[Can Anti-VEGF Injections Cause Glaucoma or Ocular Hypertension?] / Können Anti-VEGF-Injektionen Glaukom oder okuläre Hypertension verursachen?

An increasing number of patients receive intravitreal anti-vascular endothelial growth factor (anti-VEGF) injections with a high frequency for the treatment of neovascular macular disease. Since the volume of the vitreous body is temporarily increased by the injection of the substances, a short-term intraocular pressure increase after the introduction of the substance is not uncommon. However, there are more and more reports indicating that multiple injections may lead to a long-term increase in intraocular pressure. This may also be the case in patients without a glaucoma history. In some cases, this pressure increase cannot be adequately treated with local pressure-reducing medication and requires an operative procedure in order to avoid glaucoma damage. This appears to be more common in products dispensed from broken bulk or after administration of bevacizumab. The mechanism leading to inflammation and/or a sustained increase in pressure is unknown. High molecular weight molecules present in the syringe, such as monomer antibodies, aggregated proteins, or silicone oil droplets from the syringe, may lead to inflammation in the trabecular meshwork or displacement thereof and a subsequent increase of the intraocular pressure. Avoiding silicone oil droplets in the syringes would be desirable. Intraocular pressure after intravitreal injections should also be monitored long term after the procedure.

[Botulinum toxin injections for senile entropium]. / Botulinumtoxin-Injektionen bei senilem Entropium.

Involutive changes in the collagen and muscular structures of the lower lid in ageing may lead to the formation of senile entropium. Treatment of this condition may be achieved using botulinum toxin injections to the dislocated orbicularis muscle. These injections lead to cessation of the symptoms for a mean of 3.8 months. Repeat injections are possible. Botulinum toxin injections are a viable option for patients who are not amenable to surgical correction of the entropium.

[Measurement of accommodation using optical biometry]. / Messung der Akkommodation mittels optischer Biometrie.

BACKGROUND: Making accommodation possible for all age groups is a topic of great interest. We applied optical biometry in order to study the physiological mechanisms in detail. Longitudinal relations in the optical axis were measured during accommodation in volunteers of different ages and lens states. METHODS: A total of 60 subjects (children, adolescents, adults, and pseudophakes) were examined using the IOL Master. We measured anterior chamber depth (ACD), axial length (AL), and changes in these two measurements during accommodation. RESULTS: Near accommodation (NA) in adolescents caused the largest ACD decrease (0.14+/-0.03 mm). ACD decreased in adults during NA but not in pseudophakic patients of comparable age. AL increased during NA in all groups by 0.01+/-0.01 mm. CONCLUSIONS: ACD decreased with age. Using a physiological stimulus, no change in ACD was measured during NA in pseudophakic patients. The documented increase in AL needs to be evaluated further.

[Botulinum toxin injection for production of ptosis]. / Botulinumtoxin-Injektionen zur Erzeugung einer Ptosis.

Selective muscles can be paralysed or weakened for a limited time period using botulinum toxin type A. The upper eyelid muscles can be a target, leading to a temporary protective ptosis. In this report we discuss indications for this application, describe how to perform the injection, and present results. The procedure is safe and effective.

[Treatment of wrinkles with botulinum toxin]. / Faltenbehandlung durch Botulinumtoxin.

The use of botulinum toxin A for the treatment of wrinkles is increasing. Botulinum toxin A inhibits exocytosis of acetylcholine from 3 to 12 months, depending on the target tissue. Low-dose botulinum toxin A is used to smooth hyperkinetic facial lines. This is especially successful in the upper facial parts, since the target muscles (procerus, corrugator supracilii, frontalis, orbicularis oculi) all directly overlie the osseous structures of the face. This is not the case for the lower facial parts, and more side effects are encountered when treating, for example, wrinkles around the mouth. Contraindications to the use of botulinum toxin A are diseases affecting neuromuscular signal transduction, allergic reactions to components of the solution, therapy with aminoglycosides or acetylsalicylic acid prior to treatment, infections in the planned treatment area, and pregnancy and lactation. Alternative and complementary treatments include erbium-YAG or CO2 laser, as well as augmentation and surgical plastic procedures.

[Low-dose rate brachytherapy with locally integrated beta emitters after internal urethrotomy. A pilot project using an animal model]. / Low-dose-rate-Brachytherapie durch lokal integrierte Betastrahler nach Urethrotomia interna. Ein Pilotprojekt im Tierversuch.

BACKGROUND: The treatment of urethral strictures represents an unsolved urological problem. PATIENTS AND METHODS: The effect of a (32)P-coated urethral catheter in the sense of low-dose rate brachytherapy to modulate wound healing will be analyzed in an animal experiment. RESULTS: Unfortunately it is not possible to present any results because this is being studied for the first time and there are no experiences with low-dose rate brachytherapy and this form of application in the lower urinary tract. Furthermore the animal experiment will only start in the near future. Both decade-long experiences with radiotherapy to treat benign diseases and our own results of previous studies in otolaryngology and ophthalmology let us expect a significantly lower formation of urethral strictures after internal urethrotomy. CONCLUSION: This study will contribute to improving the treatment of urethral strictures as demanded in previous papers.

Blood pressure effects on retinal vessel diameter and flicker response: a 1.5-year follow-up.

PURPOSE: The study examined the influence of individual blood pressure changes overtime on retinal vessel diameter and the latter's response to flicker light. METHODS: The diameter of a retinal arterial and venous segment was measured continuously on-line with a Dynamic Vessel Analyzer in 20 patients twice (mean interval between examinations of 24 months). Eleven patients had no cardiovascular disease. Nine patients had arterial hypertension and were untreated at the time of the first measurement; at the time of the second measurement they were undergoing various antihypertensive therapies. Each test consisted of a 50-s baseline plus three 20-s periods of flicker stimulation followed by an 80-s period of observation. During the examinations the blood pressure was measured at 1-minute intervals. RESULTS: In the hypertension group changes in the mean arterial blood pressure (MAP) correlated significantly with changes in the arterial baseline diameter (y = -0.1 - 0.37x, r =0.74, p (increase) <0.03). A comparison of the two measurements showed no such relationship in the group of cardiovascularly healthy subjects. The venous baseline and the arterial and venous flicker response did not change significantly in either group between the two measurements and showed no relationship to blood pressure changes. CONCLUSIONS: In hypertensive subjects, long-term therapy-related changes in blood pressure induced a change in the arterial baseline by approximately +3.7 microm/-10 mmHg MAP. An influence of lowering MAP to the arterial flicker response could not be detected.

[Mastered with statistics: perfect eye drops and ideal screening test : Possibilities and limits of statistical methods for glaucoma]. / Mit Statistik gemeistert: perfekte Augentropfen und idealer Screeningtest : Möglichkeiten und Grenzen statistischer Methoden beim Glaukom.

BACKGROUND: The use and the understanding of statistics are very important for biomedical research and for the clinical practice. This is particularly true for estimation of the possibilities for different diagnostic and therapy options in the field of glaucoma. The apparent complexity and contraintuitiveness of statistics along with a cautious acceptance by many physicians, might be the cause of conscious and unconscious manipulation with data representation and interpretation. OBJECTIVES: Comprehendable clarification of some typical errors in the handling of medical statistical data. MATERIALS AND METHODS: Using two hypothetical examples from glaucoma diagnostics the presentation of the effect of a hypotensive drug and interpretation of the results of a diagnostic test and typical statistical applications and sources of error are analyzed in detail and discussed. RESULTS: Mechanisms of data manipulation and incorrect data interpretation are elucidated. Typical sources of error in the statistical analysis and data presentation are explained. CONCLUSION: The practical examples analyzed demonstrate the need to understand the basics of statistics and to be able to apply them correctly. The lack of basic knowledge or half-knowledge in medical statistics can lead to misunderstandings, confusion and wrong decisions in medical research and also in clinical practice.

[Possibilities and limitations of glaucoma surgery]. / Möglichkeiten und Grenzen der operativen Glaukomtherapie.

BACKGROUND: Glaucoma is the second leading cause of blindness worldwide and in many cases cannot be adequately controlled with conservative treatment. MATERIALS AND METHODS: Schematic evaluation of various surgical techniques. RESULTS: Trabeculectomy is the gold standard of glaucoma surgery and requires close follow-up care. Novel, minimally invasive procedures are suitable for patients with moderately advanced, uncomplicated stages of the disease, whereas filtrating tube implants or cyclodestructive techniques are required in patients with complex glaucoma. CONCLUSION: Various surgical techniques are available and have their specific indication window for the glaucoma surgeon, depending on the severity, progression, and risk factors of the disease.

[Possibilities and limitations of eye drops for glaucoma therapy]. / Möglichkeiten und Grenzen der medikamentösen Glaukomtherapie.

BACKGROUND: In Germany, chronic open-angle glaucoma is mostly treated by daily eye drop application. The possibilities and limitations of this form of therapy are presented. Reasons for the change in the selection of the preferred substances over time are also discussed and the limits of local drug therapy are described. OBJECTIVES: What effects can be expected of the available drugs? MATERIALS AND METHODS: The article provides a review of the literature from PubMed and clinical experience. RESULTS: In chronic open-angle glaucoma, eye drops containing a single agent can achieve an intraocular pressure decrease of 15-35 % compared to the initial pressure level. This is dependent on the substance and is achievable when used as directed. Difficulties in administration are often observed in older patients where regular use over extended periods of time is required. In addition, there are limits in the achievable pressure reduction by combining several active ingredients. Novel systems are being developed for future applications. The idea is to achieve a continuous slow release of the active substance by surgical application of a biodegradable carrier. CONCLUSION: A treatment regimen which is individually tailored to the individual patient's needs should be developed by the attending physician and the achievement of the set objectives should be monitored at regular intervals. However, restrictions induced by patients due to inadequate adherence or by the drug due to limited efficacy of the drug have to be considered. Therefore, eye drop therapy in open-angle glaucoma is not always sufficient. It should be supplemented in due time by laser or filtering surgery before the affected patients and their optic nerves suffer advanced glaucomatous damage.

[Comparison of diameter response of retinal arteries and veins to flickering light. A clinical study with healthy people]. / Vergleich der Durchmesserreaktion retinaler Arterien und Venen auf Flickerlicht. Eine klinische Studie an Gesunden.

PURPOSE: The aim of this study was to compare the diameter response of retinal arteries and veins after provocation with flickering light regarding the amplitude and temporal course. METHODS: The study included 26 healthy volunteers. The vessel diameter was automatically and continuously measured by the retinal vessel analyzer. The examination consisted of a baseline measurement (100 s) followed by five periods of 20-s flicker light provocation and 80-s follow-up observation. RESULTS: A diameter dilation was observed immediately after the end of the flicker period in arteries (6.9+/-2.8%) and veins (6.5+/-2.8%, difference n.s.). The quotient of arterial and venous dilation (AVDQ) was 1.25+/-0.69 (range: 0.2-2.8). A significant correlation of age and arterial or venous dilation or the AVDQ was not observed. The arterial diameter reduced faster than the venous and reached a minimum of -2.7+/-1.4% at 25.9+/-10.8 s after the end of the flicker phase. The veins were dilated by 0.5+/-1.3% at the time of the maximal individual arterial constriction (p<0.0001). CONCLUSIONS: Flicker-evoked response of retinal arteries and veins did not differ in the dilative amplitude but in the temporal course of the abatement of the dilation.

Unilateral open-angle glaucoma secondary to idiopathic dilated episcleral veins.

PURPOSE: To determine the cause of unilateral dilated tortuous episcleral vessels in a 34-year-old patient. METHODS: The patient underwent slit-lamp examination, visual field testing, tonographic measurement, orbital ultrasound examination, orbital color Doppler blood flow measurement, dye-enhanced computed topographic scan, and selective carotid angiography. RESULTS: Disk cupping and early scotoma were present. Gonioscopy showed Schlemm's canal engorged with blood. The only pathologic findings were an increased tonographic resistance to outflow and increased arterial and venous episcleral flow on color-coded Doppler sonography. CONCLUSION: The origin of this episcleral vessel abnormality is still unknown.

Comparison between laser scanning tomography and computerised image analysis of the optic disc.

AIMS: To study the interchangeability of the measurements of the optic disc topography obtained by one computerised image analyser and one confocal laser tomographic scanner. METHODS: One eye of 28 patients with glaucoma or glaucoma suspects was studied. All cases had simultaneous stereoscopic disc photographs taken with the fundus camera Topcon TRC-SS and optic disc examination with the Heidelberg retina tomograph (HRT) during the same visit. The optic disc photographs were digitised and analysed with the Topcon ImageNet (TI) system. Three variables of the optic disc topography provided by the TI and the HRT were compared--cup volume (CV), rim area (RA), and cup area to disc area ratio (CA/DA). RESULTS: The mean values of CV and RA provided by the TI (0.52 (SD 0.32) mm3 and 1.58 (0.39) mm2, respectively) were greater (p < 0.01) than the mean values of CV and RA determined by the HRT (0.32 (0.25) mm3, and 1.33 (0.47) mm2, respectively). The mean value of CA/DA provided by the TI (0.42 (0.14)) and the HRT (0.42 (0.18)) was similar (p = 0.93). Correlation coefficients between measurements obtained by the two methods ranged from 0.53 to 0.73. CONCLUSION: There was a significant discrepancy in the measurements of rim area and cup volume of the optic disc obtained by a computerised image analyser and a laser scanning tomograph.

Ciliary body detachment caused by capsule contraction.

A 74-year-old woman developed capsule contraction associated with hypotony and choroidal effusion 18 months after uneventful phacoemulsification with 3-piece poly(methyl methacrylate) intraocular lens implantation. Ultrasound biomicroscopy revealed ciliary body detachment and stretched zonules. A radial neodymium: YAG anterior capsulotomy was performed, resulting in the resolution of the ciliary body detachment and choroidal effusion as well as in normal intraocular pressure over 4 days.

The role of ultrasound biomicroscopy in surgical planning for limbal dermoids.

PURPOSE: Limbal dermoids usually involve corneal stroma and more rarely might extend into the anterior chamber. Depending on the size and amount of penetration of the lesion, different therapeutic approaches are indicated. Depth information is difficult to obtain by slit-lamp examination because the structure is opaque. We investigated the use of ultrasound biomicroscopic (UBM) examination for surgical planning in limbal dermoids. METHODS: The UBM (Zeiss Humphrey) with its 50-MHz probe was used for preoperative evaluation of the depth of penetration in two cases of infantile limbal dermoid. Histology specimens of the lesion corresponding to the UBM images were obtained. RESULTS: UBM was able to distinguish normal cornea from the more sonolucent lesion. Presence or absence of Descemet's membrane could be identified. Depth of involvement of limbal dermoids could be assessed. CONCLUSION: UBM is able to assess depth involvement of opaque corneal lesions such as limbal dermoids. Because planning of the surgical approach in these cases is facilitated by preoperative knowledge about the depth of penetration of these opaque lesions, UBM can be regarded as a helpful tool in the clinical management.

Does head positioning influence anterior chamber depth in pseudoexfoliation syndrome?

PURPOSE: Phacodonesis can occur in pseudoexfoliation syndrome because of impaired zonular support. This study investigates whether the increased mobility of the lens influences anterior chamber depth in patients with pseudoexfoliation while assuming a prone position. METHODS: Central anterior chamber depth was measured in 39 patients with clinically apparent unilateral pseudoexfoliation and elevated intraocular pressure. Patients were placed in a face-up position for 5 minutes, at which time anterior chamber depth and axial length were measured by A scan, and intraocular pressure was measured by Tonopen (Oculab, La Jolla, CA) in both eyes. The measurements were repeated on both eyes after 5 minutes in a face-down position. RESULTS: No significant differences in intraocular pressure or axial length between the prone and supine positions were found in either eye. Anterior chamber depth in eyes with pseudoexfoliation decreased from a mean of 3.08 mm in the supine position to a mean of 2.95 mm in the prone position, whereas mean anterior chamber depth in the fellow eyes decreased from 3.01 mm to 2.97 mm. The decrease in anterior chamber depth when facing down in the eyes with pseudoexfoliation was significantly greater than in the fellow eyes. CONCLUSIONS: In patients with clinically apparent unilateral pseudoexfoliation, the lens seems to be more mobile in the affected eye. This results in a shallower anterior chamber when the head is placed in a prone position. Whether this fact might potentially lead to transient pupillary block when engaging in activities such as facing down while reading warrants further study.

Surgical management of the symptomatic overhanging filtering bleb.

PURPOSE: Large filtering blebs that evolve after trabeculectomies can be bothersome to the patient, especially when overhanging the cornea. Partial bleb excision is warranted to relieve the patient from discomfort or even visual impairment. METHODS: Surgical partial excision of the overhanging corneal part of the bleb was performed in four patients who had undergone earlier trabeculectomy without application of antimetabolites. Duration of follow-up after excision ranged from 9 months to 4 years. RESULTS: Successful reduction of the excessive bleb and continued satisfactory control of intraocular pressure (IOP) were achieved in all four cases. Partial excision of the corneal part of the bleb did not lead to bleb leakage in any of the cases. CONCLUSION: Surgical blunt dissection of the overhanging the morphologic features of the bleb and ensuring continued control of IOP and relief of symptoms. Alternative methods, such as autologous blood injection, cryoapplication, application of trichloracetic acid, or application of Nd:YAG laser, are noninvasive but do not allow precise rearrangement of bleb architecture.

Autologous patch graft in tube shunt surgery.

PURPOSE: To evaluate an alternate method of covering the subconjunctival portion of the tube in aqueous shunt surgery. Evidence of tube erosion, graft-related infection, graft melting, or other associated intraocular complications were evaluated. METHODS: A retrospective study of 16 patients (17 eyes) who underwent tube shunt surgery at Wills Eye Hospital between July 1991 and October 1996 was conducted. An autologous either "free" or "rotating" scleral lamellar graft was created to cover the subconjunctival portion of the tube shunt. RESULTS: All patients were evaluated for at least 6 months, with a mean follow-up of 14.8 months (range 6-62 months). All eyes tolerated the autologous graft well, with no clinical evidence of tube erosion, or graft-related or intraocular complications. CONCLUSION: Autologous patch graft in tube shunt surgery appears--in selected cases--to be an effective, safe and inexpensive surgical alternative to allogenic graft materials. It also offers ease of availability, and eliminates the risk of transmitting infectious disease.

Retinal vessel reaction to short-term IOP elevation in ocular hypertensive and glaucoma patients.

PURPOSE: Regulation of ocular blood flow might be impaired in glaucoma patients. We compared the reaction of retinal vessels to a short-term increase of intraocular pressure (IOP), using a retinal vessel analyzer (RVA), in normal volunteers, ocular hypertensive patients (OH) and primary open angle glaucoma patients (POAG). METHODS: Ten healthy subjects (56+/-8 years, IOP 13.7+/-1.6 mmHg), 10 OH patients (55+/-12 years, IOD 23.4+/-4.1 mmHg) and 11 POAG patients (60+/-11 years, IOP 23.3+/-1.95 mmHg) were evaluated. Arterial and venous retinal vessel diameter was measured continuously before, during and after raising IOP to suprasystolic values by the suction cup method, described as ocular oscillo-dynamography. RESULTS: The change in vessel diameter after the IOP rise differed in its temporal sequence and in absolute values depending on the group examined. In the retinal branch veins the reduction of vessel diameter during the IOP rise was significantly different in POAG (0%+/-6.7) and volunteers (-6.7%+/-8.5; p = 0.06) and in POAG and OH (-6.7%+/-7.0; p = 0.04). At 70-130 sec after IOP increase a dilatation occurred, again differing significantly in POAG (+5.8%+/-3.9) and volunteers (+9.7%+/-4.3; p = 0.03). Systemic blood pressure did not show any significant differences between groups or during the course of the examination. DISCUSSION: At short-term rise in IOP leads to less retinal vessel reaction in POAG patients than in volunteers and OH. This might be due to impaired autoregulation to ocular perfusion changes in POAG patients.