[Femtosecond laser ablation and scanning microscopy of the internal retinal limiting membrane: an experimental study].

The investigation was undertaken to study whether femtosecond laser ablation and microscopy might be used in the internal retinal borderline membrane. Ablation of internal limiting membrane preparations removed using or not using indocyanine green was made by a low-energy femtosecond laser. Examination of the preparations by laser and electron microscopy revealed precision laser cuts of the internal retinal borderline membrane. The use of indocyanine green during laser ablation reduced laser irradiation parameters as compared to the dye not being applied. Low-energy femtosecond lasers enable precision contactless ablation of the internal borderline membrane to be carried out without collateral damage to the adjacent tissue. The parameters of laser impulses, particularly low ones used in the ablation of indocyanine green-stained preparations, prove the photosensitizing effect of the dye.

Photodetector sensitivity level and heidelberg retina flowmeter measurements in humans.

PURPOSE: In vitro models suggest that Heidelberg retina flowmeter (HRF) measurements are affected by changes in photodetector sensitivity. We measured blood flow in a single volume of human retinal tissue in vivo at various sensitivity (DC) levels. METHODS: The peripapillary retinal regions of 12 normal subjects were examined by HRF under five different sensitivity settings: (1) average DC range below 100; (2) average DC range below 125; (3) average DC range near 150 (normal sensitivity); (4) average DC range above 175; and (5) average DC range above 200 or extremely overexposed. The distributions of flow values were examined by pointwise analysis. All pixels from a common tissue location were analyzed, and the effect of their brightness on the flow measurement was evaluated by ANOVA with Fisher's protected least significant difference model. RESULTS: ANOVA analysis of image DC level showed that significantly different DC levels were achieved for each of the five sensitivity settings (P < 0.0001). Flow values decreased with increasing DC for each of the 25th percentile, 50th percentile (P: < 0.0001 for each), 75th percentile (P: = 0.0026), 90th percentile (P: = 0.0216), and mean (P: = 0.0004) flow values. The percentage of pixels with values of zero (avascular tissue) increased with increasing photodetector sensitivity (P< 0.0001). CONCLUSIONS: Improper sensitivity settings alter the detected percentage of avascular tissue and the blood flow measurements in tissue containing capillaries. Consistent assessment of retinal blood flow requires consistent photodetector sensitivity settings between longitudinal images.

Quantitative morphologic and functional evaluation of the optic nerve head in chronic open-angle glaucoma.

Glaucoma leads to morphologic changes of the optic nerve head and to functional defects. Morphologic changes in the three-dimensional surface structure of the optic nerve head at its entrance site into the globe can be examined by laser scanning tomography. The standard technique for evaluating functional defects in glaucoma is static computerized perimetry. We compared these two techniques to determine which is more sensitive for follow-up of glaucomatous damage of the optic nerve head. If decreased function is presumed to precede imminent cell death, visual field analysis should be the more sensitive method, as cell death results in absolute defects of the visual field. However, the neuronal networks do not necessarily function in this way. In the case of loss of individual elements in the neuronal network, the complex linkages, even at the retinal level, are able to maintain functions and compensate for loss of function, which means that visual field defects would not be prominent. If the damage increases with time and is accompanied by a progressive loss of ganglion cells, however, compensation is eventually no longer possible, and the functional defects then become measurable by visual field analysis. Thus, morphologic absolute changes may be more prominent than visual field defects in the early stages of glaucoma. To evaluate the quantitative relationship between morphometrically measurable defects of the optic nerve head and measurable functional defects, we first examined the visual field with static computerized perimetry and then evaluated the surface structure with a laser scanning tomograph in 90 patients with chronic open-angle glaucoma, 10 patients with ocular hypertension, and 10 patients without any eye disease. Based on the 95th percentile of the standardized rim/disk area ratio, we calculated the relative rim area loss and correlated this with the mean defect in visual field analysis. The scatterplot shows an exponential curve. In the early stages of glaucoma, visual field defects were less prominent than morphologic absolute changes; 40% of the neuroretinal rim area is lost by glaucomatous optic nerve damage before first defects in visual field analysis appear. In late stages of glaucoma, changes in perimetry are more prominent than those observed with biomorphometry. These results show that in the follow-up of patients with early stages of glaucomatous damage, special attention should be given to morphologic absolute changes. In patients with advanced glaucoma, progress of the damage should be observed by repeated functional, rather than morphologic, examinations. It is important to keep in mind, however, that the sensitivity of any method is dependent on technology. One reason why functional tests may not be as sensitive as morphologic examination in observing patients with early stages of glaucoma may simply be that functional tests are not yet sensitive enough to detect early damage.

Autologous blood injection for late-onset filtering bleb leak.

PURPOSE: To report the outcomes of autologous blood injections for late-onset filtering bleb leak. METHODS: Retrospective chart review of all eyes that had autologous blood injection(s) for filtering bleb leak occurring at least 2 months after trabeculectomy at the Indiana University Medical Center. Successful treatment was defined as resolution of the bleb leak and no need for additional glaucoma medications. Failure was defined as a persistent bleb leak, intraocular pressure greater than 21 mm Hg, or the occurrence of a vision-threatening event related to the procedure. RESULTS: Thirty-two eyes of 31 patients had autologous blood injection for filtering bleb leak and were followed for a mean of 4.9 months (SD, 9.2; range, 1 to 37 months). Twenty-three eyes (72%) were outright failures because of persistence of the leak. Nine eyes (28%) had an initially successful outcome, but the success rate decreased over time as bleb leaks recurred in three of the nine eyes at 5, 6, and 37 months. No patient characteristics correlated with outcome. Mean intraocular pressure increased from pretreatment to final examination (4.5 to 6.5 mm Hg, P =.003). Mean logarithm of minimal angle of resolution (logMAR) vision remained unchanged from pretreatment to final examination (P =.55). Blood seepage into the anterior chamber after autologous blood injection was common but transient. CONCLUSIONS: Autologous blood injection is of limited success in treating late-onset filtering bleb leak.

Effect of dorzolamide timolol combination versus timolol 0.5% on ocular bloodflow in patients with primary open-angle glaucoma.

PURPOSE: Addition of dorzolamide to timolol in primary open-angle glaucoma shows augmented reduction of intraocular pressure. It is unknown as yet if addition of dorzolamide will alter hemodynamics. METHODS: Fifteen patients with primary open-angle glaucoma were placed on a medication-dependent 1-week to 4-week washout that included maintenance on timolol. After washout, baseline measurements were taken (timolol). They were studied after a month on timolol or dorzolamide-timolol (Cosopt; Merck, Inc, Whitehouse Station, New Jersey), with the second drug preceded by another month of timolol maintenance and second baseline measurements. At each visit, visual function, intraocular pressure, and ocular hemodynamics were monitored, including indocyanine green and fluorescein angiography and color Doppler imaging. RESULTS: Cosopt significantly reduced intraocular pressure (14.7 to 13.4 mm Hg, P <.05) and increased arteriovenous passage time (superior temporal artery) of fluorescein dye (2.13 to 1.76 seconds, P =.01) but had no effect on visual function. CONCLUSIONS: When compared with timolol in primary open-angle glaucoma, Cosopt augments ocular tension reduction and reduces the amount of time required for blood to pass through the superior retinal vasculature.

Optic nerve head morphometry in healthy adults using confocal laser scanning tomography.

BACKGROUND/AIMS: To study the optic nerve head (ONH) characteristics in a cross sectional study with confocal laser scanning tomography using the Heidelberg retina tomograph (HRT I) and thereby to obtain a new HRT database for comparison of healthy and glaucomatous eyes. METHODS: White adults with no history of ocular pathology were eligible for the study. The examination comprised: assessment of visual acuity; slit lamp examination of the anterior and posterior segment; Goldmann applanation tonometry; computerised perimetry, and optic nerve head tomography with HRT. Eyes with ocular pathology were excluded. Mean (standard deviation, SD) and difference between right and left eye (RE-LE) were calculated for HRT I measurements. Differences in mean topographic parameters between male and female participants and between the age quartiles were analysed. The study included 1764 eyes of 882 healthy adults (154 females and 728 males, mean age of 46.8 (SD 8.6) years). The population investigated was larger and older in comparison with similar studies using confocal laser scanning tomography. RESULTS: With HRT I, a mean disc area of 1.82 (SD 0.39) mm(2), a mean cup area of 0.44 (SD 0.32) mm(2) and a mean cup:disc area ratio of 0.22 (SD 0.13) was observed. Right eyes showed a larger mean retinal nerve fibre layer thickness (RNFLT) (0.263 (SD 0.066) mm) compared with left eyes (0.252 (SD 0.065) mm, p<0.001). Higher values in younger volunteers (mean age 35.7 years) in comparison with elderly participants (mean age 59.1 years) were noted for disc area (1.84 mm(2)v 1.78 mm2) and mean RNFLT (0.263 (SD 0.06) mm v 0.249 (SD 0.07) mm) but were not significant (p>0.01). The presented results differ from published data on ONH measurements of healthy volunteers with different techniques. CONCLUSION: The observed differences in ONH measurements between left and right eyes seem not to be of clinical importance. This is also true for age or sex dependent changes in ONH topographies. The presented data provide a new basis for comparison of optic disc characteristics between healthy eyes and glaucomatous eyes.

New neuroretinal rim blood flow evaluation method combining Heidelberg retina flowmetry and tomography.

AIM: Accurate Heidelberg retina flowmeter (HRF) measurements require correct manual setting of the HRF photodetector sensitivity. The neuroretinal rim produces a weak signal relative to the peripapillary retina. A newly developed HRF alignment and sensitivity protocol, capable of accurate rim measurement, was investigated. METHODS: 18 eyes of nine healthy volunteers were examined by HRF. Three images of each eye were taken using three different imaging methods. Method 1: a conventional image (optic nerve head centred image with photodetector sensitivity optimised for the strong signal from the peripapillary retina); method 2: the setting of method 1 with photodetector sensitivity optimised for the weak signal from the rim; and method 3: the setting of method 2 with the temporal rim margin tangent to the lateral image border to remove the overpowering signal from the temporal peripapillary retina. The neuroretinal rim was defined by the Heidelberg retina tomograph (HRT). Blood flow and reflectivity values (DC component) in the rim area were compared for the three methods using pointwise analysis. Coefficients of variation of repeated measurements in 12 subjects have been calculated for method 3. RESULTS: The neuroretinal rim area measured by method 1 had a significantly lower brightness compared with method 2 and 3 (p=0.0002 and p=0.0002, respectively). Method 2 provided proper sensitivity for the weak signals of the rim area based on rim tissue DC values; however, this sensitivity setting was too high for the strong signal from the peripapillary retina. Method 3 avoided the strong peripapillary signal with the proper signal from the rim and provided significantly higher flow values of the rim area at 75 and 90 percentile pixels (p=0.0065 and p=0.0038 respectively) compared with method 2. Interobserver repeatability ranged from 16.85% to 21.96% for the different parameters. CONCLUSIONS: Method 3 provides an accurate and reproducible flow measurement of the neuroretinal rim area through proper sensitivity for the weak rim signal, alignment, and removal of the strong temporal signal from the image. This new method is recommended to improve accuracy of blood flow measurement in the neuroretinal rim.

Blood flow per unit retinal nerve fibre tissue volume is lower in the human inferior retina.

AIM: To determine if perfusion per unit tissue volume of retinal nerve fibre layer and optic nerve head in the inferior sector is lower than in the superior sector. METHODS: Heidelberg retinal tomogram (HRT) for topographic measurement of optic nerve head and retinal nerve fibre layer and Heidelberg retinal flowmeter (HRF) for retinal blood flow were performed on 19 normal healthy subjects. Measurements from the superior and inferior sectors were compared. The perfusion/nerve fibre ratio (PNR); the blood flow per unit retinal nerve fibre tissue volume, was calculated in each sector with a formula; HRF flow measurements divided by HRT measurements. RESULTS: Retinal nerve fibre layer thickness in the inferior retina was significantly higher than in the superior retina (p<0.05). There were, however, no differences in retinal blood flow between the superior and inferior retinal sectors. The PNR in the inferior sector were significantly lower than in the superior sector (p=0.047 for HRF mean flow/rim volume and p = 0.0282 for HRF 75th percentile flow/rim volume). CONCLUSIONS: The inferior sector of retinal nerve fibre layer and optic nerve head may have lower blood flow per unit nerve tissue volume compared to the superior sector. This result suggests that the inferior sector is more vulnerable to elevated intraocular pressure (IOP) and ischaemic insults in glaucomatous optic neuropathy.

Retinectomy for treatment of intractable glaucoma: long term results.

AIM: To report long term efficacy and complications of retinectomy as an intraocular pressure lowering procedure for intractable glaucoma. METHODS: This was a consecutive interventional case series. In 44 consecutive eyes (39 patients, 22 men and 17 women) retinectomy was performed to lower the intraocular pressure (IOP) in patients with uncontrolled IOP (>35 mm Hg for more than 4 months) despite conventional filtering surgery and drug treatment. Pars plana vitrectomy was performed and the peripheral retina was surgically excised to various degrees. The procedure was concluded by an intraocular gas tamponade of 20% C(3)F(8). Included were patients with neovascular glaucoma (12 eyes), infantile and juvenile glaucoma (three eyes), secondary glaucoma due to aphakia (13 eyes), severe ocular trauma (seven eyes), uveitis (seven eyes), and glaucoma in Ehlers-Danlos syndrome (two). RESULTS: All patients underwent successful surgical retinectomy. All patients were followed for 5 years. Mean postoperative IOP after 4 years was 15.7 (SD 9.4) mm Hg, representing a decrease of IOP by 61% compared to the preoperative level (41.2 (9.4) mm Hg). In 52.3% of eyes long term regulation of IOP could be achieved without complications. Retinectomy was least effective in neovascular glaucoma because of central retinal vein occlusion (CRVO). Eyes with glaucoma secondary to uveitis showed a tendency towards low IOP levels with subsequent phthisis bulbi. The initial visual acuity of all patients was lower than 20/50 (mean 1.8 (0.8) logMAR) in the treated eye. Final visual acuity was 2.3 (0.6) logMAR. 21 out of 44 cases developed retinal complications (retinal detachment or proliferative vitreoretinopathy (PVR)) after surgery, requiring silicone tamponade in 11 eyes (52%) either for persistent low IOP or for PVR. Nine eyes developed phthisis, seven of which were enucleated during the follow up. CONCLUSIONS: Long term results after retinectomy demonstrate its efficacy in otherwise intractable glaucoma. Efficacy and safety of retinectomy are dependent on the underlying disease.

Reproducibility of the Heidelberg retinal flowmeter in determining low perfusion areas in peripapillary retina.

AIM: To evaluate the interobserver variability and retest reproducibility of confocal scanning laser Doppler flowmeter in measuring capillary perfusion of the peripapillary retina. METHODS: Blood flow measurements were performed in one eye of 10 normal subjects by two investigators on two different days (visits). Five separate measurements of the peripapillary blood flow parameters were recorded by each observer at each visit. The Heidelberg retina flowmeter was used to record capillary perfusion in a 2560x640 microm area of the superotemporal peripapillary region and pixel by pixel analysis was done from an area adjacent to the optic disc, with a minimum of 1600 pixels. The percentage of pixels with less than 1 arbitrary unit of flow (no flow) and 10, 25, 50, 75, 90th percentiles of flow values was calculated. Interobserver measurements were compared by paired t test. Intraclass correlations (ICC) were used to determine the interobserver variability and retest reproducibility of the measurements. Intrasession coefficients of variations (CV) were also calculated. RESULTS: There were no statistically significant differences between the two observers for all measurements and between visits for the percentage of pixels with no flow. ICC was 66% (range 57.09%-77.1%) for pixels with no flow. For the 10, 25, 50, 75, 90th percentiles of flow the ICC was 63.07% (53.91%-77.81%), 71.3% (64.23%-80.85%), 72.61% (66.02%-78.96%), 65.86% (58.53%-74.77%), and 60.05% (54.34%-70.06%), respectively. CV was 16.59%, 11.47%, 9.32%, 9.03%, 11.58%, and 16.05% for the percentage of no flow pixels and the 10, 25, 50, 75, 90th percentiles of flow, respectively. CONCLUSIONS: The Heidelberg retinal flowmeter allows reproducible measurements of all levels of capillary perfusion areas when pixel by pixel analysis is used.

Ocular haemodynamic responses to induced hypercapnia and hyperoxia in glaucoma.

AIM: To determine the ocular haemodynamic response to gas perturbations in glaucoma. METHODS: Intraocular pressure (IOP), systemic systolic and diastolic blood pressure (SBP and DBP), and retrobulbar blood flow velocities, measured by colour Doppler imaging (CDI), were recorded at two visits. CDI was used to measure peak systolic and end diastolic velocities (PSV and EDV) and resistance index (RI) in the ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (SPCAs). At the first visit, measurements were taken at baseline (B1: breathing room air) and during isoxic hypercapnia (end tidal PCO(2) increased 15% above baseline) in 16 normal subjects and 12 patients with glaucoma. On another day, measurements were repeated at a second baseline (B2) and during hyperoxia (100% oxygen breathing) for 15 normal subjects and 13 glaucoma patients. Baseline systemic data were compared using paired t tests; REANOVA was performed to compare group differences at baseline and to determine the vessel response to each condition. Fisher's LSD was used for post hoc comparison. RESULTS: Baseline OA PSV was lower for the glaucoma than for the normal group (p = 0.047); the groups were otherwise similar at baseline. IOP demonstrated no response to hypercapnia, but reduced during hyperoxia for both the normal subjects (p<0.0001) and glaucoma patients (p = 0.04). During hypercapnia, SBP increased in normal subjects (p = 0.03) and glaucoma patients (p = 0.01); DBP increased in normal subjects (p = 0.021). There was a corresponding increase in ocular perfusion pressure (OPP) for normal subjects (p = 0.01) and glaucoma subjects (p = 0.028), and as a result OPP was included as a covariate in the REANCOVA model. Hypercapnia resulted in increased PSV in the CRA of normal subjects (p = 0.035) and increased PSV and EDV in the SPCAs of glaucoma patients (p = 0.041 and p = 0.030 respectively). Hyperoxia resulted in reduced PSV and EDV in the ophthalmic arteries of normal subjects only (p = 0.001 and 0.031 respectively). CONCLUSIONS: These findings suggest the presence of relative vasoconstriction in glaucoma patients, which is at least partially reversed by hypercapnia.

Clinicopathological correlation of retinal pigment epithelial tears in exudative age related macular degeneration: pretear, tear, and scarred tear.

AIMS: To analyse the histopathology of vascularised pigment epithelial detachments and tears of the retinal pigment epithelium (RPE) in age related macular degeneration (AMD). METHODS: The light microscopic architecture of 10 surgically removed subretinal specimens-three vascularised pigment epithelial detachments, four recent tears, and three scarred tears as a manifestation of AMD-were studied and correlated with the angiographic findings. RESULTS: Recent tears: a large fibrovascular membrane was found to be originally situated in Bruch's membrane. About half of the surface of the fibrovascular tissue was denuded of RPE and diffuse drusen. The RPE and diffuse drusen had retracted and rolled up, covering a neighbouring part of the intra-Bruch's fibrovascular membrane. The rolled up RPE and diffuse drusen were not interspersed with fibrovascular tissue but lay superficial to the intra-Bruch's fibrovascular membrane itself. Scarred tears: a collagen capsule surrounded the rolled up diffuse drusen and RPE. Fibrovascular tissue was found inside the rolled up material, predominantly at its choroidal side. CONCLUSION: The area of choroidal neovascularisation associated with a vascularised pigment epithelial detachment and a tear of the RPE may be larger than was hitherto thought or indicated by fluorescein angiography. This neovascular tissue may be present within the bed of the RPE tear, as well as at the site of the scrolled up RPE.

Ultrasound biomicroscopy and its value in predicting the long term outcome of viscocanalostomy.

AIMS: To examine whether the early postoperative morphology at the site of sclerectomy, as visualised by ultrasound biomicroscopy (UBM), is an indicator of the mechanisms that lower intraocular pressure (IOP) and/or predictors of the long term outcome of viscocanalostomy. METHODS: 15 eyes of 14 patients with medically uncontrolled open angle glaucoma and no history of surgery underwent viscocanalostomy according to Stegmann's technique. Ultrasound biomicroscopy was performed during the first month after surgery. The following parameters were assessed: dimensions of the intrascleral "lake," presence of a filtering bleb, presence of a subconjunctival cavity or a suprachoroidal hypoechoic area, and the thickness of the residual trabeculocorneal membrane. A complete ophthalmological examination was performed the day before and the day after surgery. Follow up visits were scheduled 1 week, 4 weeks, 6 months, and 12 months after surgery. RESULTS: At 1 year successful control of IOP (<20 mm Hg) was achieved without further manipulation or medication in six of 15 eyes. The size of the intrascleral "lake" (average 0.62 mm(3)) did not correlate with later IOP; however, a visible route under the scleral flap and accidental perforation of the trabeculocorneal membrane were associated with long term lowering of IOP. Normal thickness of the trabeculocorneal membrane (0.10-0.15 mm) was indicative of IOP control with and without medication. When UBM showed an early collapse of the intrascleral cavity, control of IOP was not achieved. Other UBM findings did not predict long term function. CONCLUSION: In accordance with previous studies, the authors found that UBM examination is a useful method to evaluate outflow mechanisms after glaucoma surgery. This study shows that UBM imaging of external filtration during the early postoperative period can be used to predict the success of viscocanalostomy. However, to establish conclusively what parameters of UBM predict successful viscocanalostomy a larger number of patients must be studied.

Reproducibility of circadian retinal and optic nerve head blood flow measurements by Heidelberg retina flowmetry.

BACKGROUND/AIM: The Heidelberg retina flowmeter (HRF) is designed to measure retinal capillary blood flow. Previous studies however showed weak reproducibility of data. The intraindividual reproducibility of circadian HRF measurements was examined in healthy subjects in three locations of the retina. METHODS: 36 healthy volunteers (27.3 (SD 4.3) years) were examined by HRF seven times a day (t0-t6). Using a default window of 10 x 10 pixels, three consecutive measurements were performed in three precise focusing planes: superficial, intermediate and deep layer, peripapillary retina, neuroretinal rim and cup, respectively. Images of identical tissue locations identified by capillary landmarks of each layer were selected to quantify the retinal microcirculation of each volunteer. Means and standard deviations of all flow results of a given subject were calculated, at t0-t6 and the coefficients of variation as a measure of reproducibility. RESULTS: The coefficients of variation ranged between 8.4% and 41.0% in the superficial layer (mean 19.8% (SD 8.4%)), 10.6%, and 43.0% in the intermediate layer (mean 24.0% (SD 8.4%)), and 9.9% and 84.0% (mean 29.6% (SD 15.8%)) in the deep layer. CONCLUSIONS: These data show the best reproducibility of measurements in the superficial layer followed by the intermediate and the deep layer. Clinically, this is an unsatisfactory intraindividual reproducibility of flow values in each studied layer.

Effect of brimonidine tartrate on ocular hemodynamics in healthy volunteers.

While alpha2-adrenergic agonists, such as brimonidine tartrate, significantly reduce the intraocular pressure (IOP), the presence of vasoconstrictor postsynaptic alpha2 receptors on vascular smooth muscle raise the possibility that brimonidine could potentially compromise ocular blood flow. Consequently, the ocular hemodynamic effects of brimonidine were studied in normal subjects. Twelve healthy volunteers were included in this prospective, double-masked, placebo controlled, crossover-designed clinical trial. They received either brimonidine tartrate 0.2% or placebo b.i.d. for 2 weeks. Goldmann tonometry and color Doppler imaging (CDI) were performed at baseline, at 2 hr, 1 week, and 2 weeks after the treatment. Fundus angiography using a scanning laser ophthalmoscope was performed at baseline and 2 weeks after treatment to determine retinal arteriovenous passage time. Brimonidine lowered IOP at 2 hr, 1 week, and 2 weeks (p = 0.058, p = 0.031, and p = 0.022, respectively). Brimonidine did not affect the retrobulbar arterial velocities measured by CDI, nor retinal arteriovenous passage time. In conclusion, two-week treatment with brimonidine reduces IOP and does not reduce the bulk retinal or retrobulbar arterial perfusion in young healthy volunteers.

[Combined cataract and glaucoma surgery. Current options]. / Kombinierte Katarakt-Glaukom-Chirurgie. Aktuelle Optionen.

Trabeculectomy is no longer the gold standard for combined cataract glaucoma surgery considering the successful results following cataract surgery combined with trabeculotomy, viscocanalostomy and canaloplasty. The main disadvantage of these mostly non-penetrating procedures is the induction of conjunctival scarring which jeopardizes subsequent filtering surgery. Ab interno glaucoma surgery, including trabecular surgery and endocyclophotocoagulation, does not interfere with the conjunctival situation. These surgical options have a relatively minor risk profile for combined cataract glaucoma surgery compared to traditional filtering surgery; however, the pressure reducing efficacy of these ab interno approaches is limited with respect to the absolute reduction of intraocular pressure (IOP) and the achievable level of IOP. This has to be kept in mind when planning surgery.

[Glaucoma with primary iris malformations. Axenfeld-Rieger syndromes, ICE syndromes (essential iris atrophy, Chandler's syndrome, Cogan-Reese syndrome), aniridia]. / Glaukome bei primären Irisveränderungen. Axenfeld-Rieger-Syndrome, ICE-Syndrome (essenzielle Irisatrophie, Chandler-Syndrom, Cogan-Reese-Syndrom), Aniridie.

Iris malformations are often associated with malformations of the entire eye and systemic diseases. Malformations of the anterior chamber angle can lead to juvenile glaucoma. Axenfeld-Rieger syndromes have autosomal dominant transmission and are associated with juvenile glaucoma in 50-60% of patients. Besides eye anomalies craniofacial malformations are also typical. The etiology of iridocorneal endothelial (ICE) syndrome is unclear but atypical endothelial cells lead to malformations of the entire anterior eye segment of the eye and glaucoma. Aniridia is a bilateral, congenital malformation which manifests sporadically and transmission is usually autosomal dominant. Glaucoma, malformations of the entire eye and systemic malformations are associated with aniridia. Conservative and microsurgical treatment of glaucoma of these syndromes need the cooperation of different medical subspecialties and are often ineffective.

[Subluxation of hydrophilic acrylate intraocular lenses due to massive capsular fibrosis]. / Subluxationsserie eines hydrophilen Kunstlinsentyps aufgrund massiver Kapselfibrose.

BACKGROUND: Compared with other biomaterials, hydrophilic acrylate provides better uveal biocompatibility, lower adhesion rates of bacteria and silicone oil, and less glare. Because of reduced capsular biocompatibility, increased fibrosis may initiate dislocation of the intraocular lens (IOL). PATIENTS: In six eyes of four patients, enhanced fibroses led to IOL dislocation, leading to an IOL exchange an average of 40 weeks after implantation of the same hydrophilic acrylate lens type. DISCUSSION: Predisposing factors were found in 90% of all reported cases of IOL dislocation in the literature, but not in the cases described here. The lens type that was implanted was unable to adapt to the massive fibrosis induced by its hydrophilic biomaterial. CONCLUSIONS: The pattern of lens opacification should receive attention when one is choosing an IOL type. Eyes showing pseudoexfoliation syndrome as well as post-uveitis eyes might require a hydrophilic IOL for less cellular reaction, whereas a posterior subcapsular cataract might need a hydrophobic IOL to prevent a massive capsular fibrosis. In the case of increased capsular contraction, unreflected YAG laser capsulotomy may result in IOL subluxation when the lens design cannot handle capsule shrinkage, as demonstrated here.

[Postoperative complications and management of filtration surgery]. / Postoperative Komplikationen und Management der Filtrationschirurgie.

Of the filtering procedures employed, trabeculectomy is the one most frequently used for surgical therapy in primary open angle glaucoma patients. Intra- and postoperative complications must be detected promptly and treated adequately. Many complications arise within the first weeks, such as bleb scaring, decreased flow beneath the scleral flap, extensive filtration with choroidal detachment and anterior chamber narrowing. Fibrin reaction, corneal dellen, iris prolapse, conjunctival leakage and ciliary body detachment are seen more rarely. With prophylactic pre- and perioperative application of antibiotics, wound infections are rare and the risk of endophthalmitis following trabeculectomy remains small. Careful surgical planning requires special consideration of the conjunctiva and provides the basis for long-term success as long as intensive follow-up treatment is ensured. The success of trabeculectomy depends on the preoperative, intraoperative as well as postoperative condition and in particular on bleb development. Early detection of postoperative complications, especially in terms of early scaring in the bleb area, enables implementation of adequate therapeutic measures, such as needling procedures and early bleb revision. Close patient monitoring substantially increases long-term success rates.