a Fourier transform-based spectral retinal imaging (SRI) system (Retinal Cube; ASI Co. Migdal Hemak, Israel), with which OS levels in the fundus could be computed at every pixel point of a 35 degrees fundus image. We calculated OS levels at five points in the retina near the optic disc and retinal arteries and veins in all eyes. The OS levels were also compared with the results analyzed using Humphrey visual field Analyzer with the program 30-2 SITA. At the superior and nasal juxta-papillary retinal points, OS level of the LT subgroup showed significant decrease as compared with the HT subgroup and the normal group (p=0.048–0.009). The LT and the HT subgroups were significantly lower than the normal group at the inferotemporal and the average of the retinal points (p=0.047–0.001). There were no statistically significant differences among the three groups in regards to the OS in the retinal artery. There was a statistical significant correlation between the mean of total deviation of the 17 points in the upper arcuate area and OS of the inferotemporal point (p=0.018), and between mean deviation and the average of OS of the inferotemporal and the superotemporal point (p=0.037) in the HT subgroup. However, there was no significant correlation in the LT subgroup. OS levels in the retina were especially decreased in the low-tension glaucoma subtype. There was a correlation between the visual field defect and OS in the HT eyes in the inferotemporal region. OS measurement may be a novel adjunct to study glaucoma patients.

Turnover of resident retinal microglia in the normal adult mouse

The retina contains two distinct populations of monocyte-derived cells: perivascular cells (macrophages) and parenchymal cells (microglia), important in homeostasis, neuroinflammation, degeneration, and injury. The turnover of these cells in the retina and their repopulation in normal physiological conditions have not been clarified. Bone marrow (BM) cells from EGFP-transgenic mice were adoptively transferred into lethally irradiated normal adult C57BL/6 mice. Eight, 14, and 26 weeks later mice were sacrificed and retinal flatmounts were prepared. Retinal microglia were identified by F4/80, CD45, and Iba-1 immunostaining. BrdU was injected into normal mice for 3-14 days and cell proliferation was examined by confocal microscopy of retinal flatmounts. Few (6.15 +/- 2.02 cells/retina) BrdU(+) cells were detected and of these some coexpressed CD11b (1.67 +/- 0.62 cells/retina) or F4/80 (0.57 +/- 0.30 cells/retina). BM-derived EGFP(+) cells were detected by 8-weeks post-transplantation. By 6 months, all retinal myeloid cells were EGFP(+). Consecutively, donor BM-EGFP(+) cells were demonstrated within the: (1) peripheral and juxtapapillary retina, (2) ganglion cell layer, (3) inner and outer plexiform layers, and (4) photoreceptor layer. EGFP(+) cells within the ganglion layer were amoeboid in shape and F4/80(high)CD45(high)Iba-1(high), whereas cells in the inner and outer plexiform layers were ramified and F4/80(low) CD45(low)Iba-1(low). Perivascular macrophages expressed less F4/80, CD45, and Iba-1 compared with parenchymal microglia. Our results suggest that BM-derived monocyte precursor cells are able to migrate across the BRB and replace retinal microglia/macrophages. The complete replacement of retinal microglia/macrophages takes about 6 months. In situ proliferation was predominantly of nonhemopoetic retinal cells.

Nimodipine Plasma Concentration and Retinal Blood Flow in Healthy Subjects

Calcium antagonists are strong vasodilators, and nimodipine is known to improve cerebral blood flow. The purpose of this study was to measure retinal blood flow and nimodipine plasma concentrations during repeated oral dosing. In a double-blind, two-way, crossover study, 20 healthy subjects (mean age, 22.8 +/- 3.7 years) underwent examination of retinal perfusion and nimodipine plasma concentrations. In a placebo-controlled fashion, nimodipine was orally administered at a dosage of 30 mg three times a day for two periods of 5 days including a 9-day washout interval. At days 1, 5, 15, and 19, plasma concentrations of nimodipine and retinal perfusion were measured 11 times within 3 hours. Stereoselective analysis of nimodipine plasma concentrations was performed with the use of liquid chromatography-tandem mass spectrometry. Scanning laser Doppler flowmetry was used to measure the microcirculation of the juxtapapillary retina. Perfusion images were evaluated with the automatic full-field evaluation procedure (AFFPIA). Areas under the plasma concentration versus time curves were similar at day 1 and day 5 of nimodipine administration (t test: P = 0.64). Values of C(max) displayed a large interindividual variance and ranged from 0 ng/mL to 57.5 ng/mL. On average, maximum nimodipine plasma concentrations (C(max)) were 16.6 +/- 14.9 ng/mL and 12.0 +/- 10.3 ng/mL at day 1 and day 5, respectively (P = 0.068). They were observed at 81 +/- 50 and at 93 +/- 40 minutes (t(max)) after the administration of nimodipine at day 1 and day 5, respectively (P = 0.43). Retinal microcirculation was greater after nimodipine than after placebo, as reflected in significantly larger areas under the curves of percentage change in blood flow from baseline versus time (P < 0.01). The maximum increase of retinal blood flow from baseline was significantly more pronounced after nimodipine (28.5% +/- 14.4% and 39.6% +/- 21.4% at day 1 and day 5, respectively) than after placebo (20.5% +/- 16.8% and 31.9% +/- 14.6% at day 1 and day 5, respectively; P = 0.032). Oral nimodipine significantly increases retinal perfusion in healthy subjects.

Functional imaging of the retinal microvasculature by scanning laser Doppler flowmetry.

to image functionally perfused retinal vessels and to assess quantitatively the intercapillary space of the retinal microvasculature. The base of functional imaging and the quantitative assessment of the retinal vasculature is the two-dimensional map of the retina encoded by the laser Doppler frequency shift. By Scanning Laser Doppler Flowmetry (HRF. Heidelberg Engineering) the laser Doppler frequency shift of 16.384 retinal sites (256 pixels x 64 lines, spatial resolution 10 mum) of a retinal area of 2.7 x 0.7 mm was gained. The image processing was performed by a recently described algorithm (AFFPIA). Using the data of the laser Doppler frequency shift of every retinal site, a color-coded retinal image was established showing perfused vessels and capillaries. By automatic pattern analysis of this image vessels and capillaries were identified and segmented. Based on this image the distances in [microm] of every retinal site to the next vessel or capillary were calculated ("distance to next capillary"). The functional imaging of the retinal perfusion was demonstrated in (1) normal retina, (2) retinal arterial occlusion, and (3) proliferative retinopathy. Intraobserver reliability of the quantitative assessment of the parameter "distance to next capillary" was estimated by measuring 10 eyes of 10 subjects at 5 different days by one observer. Interobserver reliability of the quantitative assessment was evaluated by analysing 10 perfusion maps by 5 different operators. In 93 eyes of 71 normal subjects (mean age 40.4 mu 15 years) the juxtapapillary retina was quantitatively evaluated. QUALITATIVE EVALUATION: The functional images of the retinal perfusion of eyes with normal retina, with retinal arterial occlusion, and with proliferative retinopathy corresponded well with the fluorescein angiography. Perfused vessels and capillaries became visible in a high local resolution. QUANTITITATIVE ASSESSMENT: The coefficient of reliability of the introobserver and interobserver reproducibility of the parameter 'mean distance to next capillary" was 0.74, and 0.95, respectively. The quantitative assessment of the perfusion showed that the major part of the retinal sites (>700%) had distances to the next capillary lower than 30 microm 46% of the retinal area had distances to the next capillary from 0-20 microm 26% of the retina had distances from 20-30 microm, 12% of the retina had distances from 30-40 microm 7% of the retina had distances from 40-50 microm, 4% of the retina had distances from 50-60 microm, and 4% of the retinal sites showed distances to the next capillary greater than 60 mum. The mean distance to the next capillary or vessel was calculated with 21 +/- 6.5 microm. By non-invasive Scanning Laser Doppler Flowmetry in combination with adequate software it is possible to perform a functional imaging of the retinal vasculature and to measure all index for the functional density of retinal capillaries and vessels.

A comparison of ocular blood flow in untreated primary open-angle glaucoma and ocular hypertension

Purpose: To compare ocular blood flow in untreated primary open-angle glaucoma and ocular hypertension using scanning laser Doppler flowmetry and pulsatile ocular blood flow. Method: Fourteen ocular hypertensive subjects and 10 patients with primary open-angle glaucoma were matched for intraocular pressure, mean arterial blood pressure, and age. They had scanning laser Doppler flowmetry images taken centered on the optic disk. Pulsatile ocular blood flow readings were performed in sitting, standing, and supine positions. No subjects were receiving topical antiglaucoma treatment, systemic β-blockers, calcium antagonists, or nitrates at the time of measurement. Results: Laser Doppler flowmetry results showed a significant reduction in blood velocity, volume, and flow at the lamina cribrosa and the temporal neuroretinal rim in glaucoma compared to ocular hypertension ( P < .05). No difference was found between the groups at the nasal neuroretinal rim or the nasal juxtapapillary retina. There was a significant increase in minimum velocity ( P = .03) at the temporal juxtapapillary retina in glaucoma compared to ocular hypertension. The ocular pulse amplitude, pulse volume, and pulsatile ocular blood flow were significantly lower ( P < .05) in the glaucoma group compared to ocular hypertension in sitting and standing positions. Conclusion: Having controlled for factors known to affect perfusion pressure, we found evidence of reduced ocular blood flow in primary open-angle glaucoma compared with ocular hypertension. Our findings indicate a reduction in choroidal and short posterior ciliary artery circulation in primary open-angle glaucoma. Whether these changes in blood flow are a cause or a consequence of glaucomatous optic atrophy is still unknown.

Visual field defect and perfusion of the juxtapapillary retina and the neuroretinal rim area in primary open-angle glaucoma.

At this time little information is available about the relationship between glaucomatous visual field defects and impaired blood flow in the optic nerve head. The purpose of this study was to examine blood flow of the juxtapapillary retina and the rim area of the optic nerve head in primary open-angle glaucoma with a borderline visual defect. Juxtapapillary retinal and neuroretinal rim area blood flow was measured by scanning laser Doppler flowmetry (SLDF). The visual field was evaluated by static perimetry (Octopus-G1). The optic nerve head was assessed on 15 degrees color stereo photographs. We examined 116 eyes of 91 patients with POAG with controlled IOP and 66 eyes of 44 healthy individuals. The POAG group was divided into eyes with a mean defect lower than 2 dB (POAG group I) and in eyes with a mean defect equal to or greater than 2 dB (POAG group II). The mean age of POAG group I and POAG group II was 55 +/- 11 years and 57 +/- 10 years, respectively. The mean age of the control group was 45 +/- 15 years. The eyes of POAG group I had an average C/D ratio of 0.71 +/- 0.18 with an average mean defect of the visual field of 0.97 +/- 0.68 dB; the eyes of POAG group II had an average C/D ratio of 0.80 +/- 0.17 with an average mean defect of the visual field of 8.2 +/- 6.0 dB. The intraocular pressure on the day of measurement in POAG group I was 18.2 +/- 3.7 mmHg, in POAG group II 17.6 +/- 4.0 mmHg, and in the control group 15.1 +/- 2.5 mmHg. For statistical analysis, age-matched groups of 32 normal eyes of 32 subjects (mean age 52 +/- 10 years) were compared to 18 glaucomatous eyes of 18 patients (POAG group I, mean age 55 +/- 11 years) and 59 glaucomatous eyes of 59 patients (POAG group II, mean age 55 +/- 10 years). In the eyes of POAG group I and POAG group II, both juxtapapillary retinal blood flow and neuroretinal rim area blood flow were significantly decreased compared to an age-matched control group: neuroretinal rim area "flow" POAG group I -65%, POAG group II -66%; juxtapapillary retina "flow" POAG group I -52%, POAG group II -44%. All eyes of the POAG group I (MD < 2 dB) and 56 of 61 eyes of the POAG group II (MD > = 2 dB) showed a retinal perfusion lower than the 90% percentile of normal blood flow. We found no correlation between reduction of juxtapapillary or papillary blood flow and mean defect in POAG eyes. Glaucomatous eyes with no defects or borderline visual field defects as well as glaucomatous eyes in an advanced disease stage show significantly decreased optic nerve head and juxtapapillary retinal capillary blood flow.

Optical Coherence Tomography of Macular Lesions Associated with Optic Nerve Head Pits

Although optic pits were described more than a century ago, the pathogenesis and pathologic nature of the associated macular lesions remain controversial. The authors used the technique of optical coherence tomography (OCT) to further define the anatomic relation that exists between optic pits, macular schisis-like spaces, and macular detachments. Four eyes of three consecutive patients with optic pit-related macular pathology were evaluated. Cross-sectional OCT images were correlated with findings from slit-lamp biomicroscopy and stereo fundus photography. All eyes previously had undergone unsuccessful photocoagulation to the temporal juxtapapillary retina. One eye had undergone vitrectomy and intraocular gas tamponade, resulting in partial resorption and displacement of the submacular fluid. Retinal edema and cystic degeneration were present, overlying macular neurosensory detachments in all four eyes. The most prominent edema was present in the outer retina at the level of the outer plexiform layer. This mimicked a true retinoschisis cavity, although bridging retinal elements were identifiable. A lesser degree of edema was present in the inner retina, predominantly located between the disc and fovea. In one eye, a lamellar hole was shown to be a defect in the outer neurosensory retina. In another eye, a macular detachment developed under a pre-existing schisis-like cavity. The schisis-like cavity or edematous retina communicated with the optic disc in all eyes, whereas none of the eyes demonstrated a direct connection between the macular detachment and optic pit. These findings support the concept of a bilaminar structure in which a macular detachment develops secondarily to a pre-existing schisis-like lesion consisting of severe outer retinal edema. Fluid may enter from the optic pit into the retinal stroma and not directly into the subretinal space, explaining the prolonged recovery and frequency of treatment failure after photocoagulation to the juxtapapillary retina.

Perfusion of the Juxtapapillary Retina and the Neuroretinal Rim Area in Primary Open Angle Glaucoma

The objective of this study is to evaluate capillary blood flow of the juxtapapillary retina and neuroretinal rim area in primary open angle glaucoma (POAG) by a new noninvasive method performing a high-definition topography of perfused vessels of the retina and the optic nerve head with simultaneous evaluation of blood flow. Juxtapapillary retinal and neuroretinal rim area blood flow were measured by scanning laser Doppler flowmetry (SLDF). This new technique is a combination of a laser Doppler flowmeter with a scanning laser system by which the retinal perfusion is simultaneously quantified in 16,000 sites of a retinal area of 2.7 x 0.7 mm. In study I, retinal and optic nerve head blood flow were evaluated by SLDF in 43 patients with POAG and 43 healthy individuals. The mean age of the POAG group was 56 +/- 12 years and of the control group 42 +/- 15 years. In study II, age-matched normals (n = 21) were compared with glaucoma eyes with topical therapy (n = 30) and with glaucoma eyes without topical therapy (n = 16). In study I, the eyes with POAG had an average cup/disc ratio (C/D) of 0.75 +/- 0.20, with an average mean defect of the visual field of 5.3 +/- 5.4 dB. The actual intraocular pressure was 17.8 +/- 4.18 mm Hg in the POAG group and 15.45 +/- 1.82 mm Hg in the control group. For statistical analysis, two age-matched groups of 28 normal eyes of 28 persons with 27 glaucomatous eyes of 27 patients were compared. In normals the blood flow of the neuroretinal rim area was significantly higher than that of the juxtapapillary retinal area (+7.73%, p < 0.01). In POAG both juxtapapillary retinal blood flow and neuroretinal rim area blood flow were significantly decreased compared to an age-matched control group: neuroretinal rim area flow -71% and juxtapapillary retina flow -49%. The decrease of neuroretinal rim area blood flow did significantly correlate with C/D. We found no correlation between reduction of juxtapapillary retinal blood flow and C/D or mean defect. Both glaucoma eyes with and glaucoma eyes without topical therapy showed significant decreased juxtapapillary blood flow compared to normals. We found no significant difference in the juxtapapillary blood flow between glaucoma eyes with and without topical therapy. In POAG, optic nerve head blood flow and juxtapapillary blood flow were significantly decreased.

Principle, Validity, and Reliability of Scanning Laser Doppler Flowmetry

The objective of this study is to present the reliability and validity of scanning laser Doppler flowmetry (SLDF) performing a high-definition topography of perfused vessels of the retina and the optic nerve head with simultaneous evaluation of blood flow. The examination of blood flow by SLDF is based on the optical Doppler effect. The data acquisition and evaluation system is a modified laser scanning device; the wavelength of the laser source is 670 mm, with a power of 100 microW (Heidelberg Engineering, HRF). The reliability of SLDF was estimated by performing five separate measurements in 10 eyes on 5 days. The validity of the method was tested by two experiments. First, in an experimental set-up, the capability of SLDF to measure the velocity of a moving plane in absolute units was estimated. Second, comparative measurements were performed of retinal blood flow in normal eyes and in 33 glaucomatous eyes with SLDF and a commercially available single-point laser Doppler flowmeter (Oculix). We found SLDF to produce a high reliability. The reliability coefficients r1 of flow, volume, and velocity were 0.82, 0.81, and 0.83, respectively. Comparative measurements of the retinal blood flow by SLDF and a single-point laser Doppler flowmeter of corresponding retinal points showed a linear and significant relationship between flow (r = 0.83, p < 0.0001), volume (r = 0.51, p < 0.0001), and velocity (r = 0.59, p < 0.0001). In the experimental set-up, SLDF was able to quantitatively measure velocity in absolute units. SLDF enables the visualization of perfused vessels of the juxtapapillary retina and the optic nerve head in high resolution by two-dimensional mapping of the optical Doppler shift and a reproducible evaluation of capillary blood flow.

Malignant Melanoma Associated with Melanocytoma of the Optic Disc

A 61-year-old white man underwent enucleation because of progressive growth of a pigmented epipapillary tumor that was diagnosed 9 years earlier as an optic nerve and juxtapapillary melanocytoma. Histopathologic studies showed the tumor was a malignant melanoma of the optic disc and juxtapapillary retina and choroid. Foci of typical melanocytoma cells were within the tumor. The tumor produced segmental atrophy of the optic nerve. This is a rare example of a malignant melanoma developing in conjunction with a lesion that possessed typical clinical and histopathologic features of a melanocytoma of the optic disc.

Combined Hamartoma of the Retina and Retinal Pigment Epithelium of the Juxtapapillary Retina and Optic Disc (With 1 color plate)

An 11-year-old Japanese girl had a greenish-gray, slightly elevated lesion at the optic disc and juxtapapillary retina of the right eye that was diagnosed as a combined hamartoma of the retina and retinal pigment epithelium. A gliotic epiretinal membrane partially covered the lesion. Tortuous retinal vessels, which leaked fluorescein dye, were noted ophthalmoscopically. The lesion remained stable during a follow-up period of 1 year. After reviewing the Japanese literature, we concluded that the combined hamartoma may not be as rare in Japan as previously thought.

Papilla nigra und Melanosis retinae acquisita nach Operation eines Orbitameningeoms - Klinische, histologische und ultrastrukturelle Befunde

Resection of an orbital meningioma in a 53-year-old patient caused an occlusion of the central retinal artery and total ophthalmoplegia. Eight weeks postoperatively rapid development of a black disc was observed with migration of pigment into the juxtapapillary retina. One year later the eye was removed during a radical reoperation. Histological and ultrastructural examination showed that the melanosis of the disc and the retina was apparently due to reactive proliferation of the juxtapapillary pigment epithelium which had migrated into the atrophic tissues of the retina and the disc. The histological differentiation from hamartomatous proliferations of the juxtapapillary pigment epithelium is discussed. The proliferated pigment epithelium cells in this patient resemble those described in epiretinal membranes apart from abundant RER and actin filaments. In the absence of mechanical or inflammatory factors it must be assumed that hypoxia was the stimulus responsible for the proliferation. The presence of fenestrated retinal capillaries in the proliferation zone is described and the significance of this finding is discussed.

Sessile and Exophytic Capillary Angiomas of the Juxtapapillary Retina and Optic Nerve Head

This report concerns six patients with sessile and exophytic capillary hemangiomas of the optic nerve head and juxtapapillary retina. These are probably retinal vascular hamartomas, which are frequently misdiagnosed as unilateral papilledema, papillitis, choroiditis, choroidal neovascularization, or choroidal hemangioma. Stereo fluorescein angiography is essential in identifying these tumors that usually cause loss of central vision by intraretinal and subretinal exudation into the macular region. Photocoagulation treatment was successful in two patients.