Investigation of scleral thermal injuries caused by ultrasonic pars plana phacoemulsification and aspiration using pig eyes.

PURPOSE: The purpose of this study was to investigate the thermal injuries caused by ultrasonic pars plana phacoemulsification and aspiration (PPPEA) using pig eyes. METHOD: Using a 20-gauge (G) vitrectomy system (Accurus®, Fragmatome; Alcon Laboratories) in both the 'open-tip' and 'closed-tip' techniques, PPPEA was performed in pig eyes and the subsequent thermal injuries generated around the scleral wound were measured by infrared thermal imaging (thermography). Post surgery, the state of the scleral wound was observed under a microscope, and a tissue slice containing the scleral wound was then prepared and observed under an optical microscope. RESULTS: Thermography measurements revealed a slight temperature rise around the scleral wound in the open-tip case, yet a marked temperature rise in the closed-tip case. The scleral wound incision produced by the open tip was linear, while that produced by the closed tip was expanded. Histological examination revealed mild degeneration of the sclera around the wound in the open-tip case, yet marked tissue degeneration by thermal injuries in the closed-tip case. CONCLUSION: Our findings showed that in PPPEA, the temperature of the tip of a 20G vitrectomy system rapidly increases due to the closed-tip technique, thus producing obvious thermal damage to the scleral wound. In order to prevent thermal injuries to the scleral wound during PPPEA, it is important to shorten the time of ultrasonic oscillation during surgery as much as possible while the tip is occluded with nuclear fragments.

Immunohistochemical Detection of Propionibacterium acnes in the Retinal Granulomas in Patients with Ocular Sarcoidosis.

The etiology of sarcoidosis is still obscure; however, Mycobacteria and Propionibacterium acnes are considered the most implicated etiological agent for sarcoidosis. To investigate whether P. acnes is an etiological agent for sarcoid uveitis, we analyzed the frequency of P. acnes detected within the biopsied retinas from patients with ocular sarcoidosis by immunohistochemistry with a P. acnes-specific monoclonal antibody (PAB antibody). Eleven patients (12 eyes) with sarcoid uveitis were enrolled in this study. Eight patients with rhegmatogenous retinal detachment, two patients with non-sarcoid uveitis, and two patients with vitreoretinal lymphoma were enrolled as controls. In the sarcoidosis group, granulomas were mainly observed in the inner retinal layer filled with CD4+ cells and CD68+ cells, indicating the Th1 immune response. P. acnes, identified as round bodies that reacted with the PAB antibody, were present in 10/12 samples (83%) from 9/11 patients (82%) with sarcoidosis. These round bodies were scattered within the retinal granulomas mainly in the inner retinal layer. In the control group, no round bodies were detected. Our results suggested that P. acnes could be associated with sarcoid uveitis. We hypothesize that sarcoid granulomas may be formed by a Th1 immune response to P. acnes hematogenously transmitted to the retina.

The CD4/CD8 ratio in vitreous fluid is of high diagnostic value in sarcoidosis.

PURPOSE: Sarcoidosis is an idiopathic inflammatory disorder involving multiple organs, and ocular manifestation (represented by granulomatous uveitis) is one of the common features. A well-known immunologic feature in sarcoidosis is an increased CD4+ helper T-cell type 1 lymphocyte subset in bronchoalveolar lavage (BAL) fluid. The current study investigated the vitreous lymphocyte subsets of ocular sarcoidosis to elucidate the immunologic features of this disorder in the eye. DESIGN: Case-control study. PARTICIPANTS AND CONTROLS: Fifty-one eyes of 38 patients with ocular sarcoidosis, confirmed by international diagnostic criteria, were enrolled in this study. Twenty-seven eyes of 26 patients with other causes of uveitis were enrolled as nonsarcoid controls. METHODS: Evaluation of diagnostic tests for cell profiles of ocular sarcoidosis. Lymphocytes in the vitreous samples were analyzed by cytology, polymerase chain reaction, and flow cytometry. Peripheral blood was also obtained from each patient and analyzed in comparison with the vitreous samples. MAIN OUTCOME MEASURES: CD4/CD8 ratios of vitreal and peripheral T lymphocytes. RESULTS: CD4/CD8 ratios of the vitreous T lymphocytes were significantly higher in ocular sarcoidosis than in nonsarcoidosis vitreous samples. In the patients with ocular sarcoidosis, the CD4/CD8 ratios of vitreal T lymphocytes were significantly higher than the CD4/CD8 ratios of peripheral T lymphocytes. No significant differences were found between the CD4/CD8 ratios of vitreal and peripheral T lymphocytes in the patients without sarcoidosis. Moreover, the CD4/CD8 ratios of peripheral T lymphocytes in the patients with ocular sarcoidosis were significantly higher than in patients without sarcoidosis. The sensitivity and specificity of the vitreal CD4/CD8 ratio were 100% and 96.3%, respectively, for the diagnosis of ocular sarcoidosis. CONCLUSIONS: Our findings suggest that the CD4/CD8 ratio of vitreous-infiltrating lymphocytes has high diagnostic value in ocular sarcoidosis, comparable to that of the CD4/CD8 ratio in BAL fluid lymphocytosis for pulmonary sarcoidosis. Furthermore, a high CD4/CD8 ratio of peripheral blood T lymphocytes should be one of the laboratory findings for ocular sarcoidosis. Diagnostic vitrectomy using flow cytometric analysis may be a useful adjunct for the diagnosis of ocular sarcoidosis, particularly in complex cases.

[Active systemic steroid therapy employed in a case of bilateral frosted branch angiitis with acute chorioretinal circulatory insufficiency].

BACKGROUND: Steroid treatment is believed to be effective for frosted branch angiitis, but frosted branch angiitis with retinal circulatory insufficiency does not have a good prognosis by steroid treatment alone. Here, we present a case of a patient that had a good outcome when treated with long-term active systemic betamethasone and vasodilation therapy for bilateral frosted branch angiitis with acute chorioretinal circulatory insufficiency. CASE: A 69-year-old male presented with sudden visual loss in his left eye. The visual acuity was 1.0 in the right eye and 0.1 in the left eye. In his left eye, only mild inflammation occurred in the anterior chamber, but extensive inflammation such as sheathing of retinal vessels, retinal hemorrhage, and edema of the optic disc was present. Fluorescein angiography showed a delay of the arm-retinal artery circulation time and severe dye leakage from the retinal vessels. The following day, the visual acuity worsened to 0.1 in the right eye and hand motion in the left eye. Moreover, extensive inflammation was now present in both the anterior and posterior segments, and the sheathing of the retinal vessels developed to frosted branch-like angiitis. Doppler examination showed flow in the bilateral ophthalmic artery but did not show flow in the central retinal artery or posterior ciliary artery. These findings were compatible with the diagnosis of frosted branch angiitis with chorioretinal circulatory insufficiency. We initiated active systemic steroid therapy for 7 months and vasodilation therapy for 3 months. Two years later, the visual acuity improved to 0.5 in both eyes. CONCLUSION: Long-term active systemic steroid therapy for frosted branch angiitis with severe circulatory insufficiency in the retina and choroid may improve visual function.

Transforming growth factor beta(2) increases in subretinal fluid in rhegmatogenous retinal detachment with subretinal strands.

PURPOSE: To compare transforming growth factor (TGF) beta(2) levels in subretinal fluid of rhegmatogenous retinal detachment with or without subretinal strand formation. METHODS: We assessed total and mature TGF-beta(2) levels in subretinal fluid obtained from 24 eyes with rhegmatogenous retinal detachment using an enzyme-linked immunosorbent assay. Group I comprised 18 specimens from eyes without subretinal strands, while group II comprised 6 specimens from eyes with subretinal strands. RESULTS: Total and mature TGF-beta(2) levels were higher in group II than in group I (p=0.01 and p=0.07, respectively). CONCLUSION: The concentrations of total and mature TGF-beta(2) were higher in cases of rhegmatogenous retinal detachment associated with subretinal strand formation compared to those without subretinal strand formation.

A new non-trocar system for 25-gauge transconjunctival pars plana vitrectomy.

PURPOSE: To introduce a new non-trocar system for 25-gauge transconjunctival pars plana vitrectomy (PPV). DESIGN: Study of a new surgical instrument. METHODS: This new non-trocar system for 25-gauge transconjunctival PPV consists of a contact lens ring featuring four projections containing 1.0-mm diameter holes located 3.0 mm from the ring edge, a wedge-shaped 25-gauge infusion cannula, and two plugs. RESULTS: The ring is fixed with 7-0 silk sutures at the 3- and 9-o'clock positions on the limbus. Using the 25-gauge needle, three conjunctival and scleral incisions (n = 3) are made at the projection holes located inferotemporally, superonasally, and superotemporally. No intra- or postoperative complications were encountered in 14 patients treated by this non-trocar 25-gauge transconjunctival PPV. CONCLUSION: Using the system introduced here, 25-gauge transconjunctival PPV can be performed without suturing sclerotomies and without intra- or postoperative complications.

The presence of Propionibacterium spp. in the vitreous fluid of uveitis patients with sarcoidosis.

PURPOSE: An immunological reaction to a bacterial antigen, such as Mycobacterium tuberculosis or Propionibacterium spp., is suspected to be an initial mechanism in the disorder known as sarcoidosis. We investigated whether or not P. acnes, P. granulosum or M. tuberculosis are present in the vitreous fluid of eyes suffering from uveitis with sarcoidosis. METHODS: Using polymerase chain reaction, we analysed the presence of P. acnes, P. granulosum and/or M. tuberculosis DNA in vitreous samples taken from six eyes with sarcoidosis and six control eyes. RESULTS: Among the six uveitis eyes with sarcoidosis, we detected P. acnes DNA in two eyes, P. granulosum DNA in four eyes, and both P. acnes and P. granulosum DNA in one eye, but no Propionibacterium spp. in the control eyes. M. tuberculosis DNA was not present in any of the patient or control eyes. CONCLUSIONS: This is the first report indicating the presence of Propionibacterium spp. and/or its DNA in the vitreous fluid of sarcoidic eyes with uveitis. This, therefore, supports the idea that Propionibacterium spp. are involved in the aetiology of uveitis in sarcoidosis.

[Low power transpupillary thermotherapy of choroidal neovascularization].

PURPOSE: To assess the effectiveness of low power transpupillary thermotherapy (TTT) for choroidal neovascularization (CNV). METHOD: We performed TTT on 55 eyes of 55 patients with subretinal CNV between April 2001 and December 2002, and observed them after therapy for more than 6 months. The laser power ranged from 80 to 320 mW when the spot size was 3 mm. We evaluated visual acuity, subretinal fluid (SRF), and CNV size. RESULTS: Visual acuity improved by 2 lines or more in 16 eyes (29%), was unchanged in 19 eyes (35%), and decreased in 20 eyes (36%). SRF decreased in 30 eyes (54%), was unchanged in 13 eyes (24%), and increased in 12 eyes (22%). CNV diminished in 33 eyes (60%), was unchanged in 10 eyes (18%), and became enlarged in 12 eyes (22%). CONCLUSIONS: Low power TTT can be an effective treatment for subgroups of patients with subfoveal CNV.

Platelet aggregates in various stages of diabetic retinopathy: evaluation using the particle-counting light-scattering method.

AIMS: To investigate the possible correlation between platelet aggregation and the severity of diabetic retinopathy using the light-scattering method. METHODS: Using a light-scattering platelet aggregometer, we measured spontaneous platelet aggregation in 86 diabetics with retinopathy of varying severity and 30 healthy volunteers (controls). Platelet aggregates were classified as small, medium, and large according to their light intensity; patients were grouped based on the severity of retinopathy. In each patient group, we recorded for 10 min the total light intensities emitted by each aggregate size in the area under the curve (AUC). Then, we compared the AUC of each level of retinopathy severity with the controls and determined the correlation between the AUC of each aggregate size and each severity level. RESULTS: Of the 86 diabetics, 22 had no apparent retinopathy (NAR), 13 had mild nonproliferative diabetic retinopathy (NPDR), 17 had moderate NPDR, 12 had severe NPDR, and 22 had proliferative diabetic retinopathy (PDR). While the NAR group manifested significantly more small aggregates than the controls (20.5 x 10(6) versus 8.3 x 10(6) a.u., p=0.024), none of the other groups showed a significant increase in aggregates of any size. In the AUC of large aggregates, there was a weak-positive correlation with the severity of retinopathy (r=0.255, p=0.018); in the AUC of small and medium aggregates, there was no correlation. CONCLUSION: Although we did not find a significant correlation between platelet aggregation and the severity of diabetic retinopathy, our pilot study did detect some tendencies. Further studies on larger populations are underway to determine whether these tendencies are real.

Comparative effect of antiplatelet therapy in retinal vein occlusion evaluated by the particle-counting method using light scattering.

PURPOSE: To evaluate platelet aggregation in patients with retinal vein occlusion (RVO) by the light-scattering method and compare the effects of three antiplatelet drugs on aggregate formation. DESIGN: Prospective, nonrandomized, interventional clinical trial. METHODS: (1) Platelet aggregation was measured in 42 patients with untreated branch RVO (BRVO), 26 patients with central RVO (CRVO), and 30 healthy control subjects using a light-scattering platelet aggregometer. Platelet aggregates were classified as small, medium, and large according to light intensity. Total light intensities of each aggregate size were compared between BRVO, CRVO, and control subjects. (2) In 33 patients with RVO, platelet aggregation before and 2 weeks after the administration of ticlopidine, beraprost, or aspirin were compared. RESULTS: (1) There was a statistically significant difference (P = 0.0073) between the control subjects (8.3 x 10(6) a.u.) and CRVO patients (22.9 x 10(6) a.u.) with respect to small aggregates. There was no statistically significant difference with respect to medium and large aggregate formation between the control subjects and either patient group. (2) Compared with aggregates formed in the absence of antiplatelet drugs, ticlopidine significantly inhibited only the formation of small aggregates and beraprost that of all sizes; aspirin did not significantly inhibit the formation of any aggregate sizes. CONCLUSIONS: Increase in small platelet aggregates may be attributable to RVO pathogenesis. Beraprost and ticlopidine appear to inhibit small aggregate formation in RVO patients and may represent effective antiplatelet treatments. The light-scattering method is useful to investigate the pathogenesis of RVO and the effects of antiplatelet drugs.

Macular translocation with chorioscleral outfolding: 2-year results.

PURPOSE: To evaluate the results of macular translocation with radial chorioscleral outfolding in patients with subfoveal choroidal neovascularization (CNV) and to identify factors associated with decreased postoperative visual acuity. DESIGN: Retrospective interventional case series. METHODS: Twenty-seven consecutive patients with surgically treated subfoveal CNV were operated on and followed for more than 2 years. Macular translocation with radial chorioscleral outfolding was performed using titanium clips. Surgical outcomes including visual acuity, foveal displacement, surgically induced astigmatism, and complications were recorded. Factors associated with decreased visual acuity postoperatively were identified by multiple logistic regression analysis. RESULTS: Foveal displacement ranged from 349 to 3391 (median, 1576) microm. Surgically induced astigmatism ranged from 0 to 3.0 (median, 0.5) diopters. Visual acuity after surgery improved in 19 of the 27 patients (70.4%; median, 5 lines), but in 14, final vision ultimately decreased from the best postoperative level. Final visual acuity improved from the preoperative level in 11 patients (40.7%), remained unchanged in seven (25.9%), and decreased in nine (33.3%). In our series, the mean preoperative vision was 20/174, the best postoperative visual acuity was 20/74, and the mean final vision was 20/167. Factors associated with a decrease in postoperative visual acuity included the postoperative enlargement of CNV. CONCLUSION: Macular translocation with radial chorioscleral outfolding improved or stabilized the vision in 66.7% of patients with subfoveal CNV over the course of more than 2 years. Closing the CNV or preventing its further growth is required to maintain a better postoperative visual acuity.

Spontaneous remodelling of retinal veins accidentally severed during vitreous surgery.

BACKGROUND: To report the spontaneous remodelling of retinal veins inadvertently severed during vitreous surgery. METHODS: Four diabetic patients who underwent vitrectomy during which retinal veins were damaged were followed for at least 6 months. Haemorrhages from severed veins were controlled by raising intraocular pressure and by endodiathermy of the distal ends of the veins. This was followed by fluid/gas exchange. RESULTS: Remodelling of venous channels in the damaged areas was observed in all eyes. In three of the four eyes we found evidence of collateral veins. In the other eye we noted the connection of two ends of an interrupted vein. No signs of retinal vein occlusion (e.g. superficial retinal haemorrhages and retinal oedema) were observed. CONCLUSION: These findings suggest that a spontaneous remodelling mechanism to repair damaged venous channels may exist in retina.