Mass dense vacuoles in Drosophila Malpighian tubules contain zinc, not sodium. A reinvestigation by X-ray microanalysis of cryosections.

The intracellular storage of zinc in Malpighian tubules of Drosophila hydei was studied by X-ray microanalysis of freeze-dried cryosections. Mass dense vacuoles in the proximal region of the anterior larval Malpighian tubule cells were found to accumulate zinc, not sodium. The zinc content was enhanced considerably after addition of zinc to the food of the larvae. Zinc-containing vacuoles were also found after pupation. After starvation of larvae in sea water, Na was detected in these vacuoles in addition to Zn. A small increase of Na and a remarkable increase of Zn was found in the vacuoles after injection of Ringer solution with ouabain into the larvae. Similar vacuoles in cells of untreated posterior tubules exhibit only low zinc levels.

The importance of the Golgi complex for epithelial ion transport in Drosophila Malpighian tubules, studied by electron microscopy, cytochemistry and X-ray microanalysis.

The distribution of potassium in the cells of Drosophila Malpighian tubules is not homogeneous. In the microvilli of the apical part of the cell the cytoplasmic potassium content was found to be 2 to 3 times higher than in the neighboring intermediate cytoplasm. Data obtained by electron microscopy, histochemistry and electron probe X-ray microanalysis indicate that glucosaminoglycans (GAGs), synthesized by the Golgi-ER complex, are responsible for potassium accumulation in the apical microvilli. Vesicles bud from the Golgi complex and then move to the apical cell region, where they discharge their contents into the cytoplasm or into the lumen. Budded vesicles also discharge their contents into the hemolymph space between the folds of the basal plasma membrane. GAGs, transformed to proteoglycans (PGs), were identified on the folds of the basal cell surface including basal lamina by reaction with alcian blue. Brefeldin A (BFA) was found to disintegrate Golgi-ER structures to vesicles, whereas budded vesicles vanished. Within the microvilli the K+-content decreased to 32%, the water content to 77%. These data provide evidence that the ER-Golgi complex is involved in the delivery of GAGs (and PGs) into the luminal space and the hemolymph. After disintegration of the Golgi complex, GAGs are missing as temporary ion stores from the vicinity of the membrane transporters.

Intracellular storage of sodium and magnesium in Drosophila Malpighian tubules. X-ray microanalysis of native cryosections.

Using electron probe X-ray microanalysis after cryofixation, cryosectioning and freeze-drying we investigated the content of electron-dark vacuoles in the intermediate cell region of the proximal segment of Malpighian tubules in Drosophila larvae. According to this method these vacuoles store sodium and magnesium in a high correlation (r = 0.98) of 5:1 ratio. Phosphorus, potassium and sulfur are also stored. In the intermediate groundplasm surrounding the vacuoles the element content is different from that in the vacuoles. The significance of vacuolar sodium and magnesium storage for the ionic metabolism is unknown. In addition to Na, Mg, P, K and S the vacuoles also contain 3-OH-kynurenine and other fluorochromes. With the pyroantimonate technique intravacuolar precipitates were demonstrated. X-ray microanalysis of the precipitates revealed sodium and calcium, although following cryofixation calcium was not detectable in the vacuoles by X-ray analysis.

Congenital retino-pigment epithelial malformation, previously described as hamartoma.

Six patients with a congenital malformation of the retina and pigment epithelium had a slightly elevated greenish-blue or gray lesion in the macular area or fundus periphery composed of a flat, outer pigmented portion consisting of a layer of hyperpigmented, presumably hypertrophied retinal pigment epithelium and a prominent, unpigmented inner portion consisting of malformed thickened retina. Marked tortuosity of the retinal vessels was explained by an intraretinal disturbance of the retinal layering and the presence of preretinal membranes. Angiography revealed blockage of the background fluorescence caused by the abnormal retinal pigment epithelium and leakage from dilated, abnormal capillaries. Typically, the lesion was unilateral and was found in children or young adults who had monocular strabismus, reduced visual acuity, and often hyperopia. Most of the patients were males, and their cases were frequently misdiagnosed as tumors.

Nine cases of cavernous hemangioma of the retina.

The findings in nine patients with cavernous hemangioma of the retina confirmed the accepted characteristics of this malformation. Clusters of dark-red saccular aneurysms within the inner retinal layers were partly covered by a white epiretinal membrane. There was no clinical or angiographic evidence of exudation from the angioma and there was no growth during a median follow-up period of 6.3 years. The size of the aneurysms, the extent of the lesion, and the associated venous malformations varied greatly from case to case. Fluorescein angiographic findings during follow-up periods of as much as 16 years suggested progressive thrombosis and organization of the angioma.

Long-term results of pars plana vitrectomy in the management of complicated uveitis.

This retrospective study evaluates the long term efficacy of pars plana vitrectomy on the preservation of vision in complicated chronic uveitis, including endogenous intermediate uveitis and other entities. Combined vitrectomy-lensectomy was performed in 10 eyes with complicated cataracts, and 18 vitrectomies were done without lensectomies. The mean follow up was 45 months. Additional retinal surgery (for example, scleral buckling) was performed in five eyes. Visual acuity improved in 23 eyes (82.8%) following surgery, with 16 eyes (57%) achieving a vision better than 6/24. The main causes for vision less than 6/24 were persistent cystoid macular oedema (three eyes), macular puckers (one eye), retinal vascular obliterations (four eyes), optic atrophy (five eyes), and chorioretinal scars (seven eyes). Postoperative complications were cataract formation (seven eyes), cystoid macular oedema (one eye), and tractional retinal detachments (three eyes). The surgical intervention resulted in a remarkable reduction of the severity of inflammation or frequency of exacerbations, and allowed significant tapering (11 eyes) or withdrawal (11 eyes) of the topical steroids, or oral corticosteroids (10 cases). Pre-existent cystoid macular oedema resolved in three eyes. Pars plana vitrectomy, eventually combined with lensectomy, may visually rehabilitate eyes with chronic uveitis and media opacities, and may reduce the activity of disease postoperatively.

Long-term results after low dose ocular irradiation for choroidal haemangiomas.

AIM/BACKGROUND: The most common choice of treatment for choroidal haemangiomas (CH) in the past has been the employment of scatter photocoagulation of the surface. This management often requires repetitive treatment or additional invasive management due to massive exudative detachment of the retina. The aim of this retrospective study was to investigate the outcome of the alternative application of low dose external beam irradiation with high energetic photons on these tumours. METHODS: A total absorbed dose of 20 Gy was applied to a total of 51 symptomatic eyes: 36 with a circumscribed CH of the posterior pole and 15 with diffuse CH as part of the Sturge-Weber syndrome. The indication for treatment was an exudative retinal detachment including or threatening the fovea. The mean follow up times in each group were 4.5 and 5.3 years, respectively. Out of a group of 33 patients from whom reliable data could be derived, 17 had symptoms lasting longer than 6 months. RESULTS: In 23 cases (63.8%) with circumscribed CH complete resolution of the subretinal fluid was achieved; the remaining 13 cases (36.2%) showed residual serous detachment distant to the fovea. The visual acuity improved by two or more lines in 14 cases (38.9%), remained stable in 14 cases (38.9%), and decreased in eight cases (22.2%). The functional success was dependent on the lag duration between onset of first subjective symptoms and treatment. The morphological results with diffuse CH were similar to those of the group of circumscribed CH. The visual acuity (VA) at last examination was improved in seven cases (46.6%); in the remaining eight cases, VA was unchanged or had deteriorated. The poor functional outcome in the latter was mainly attributable to secondary glaucoma. CONCLUSION: External beam irradiation is a useful and a low invasive therapeutic option for CH. A successful functional outcome is dependent on the time delay between first onset of symptoms and the beginning of therapy, the formation of subretinal fibrosis, and also on secondary glaucoma in the case of Sturge-Weber syndrome.

[Retinal angiomatosis. Long-term follow-up]. / Angiomatosis retinae. Langzeitbeobachtungen.

UNLABELLED: Meyer-Schwickerath reported his first results with light coagulation in 1959. This report on the results of treatment in this disease is based on more than 34 years experience at the university eye hospital in Essen. Important prognostic factors are the number of retinal hemangiomas and secondary retinal lesions, such as exudative retinal detachment, lipid deposits, vitreous hemorrhages, preretinal membranes and traction retinal detachment. PATIENTS: Treatment was performed in 156 patients, with 220 involved eyes. The median follow-up was 8.9 years and the average age before treatment, 27.5 years. RESULTS: A positive family history was found in 36.5% and extraocular hemangiomas in 24% of all cases. There were 64 patients with bilateral hemangiomas. In 64.5% of cases the tumor was destroyed without further recurrences. Xenon light coagulation was the only treatment applied in 70%. The other patients received combined procedures with light coagulation, cryocoagulation, Ru 106 plaque and proton beam. Salvage of 90% of all treated eyes was achieved. CONCLUSION: Treatment at an early stage of the disease, before any secondary retinal damage has developed, seems to be crucial for satisfactory results. Light coagulation is extremely effective at this stage. However, the treatment options for advanced cases have also become better recently.

[Change in hole size and area of retinal detachment after pars plana vitrectomy in Gass stage III macular foramina]. / Anderung der Lochgrösse und des abgehobenen Netzhautbereichs nach Pars-plana-Vitrektomie bei Makulaforamen im Stadium III nach Gass.

UNLABELLED: In 15 patients with a stage III macular hole a pars plana vitrectomy with membrane peeling was performed. At the end of the operation a gas/air exchange was performed and patients had to lie face down for some days. METHODS: Before and 4-7 months after the operation a picture of the posterior pole was taken with a Zeiss fundus camera. Pictures were digitized, and the area of the hole and of the surrounding detached retina was measured using a special image analyzer software. RESULTS: In seven cases an improvement of visual acuity was found; in the remaining eight cases visual acuity remained unchanged. In five cases (33%) the retina was totally attached around the hole. In eight cases the detached area had become smaller, in two cases larger, and in two cases we could no longer observe the rim of the hole. In the remaining cases the area of the holes changes by less than 10%. CONCLUSIONS: The results show that even in cases where total attachment of the surrounded retina cannot be achieved, reduction of the detached area can be expected in most cases. Simultaneously, a reduction of metamorphopsia can be observed. However, the improvement of visual acuity is not very high. That is why we will perform pars plana vitrectomy in stage III holes only in exceptional cases.

[Focal proliferations of retinal pigment epithelium. Risk factor in senile macular degeneration]. / Fokale Proliferationen des retinalen Pigmentepithels. Risikofaktor bei der altersabhängigen Makuladegeneration.

BACKGROUND: Clinical studies have demonstrated the relevance of focal RPE proliferations in early AMD as risk factors for visual loss caused by late AMD. Angiographically these focal RPE proliferations are characterized as small hypofluorescent spots with hyperfluorescent rim without leakage. Corresponding to histological and experimental studies they can be interpreted as small areas of occult choroidal neovascularizations covered by proliferated RPE cells. The characterization of the long-term prognosis of these lesions was the aim of the present study. PATIENTS AND METHODS: Ninety-eight patients (52 female, 46 male) were reexamined clinically and angiographically with a follow-up of 2-12 years (mean 6.5 years). RESULTS: Visual loss of two lines or more could be observed in 64.5% of patients with final visual acuity less than 20/100 in 24.5% of patients. Morphologically the changes in visual acuity were related to the progression towards classical choroidal neovascularizations in 32.7% of patients. In addition 11.2% of patients demonstrated a regression of the small occult membrane with the development of small areas of RPE atrophy covering the size of the original occult neovascularization. In 10.2% of the patients enlargement of the lesion was observed, resulting in a large occult choroidal neovascularization without signs of classical membranes, and in 45.9% of patients the clinical and angiographical situation was unchanged. The most important prognostic factor correlating with visual loss was the presence of a disciform lesion in the fellow eye and of multiple drusen in the examined eye. Other factors like the size or location of the focal RPE proliferation and the duration of follow-up did not correspond with visual loss. CONCLUSIONS: Focal RPE proliferations in early AMD interpreted as small occult choroidal neovascularizations are associated with a high risk of visual loss. Especially if these lesions are associated with multiple drusen and a disciform lesion in the fellow eye, nearly all patients are at risk for visual loss. These changes may therefore characterize a special high-risk group for future prophylactic treatments in early AMD, but because of the high risk for the development of classical choroidal neovascularizations in this group, these results are also very important for the planning of prophylactic laser trials for drusen in early AMD.

[Observations of different presentations of choroid neovascularization in indocyanine green angiography]. / Beobachtungen zur unterschiedlichen Darstellung choroidaler Neovaskularisationen in der Indozyaningrün Angiographie.

The interpretation of choroidal neovascular membranes (CNV) in indocyanine green angiography (ICG-A) is difficult. It is not known whether demarcated hyperfluorescence in the ICG-A reliably reflects the true morphology and the total extent of a CNV. Therefore, in this retrospective study, the patterns of fluorescein and ICG angiograms were evaluated and compared in both occult and well-defined CNV. In 153 out of a total of 168 cases with CNV, age-related macular degeneration (AMD) was the underlying disease. CNV was occult in 114 and well-defined in 39 cases. The angiographic examinations with both dyes were performed with a modified fundus camera combined with a digital imaging system. In the group of AMD patients with occult or ill-defined CNV. 42 cases (36.8%) showed a defined membrane in the ICG stain. The filling patterns of ICG were extremely variable. In the group of AMD patients with classic CNV, ICG-A showed evidence of staining in the early and late phase in 14/39 cases (36%), exclusively in the early phase in 5/39 (13%) cases and only in the late phase in 17/39 cases (44%). Surprisingly, three well-defined membranes in fluorescein angiography (FLA) were not seen in any phase of the ICG-A. Compared with FLA, the 17 CNVs with demarcation only in the late phase of the ICG-A were seen to be larger in 8 and smaller in 9 cases while all CNVs seen in the early phase, or in both early and late phase, were of identical size with the early fluorescein staining. The pattern of ICG staining of CNV is complex. The single finding of a demarcated hyperfluorescence in the late phase of ICG-A should be interpreted with utmost caution, particularly in regard to planning laser therapy.

[The Bruch membrane and choroid. Angiography and functional characteristics in age-related changes]. / Bruch-Membran und Aderhaut. Angiographische und funktionelle Charakteristika der altersabhängigen Veränderungen.

Age-related changes in the retinal pigment epithelium and Bruch's membrane are believed to play an important role in the pathogenesis of age-related macular degeneration. Ophthalmoscopically visible drusen in the macular area may precede the complications causing visual loss. In addition to these localized depositions of debris in Bruch's membrane, histological methods could demonstrate linear deposits in Bruch's membrane which may also profoundly influence the development of complicated macular aging changes. It is difficult to identify linear deposits clinically, but as an indirect criterion for diffuse thickening and linear deposits in Bruch's membrane regression of the choriocapillaris with consequent prolongation of the choroidal filling phase in fluorescein angiography is suggested. This feature was observed in 26% of elderly patient. In association with these areas of regressed choroidal capillaries, loss of visual function was found in fine matrix perimetry.

[Biochemical and histochemical analysis of age related lipid deposits in Bruch's membrane]. / Biochemische und histochemische Analyse altersabhängiger Lipidablagerungen in der Bruchschen Membran.

In histochemical studies the age-related deposition of different lipids in Bruch's membrane has been seen. This is important for the pathogeneses of age-related macular degeneration due to changes in diffusion characteristics. Because the specificity of histochemical results is limited, a correlation of histochemical lipid analysis with biochemical methods was performed. The macular Bruch's membrane of 27 donors (age 1-97 years) was analyzed. The results of this analysis demonstrated that the increasing histochemical staining for lipids in Bruch's membrane corresponded with an increasing amount of lipids extracted from Bruch's membrane in biochemical analysis. This lipid deposition progressed exponentially with age. However, a large variation in the type of lipid deposited could be observed, with predominant deposition of phospholipids in some eyes and of neutral lipids in others. Furthermore, the phospholipids extracted were differentiated into 50% phosphatidylcholine, 30% phosphatidylethanolamine and 20% phosphatidylinositol and phosphatidylserin. The deposition of lipids, especially neutral lipids, in Bruch's membrane may change its diffusion characteristics. This appears to be important for the pathogenesis of age-related pigment epithelium detachments. The composition of the phospholipids extracted from Bruch's membrane supports, furthermore, the concept that the material deposited is the result of metabolic limitations in the degradation of photoreceptor outer segment material.

[Late vision loss after focal hemorrhagic chorioretinopathy]. / Später Visusverlust nach fokaler hämorrhagischer Chorioretinopathie.

Prospective clinical studies about photocoagulation of extrafoveolar choroidal neovascularizations in focal hemorrhagic chorioretinopathy (CR) have demonstrated that the risk of visual loss years after successful treatment is related to the development of retinal pigment epithelium (RPE) atrophy around the laser scar. The reason for this event was thought to be late damage of RPE cells due to the laser treatment. However, because RPE atrophy can also be seen in untreated patients, a prospective study was started to test this pathogenetic hypothesis and to analyze the pathogenetic factors and prognostic importance of RPE atrophy in focal hemorrhagic CR. Eighty-eight patients (52 women, 36 men, 15-45 years old; mean follow-up 62 months; 26 patients treated by photocoagulation) with focal hemorrhagic CR were reexamined. Fifty-two patients (15 treated by photocoagulation and 37 untreated) showed clinically visible RPE atrophy. In these 52 patients the initial and final visual acuity, the amount of initial subretinal fluid (34.6% < 500 microns, 50% 500-750 microns, 15.4% > 750 microns) and the amount RPE atrophy (23.2% < 500 microns, 53.6% 500-750 microns, 23.2% > 750 microns) were analyzed. The development of RPE atrophy was dependent on the time of follow-up (36 patients without RPE atrophy, mean follow-up 29 months; 52 patients with RPE atrophy, mean 84 months, P < 0.001). Of the 52 patients with RPE atrophy, 15 were treated by photocoagulation. The distribution of RPE atrophy was similar to what was found in the 37 untreated patients (P = 0.4). With pronounced RPE atrophy, a decrease in final visual acuity was seen (RPE atrophy < 500 microns, mean visual acuity 0.5; 500-750 microns mean visual acuity 0.3; > 750 microns, mean visual acuity 0.1; P = 0.005). Increased RPE atrophy was also associated with a higher incidence of visual loss (p = 0.009). The amount of RPE atrophy was not dependent on the time of follow-up (P = 0.3), but only correlated with the initial amount of subretinal fluid (atrophy < 500 microns: subretinal fluid < 500 microns 15.4%, 500-750 microns 7.7%, > 750 microns 0%; atrophy 500-750 microns: subretinal fluid < 500 microns 19.2%, 500-750 microns 32.7%, < 750 microns 1.9%; atrophy > 750 microns: subretinal fluid < 500 microns 0%, 500-750 microns 9.6%, > 750 microns 13.5%; P < 0.0001). Because RPE atrophy in focal hemorrhagic CR was seen in patients both with and without photocoagulation therapy, laser treatment cannot be the causative factor. With increased follow-up the risk of the development of RPE atrophy increases in all patients. The resulting amount of RPE atrophy was only dependent on the initial amount of subretinal fluid. If the fovea is included in the exudative detachment, there is a higher risk of long-term visual loss.

[Focal hemorrhagic chorioretinopathy. Clinical differentiation and visual prognosis]. / Fokale hämorrhagische Chorioretinopathie. Klinische Differenzierung und Visusprognose.

Macular choroidal neovascularization in young adults without any known underlying diseases is referred to under the general term of focal hemorrhagic chorioretinopathy. In endemic areas of the USA an infection with Histoplasma capsulatum is thought to be the causative agent, but in Europe the pathogenesis of this condition is unknown. With the aim of finding how European patients with this disease might be detected by clinical examination and to estimate the prognosis for sight in the affected eye and the fellow eye, a follow-up examination (follow up 1-24 years, mean 7 years) of 88 patients (age 15-48 years, mean 33.6 years) was undertaken. Most patients were between 20 and 40 years of age and mildly myopic. The number of chorioatrophic scars associated with the choroidal neovascularization in particular varied widely between patients. Therefore, this characteristic is most useful for clinical differentiation between patients. In contrast, the development of an atrophic conus at the optic disc was predominantly correlated with worsening myopia. One-third of all patients experienced decreased vision during follow-up. In two-thirds of the group, however, the final vision was still 0.1 or better. The initial visual prognosis in the eye affected was predominantly dependent upon the location of the neovascular membrane in relation to the fovea and therefore upon the possibility of photocoagulation treatment. Long-term follow up in these patients revealed visual acuity decreased further only in eyes with increasing atrophy of the retinal pigment epithelium surrounding the disciform or laser scar. One-fifth of the patients also developed choroidal neovascularization in the fellow eye.(ABSTRACT TRUNCATED AT 250 WORDS)

[Long-term outcome of radiotherapy of choroid hemangioma]. / Langzeitresultate der Strahlentherapie von Aderhauthämangiomen.

The usual therapeutic approach to circumscribed choroidal hemangiomas of the posterior pole consists of scatter photocoagulation of the tumor surface. This may often require repetitive treatment or additional invasive measures prior to coagulation due to massive exudative detachment of the retina. In this study, external beam irradiation with high-energy photons (total absorbed dose: 20 Gy) was applied to 36 symptomatic patients. The indication for treatment was exudative retinal detachment including or threatening the fovea. The mean duration of follow-up was 4.5 years (4 months to 24 years, median 4 years). In 23 cases (63.8%) complete resolution of the subretinal fluid could be achieved; 13 cases (36.2%) showed residual serous detachment at some distance from the fovea. The visual acuity improved by two or more lines in 14 cases (38.9%), remained stable in 14 cases and decreased in only 8 cases (22.2%). The functional success was dependent on the interval between onset of first subjective symptoms and treatment. External beam irradiation is a successful form of treatment for choroidal hemangiomas.

[A clinicopathological study of 297 cases of retinoblastoma].

OBJECTIVE: To find a morphological criterion of classification for choroidal invasion of retinoblastoma in order to further study clinical pathology of retinoblastoma (Rb) under an integrate rule. METHODS: The changes of retinal pigment epithelium, Bruch's membrane and choroid on histopathological sections of primarily enucleated eyes with Rb in 297 cases were observed under a light microscope. RESULTS: The globe wall invasion could be morphologically divided into four stages (briefly pigment epithelium-choroid classification). Stage I: Only retinal pigment epithelium was infiltrated, the Bruch's membrane was intact. Stage 2.: The Bruch's membrane was destructed, but the choriocapillaries were not invaded. Stage 3: The invasion reached middle choroidal blood vessels close to the choriocapillaris in a limited scope. Stage 4: Massive choroidal infiltration of all choroidal layers existed and the sclera could be simultaneously involved. The mortality for stage 4 was 11.5% and for stage 1 to 3 was 0.4%. CONCLUSION: The pigment epithelium-choroid stage (PEC-stage) classification in our study can be used as an integrate rule to compare the invasion degree of retinoblastoma in different individuals and studies.