[Revision after filtration surgery]

BACKGROUND

In contrast to all other glaucoma surgeries, filtration surgery is associated with biomicroscopically visible wound healing, which enables the surgeon to perform revision surgeries if necessary.

OBJECTIVES

The aim of this review is to provide general considerations and to give a structured overview about bleb revisions after trabeculectomy.

MATERIALS AND METHODS

The different revision techniques are explained in detail and in the context of perioperative management.

RESULTS

Preoperative preparation and modifications of the surgical techniques reduce the incidence of postoperative revisions. The site of the fibrosis defines the revision technique (bleb needling, needle revision, bleb revision with reopening). The increased percolation rate of aqueous humor in postoperative hypotony contributes to fibrosis and may lead to maculopathy, choroidal effusion, and suprachoroidal hemorrhage.

DISCUSSION

Discontinuing administration of local medication and pretreatment with steroids without preservative for at least one week prior to surgery increase surgical success of trabeculectomy and reduce the incidence of postoperative revisions. Postoperative management after filtration surgery should be performed after consulting the surgeon. The primary endpoint of trabeculectomy is an intraocular pressure between 8 and 12 mm Hg without local antiglaucomatous medication. In postoperative hypotony revisions should be done earlier and based on the pathological findings.

[Medicinal glaucoma therapy. What can we learn from large randomized clinical trials?]

The prospective multicenter randomized controlled clinical trials (RCTs) Ocular Hypertension Glaucoma Treatment Study (OHTS), Early Manifest Glaucoma Trial (EMGT), Advanced Glaucoma Intervention Study (AGIS), Collaborative Initial Glaucoma Treatment Study (CITGS) and Collaborative Normal Tension Glaucoma Study (CNGTS) are often named as landmarks for glaucoma management as the results of these studies provided the evidence for numerous therapeutic decisions in clinical practice. The studies confirmed the consensus that reduction of intraocular pressure reduces the risk of glaucoma progression covering the whole spectrum of glaucoma from ocular hypertension to advanced glaucoma. Furthermore, the identification of new risk factors allows a higher precision of assessment of the risk of progression. The RCTs achieved the main goal of high level of evidence, thus making progress in the understanding of glaucoma and its treatment and bridging consensus-based and evidence-based decisions. However, the implementation of the results into clinical practice needs adequate and accurate interpretation of the results.

[Diagnosis and therapy of pseudoexfoliation glaucoma]

Pseudoexfoliation (PEX) glaucoma is the most frequent and most important type of secondary glaucoma, accounting for approximately 25% of open angle glaucoma worldwide and currently representing the most common identifiable cause of glaucoma overall. Due to high intraocular pressure levels, marked diurnal pressure fluctuations and spikes, and rapid optic nerve damage and visual field loss, PEX glaucoma represents a relatively severe and progressive type of glaucoma. Therefore, hard and fast lowering of intraocular pressure is necessary. Fixed combinations in medical therapy and early glaucoma surgery are recommended. When considering a surgical procedure (e.g. selective laser trabeculoplasty, bleb-dependent or bleb-independent surgery) the timing of cataract surgery plays a major role. Pathogenesis, clinical characteristics and therapeutic aspects of PEX glaucoma are described in the following article.

[Selective lacrimal sac biopsy for external dacryocystorhinostomy: a clinical pathological study]

BACKGROUND

Tumors of the lacrimal drainage system are rare but potentially life-threatening. The purpose of this study was to investigate the applicability of selective lacrimal sac biopsy in 500 cases of external dacryocystorhinostomy for acquired dacryostenosis.

PATIENTS AND METHODS

Lacrimal sac biopsy was obtained selectively for atypical clinical and/or intraoperative findings. The frequency and spectrum of biopsies were recorded and correlated with the follow-up results.

RESULTS

Lacrimal sac biopsy was performed in 19 external dacryocystorhinostomies (3.8%) including non-Hodgkin B-cell lymphoma (3), squamous carcinoma (2), mucoepidermoid carcinoma (1), malignant melanoma (1), oncocytoma (1), pyogenic granuloma (4), Wegener's granulomatosis (4) and sarcoidosis (3). Within 5 years none of the patients without biopsy developed systemic inflammatory diseases or lacrimal neoplasms. The 5-year survival was 87% in patients with significant lacrimal sac pathology and 96% in patients without significant pathology.

CONCLUSION

External dacryocystorhinostomy with selective biopsy for atypical clinical and intraoperative findings allows safe diagnosis and management of potentially life-threatening lacrimal lesions.

[Web-based electronic patient record as an instrument for quality assurance within an integrated care concept]

OBJECTIVE

A prerequisite for integrated care programmes is the implementation of a communication network meeting quality assurance standards. Against this background the main objective of the integrated care project between the University Eye Hospital Erlangen and the health insurance company AOK Bayern was to evaluate the potential and the acceptance of a web-based electronic patient record in the context of cataract and retinal surgery.

METHODS

Standardised modules for capturing pre-, intra- and post-operative data on the basis of clinical pathway guidelines for cataract- and retinal surgery have been developed. There are 6 data sets recorded per patient (1 pre-operative, 1 operative, 4-6 post-operative). For data collection, a web-based communication system (Soarian Integrated Care) has been chosen which meets the high requirements in data security, as well as being easy to handle. This teleconsultation system and the embedded electronic patient record are independent of the software used by respective offices and hospitals. Data transmission and storage were carried out in real-time.

RESULTS

At present, 101 private ophthalmologists are taking part in the IGV contract with the University Eye Hospital Erlangen. This corresponds to 52% of all private ophthalmologists in the region. During the period from January 1st 2006 to December 31st 2006, 1844 patients were entered. Complete documentation was achieved in 1390 (75%) of all surgical procedures. For evaluation of this data, a multidimensional report and analysis tool (Cognos) was used. The deviation from target refraction as one quality indicator was in the mean 0.09 diopter.

CONCLUSIONS

The web-based patient record used in this project was highly accepted by the private ophthalmologists. However there are still general concerns against the exchange of medical data via the internet. Nevertheless, the web-based patient record is an essential tool for a functional integration between the ambulatory and stationary health-care units. In addition to the telemedicine functions of the system, we achieved the export of the data to a data warehouse system in order to provide a flexible and powerful tool for quality assurance analysis and reporting.

[Peripheral suprathreshold stimulation in preperimetric glaucoma]

BACKGROUND AND PURPOSE

Early glaucomatous visual field defects can occur outside the central 30 degrees , which is usually examined in perimetric tests used for glaucoma diagnosis and screening. This study aimed to evaluate the diagnostic value of peripheral suprathreshold stimulation in open angle glaucoma before the development of reproducible visual field damage in standard 30 degrees automatic white-on-white perimetry.

METHODS

A total of 352 eyes of 352 patients (ages 35-69 years; visual acuity 0.8 or better) from the Erlanger Glaucoma Registry were included in this study. They were divided into two groups: normal eyes and preperimetric glaucoma. All patients underwent a standardized glaucoma examination including Octopus 500EZ static perimetry (G1 program, all three phases); 95 eyes of 95 patients also received a 135-point suprathreshold test pattern of the Humphrey Field Analyzer (model 750i) for detecting peripheral visual field defects. Sensitivity and specificity were calculated for any single test point in phase 3 of the G1 test pattern and the Humphrey 135-point pattern. A score was calculated, and cluster analysis was performed.

RESULTS

In 33 of 176 (18.8%) eyes with preperimetric glaucoma, the score was 3 or higher in phase 3 of the G1 program (normal eyes: 19 of 196; 9.7%). For both examination modalities, the highest sensitivity was found in test locations in the superior nasal midperiphery, corresponding to neuroretinal rim loss predominantly in the inferotemporal sector in early glaucomatous optic disc atrophy.

CONCLUSION

Positive test results using suprathreshold stimulation in the midperiphery can be found in patients with preperimetric glaucoma at a significantly higher frequency than in normal subjects. Longitudinal studies will show whether such tests can be useful for predicting perimetric manifestation of the disease.

Increased homocysteine levels in tear fluid of patients with primary open-angle glaucoma

AIMS

We assessed homocysteine (Hcy) levels in tear fluid and plasma of patients with primary open-angle glaucoma (POAG). We determined the association between Hcy levels, dry eye syndrome and B vitamin status.

METHODS

This prospective case-control study included 36 patients with POAG and 36 controls. Hcy concentrations were measured by high-performance liquid chromatography.

RESULTS

Patients with POAG had significantly higher mean Hcy levels both in tear fluid (205 +/- 84 nmol/l; p < 0.001, t test) and in plasma (13.43 +/- 3.53 micromol/l; p = 0.001, t test) than control subjects (130 +/- 53 nmol/l and 10.50 +/- 3.33 micromol/l, respectively). Hcy in tear fluid was significantly correlated with plasma Hcy in POAG patients (r = 0.459; p = 0.005, Pearson's correlation), but not in controls (r = 0.068; p = 0.695). POAG patients with dry eye disease had significantly higher Hcy levels both in tear fluid and plasma than POAG patients without dry eye disease. There was no association between Hcy levels and B vitamin status in subjects with POAG.

CONCLUSIONS

The study suggests increased Hcy levels in tear fluid and plasma of patients with POAG. Elevated Hcy levels might be a risk factor for POAG and dry eye syndrome in subjects with glaucoma.

[Eye disease and mode of delivery]

Many ophthalmologists and obstetricians recommend either an assisted vaginal delivery with forceps or vacuum extraction or a Caesarean section in cases of pre-existing eye diseases such as severe myopia, retinal detachment, diabetic retinopathy, or glaucoma. These recommendations, however, are not evidence-based. None of the published trials have reported any retinal changes after vaginal delivery. In general, eye disease is not an indication for an instrumental or operative delivery provided that regular eye examinations (once each trimester) have been performed.

Vitamin deficiency and hyperhomocysteinemia in pseudoexfoliation glaucoma

Pseudoexfoliation syndrome (PEX) is a systemic disorder characterized by the deposition of an abnormal fibrillar material in ocular and various extraocular tissues. It represents the most common identifiable cause of glaucoma (PEX glaucoma = PEXG). Due to similar pathogenetic mechanisms, glaucoma has been called "ocular Alzheimer's disease". PEXG and Alzheimer's disease share common associations such as the higher prevalence of hyperhomocysteinemia in both disorders. In order to investigate the cause of hyperhomocysteinemia in PEXG, we evaluated B-vitamin levels (folate, B12, B6) and their associations with homocysteine (Hcy) in plasma of 70 PEXG patients and 70 control subjects. Folate, vitamin B12 and B6 levels were significantly decreased and associated with elevated Hcy levels in PEXG. Low B-vitamin levels in PEX might also help explain, at least in part, the higher prevalence of B-vitamin deficiency in disorders associated with PEX such as Alzhemier's disease.

Homocysteine levels in aqueous humor and plasma of patients with primary open-angle glaucoma

We determined homocysteine (Hcy) levels in aqueous humor (AH) and plasma and their association with B-vitamin levels in patients with primary open-angle glaucoma (POAG) and controls. Both AH Hcy and plasma Hcy levels were significantly increased in POAG, and elevation of AH Hcy and plasma Hcy was a significant risk factor for POAG. In contrast to controls, neither plasma nor AH Hcy of POAG patients demonstrated a significant association with important non-genetic determinants of elevated Hcy such as low B-vitamin levels, increasing age and caffeine consumption. Considering that Hcy is a neurotoxin that induces apoptotic retinal ganglion cell death via stimulation of the N-methyl-D-asparate (NMDA) receptor, increased Hcy concentrations in AH and plasma might contribute to the optic nerve damage in POAG.