Jost Hillenkamp

Light-Induced Decomposition of Indocyanine Green

PURPOSE To investigate the light-induced decomposition of indocyanine green (ICG) and to test the cytotoxicity of light-induced ICG decomposition products. METHODS ICG in solution was irradiated with laser light, solar light, or surgical endolight. The light-induced decomposition of ICG was analyzed by high-performance liquid chromatography (HPLC) and mass spectrometry. Porcine retinal pigment epithelial (RPE) cells were incubated with the light-induced decomposition products of ICG, and cell viability was measured by trypan blue exclusion assay. RESULTS Independent of the light source used, singlet oxygen (photodynamic type 2 reaction) is generated by ICG leading to dioxetanes by [2+2]-cycloaddition of singlet oxygen. These dioxetanes thermally decompose into several carbonyl compounds. The decomposition products were identified by mass spectrometry. The decomposition of ICG was inhibited by adding sodium azide, a quencher of singlet oxygen. Incubation with ICG decomposition products significantly reduced the viability of RPE cells in contrast to control cells. CONCLUSIONS ICG is decomposed by light within a self-sensitized photo oxidation. The decomposition products reduce the viability of RPE cells in vitro. The toxic effects of decomposed ICG should be further investigated under in vivo conditions.

Acute Retinal Necrosis: Clinical Features, Early Vitrectomy, and Outcomes

OBJECTIVE To determine the viral diagnosis and the outcome of eyes with acute retinal necrosis (ARN) treated with intravenous acyclovir and oral prednisolone alone or combined with early vitrectomy and intravitreal acyclovir lavage. DESIGN Nonrandomized, retrospective, interventional, comparative, consecutive series. PARTICIPANTS A cohort of 27 human immunodeficiency virus-negative patients with ARN comprising 24 unilateral and 3 bilateral cases. INTERVENTION Vitreous biopsy for viral diagnosis. Twenty eyes were treated with intravenous acyclovir in combination with oral prednisolone (group A). Ten eyes were treated additionally with early vitrectomy, intravitreal acyclovir lavage, laser demarcation of necrotic retinal areas when feasible-with or without scleral buckling, and gas or silicone oil tamponade (group B). Vitrectomy was performed in all cases of secondary rhegmatogenous retinal detachment (RD). MAIN OUTCOME MEASURES Results of vitreous biopsy, rate of RD, rate of phthisis bulbi, and course of best-corrected visual acuity (BCVA). RESULTS Varicella zoster virus (VZV) was detected in 26 eyes, followed by herpes simplex virus (5 eyes), and Epstein-Barr virus (2 eyes, in conjunction with VZV). An RD developed in more eyes in group A (18 of 20 eyes) than in group B (4 of 10 eyes; P = 0.007). In 2 of 20 eyes in group A and in 0 of 10 eyes in group B, phthisis bulbi developed without a significant difference between groups A and B. Mean BCVA (logarithm of the minimum angle of resolution) at first visit was 1.09 (standard deviation [SD], 0.83), and mean final BCVA was 1.46 (SD, 0.88) without significant difference between groups A and B. CONCLUSIONS Varicella zoster virus is the leading cause of ARN. Visual prognosis is guarded. Early vitrectomy with intravitreal acyclovir lavage was associated with a lower incidence of secondary RD; however, it did not improve mean final visual acuity.

Macular function and morphology after peeling of idiopathic epiretinal membrane with and without the assistance of indocyanine green

Aim: To investigate macular function and morphology after surgical removal of idiopathic epiretinal membrane (IEM) with and without assistance of indocyanine green (ICG). Methods: A retrospective study as a consecutive case series, of 39 patients with IEM. 39 patients, 23 female, 16 male, mean age 67 years, underwent standard three port pars plana vitrectomy with removal of epiretinal membrane. Two groups of patients were consecutively operated: in 20 patients ICG 0.1% in glucose 5% was used to stain the epiretinal membrane. 19 patients underwent the identical procedure but without use of ICG. Postoperative follow up was 1–92 months (mean 15.5 months). Functional outcome was assessed with subjective improvement, best corrected visual acuity (BCVA), Amsler grid test, 10° and 30° automated perimetry (Heidelberg visual field analyser) (HFA), and Goldmann kinetic perimetry. Macular morphology was assessed with stereoscopic biomicroscopy and optical coherence tomography (OCT). The main outcome measures were macular function as determined by BCVA, presence of visual field defects, and metamorphopsia as determined by Amsler grid test, macular morphology as determined by slit lamp biomicroscopy, and OCT. Results: BCVA improved in 28 patients, remained unchanged in eight patients, and decreased in three patients. Improvement of BCVA was statistically significant in both groups (p = 0.003). Mean BCVA in patients operated with ICG improved from 0.33 preoperatively to 0.53 postoperatively. Mean BCVA in patients operated without ICG improved from 0.32 preoperatively to 0.54 postoperatively. Reduction of macular oedema as measured by OCT was statistically significant in both groups (p<0.01). There was no statistically significant difference in postoperative BCVA, macular oedema as measured by OCT, postoperative Amsler grid test, and subjective improvement between the two groups. The incidence of residual or recurrent epiretinal membrane was greater in the group operated without ICG (p = 0.014). Visual field defects were detected in one patient operated with ICG and in three patients operated without ICG. Conclusions: Removal of epiretinal tissue with or without assistance of ICG improved visual function and reduced macular oedema in most patients. Adverse effects clearly attributable to the use of ICG were not observed but further investigation is warranted.

Subretinal coapplication of recombinant tissue plasminogen activator and bevacizumab for neovascular age-related macular degeneration with submacular haemorrhage

Aim: To evaluate the efficacy and safety of pars plana vitrectomy (ppV) with subretinal coapplication of recombinant tissue plasminogen activator (rtPA) and bevacizumab, and fluid–gas exchange for neovascular age-related macular degeneration (AMD) with submacular haemorrhage (SMH). Methods: Consecutive interventional case series of 12 patients with neovascular AMD with SMH with a maximum history of 14 days. All patients underwent ppV with subretinal coapplication of rtPA and bevacizumab, and fluid–gas (20% SF6) exchange. Phakic patients underwent concomitant cataract surgery. Additional injections of bevacizumab were applied intravitreally 4 and 8 weeks postop. Results: Complete displacement of SMH from the fovea was achieved in 9 of 12 patients. The mean best-corrected visual acuity (BCVA) improved significantly from preop logMAR 1.9 (range 3.0 to 0.7) to logMAR 1.2 (range 3.0 to 0.3) at 4 weeks postop (p = 0.01) and to logMAR 0.9 (range 1.6 to 0.2) at 12 weeks postop (p = 0.006). The mean improvement of BCVA 4 weeks postop as compared with preop was logMAR 0.7 (range −0.2 to 2.3). The mean improvement of BCVA 12 weeks postop as compared with preop was logMAR 0.96 (range −0.3 to 2.8). Overall, at 12 weeks postop, BCVA had improved in 10 patients, remained unchanged in one patient and worsened in one patient. Conclusion: PpV with subretinal coapplication of rtPA and bevacizumab, and fluid–gas exchange effectively displaces SMH and improves visual acuity in most patients.

Long-term outcome of subretinal coapplication of rtPA and bevacizumab followed by repeated intravitreal anti-VEGF injections for neovascular AMD with submacular haemorrhage

Aim To evaluate short-term and long-term outcomes of subretinal coapplication of recombinant tissue plasminogen activator (rtPA) and bevacizumab followed by intravitreal injections of bevacizumab or ranibizumab for neovascular age-related macular degeneration with submacular haemorrhage (SMH). Methods Retrospective, consecutive, interventional case series of 41 eyes of 40 patients. All patients underwent pars plana vitrectomy with subretinal coapplication of rtPA and bevacizumab and intravitreal gas tamponade. Postoperatively, repeated intravitreal injections of bevacizumab or ranibizumab were applied following a flexible, predominantly visual acuity-driven re-treatment regimen. Results Mean diameter of SMH was 4.5 disc diameters (range 1.5–12). Complete displacement of SMH was achieved in 35 of 41 eyes. Large and prominent SMH extending beyond the vascular arcades were completely displaced in six of eight eyes. SMH recurred in eight eyes after a mean of 9.1 months (2–19). A mean of 4.5 (2–9) intravitreal anti-vascular endothelial growth factor injections were applied during 12 months postoperatively. Short-term (3 months, n=41), mean best corrected logMAR visual acuity (BCVA) improved significantly from the preoperative value 1.7 (3.0–0.5) to 0.8 (1.6–0.2). 12 eyes had reading ability (≤logMAR 0.4) and 29 eyes had gained ambulatory visual acuity (≤logMAR 1.6). Long-term (mean 17 months (12–32), n=26) BCVA was 0.9 (1.6–0.1). Compared with short-term, BCVA had decreased in 12 of 26 eyes. Conclusion The operation effectively displaces small and large SMHs. In the long-term, a predominantly visual acuity-driven re-treatment regimen puts the initial functional improvement at risk. More sensitive re-treatment parameters may help to improve long-term functional outcome.

Maintenance of adult porcine retina and retinal pigment epithelium in perfusion culture: Characterisation of an organotypic in vitro model *

The purpose of this study was to characterise an ex-vivo adult porcine retina-retinal pigment epithelium (RPE) perfusion organ culture model. Fresh porcine full-thickness retina-RPE-choroid tissue samples were clamped into tissue carriers and mounted in two-compartment containers. The retinal and choroidal sides were continuously perfused with culture medium. pO(2), [Na(+)], [K(+)], [Cl(-)], [glucose], [lactate], and pH were measured in the medium. Tissue samples were examined after 24h, 4, 7, and 10 days in culture. The morphology of the retina and the RPE was examined by light and electron microscopy (LM, EM). The retinal cellular integrity was further examined by immunohistochemistry (Ki 67, GFAP, rhodopsin, synaptophysin, syntaxin, NF 200, TUNEL-test). Fresh porcine full-thickness retina-RPE-choroid tissue samples and tissue samples in static organ culture served as controls. LM, EM, and immunohistochemistry showed intact retinal and RPE cytoarchitecture kept in perfusion culture. Photoreceptor outer segments showed first signs of degeneration after 24h, significant signs of apoptosis and necrosis appeared in the retina after 4 days in perfusion culture. Control tissue samples kept in static culture showed disintegration of the retinal cytoarchitecture after 4 days in culture. The data show that adult porcine retina-RPE tissue can be maintained morphologically intact in perfusion organ culture for at least 10 days. Although first signs of degeneration set in after 24h the structural preservation of the tissue in perfusion organ culture is superior to that in static culture. The perfusion culture model of the retina refines organotypic in vitro test systems and may help to reduce the number of necessary animal experiments in retina and RPE research. It offers new perspectives for the safety testing of substances designed for intraocular application.

Retreatment of full-thickness macular hole : predictive value of optical coherence tomography

Aim: To determine whether the efficacy of re-operation for idiopathic full-thickness macular hole (FTMH) remaining open after initial surgery with internal limiting membrane (ILM) peeling is correlated with macular hole configuration as determined by optical coherence tomography (OCT), macular hole size, macular hole duration before the first operation, or type of tamponade (gas or silicone oil). Methods: A retrospective consecutive interventional case series of 28 patients (28 eyes) with a persisting macular hole after vitrectomy, ILM peel, and gas tamponade. 28 patients underwent repeat surgery involving vitrectomy and gas (n  =  15) or silicone oil tamponade (n  =  12) or no tamponade (n  =  1). Autologous platelet concentrate (n  =  22), autologous whole blood (n  =  1), or no adjuvant (n  =  5) was used. Preoperative OCT was undertaken in all eyes. The main outcome measures were anatomical closure and improvement of best-corrected visual acuity (BCVA). Results: Anatomical closure was achieved in 19 of 28 eyes (68%). BCVA improved in 12 eyes, remained unchanged in nine, and worsened in seven. BCVA improved in 11 of 19 eyes with anatomical closure, and in one of eight eyes without closure. Anatomical closure and improvement of BCVA correlated with preoperative macular hole configuration on OCT, with higher rates of closure (18 of 20 eyes versus one of eight eyes, p = 0.001) and greater improvement of BCVA (p = 0.048) in eyes with a cuff of subretinal fluid at the break margin. Macular hole size, type of tamponade, macular hole duration before the first operation, or preoperative BCVA did not significantly correlate with visual or anatomical outcome. Conclusion: Macular hole configuration seems to be a strong prognostic indicator of anatomical closure and may help identify those patients most likely to benefit from re-operation.

Foveal Structure and Thickness of Retinal Layers Long-Term after Surgical Peeling of Idiopathic Epiretinal Membrane

PURPOSE To better understand the long-term effect of idiopathic epiretinal membrane peeling on retinal anatomy, the foveal structure and the thickness of individual retinal layers were analyzed with frequency-domain optical coherence tomography (fdOCT). The long-term postoperative course of macular thickness was followed. METHODS fdOCT scans were obtained from the horizontal midline in 33 eyes long-term (mean 46 ± 13 months) after surgery and in 30 eyes of age-matched controls. Raw images were exported, and the thickness of retinal layers was measured with a manual segmentation procedure aided by a customized computer program. Macular thickness was quantified over time with the time-domain (td) OCT Fast Macular Thickness program. RESULTS Thickness of retinal layers between the outer nuclear and the ganglion cell plus inner plexiform layers in the horizontal midline of the fovea and the nasal parafovea was greater than normal, whereas that of the RPE, photoreceptor, and retinal nerve fiber layers was not different from controls. Twelve of 33 eyes had a foveal pit though the median foveal shape was distorted. Central macular thickness quantified with tdOCT remained increased, whereas the decrease of nasal macular thickness toward normal values was incomplete and delayed to 35 months after surgery. Superior, temporal, and inferior macular thickness returned to normal 12 to 14 months after surgery. CONCLUSIONS Long-term after surgery, the fovea and the nasal parafovea remain thickened between the outer nuclear layer and the ganglion cell layer, whereas the superior, temporal, and inferior macular thickness returns to normal. Long-term observations are required in the assessment of macular recovery from mechanical stress.

Different collagen types define two types of idiopathic epiretinal membranes

Kritzenberger M, Junglas B, Framme C, Helbig H, Gabel V‐P, Fuchshofer R, Tamm E R & Hillenkamp J
(2011) Histopathology 58, 953–965

The Outcome of Early Surgical Repair With Vitrectomy and Silicone Oil in Open-Globe Injuries With Retinal Detachment

PURPOSE To determine the functional and anatomic outcome of early surgical repair with vitrectomy and silicone oil in open-globe injuries with retinal detachment (RD). DESIGN Retrospective consecutive interventional case series. METHODS All patients with open-globe injuries with RD treated between 1997 and 2007 underwent primary repair including vitrectomy with silicone oil within 8 hours after presentation. For data analysis, patients were divided into 3 groups according to the BETT classification: Group 1, intraocular foreign body; Group 2, penetrating injury; Group 3, globe rupture. Outcome measures were final reading visual acuity (0.4 logMAR or better), final ambulatory visual acuity (1.6 logMAR or better), endophthalmitis, and postoperative proliferative vitreoretinopathy (PVR). RESULTS Eighty-eight patients were included (Group 1, n = 13; Group 2, n = 36; Group 3, n = 39). Mean follow-up was 22 months (standard deviation [SD] = 23, range 6-107 months). Eight percent of patients retained reading vision without significant difference between the 3 groups. Fewer patients in Group 3 than in Group 1 or 2 retained ambulatory visual acuity (Group 1, 62%; Group 2, 64%; Group 3, 33%, P = .024). Endophthalmitis occurred in 3.4% of eyes (1 eye in each group). PVR grade B-C, type 1-3 developed in 44% of patients without significant difference between the 3 groups. Re-RD occurred in 38% of eyes. CONCLUSIONS Few patients achieved reading vision while 50% of patients retained ambulatory visual acuity. Final visual outcome is related to the severity of the injury. The frequency of postoperative endophthalmitis is low. Postoperative development of advanced PVR is avoided in most patients.