Short-term reaction of choroidal neovascularization and choriocapillaris to photodynamic therapy in age-related macular degeneration.

PURPOSE: To identify the number of primary angiographic nonresponders to photodynamic therapy (PDT) with verteporfin, to determine the rate and speed of reperfusion of choroidal neovascularization (CNV) within a short observation period of only 5 weeks, and to examine the reaction of the underlying choroidal vessels. METHODS: PDT according to the TAP regimen was carried out in 36 eyes with subfoveal classic CNV secondary to age-related macular degeneration. The response to PDT was examined 1 (T1) and 5 (T2) weeks following treatment. At all visits distant visual acuity was measured and both fluorescein and indocyanine green angiography was carried out. RESULTS: One week after treatment (T1), complete closure of classic CNV had not been achieved in 17% of eyes (primary angiographic nonresponders). At T2, 91% of eyes showed reperfusion of the CNV. In 83% of the primary angiographic nonresponders the CNV size was larger than before treatment. Choroidal shadowing was present in 82% at T1 and in 48% at T2. CONCLUSIONS: Primary angiographic PDT nonresponders are relatively rare; however, in contrast to former reports, they exist and can be identified by follow-up examination 1 week after PDT. Recurrence of leakage occurred earlier than expected and may require closer follow-up and earlier retreatment than recommended by the TAP trial.

[Interval reduction of photodynamic therapy (PDT) in age-related macular degeneration (AMD) is not advantageous. A pilot project]. / Intervallverkürzungen der photodynamischen Therapie (PDT) bei altersbedingter Makuladegeneration (AMD) bringen keine Vorteile. Pilotstudie.

PURPOSE: To find out if carrying out PDT again 6 weeks after initial PDT will improve the results at 3 months. METHODS: A total of 22 eyes were treated according to the dose regimen proposed by the TAP study. RESULTS: After the first PDT, the CNV remained permanently closed in 14% of the eyes. Repeating the treatment 6 weeks later did not lead to permanent closure of more CNVs or a diminished size at 3 months. Short-term re-treatment had no substantial effect on the underlying choriocapillaries. Visual acuity did not profit or suffer from early re-treatment. CONCLUSION: Shortening of the treatment interval has no serious side-effects, but does not seem to improve the results reported in the TAP study.

DMSO mimics inhibitory effect of thalidomide on choriocapillary endothelial cell proliferation in culture.

AIM: To evaluate the effect of thalidomide on bovine choriocapillary endothelial cell proliferation. METHODS: Posterior segments of bovine eyes were incubated with trypsin. After digestion of the tapetum, pieces of Bruch's membrane with the adherent choriocapillaris were scraped, digested again with a cocktail of enzymes, washed and cultured in MCDB 131 medium. Cells were incubated with 100 micro g/ml thalidomide (dissolved in DMSO as recommended). Control cultures were incubated with DMSO alone or without any supplement. Cell proliferation after 24 hours was determined in a counting chamber. Purity of the cultures was controlled by immunohistochemical staining and labelling with low density lipoprotein. RESULTS: Thalidomide dissolved in DMSO inhibited proliferation of choriocapillary endothelial cells compared to control cultures incubated without any supplement. However, DMSO alone suppressed cell proliferation equally well. CONCLUSION: In cultured bovine choriocapillary cells the inhibiting effect of thalidomide may at least in part be attributed to the solvent DMSO alone.

Typical ocular findings in a patient with multiple endocrine neoplasia type 2b syndrome.

BACKGROUND: Multiple endocrine neoplasia (MEN) type 2b syndrome is accompanied by typical ocular findings; however, the disease is often only diagnosed at an advanced stage by symptoms of C-cell carcinoma or pheochromocytoma and is then fatal in most cases. Therefore, the importance of ophthalmic assessment in making the diagnosis has to be stressed. METHODS: The history and ocular findings of a patient with MEN 2b syndrome are described, and a brief overview of the syndrome is given. RESULTS: Slit-lamp examination showed extremely thickened corneal nerves as well as multiple small plexiform and nodular subconjunctival tumors. Both eyes also displayed thickened upper and lower eyelids. A molecular genetic study of the RET proto-oncogene showed a heterozygous ATG to ACG mutation in codon 918 of exon 16. CONCLUSION: Greatly thickened corneal nerves and subconjunctival tumors may be the first hint of MEN 2b. Whenever greatly thickened corneal nerves are detected, MEN 2b must be ruled out.

Topological-histological investigation of the pterygium.

BACKGROUND: It is a wide-spread assumption, never proven scientifically, that the pterygium is a duplication of the conjunctiva, with an intervening gap at the limbus. We therefore conducted a histological reinvestigation, primarily to clarify the topological relation between normal bulbar tissue and lesion. METHODS: Excised pterygia were prepared for light microscopy and embedding in paraffin. Two pterygia were serially sectioned, and samples of 49 others were removed, sectioned and stained (stains: H&E, alcian blue, toluidine blue, PAS; antibody: cytokeratin 18). RESULTS: The pterygium is an epithelium-covered protuberance of connective tissue, projecting over the normal surface of the eyeball; it consists of a base, which extends in the direction of growth, and lateral lobes. It is therefore impossible to insert a probe all the way under a pterygium. The bulbar tissue adjacent to the pterygial protuberance can likewise be histologically altered. That is, a narrow layer of connective tissue, well supplied with capillaries, may be present in the corneal section of the pterygium between Bowman's layer and the epithelium. CONCLUSION: Histological alterations of the stroma predominate quantitatively over those of the epithelium. The topographical anatomy of the lesion and the fact that bulbar tissue is modified along with the pterygium should be taken into account when excision is undertaken. We predict that if all the altered tissue is removed, the rate of recurrence will be reduced.

Effect of ultraviolet radiation on melanogenesis in four different types of cultured bovine ocular pigmented cells.

BACKGROUND: Ultraviolet radiation is thought to play a causative role in various ocular diseases such as macular degeneration, cataract, and possibly melanomas. Since most of the energy is absorbed by pigmented cells, the aim of this study was to examine and compare the reactions of different ocular melanocytic cells to ultraviolet light in vitro. MATERIALS AND METHODS: Bovine iris melanocytes, choroidal melanocytes, iris pigment epithelial cells, and retinal pigment epithelial cells were isolated and cultured. Semiconfluent cultures were exposed to ultraviolet radiation (280-380 nm). Cell number and melanin content were measured 10 days after radiation. Selected samples were examined by transmission electron microscopy. RESULTS: Following irradiation with ultraviolet light for 30 s, 60 s, and 120 s, the number of cells in culture decreased markedly. In contrast, total melanin content in the cultures of iris melanocytes, choroidal melanocytes, and iris pigment epithelial cells did not decrease despite the reduced number of cells. This finding suggested an increase in melanin per cell. However, the increase in average melanin content observed was not due to melanogenesis, because treatment with the melanogenesis inhibitor alpha-methyl-p-tyrosine did not reduce the melanin content of the cultures and electron-microscopic examination showed no morphological evidence of increased melanogenesis. CONCLUSION: In vitro, there was no convincing evidence of ultraviolet radiation-induced melanogenesis in ocular pigmented cells. Thus, it seems that ultraviolet radiation is a selection factor: more densely pigmented cells survive the treatment better than less pigmented cells.

Tumours may be innervated.

It is generally assumed that tumours are not innervated. However, following an accidental observation of a nerve fibre within an adenoma of the ciliary body epithelium of the eye, we have further examined two such tumours. One pigmented and one non-pigmented adenoma of the ciliary body epithelium (APCE and ANCE, respectively) that had been surgically removed from two human eyes were processed for ultrastructural evaluation and systematically screened and analysed for the occurrence of nerve tissue under a transmission electron microscope. The adenomas were composed of epithelial tumour cell strands and interposed vascularised connective tissue. Both tumours contained a small number of fine unmyelinated nerve fibres containing clear and dense core vesicles. In both adenomas, the nerve fibres were located in the tumour periphery close to blood vessels and tumour cells. In the APCE, they were also seen in more central areas. Since nerves always have a function, this finding, if confirmed in other neoplasms, may influence our understanding of such innervated tumours.

Short-time application of latanoprost does not stimulate melanogenesis in bovine ocular melanin-containing cells in vitro.

Topical use of latanoprost for glaucoma can lead to an increase in iris and eye lash pigmentation but the precise mechanism is unclear. To study the possible effect of this drug on ocular melanogenesis, we used cultures of bovine iris melanocytes, iris pigment epithelial cells, retinal pigment epithelial cells, and choroidal melanocytes. Latanoprost (at concentrations of 10(-8) and 10(-6) mol) was applied for 3 days, and cell numbers as well as melanin content were measured prior to and 10 days after exposure and compared to untreated controls. In none of the cell types examined a significant increase in melanin content or an increase in cell proliferation was observed. Additional treatment with the tyrosinase inhibitor alpha-methyl-p-tyrosine showed no significant effect either. Our results support the concept of a rather complex mechanism underlying the increased iris pigmentation after treatment with latanoprost.

Radiotherapy for age-related macular degeneration: is there a benefit for classic CNV?

AIM: To evaluate the efficacy of radiotherapy in the treatment of subfoveal classic and occult choroidal neovascularization (CNV) in age-related macular degeneration (AMD) under strict fixation control. METHODS: Twenty-seven eyes of 27 patients with subfoveal CNV as a result of AMD were treated with a total dose of 20 Gy in 10 fractions (10 well-defined, 17 occult). Fixation monitoring was achieved by installing a TV camera with an attached fixation light 3 cm from the cornea of the eye being treated. Visual acuity and fluorescein angiography were obtained before and 6 months after treatment. Fifteen eyes of 15 patients served as controls (4 well-defined, 11 occult). RESULTS: After 6 months the treated group showed an average decrease in visual acuity of 27%; the control group experienced a decrease of 31%. Membrane size increased by 56% in the treated group and by 28% in the control group. There was no statistically significant difference. Within the subgroup analysis, however, patients with classic CNV suffered significantly less visual loss than in the control group. CONCLUSION: Radiation therapy under optimized treatment conditions by fixation monitoring failed to control further growth in membrane size in both classic and occult CNV. Regarding visual acuity, however, patients with classic CNV seem to benefit from radiation treatment compared to the natural course.

Long-term results of pneumatic retinopexy.

PURPOSE: To evaluate the long-term outcome (>6 years) of retinal reattachment by pneumatic retinopexy. METHODS: Seventy-eight eyes were examined retrospectively after treatment of a retinal detachment with pneumatic retinopexy. The average follow-up period was 6.35 years. The fundus was examined and visual acuity was documented and compared to that of the fellow eye. Any reoperations were evaluated. RESULTS: In 98.7% of cases permanent reattachment of the retina was achieved. In 85.9% the primary intervention had been successful. However, the retina redetached in 19.4% of these during the first 3 months and in a further 4.5% later during the observation period, requiring reoperation. The average number of operations necessary to obtain permanent reattachment of the retina in the 77 eyes was 1.39. One eye was lost due to phthisis bulbi and had to be enucleated. Six years after the first intervention visual acuity of the eyes without reoperation was 0.57 (+/-0.25 SD) with initially detached macula [fellow eye 0.67 (+/-0.27)] and 0.7 (+/-0.27) with attached macula [fellow eye 0.7 (+/-0.25)]. Visual acuity of the eyes with reoperation was 0.36 (+/-0.3) [fellow eye 0.51 (+/-0.29)] with initially detached macula and 0.64 (+/-0.26) [fellow eye 0.63 (+/-0.35)] with attached macula. CONCLUSION: Six years after initial pneumatic retinopexy the retina was found to be attached in 98.7% of eyes. In 65.4% this result had been achieved by minimally invasive primary surgery alone. The need for reoperation was evident during the first 3 months in 89% of the cases. The final visual outcome was satisfactory overall.

Adenoma of the pigmented ciliary epithelium: ultrastructural and immunohistochemical findings.

We report the clinical and histological findings in a tumor of the pigmented ciliary epithelium. The tumor was detected because it had caused a unilateral cataract, and it was removed by local resection because a malignant melanoma could not be excluded. The diagnosis was established by light microscopy, and additional immunohistochemical and detailed ultrastructural studies were performed. The so-called foam cells which are considered typical of these adenomas appear to be mostly light microscopic artifacts and had no ultrastructural equivalent in the sections examined from our tumor. Our results also strongly support the hypothesis that no true glandular elements are formed and that, apart from the neoplastic tissue architecture, most of the pathological findings are related to melanosomes.

Radiotherapy for age related macular degeneration causes transient lens transparency changes.

AIM: Evaluation of potential side effects of photon radiotherapy on the transparency of the lens. METHODS: The anterior segments of 14 phakic eyes from patients suffering from subfoveal neovascularisation as a result of age related macular degeneration (AMD) were documented by Scheimpflug photography (Topcon SL-45, Kodak Tmax 400) before the start of radiotherapy as well as 6 and 12 months afterwards. All negatives were evaluated by microdensitometry, and peak heights for distinct layers of the lens were used for statistical comparison. External beam radiotherapy (6 MeV photons) consisted of a total dose of 20 Gy, delivered as 10 fractions of 2 Gy. RESULTS: Six and 12 months following irradiation statistical comparison of the ratios in density change of lenses from irradiated versus non-irradiated fellow eyes revealed statistically significant (p

Vasoactive intestinal polypeptide (VIP) innervation of the human eyelid glands.

This study was conducted to obtain morphological proof of innervating nerve fibres in the glands of the human eyelid (accessory lacrimal glands of Wolfring, meibomian glands, goblet cells, glands of Zeis, glands of Moll, sweat glands, glands of lanugo hair follicles) and identification of the secretomotorically active neuropeptide vasoactive intestinal polypeptide (VIP) as a common transmitter. Epoxy-embedded ultrathin sections of tissue samples from human eyelids were studied using electron microscopy. Paraffin sections fixed in Bouin-Hollande solution were immunostained with rabbit antiserum against VIP. With the electron microscope we were able to identify nerves in the glandular stroma of all the glands examined with the exception of goblet cells. Intraepithelial single axons were only seen in the parenchyma of Wolfring glands. The morphological findings corresponded with the immunological finding of VIP-positive, nerve-like structures in the same locations, with the exception of lanugo hair follicle glands, and goblet cells. Our findings indicate that the glands of the eyelids and main lacrimal gland represent a functional unit with VIP as a possible common stimulating factor.

Fixation monitoring during radiation therapy for subfoveal neovascularization.

PURPOSE: The aim of the study was to determine movement of the fovea during each irradiation session by monitoring movement of the cornea. Knowing the extent of foveal deviation permits minimization of the field size. METHODS: (1) Eye movement was monitored in 10 patients during irradiation. A TV camera with an attached fixation light was installed 3 cm away from the cornea of the treated eye. The fixation light was positioned at a 10 degrees angle to the TV camera on the opposite side of the gantry, resulting in a 90 degrees angle between the optical axis of the eye and the irradiation beam. (2) The relationship between movement of the anterior and posterior eye segments of 10 volunteers was examined using a scanning laser ophthalmoscope (SLO). Volunteers were asked to fix their gaze on positioning lights installed in the SLO. Gaze movements of the anterior and posterior eye segments were recorded simultaneously. RESULTS: (1) The patients' ability to retain fixation differed interindividually. The median corneal deviation during 10 irradiation sessions was 1 mm mediolaterally and 0.7 mm craniocaudally. (2) Deviation of the fovea could be determined by monitoring deviation of the cornea. Measured by SLO, the correlation between movements of the anterior and posterior eye segments was 1:0.9 horizontally and 1:1.5 vertically. CONCLUSION: (1) Irradiation field size can be reduced, depending on the patient's fixation stability. (2) If monitoring reveals a foveal deviation beyond the 95% isodose, irradiation can be interrupted.

Effects of perfluorooctylbromide and vitamin E on ischemia induced retinal oxidative tissue damage.

The aim of this study was to investigate the extent to which ischemia and reperfusion lead to oxidative damage of the retinal tissue and investigate how ischemic and reperfused retinal tissues react to the application of perfluorooctylbromide (PFOB) and, if this reaction can be influenced by protective drugs such as vitamin E (Vit.E). The experiments were performed with 60 male Wistar rats, divided into 12 groups using an established model of reversible ischemia and reperfusion of the globe. Grouping of animals was carried out according to different ischemia and reperfusion periods and different therapeutic regimens (PFOB, Vit.E). Treatment with PFOB and/or Vit.E was performed after 60 min of ischemia with 60 min of reperfusion. At the end of the experiments thiobarbituric acid reactive substances (TBARS) were determined in the retinal tissues and served as parameters of oxidative tissue damage. Ischemia of up to 60 min led to a significant increase in TBARS values. Ninety and 120 min of ischemia led to no further significant elevation compared to the 60 min or 90 min group. Following 60 min of ischemia, a reperfusion period of 15 min led to an increase in TBARS values that was significant (P<0.05) after 30 and 60 min. Addition of PFOB resulted in a further significant (P<0.05) increase in TBARS values as compared to the respective group without treatment. Vit. E alone did not change the values significantly compared to the respective group without treatment. However, the application of Vit.E in addition to PFOB led to a significant reduction in TBARS values. Ischemia resulted in severe oxidative retinal tissue damage, which increased during reperfusion. The reperfusion damage might be due to the known depletion of protecting substances such as vitamin E. Enhancement of oxygen supply by PFOB during reperfusion without any tissue protection leads to more severe damage. Thus, additional protection of the tissue by powerful antioxidants is necessary when providing oxygen for better tissue recovery.

Effects of different perfluorochemicals on dorsal root ganglion cells in vitro.

BACKGROUND: Investigation of the effects of different perfluorochemicals (PFC) on cultured dorsal root ganglion (DRG) cells. METHOD: DRG cell cultures from 9- to 11-day-old chicken embryos were exposed to emulsified perfluorodecalin (PFD; C10F18; 0.5%, 1% and 10%) or perfluorooctylbromide (PFO; C8F17Br; 0.5%, 1% and 10%). The cells were evaluated under phase-contrast optics after 30 h and 120 h for 0.5 and 1% and after 5 h for 10%. To study the integrity of neuronal cells, immunohistochemical labelling for neurofilaments (NF) and tubulin (TUB) was performed. RESULTS: Concentrations of 0.5% and 1% of PFD or PFO did not change immunohistochemical labelling of DRG cells. Co-cultured macrophages showed a foam cell response, presumably representing ingested PFC. At both concentrations PFD induced a weaker foam cell response than PFO. A concentration of 10% led to the death of DRG cells and macrophages within 5 h. CONCLUSION: PFC caused a dose-dependent damage of neuronal cells. Co-cultured macrophages developed a foam cell response similar to that observed in vivo after prolonged presence of PFC in the vitreous body. These observations indicate that PFD and PFO may not be suitable for long-term vitreous replacement in vitreoretinal surgery. However, the model is limited by several factors: (1) there are physiological differences between DRG cells and retinal ganglion cells; (2) in vivo retinal ganglion cells are protected by the overlying tissues; (3) the PFC used in tissue culture must be emulsified.

Distribution pattern of nervous tissue and peptidergic nerve fibers in accessory lacrimal glands.

PURPOSE: Demonstration of the distribution pattern of nervous tissue and the occurrence of neuropept human accessory lacrimal glands by means of immunohistochemical methods. METHODS: Paraffin sections of tissue samples were incubated with antisera against protein gene product (PGP), S-100 protein (S-100), calcitonin gene-related peptide (CGRP) and substance P (SP). The immunoreactions were visualized using both species-specific secondary antibodies and a streptavidin-biotin-peroxidase complex (ABC method). RESULTS: PGP- and S-100-immunoreactive nerve fibers were distributed in the entire intertubular stroma. In addition, myoepithelial cells, a few clusters of tubulus cells, groups of wandering cells, and scattered cells of the excretory duct system were S-100-immunoreactive. CGRP- and SP-immunoreactivity was found in a few nerve fibers in the intertubular glandular stroma with an association to secretory tubules, blood vessels, intralobular ducts and excretory duct. CONCLUSIONS: These observations are in agreement with findings in the main lacrimal gland.

Immunomodulating activity of allopurinol in experimental lens-induced uveitis.

PURPOSE: The aim of this study was to evaluate the immunomodulating activity of allopurinol using a model of lens-induced uveitis (LIU) and to compare these effects to those of steroids. METHODS: We tested the sera of both LIU and control rats against western blots (WB) of SDS-PAGE separations of protein fractions from normal and LIU rat lenses. These blots were scanned using digital image analysis. A newly developed technique was used to compare the complex autoantibody (AAB) repertoires. Five groups of LIU rats were investigated: no treatment; single doses of methylprednisolone (MPR; 7.5 mg/kg body wt.i.v.); allopurinol (AL; 50 mg/kg body wt. i.v.); a combination of both drugs (AL and MPR); repeated application of AL (ALFR; 50 mg/kg body wt.i.v. every 2 weeks during the immunization period and a daily dose of approx. 25 mg/kg body wt. orally). RESULTS: Immunization induced complex antibody repertoires against lens proteins. Antibody repertoires of LIU rats were identical, regardless of whether the proteins were obtained from control, uveitis eyes, or corresponding healthy eyes of the same individual. AL showed a dose-dependent immunological effect in LIU treatment. Given as a single dose, AL revealed no significant change in the AAB repertoire; however, ALFR showed very clear modification of the AAB repertoires compared to both controls and rats receiving steroids. CONCLUSIONS: These results suggest dose-dependent effects of allopurinol in LIU treatment. Repeated application during the immunization period induced a strong immunomodulating effect of AL that was not observed after single doses.