Starvation insult induces the translocation of high mobility group box 1 to cytosolic compartments in glioma.

High mobility group box 1 (HMGB1) is a highly conserved and ubiquitous nuclear protein in eukaryotic cells. In response to stress, it transfers from the nucleus to the cytoplasm and finally, to the extracellular matrix, participating in inflammation and carcinogenesis. Increased HMGB1 protein levels are frequently associated with the reduced survival of patients with glioma. HMGB1 plays contextual roles depending on its subcellular localization. However, the mechanisms underlying its subcellular localization and secretion remain unclear. In the present study, the subcellular localization and secretion of HMGB1 in starved glioma cells were investigated using immunofluorescence microscopy, enzyme­linked immunosorbent assay, subcellular fractionation, western blotting and immunoelectron microscopy. The results demonstrated that starvation induced HMGB1 translocation from the nucleus to the cytoplasm and finally, to the extracellular milieu in glioma cells. HMGB1 was localized in the mitochondria, endoplasmic reticulum (ER), peroxisomes, autophagosomes, lysosomes, endosomes and the cytoskeleton. Immunoelectron microscopy confirmed that HMGB1 was present within or around cytosolic compartments. Subcellular fractionation further demonstrated that HMGB1 transferred to membrane­bound compartments. In addition, HMGB1 was localized to specific contact areas between the ER and mitochondria, known as mitochondria­associated membranes. On the whole, the results of the present study suggest that starvation induces HMGB1 secretion, which can be inhibited through the suppression of autophagy. Starvation insult induces HMGB1 translocation to the cytosolic compartments of glioma cells, and autophagy may be involved in the extracellular secretion of HMGB1 in starved glioma cells.

Neuronal p58IPK Protects Retinal Ganglion Cells Independently of Macrophage/Microglia Activation in Ocular Hypertension.

p58IPK is a multifaceted endoplasmic reticulum (ER) chaperone and a regulator of eIF2α kinases involved in a wide range of cellular processes including protein synthesis, ER stress response, and macrophage-mediated inflammation. Systemic deletion of p58IPK leads to age-related loss of retinal ganglion cells (RGC) and exacerbates RGC damage induced by ischemia/reperfusion and increased intraocular pressure (IOP), suggesting a protective role of p58IPK in the retina. However, the mechanisms remain elusive. Herein, we investigated the cellular mechanisms underlying the neuroprotection action of p58IPK using conditional knockout (cKO) mouse lines where p58IPK is deleted in retinal neurons (Chx10-p58IPK cKO) or in myeloid cells (Lyz2-p58IPK cKO). In addition, we overexpressed p58IPK by adeno-associated virus (AAV) in the retina to examine the effect of p58IPK on RGC survival after ocular hypertension (OHT) in wild type (WT) mice. Our results show that overexpression of p58IPK by AAV significantly improved RGC survival after OHT in WT mice, suggesting a protective effect of p58IPK on reducing RGC injury. Conditional knockout of p58IPK in retinal neurons or in myeloid cells did not alter retinal structure or cellular composition. However, a significant reduction in the b wave of light-adapted electroretinogram (ERG) was observed in Chx10-p58IPK cKO mice. Deletion of p58IPK in retinal neurons exacerbates RGC loss at 14 days after OHT. In contrast, deficiency of p58IPK in myeloid cells increased the microglia/macrophage activation but had no effect on RGC loss. We conclude that deletion of p58IPK in macrophages increases their activation, but does not influence RGC survival. These results suggest that the neuroprotective action of p58IPK is mediated by its expression in retinal neurons, but not in macrophages. Therefore, targeting p58IPK specifically in retinal neurons is a promising approach for the treatment of neurodegenerative retinal diseases including glaucoma.

Macular Morphology in Patients With Diabetic Retinopathy Treated by ILM Peeling: A Propensity Score-Matched Analysis.

BACKGROUND AND OBJECTIVE: To analyze the effects of vitrectomy combined with internal limiting membrane (ILM) peeling in patients with diabetic retinopathy (DR) by propensity score-matched analysis. PATIENTS AND METHODS: Patients with proliferative DR that underwent pars plana vitrectomy were divided into two groups: without or with additional ILM peeling. Propensity score-matched analyses of variables were carried out. Optical coherence tomography (OCT) was conducted at the 6-month follow-up. The primary outcome measures were epiretinal membrane (ERM), intraretinal cystic changes, recurrent macular edema, and blurring of the inner segment/outer segment (IS/OS) margin. RESULTS: There were 41 patients in Group 1 (non-ILM peeling) and 41 patients in Group 2 (ILM peeling). ERM was observed in 11 of 41 eyes (26.8%) in Group 1, and three of 41 eyes (7%) in Group 2 at the 6-month follow-up (P = .019). Intraretinal cystoid changes were observed in 13 eyes of Group 1 and four eyes of Group 2 (P = .014). The median central macular thickness was 250.00 ± 135.09 µm in Group 1 and 235.00 ± 101.55 µm in Group 2 (P = .738). Macular edema was observed in 24 eyes (58.5%) in Group 1 and 19 eyes (46.3%) in Group 2 (P = 0.269). There was no significant difference in foveal dip angle between the groups (P = .820). The IS/OS margin was disrupted in 48.8% and 56.1% of eyes in Groups 1 and 2, respectively, without significant difference. There was also no significant difference in best-corrected visual acuity (BCVA) between two groups before surgery, and there was no significant difference in BCVA between two groups at 6 months after surgery (P = .13). CONCLUSION: The authors' results indicate that vitrectomy combined with ILM peeling can minimize ERM formation and eliminate intraretinal cystoid changes, but the functional recovery is limited. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:420-425.].

Glioma cells are resistant to inflammation­induced alterations of mitochondrial dynamics.

Accumulating evidence suggests that inflammation is present in solid tumors. However, it is poorly understood whether inflammation exists in glioma and how it affects the metabolic signature of glioma. By analyzing immunohistochemical data and gene expression data downloaded from bioinformatic datasets, the present study revealed an accumulation of inflammatory cells in glioma, activation of microglia, upregulation of proinflammatory factors (including IL­6, IL­8, hypoxia­inducible factor­1α, STAT3, NF­κB1 and NF­κB2), destruction of mitochondrial structure and altered expression levels of electron transfer chain complexes and metabolic enzymes. By monitoring glioma cells following proinflammatory stimulation, the current study observed a remodeling of their mitochondrial network via mitochondrial fission. More than half of the mitochondria presented ring­shaped or spherical morphologies. Transmission electron microscopic analyses revealed mitochondrial swelling with partial or total cristolysis. Furthermore, proinflammatory stimuli resulted in increased generation of reactive oxygen species, decreased mitochondrial membrane potential and reprogrammed metabolism. The defective mitochondria were not eliminated via mitophagy. However, cell viability was not affected, and apoptosis was decreased in glioma cells after proinflammatory stimuli. Overall, the present findings suggested that inflammation may be present in glioma and that glioma cells may be resistant to inflammation­induced mitochondrial dysfunction.

Real-time segmentation and tracking of excised corneal contour by deep neural networks for DALK surgical navigation.

OBJECTIVE: Corneal disease is one of the main causes of blindness for humans globally nowadays, and deep anterior lamellar keratoplasty (DALK) is a widely applied technique for corneal transplantation. However, the position of stitch points highly influences the success rate of such surgery, which would require accurate control and manipulation of surgical instruments. METHODS: In this paper, we present a deep learning framework for augmented reality (AR) based surgery navigation to guide the suturing in DALK. It can robustly track the excised corneal contour by semantic segmentation and the reconstruction of occlusion. We propose a novel optical flow inpainting network to recover the missing motion caused by occlusion. The occluded regions are detected by weakly supervised segmentation of surgical instruments and reconstructed by key frame warping along the completed optical flow. Then we introduce two types of loss function to adapt the inpainting network in the optical flow space. RESULTS: Our techniques are tested and evaluated by a number of real surgery videos from Shandong Eye Hospital in China. We compare our approaches with other typical methods in the corneal contour segmentation, optical flow inpainting and occlusion regions reconstruction. The tracking accuracy reachs 99.2% in average and PSNR reaches 25.52 for the reconstruction of the occluded frames. CONCLUSION: From the experimental evaluations and user study, both the qualitative and quantitative results indicate that our techniques can achieve accurate detection and tracking of corneal contour under complex disturbance in real-time surgical scenes. Our prototype AR navigation system would be highly useful in clinical practice.

Downregulation of reelin predicts poor prognosis for glioma.

Aim: In the present study, we studied the relationship between RELN and prognosis in glioma. Materials & methods: Expression profiles and methylation data of RELN were obtained from bioinformatic datasets. Correlations between RELN and clinicopathological features and overall survival were respectively assessed using chi-square test and Kaplan-Meier analysis. Results:RELN was downregulated in glioma, and its downregulation correlated well with glioma malignancy and overall survival. Meanwhile, hypermethylation of RELN was significantly correlated with low RELN expression. Additionally, gene set enrichment analysis demonstrated that low expression of RELN correlated with many key cancer pathways, possibly highlighting the importance of RELN in carcinogenesis of brain. Conclusion:RELN may serve as a potential prognostic marker and promising target molecule for new therapy of glioma.

The association between high mobility group box 1 chromatin protein and mitotic chromosomes in glioma cells.

High mobility group box 1 (HMGB1) is an abundant non-histone nuclear protein that functions as a structural protein of chromatin, regulating genome replication and recombination, mRNA transcription and DNA repair. HMGB1 has been implicated in the tumorigenesis of various cancer types, and the upregulation of HMGB1 has been demonstrated in glioma cells. However, the association between HMGB1 and the mitotic chromosomes in glioma remains uncharacterized. In the present study, the sub-cellular localization of HMGB1 in glioma tissues and cells was investigated. In addition, enhanced green fluorescent protein (EGFP)-tagging of the human HMGB1 protein and chromosome spreading were used to investigate the combination of HMGB1 with mitotic chromosomes. The results of the current study indicated that HMGB1 was localized to the nucleus and the cytoplasm, and it was determined to combine with the condensed chromosomes of proliferating cells in paraformaldehyde (PFA)-fixed glioma tissues. However, HMGB1 was also associated with interphase (but not mitotic chromosomes) when fixed with chilled methanol and 5% (v/v) acetic acid or PFA in vitro. Data from live cell imaging and chromosome spreading indicated the association of HMGB1 with mitotic chromosomes in glioma cells. The present results suggest that HMGB1 combines with mitotic chromosomes in glioma cells, and that the use of fixatives may result in the dissociation of the HMGB1-DNA interaction. Therefore, in live specimens and chromosome spreads, EGFP fusion proteins may represent an accurate indicator for the determination of the correct localization and interaction of HMGB1 in glioma cells.

SURGICAL OUTCOMES OF 25-GAUGE PARS PLANA VITRECTOMY USING AIR AS AN INTERNAL TAMPONADE FOR PRIMARY RHEGMATOGENOUS RETINAL DETACHMENT.

PURPOSE: To report surgical outcomes of 25-gauge pars plana vitrectomy using air as an internal tamponade for patients with primary rhegmatogenous retinal detachment (RRD). METHODS: A retrospective clinical study of 59 eyes of 59 consecutive patients presented with primary RRD at the Beijing Tongren Eye Center in China. From August 2016 to May 2018, medical records of the patients who underwent 25-gauge pars plana vitrectomy with air tamponade for RRD were reviewed. The main outcome measures were primary and final anatomical success (retinal re-attachment) rates, and postoperative complications. RESULTS: Of the 59 patients, aged 54.47 ± 11.81 years, 31 (52.5%) were men. Vitrectomy was performed 3 to 40 (averaged 16.98 ± 10.17) days after the onset of symptoms, and the mean follow-up period was 12.90 ± 5.92 months (ranging 6.07-26.10 months). Forty-two eyes (71.2%) had RRD with retinal breaks in the superior half of the retina, and the mean number of retinal breaks was 1.75 ± 0.94. Three eyes (5.1%) had RRD with giant retinal tears. Of the 59 eyes, 35 (59.3%) had RRD with inferior quadrants involved. Proliferative vitreoretinopathy (PVR) gradings were C1 in 2 (3.4%) eyes and B or below in 57 (96.6%) eyes. The primary and final anatomical success rates were 94.9% (56/59) and 98.3% (58/59), respectively. Of the three eyes which developed re-detachment of the retina, one eye had postoperative progression of PVR and two eyes were RRD associated with macular hole in high myopia. Postoperative complications included 5 eyes (8.5%) with serous choroidal detachment within 3 days after surgery and 4 eyes (6.8%) with macular epiretinal membrane formation 1 to 8 months after surgery. Secondary cataract surgery was performed in 13 of the 53 phakic eyes (24.5%) during follow-up. CONCLUSION: Small-gauge pars plana vitrectomy with air tamponade may be effective in treating selected cases of relatively simple primary RRD. Additional studies are needed to verify the efficacy of this surgical approach for more complicated cases such as those with giant retinal tears.

Risk Factors of Recurrent Retinal Detachment Following Surgical Treatment for Rhegmatogenous Retinal Detachment: A Retrospective Study.

OBJECTIVE: To identify potential risk factors for recurrent retinal detachment after surgical treatment for rhegmatogenous retinal detachment with choroidal detachment (RRD-CD) in a Chinese population. METHODS: A total of 1212 patients with RRD-CD admitted to Beijing Tongren Hospital from 2004 to 2018 were reviewed retrospectively. The rate of recurrent retinal detachment was calculated, and risk factors were analyzed by logistic regression analysis. RESULTS: The average age of the patients was 48.51 years, 760 patients (62.7%) were male, and 630 patients (52.0%) had right eye disease. The recurrence rate in the same eye was 21.3%. The incidence of recurrence retinal detachment was higher in patients who were male, middle age, and with poor preoperative vision, longer axial length, and scleral buckling. Recurrence usually occurred 3 months after surgery. CONCLUSION: Male, middle age, longer axial length, and scleral buckling could be risk factors for recurrent retinal detachment following surgical treatment in patients with RRD-CD.

Overexpression of high mobility group box 1 (HMGB1) has no correlation with the prognosis in glioma.

Aim: We aimed to characterize the role of HMGB1 overexpression in glioma and to evaluate its use as a biomarker. Materials & methods: We used the gene expression datasets and tissue microarray to assess the expression levels of HMGB1 among gliomas of all grades; We then assessed its correlation with the malignancy and outcome of glioma. Results: The increase in HMGB1 mRNA and protein levels was found in glioma, but there was no correlation between HMGB1 expression and glioma malignancy, and overall survival and vital status of glioma patients. Conclusion: Overexpression of HMGB1 is not associated with the malignancy and outcome in glioma. And it is not the valuable biomarker for the early diagnosis of glioma.

Idiopathic Hypertrophic Pachymeningitis Mimicking Meningioma with Occlusion of Superior Sagittal Sinus: Case Report and Review of Literature.

BACKGROUND: Idiopathic hypertrophic pachymeningitis is a rare inflammatory condition with diffuse thickening of the dura mater, which may cause a compressive effect or vascular compromise. CASE DESCRIPTION: A 40-year-old Chinese man presented with persistent headache for 6 months and a sudden epileptic seizure 2 days ago. Magnetic resonance imaging demonstrated a large (71 × 34 × 27 mm) extra-axial mass at the right frontal convexity with severe edema mimicking meningioma. The lesion and peripheral dura mater showed contrast enhancement. Additionally, the skull near the lesion was eroded. Meningioma was diagnosed, and the patient underwent surgery. During the operation, we found the lesion texture was very tough, and the superior sagittal sinus was occluded. Histopathologic findings revealed a large number of infiltrated lymphocytes with fibrosis and microabscess formation; intracranial idiopathic hypertrophic pachymeningitis was diagnosed. Follow-up magnetic resonance imaging performed 3 months after surgery demonstrated the enhancement was notably alleviated. CONCLUSIONS: Idiopathic hypertrophic pachymeningitis should be part of the differential diagnosis of some cases of meningioma.

LncRNA SNHG20 knockdown suppresses the osteosarcoma tumorigenesis through the mitochondrial apoptosis pathway by miR-139/RUNX2 axis.

Increasing evidence has indicated the important roles of long noncoding RNAs (lncRNAs) in human osteosarcoma tumorigenesis. In present study, we aim to investigate the roles of lncRNA SNHG20 (small nucleolar RNA host gene 20) in osteosarcoma tumorigenesis and explore the in-depth molecular mechanism. Results showed that lncRNA SNHG20 expression was up-regulated in osteosarcoma samples and its high-expression indicated the poor prognosis. Loss-of-functional experiments indicated that SNHG20 knockdown inhibited the proliferation, invasion and induced the apoptosis of osteosarcoma cells in vitro. Specifically, SNHG20 knockdown up-regulated the expression levels of caspase-9, caspase-3 and Bax, indicating that SNHG20 knockdown accelerated the apoptosis of osteosarcoma cells via mitochondrial apoptosis pathway. Bioinformatics analysis revealed that miR-139 both targeted with the 3'-UTR of runt-related transcription factor 2 (RUNX2) and SNHG20, which was verified by luciferase reporter assay and RNA immunoprecipitation (RIP). In conclusion, our data reveals that lncRNA SNHG20/miR-139/RUNX2 axis modulates the osteosarcoma tumorigenesis and apoptosis via mitochondrial apoptosis pathway, providing a novel insight for the pathophysiological process.

Surface-modified PLGA nanoparticles with chitosan for oral delivery of tolbutamide.

The main purpose of present study was to develop novel chitosan-modified polylactic-co-glycolicacid nanoparticles (CS@PLGA NPs) for improving the bio-availability of tolbutamide (TOL). The TOL-loaded CS@PLGA NPs (TOL-CS@PLGA NPs) were fabricated with the solvent evaporation method. The cargo-free CS@PLGA NPs showed a diameter of 228.3±2.5nm monitored with a laser light particlesizer, and the transmission electron microscope (TEM) photographs revealed their "core-shell" structures. The Zeta potential of the original PLGA NPs and the cargo-free CS@PLGA NPs was measured to be -20.2±3.21mV and 24.2±1.1mV, respectively. The changes in Zeta potential indicated the CS chains were coated on the surfaces of the original PLGA NPs. The thermal gravity analysis (TGA) curves suggested that the CS chains improved the thermostability of the original PLGA NPs. The results of cells viability indicated the cargo-free CS@PLGA NPs were nontoxicity. The in vitro release profiles suggested that TOL-CS@PLGA NPs could release TOL in pH 7.4 phosphate buffer solution (PBS) at a sustained manner. Streptozotocin (STZ) was employed to build the diabetic rat models. The physiological changes in the islet ß cells confirmed the obtaining of diabetic rats. After treatment by gavage, the TOL-CS@PLGA NPs showed an excellent hypoglycemic effect. Therefore, the TOL-CS@PLGA NPs had a potential application in oral delivery of TOL.

A common variant mapping to CACNA1A is associated with susceptibility to exfoliation syndrome.

Exfoliation syndrome (XFS) is the most common recognizable cause of open-angle glaucoma worldwide. To better understand the etiology of XFS, we conducted a genome-wide association study (GWAS) of 1,484 cases and 1,188 controls from Japan and followed up the most significant findings in a further 6,901 cases and 20,727 controls from 17 countries across 6 continents. We discovered a genome-wide significant association between a new locus (CACNA1A rs4926244) and increased susceptibility to XFS (odds ratio (OR) = 1.16, P = 3.36 × 10(-11)). Although we also confirmed overwhelming association at the LOXL1 locus, the key SNP marker (LOXL1 rs4886776) demonstrated allelic reversal depending on the ancestry group (Japanese: OR(A allele) = 9.87, P = 2.13 × 10(-217); non-Japanese: OR(A allele) = 0.49, P = 2.35 × 10(-31)). Our findings represent the first genetic locus outside of LOXL1 surpassing genome-wide significance for XFS and provide insight into the biology and pathogenesis of the disease.

Expression and tissue localization of renalase, a novel soluble FAD-dependent protein, in reproductive/steroidogenic systems.

Renalase was initially identified in human kidney as a soluble monoamine oxidase. Here we show that renalase is predominantly expressed in reproductive/steroidogenic systems, with particularly substantial expression in oocytes, granulosa, interstitial and luteal cells of ovary, spermatogenic cells of testis, and cortex of adrenal gland, suggesting its function(s) in maturation of germ cells and steroid hormone regulation. Renalase expression increases in testes and ovaries as mice develop and its expression is further enhanced in the ovaries of pregnant mice, indicating an activity of renalase in reproduction. Gonadotropin-releasing hormone (GnRH) antagonist, cetrorelix, repressed renalase expression in mice ovaries and testes, suggesting that steroids regulate renalase expression. Leptin is an effector and modulator of steroid hormones and reproduction. Surprisingly, knockout of leptin causes a dramatic increase of renalase expression in mice testes. Taken together, our results suggest that reproductive/steroidogenic systems are also the sources for renalase secretion and renalase may play a critical role in reproduction and hormone regulation. This provides a novel insight into understanding the function of renalase.

Early Blockade of TLRs MyD88-Dependent Pathway May Reduce Secondary Spinal Cord Injury in the Rats.

To determine the role of toll-like receptors (TLRs) myeloid differentiation factor 88 (MyD88) dependent pathway in the spinal cord secondary injury, compression injury was made at T8 segment of the spinal cord in adult male Sprague-Dawley rats. Shown by RT-PCR, TLR4 mRNA in the spinal cord was quickly elevated after compression injury. Intramedullary injection of MyD88 inhibitory peptide (MIP) resulted in significant improvement in locomotor function recovery at various time points after surgery. Meanwhile, injury area, p38 phosphorylation, and proinflammation cytokines in the injured spinal cord were significantly reduced in MIP-treated animals, compared with control peptide (CP) group. These data suggest that TLRs MyD88-dependent pathway may play an important role in the development of secondary spinal cord injury, and inhibition of this pathway at early time after primary injury could effectively protect cells from inflammation and apoptosis and therefore improve the functional recovery.

Correction of the disease phenotype of myocilin-causing glaucoma by a natural osmolyte.

PURPOSE: To characterize a novel Asp384Asn (D384N) mutant myocilin (MYOC) that causes juvenile-onset open-angle glaucoma (JOAG) and investigate the correction of mutant phenotype by a natural osmolyte, trimethylamine N-oxide (TMAO). METHODS: A Chinese JOAG family was recruited and genomic DNA was extracted from peripheral blood obtained from 44 family members. Coding regions of the MYOC were sequenced. Two hundred individuals (>60 years old) without ocular hypertension or glaucoma were the control subjects. Full-length human wild-type MYOC cDNA was cloned in p3xFLAG-myc-CMV-25 and missense mutation was introduced by site-directed mutagenesis. Transfected human trabecular meshwork cells were treated with small-molecule chemical chaperones. Secreted MYOC was analyzed by combined immunoprecipitation-Western blot analysis. Intracellular myocilin was fractionated into Triton X-100-soluble and insoluble fractions, and analyzed by Western blot analysis. Intracellular aggregate and apoptosis were assayed by immunofluorescence. The effect of TMAO on subcellular myocilin distribution was analyzed by density gradient fractionation, followed by Western blot analysis. RESULTS: A novel c.1150G>A change of MYOC was identified. Screening of optineurin, WDR36, and CYP1B1 showed an absence of disease-causing polymorphisms. Mutated D384N myocilin had reduced solubility and was aggregation-prone and nonsecreted. Treatment of transfected cells with TMAO improved the solubility of the D384N mutant, which was corrected for secretion in a dose-response manner. TMAO reduced the distribution of the D384N mutant in the endoplasmic reticulum (ER), alleviated ER stress, and rescued cells from apoptosis. CONCLUSIONS: The results indicate that TMAO, with chaperoning activity, facilitated the folding and secretion of mutant MYOC. This therapeutic approach assisted by a chemical chaperone can be developed for treating glaucoma.

[Photodynamic therapy of pigmented choroidal melanomas in rabbits using hematoporphyrin monomethyl ether].

OBJECTIVE: The purpose is to determine the effectiveness of photodynamic therapy of experimental choroidal melanoma in rabbits using hematoporphyrin monomethyl ether (HMME). METHODS: Pigmented choroidal melanomas were established in 46 New Zealand albino rabbit eyes. The animals were treated with daily injection of cyclosporine A. The tumors were followed up with funduscopic examination and ultrasonography until they were 1.5 to 4.6 mm in height. Then the rabbits were divided randomly into two groups. In the treatment group, 41 rabbits were injected intravenously with hematoporphyrin monomethyl ether (HMME, 10 mg/kg). 3 hours later, the tumors were irradiated at 630 nm through an He-Ne laser at estimated total light doses of 60 approximately 150 J/cm(2). Control animals (5 rabbit eyes) were treated with light only (2 rabbit eyes), photosensitizer only (2 rabbit eyes), or observation only (1 rabbit eyes). Each animal then was followed up for 4 to 5 weeks with indirect ophthalmoscopy, ultrasonography, and fundus photography (16 rabbit eyes among the treatment group were extirpated for pathologic examination 24 hours or 1 week after the treatment). In the end, all the rabbits were sacrificed and the pathologic examinations were performed. RESULTS: With the fluences of >or= 70 J/cm(2), all the tumors regressed evidently. With the fluence of 60 J/cm(2), not all the animals showed complete tumor arrest. In the control group, all the tumors showed continuous growth and filled most of the vitreous cavity in 2 to 3 weeks. CONCLUSION: The photodynamic therapy with homemade photosensitizer HMME may have a role in the treatment of pigmented choroidal melanomas.