[Multicentric study regarding assessment of the driving ability of LASIK and orthokeratology patients compared with conventionally corrected persons]

PURPOSE

Corneal optical zone induced by LASIK and orthokeratology (Ortho-K) treatment modifies the refraction of the incoming light bundle in its border area in situations of dawn and darkness. Considering the legal regulations of the driver's license and the recommendations of the German Society of Ophthalmology (DOG) and the American Academy of Ophthalmology (AAO), the vision for driving suitability of ortho-K patients is tested and compared with that of LASIK patients and a reference group (juvenile: < 30 years, adult: > 40 years) under different criterions. The examination of the visual acuity, contrast sensitivity under mesopic conditions and glare contrast sensitivity are main topics of the study.

METHODS

This multicentre retrospective study includes 333 eyes of 167 subjects. 65 subjects were habitual wearers of reverse-geometry contact lenses, 60 subjects were treated by LASIK. 42 subjects use glasses, contact lenses or none of them. The follow-up time was 22.8 ± 11.9 months. The measurement of the visual acuity was based on DIN Standard 58220 part 3 and the ISO Standard 8596. The Mesotest II (Oculus Inc.) was used for testing contrast sensitivity under mesopic conditions and glare contrast sensitivity. Detecting the personal evaluation of vision and satisfaction, subjects were instructed to complete a questionnaire (NEI-RQL-42).

RESULTS

Relating to the legal requirements in Germany, sufficient visual acuity was found in 76.7 % of the LASIK group, in 73.9 % of the Ortho-K users and in 85.7 % of the reference group (72.7 % in the adult group, 100 % in the juvenile group). Considering the DOG recommendations under inclusion of mesopic vision and glare sensitivity, 71.7 % of the LASIK subjects and 95.7 % of the Ortho-K subjects are suitable for driving a motor vehicle of the German classes A, A1, B, BE, M, S, L and T. With regard to the legal situation in the USA, 100 % of the Ortho-K users, 93.2 % of the LASIK group, 86.4 % of the adult reference group and 100 % of the juvenile reference group are fit to drive. The evaluation of the subjective questionnaire showed very high ratings in the Ortho-K (mean 85 of 100 points) and the LASIK (mean 86 of 100 points) group with no statistically significant differences.

CONCLUSION

Considering the legal regulations, the volume of the subjects of Ortho-K and LASIK showed no significant difference of individuals considered fit to drive in comparison to a reference group. Neither LASIK nor Ortho-K patients have any restriction in the ability to drive a vehicle. The requirements of the DOG with regard to contrast sensitivity under mesopic conditions and glare contrast sensitivity for driving a vehicle are better fulfilled in the Ortho-K group compared to the group of LASIK patients. According to the DOG recommendations there are fewer subjects that are suitable for driving a motor vehicle as in the reference group. This fact must be discussed preoperatively.

[LASIK - a new treatment or the standard]

Classification of LASIK in refractive surgery and treatment by health insurance, and education by the physician. Results in clinical studies and case law in Germany 2010.

[Mutational analysis of VSX-1 in one patient with posterior polymorphous corneal dystrophy and in three families with hereditary Fuchs endothelial dystrophy]

BACKGROUND

Fuchs endothelial corneal dystrophy is the most common disease of the corneal endothelium. Besides some sporadic cases, an autosomal dominant inheritance is frequently described. Mutations in the VSX-1 gene are identified as the underlying gene defect for a rarer kind of endothelial dystrophy, posterior polymorphous endothelial dystrophy. We report on mutational analysis of the VSX-1 gene in affected and non-affected family members of three families with autosomal dominant inherited Fuchs endothelial corneal dystrophy and one male patient showing posterior polymorphous endothelial dystrophy.

PATIENTS/MATERIALS AND METHODS

From one patient with posterior polymorphous endothelial dystrophy and 10 affected and 15 non-affected family members of three families with autosomal dominant inherited Fuchs endothelial corneal dystrophy DNA was extracted from leukocytes of the peripheral blood and mutational analysis was performed by direct sequencing of the VSX-1 gene.

RESULTS

Screening of the VSX-1 gene did not reveal sequence variants in any affected or non-affected individuals from the three families with Fuchs endothelial corneal dystrophy or the patient with posterior polymorphous endothelial dystrophy.

CONCLUSIONS

The absence of pathogenic mutations in the VSX-1 gene in affected family members of 3 pedigrees indicates that other genetic factors are involved in the development of familial Fuchs endothelial corneal dystrophy. In addition, VSX-1 seems unlikely to be the crucial gene in our patient with posterior polymorphous endothelial dystrophy.

[Results of low-vision rehabilitation in vision impaired patients]

PURPOSE

Diseases of the retina, the optic nerve and the cornea may lead to a non-treatable loss of central vision. We report on low vision rehabilitation in 100 vision impaired patients.

METHODS

Low vision rehabilitation was performed in 100 consecutive patients (61 % AMD, 23 % diabetic retinopathy, 16 % other diseases). Most of the patients were between 70 and 90 years old (78 %). In 62 cases we fitted optic systems for visual rehabilitation of the far distance (Galilei systems 54; Kepler systems 8), in additional 54 of them we fitted optic systems for the reading distance (additional lens 40; others 14; e. g. magnifier, television reader) and in 38 patients we fitted optic systems for visual rehabilitation only of the reading distance (magnifier 21, reading glasses with higher refraction and additional prism system 17).

RESULTS

In 62 patients with low vision fitted with a system for the far distance we reached an increase of the visual acuity of more than one line in 95 %. In all 92 patients fitted with a system for the reading distance the reading of newspaper letters was possible. In 8 patients we could not fit a low vision systems due to handling difficulties.

CONCLUSIONS

We could reach a satisfactory improvement of visual acuity in more than 90 % of the patients fitted for the far and the reading distance. Especially in elderly, vision impaired patients significant improvements in overall quality of life and specific areas of daily living are possible.

TGFBI (BIGH3) gene mutations in German families: two novel mutations associated with unique clinical and histopathological findings

BACKGROUND

To report the clinical, histopathological and immunohistochemical findings of two novel mutations within the TGFBI gene.

METHODS

The genotype of 41 affected members of 16 families and nine sporadic cases was investigated by direct sequencing of the TGFBI gene. Clinical, histological and immunohistochemical characteristics of corneal opacification were reported and compared with the coding region changes in the TGFBI gene.

RESULTS

A novel mutation Leu509Pro was detected in one family with a geographic pattern-like clinical phenotype. Histopathologically we found amyloid together with non-amyloid deposits and immunohistochemical staining of Keratoepithelin (KE) KE2 and KE15 antibodies. In two families and one sporadic case the novel mutation Gly623Arg with a late-onset, map-like corneal dystrophy was identified. Here amyloid and immunohistochemical staining of only KE2 antibodies occurred. Further, five already known mutations are reported: Arg124Cys Arg555Trp Arg124His His626Arg, Ala546Asp in 13 families and five sporadic cases of German origin. The underlying gene defect within the TBFBI gene was not identified in any of the four probands with Thiel-Behnke corneal dystrophy.

CONCLUSIONS

The two novel mutations within the TGFBI gene add another two phenotypes with atypical immunohistochemical and histopathological features to those so far reported.

[Molecular genetic and histopathological examinations for genotype-phenotype analysis in patients with TGFBI-linked corneal dystrophy]

PURPOSE

Different missense mutations in the TGFBI gene cause granular (Groenouw CDGG1, Avellino CDA, Reis-Bücklers CDB1) and lattice (Type I; Biber-Haab-Dimmer; CDL1) corneal dystrophies and, in some reports, corneal dystrophy Thiel-Behnke (CDB2). We report on the mutation spectrum and the genotype-phenotype correlations on the basis of clinical and histopathological examinations of 13 German families with TGFBI-linked corneal dystrophies.

METHODS

In 31 patients with different corneal dystrophies, DNA was extracted from leukocytes of the peripheral blood and mutation analysis was performed by direct sequencing of the TGFBI gene. Clinical and histopathological findings were compared with the molecular genetic findings for genotype-phenotype correlations.

RESULTS

In 6 patients (2 families/one single person) with clinical and histopathological CDL1 we found a Missense mutation Arg124Cys and in 7 patients (3 families/one single person) with clinical and histopathological CDA we found a Missense mutation Arg124His in the exon 4 of the TGFBI gene. In 12 patients (4 families/2 single persons) with clinical and histopathological CDGG1 we found a Missense mutation Arg555Trypt in the codon 12 of the TGFBI gene. In all five patients (1 family/4 single persons) with clinical and histopathological CDB2 we could not find any mutation in the TGFBI gene. In one patient with exceptional clinical and histopathological findings we found a Missense mutation Ala546Asp, which was reported before only twice in connection with polymorphous corneal amyloidosis.

CONCLUSIONS

In comparison of our clinical and histopathological findings and the molecular genetic results we found a strong genotype-phenotype correlation in patients with TGFBI-linked corneal dystrophies. Rare mutations can lead to exceptional clinical and histopathological findings which cannot be classified into the different groups of corneal dystrophies. In our patients with CDB2 we could not find any molecular genetic correlation to the TGFBI gene.

[Principals and clinical applications of optical coherence tomography in glaucoma]

Optical coherence tomography (OCT) supplies morphological information from different retinal layers. In glaucoma, analysis of the nerve fiber layer is gaining more and more significance: Losses in this layer often precede by years functional losses in the visual field and end up in optical nerve head changes. OCT offers a means for imaging and for measurement of the nerve fiber layer besides morphological analysis of ONH as one of the earliest sensitive parameters in modern glaucoma diagnostics. However, because of the lack of extensive comparative data, the priority use of optical coherence morphometry is to be seen mainly in intraindividual follow-up.

[The autologous ipsilateral rotating penetrating keratoplasty: an early surgical procedure to prevent deep irreversible amblyopia in Peters anomaly]

PURPOSE

It is a challenge to prevent irreversible amblyopia in infants suffering from Peters anomaly. In some cases of centrally located corneal opacifications an optical sector iridectomy can not lead to a clear optical axis. The homologous penetrating keratoplasty as early surgical procedure has shown an extremely poor outcome with a high risk of irreversible graft failure. We report on the autologous ipsilateral rotating penetrating keratoplasty in an eight-week-old infant suffering from Peters anomaly.

PATIENTS

An autologous ipsilateral rotating penetrating keratoplasty was performed in an eight-week-old infant suffering from Peters anomaly to prevent irreversible amblyopia.

RESULTS

After a follow-up time of 8 months we saw a clear graft within the optical axis without any complications in wound healing. We removed the single sutures two months after keratoplasty. Postoperative astigmatism could be corrected first by fitting a special nursery contact lens and after reduction of astigmatism because of suture removal we fitted special nursery glasses. The intraocular pressure remained within the normal range during the follow-up period.

CONCLUSION

The autologous ipsilateral rotating penetrating keratoplasty should be considered superior to homologous keratoplasty in infants with Peters anomaly if sector iridectomy is not advisable because of a central corneal opacification. Resulting high refractive errors can be successfully corrected by special contact lens fitting or by nursery glasses.

Lidloading und Augeninnendruck

BACKGROUND

Implantation of rigid gold or platinum lid weights (lidloading) represents the most common method for therapy of patients with lagophthalmus as a result of facial palsy. In a more recent approach also flexible platinum chains have been used. Glaucoma has frequently been described as a contraindication for lidloading. The aim of this study was to proof if lid weights lead to an increase of the intraocular pressure (IOP).

PATIENTS AND METHODS

In a prospective study the IOP has been measured before and after implantation of 46 rigid gold implants and 39 flexible platinum chains in patients with paralytic lagophthalmos.

RESULTS

Neither the implantation of rigid gold implants nor the use of the flexible platinum chain lead to a statistically significant change of the IOP. There was also no difference between the two groups.

CONCLUSION

With this study we could demonstrate that glaucoma is not an absolute contraindication for the use of lid weights in patients with paralytic lagophthalmos. Moreover a lid weight is easily removable if complications should occur.

Das intraokulare Non-Hodgkin-Lymphom und seine Therapie - eine Fallserie mit 10 Patienten

BACKGROUND

The timely and correct diagnosis of intraocular non-Hodgkin's lymphoma represents a huge challenge to clinicians. Two thirds of intraocular lymphomas are a manifestation of a primary CNS lymphoma (PCNSL) arising outside the lymphatic system and are localized in the brain, the meninges or the spinal chord. Ten to twenty percent commence as vitreous or retinal infiltrates mimicking uveitis. Ninety five percent of PCNSL are B cell lymphomas.

PATIENTS

Three exemplary cases from a group of ten patients treated between 1998 and 2002 are presented. A table provides a summary of the relevant details of all ten patients.

RESULTS

The mean age at presentation was 63.5 years with a female to male ratio of 6 to 4. Nine patients were diagnosed as having intermediate or posterior uveitis, in one patient choroidal metastases were suspected. Six patients had a concomitant CNS lesion while four patients showed isolated intraocular lymphoma only. The presence of a highly malignant B cell lymphoma was proven by vitreous biopsy in nine cases and by stereotactic biopsy of a CNS lesion in one patient. All patients were treated by intravenous chemotherapy, however, no binding recommendations with regard to treatment exist to date.

CONCLUSIONS

We give an overview of all current treatment regimens and their pitfalls. At present it is recommended that all patients with proven PCNSL be entered in a multicenter randomized study under the auspices of the Department of Internal Medicine III of the Benjamin-Franklin-University-Hospital, Berlin and the Department of Neurology of the University Hospital of Tuebingen.

Morphological and functional changes due to drug-induced lysosomal storage of sulphated glycosaminoglycans in the rat retina

A series of dicationic amphiphilic drugs, most of them immunomodulatory agents, are known to induce generalised lysosomal storage of sulphated glycosaminoglycans (GAGs) in rats and in cultured cells of several species including man. The present study deals with the cytological effects of two experimental immunomodulatory acridine derivatives upon the retina of rats. The animals were treated orally with compound CL-90.100 (3,6-bis[2-(diethylamino)ethoxy]acridine) or an analogue for periods up to 22 weeks at a dose range of 60-90 mg/kg body weight and the retinae examined by light and electron microcopy. ERG measurements were done initially and after 16 weeks of treatment. All types of retinal cells developed abnormal cytoplasmic vacuoles which represented the ultrastructural counterpart of lysosomal GAG storage as demonstrated by histochemical and cytochemical staining experiments. The retinal pigment epithelium and the Müller cells were most prominently affected, photoreceptor cells to a lesser degree, and retinal neurons to varying degrees. The topographical distribution of the drug as detected by fluorescence microscopy closely resembled the distribution of the GAG accumulation in the retinal layers. After treatment for 16 weeks, the a-and b-wave amplitudes in the ERG were significantly reduced compared with the controls.

CONCLUSION

the glycosaminoglycan storage in pigment epithelium is reminiscent of that seen in some inherited mucopolysaccharidoses of humans. When a given cell type shows lysosomal accumulation of glycosaminoglycans as a consequence of impaired degradation, it can be assumed to be engaged in the turnover of glycosaminoglycans under normal conditions. Thus the present results suggest that not only the retinal pigment epithelium but also Müller cells, photoreceptor cells, and, to variable degree, retinal neurons are normally involved in the catabolism of sulphated glycosaminoglycans. We believe that the lysosomal storage of glycosaminoglycans caused secondary cellular disturbance responsible for the functional changes shown by electroretinography.

[Antimicrobial decontamination of corneal donor material: infection prevention and quality assurance]

BACKGROUND

Microbiological examinations in eye banks have found an increased contamination rate in preservation media. We studied the effect of prolonged submersion time for decontaminating donor globes.

MATERIALS AND METHODS

We retrospectively analyzed the primary contamination of conjunctival smears in 76 cornea donors. The submersion time of donor eyes in PVP iodine solution before preparation was prolonged from 1 min to 5 min, and the contamination rate of storage vessels was compared.

RESULTS

In 13 of the 76 conjunctival smears we found no contamination. Before prolonging submersion time, the preservation medium was contaminated in 15 cases, but after 5 min no contamination was observed.

CONCLUSION

Prolonging the submersion time of donor globes from 1 to 5 min was effective. The model presented here provides guidelines for existing eye banks as well as for those yet to be established.

Microbiological investigations to validate the preparation of corneal transplants

The globe and cornea are colonized by microorganisms and cannot be removed as sterile products. Antiseptic measures and storage of the cornea in medium containing antibiotics lead to an obvious reduction of the microbial flora. Unfortunately there is the possibility of secondary microbial contamination during the preparation. Large amounts of bacteria or resistant bacteria can ruin attempts to reduce the microbial flora. To validate the whole process of preparation we investigated the contamination of removed globes, environment, materials, instruments and media for each sequence of operation and eliminated sources of contamination. Recommendations are given to ensure a virtually sterile product at the end of preparation.

[Bilateral inferior hemianopsia as an early symptom of Heidenhain type Creutzfeldt-Jakob disease]

BACKGROUND

The Heidenhain variant is a subtype of Creutzfeldt-Jakob disease (CJD) where visual symptoms are leading.

HISTORY AND SIGNS

We report on a 60-year-old woman who developed within a few weeks bilateral inferior hemianopsia. Morphological findings of the eyes were normal. Neurological examination and cerebral CT/MRI were normal too. P 100 latency of visual evoked potentials (VEP) of both eyes, however, was delayed.

OUTCOME

During the course of the disease visual field narrowed progressively and 3 months after the first symptoms the patient went blind. Only at that time myoclonia, hyperkinesia, and psychiatric symptoms appeared. Changes of EEG and cerebrospinal fluid were suggestive of Creutzfeldt-Jakob disease (CJD). The patient died after 5 1/2 months and diagnosis was confirmed neuropathologically with mainly occipital spongiform encephalopathy.

CONCLUSION

This case illustrates the diagnostic difficulties of the Heidenhain type of CJD and demonstrates that in patients with progressive visual field defects without morphological abnormalities of the eyes or radiological abnormalities of the brain CJD should be considered. It should be looked out for additional neurological (especially extrapyramidal) and psychiatric symptoms.

[Severe intra- and postoperative supra-choroid hemorrhage. Risk factors, therapy, results]

BACKGROUND

The aim of this study was to analyze risk factors, therapeutic strategies, and functional and anatomic results of eyes with severe suprachoroidal hemorrhage.

PATIENTS

Eight of 11 bleeding episodes occurred intraoperatively and 3/11 postoperatively. Bleeding was associated with the following surgical procedures: perforating keratoplasty (5x), extracapsular cataract extraction (3x), pars plana vitrectomy (2x), intracapsular cataract extraction (1x).

RESULTS

Nine operations were performed with general anesthesia, two after retrobulbar injection. Ocular risk factors (e.g., prior operations, ocular diseases) and general risk factors (e.g., cardiovascular diseases, diabetes) were analyzed. At the end of the follow-up time visual acuity had improved in three eyes, and it was unchanged in one eye and worse in seven eyes. Four eyes were amaurotic; two of them had to be enucleated.

CONCLUSIONS

In spite of using state-of-the-art surgical techniques the prognosis of suprachoroidal bleeding remains serious. Patients who have a combination of several ocular and general risk factors almost exclusively are the ones who afflicted by this complication.

[Examination of resistance of the lens capsule against the waterjet]

BACKGROUND

Although cataract surgery is highly developed today, there are still problems such as secondary cataract. In polishing the posterior capsule lens, epithelial cells often remain, causing secondary cataracts. Additionally, there are the problems of tissue heating and endothelial cell loss during phacoemulsification by ultrasound. This could be another field for improvement of cataract surgery by using the waterjet.

METHODS

After removing the cornea of freshly enucleated porcine bulbs, we used the water jet from 4 to 12 bar. The hit angel on the capsule varied between 45 degrees and 90 degrees.

RESULTS

Rupture of the posterior capsule occurred at a mean of 8.5 bar using the jet at 45 degrees and a mean of 8.6 bar using the jet at 90 degrees.

CONCLUSION

The waterjet pressure should not be over 4 bar during polishing of the posterior capsule.

[Corneal astigmatism as a special complication after lid-loading in patients with lagophthalmos]

Lid-loading with precious metals, described by Illig in 1958, has become increasingly important. because of its good functional and cosmetic results this method is superior to tarsorrhaphy. Furthermore, lid-loading can be combined with additional surgical techniques to achieve more dynamic lid-closure. In a prospective study we examined the results after lid-loading and discuss postoperative changes of the cornea.

PATIENTS AND METHODS

Between May 1994 and June 1998, 36 patients with peripheral facial paresis and lagophthalmos were treated with a pretarsally fixed upper-lid implant. We used 99.99% gold for the implants with a weight of 1.5 g on average.

RESULTS

In all cases we obtained sufficient postoperative lid closure which resulted in a statistically significant reduction in lagophthalmos and improved keratopathy. Postoperative complications were: pseudoptosis, remaining lagophthalmos, bulge, extrusion, migration and corneal astigmatism. Depending on the implant pressure, an astigmatism of 1-2 D developed in the vertical meridian. In all cases the initial visual acuity was reached by an ordination of cylindrical glasses.

CONCLUSIONS

So far, corneal astigmatism as a complication after lid-loading has not received much attention in the literature. In our opinion, the development of astigmatism is caused by implants that are too heavy, an incorrect implant radius and individual cofactors (consistency of lid and cornea). There has been no need for an explantation in any case.

Early expression of proinflammatory cytokines interleukin-1 and tumor necrosis factor-alpha after corneal transplantation

This study's aim was to determine the early postoperative expression of proinflammatory cytokines interleukin-1 (IL-1) and tumor necrosis factor-alpha (TNF-alpha) by corneal grafts. BALB/c (n = 90) and C57BL/6 (n = 90) murine recipients were grafted with donor corneas from either syngeneic or allogeneic mice. At 7 and 14 days after surgery, corneal grafts were excised and the recipient rims separated from the donor tissue. Corneal segments were cultured and assayed for cytokines by enzyme-linked immunosorbent assay (ELISA). There was profound upregulation in expression of both IL-1alpha and TNF-alpha after corneal transplantation. Among both low-rejecting BALB/c and high-rejecting C57BL/6 hosts, levels of IL-1alpha were significantly (p < 0.01) more marked in allogeneic as compared to syngeneic grafts. TNF-alpha overexpression was similarly more marked in allogeneic as compared to syngeneic grafts in both BALB/c and C57BL/6 hosts, although the difference was generally more marked among high-rejecting C57BL/6 recipients. In the case of both IL-1alpha and TNF-alpha, the principal source of cytokine expression in the transplanted tissue was the recipient rim. There is significant overexpression of both IL-1alpha and TNF-alpha during the first 2 weeks after transplantation in both syngeneic and allogeneic orthotopic corneal grafts. However, whereas in syngeneic grafts cytokine expression generally decreases after the first postoperative week, significantly elevated cytokine levels are sustained in allogeneic grafts, implicating IL-1 and TNF-alpha as mediators of the alloimmune response in corneal transplantation.

[Cutting edges after automatic lamellar keratotomy]

BACKGROUND

In order to perform an automatic lamellar keratotomy microkeratomes are used, which differ from each other in several technical details. This study was done to examine, whether there are characteristics of the cutting edge, typical of each device, and whether there are some correlations between the cutting quality and technical parameters.

METHODS

In Germany seven different keratomes are used today. We performed the procedure of automatic lamellar keratotomy by using each of them on 8 fresh enucleated pig eyes and we examined the corneal tissue by means of scanning electron microscopy. The cutting edges were judged by their smoothness and sharpness.

RESULTS

A dominantly smooth cutting edge was found on the corneas cut by the MKM-System, the Universal Keratome and the BK-Microkeratome Set, while the Automatic Corneal Shaper, the Microtech-Mikrokeratom, the Rotor-Keratom and the Schwind-Mikrokeratom mostly produced a saw-toothed edge.

CONCLUSIONS

The quality of the cutting edge may be influenced by the relationship of the speed of the pass and the rate of blade oscillation/rotation. Therefore it seems that a lower feed during one oscillation/rotation results in a more smooth pattern of the cutting edge.

[Potential of the water jet in cataract surgery]

Though cataract surgery is highly developed today, there are still problems such as endothelial cell loss after surgery and the occurrence of aftercataract. To reduce these complications we looked for techniques with a high degree of safety and precision. We found the water jet, an instrument already well established in liver surgery. We tested the possibility of improving the results of cataract surgery using the water jet method.

METHODS

We performed cataract surgery--phacoemulsifikation and polishing of the capsule--on freshly enucleated porcine bulbs using water jet and by conventional procedures. By scanning electron microscope examination we compared the results. Additionally we emulsified human lens nuclei obtained by extracapsular cataract extraction using the water jet.

RESULTS

The epithelial cells and lens fragments on the capsule were considerably reduced after the water jet procedure.

CONCLUSION

The results show the possibility of improvement of cataract surgery by using the water jet. Further studies are necessary to adapt this technique to routine surgery in humans.

Effects of the pharmaceutical cosolvent hydroxypropyl-beta-cyclodextrin on porcine corneal endothelium

BACKGROUND

The influence of the pharmaceutical cosolvent hydroxypropyl-beta-cyclodextrin (HPBCD) on porcine corneal endothelium was investigated. The purpose was to find out if this substance causes severe damage to the cornea. METHODS; One hundred and ninety-five pig corneas were preserved in Eagle's minimal essential medium with dextran and HPBCD. They were stained with trypan blue, examined using a light microscope and then reincubated. Changes in cell density and cell morphology as a function of the duration of preservation and the HPBCD concentration were evaluated. We developed a morphological classification combining the morphological aspects observed using the light microscope and the scanning electron microscope. The vitality of the endothelium was analyzed by cell separation and monolayer cultivation.

RESULTS

The cell density stayed stable without significant alterations in 0.1% HPBCD, 1% HPBDC and control solutions. In 10% HPBDC, however, the endothelium showed significant loss of cells. The morphological classification revealed high-grade endothelial damage in 10% HPBDC and low-grade damage in 1% HPBCD. The changes observed in 0.1% HPBCD and control medium were comparable. The degree of alteration conformed to the results of monolayer cultivation: endothelial cells of damaged corneoscleral buttons were limited in their ability to proliferate.

CONCLUSION

Severe endothelial destruction in 10% HPBCD and changes in membrane integrity at lower concentrations limit the use of HPBCD in ophthalmic solutions.

[Consequent use of the Aachen therapy concept after severe chemical burns of both eyes]

BACKGROUND

Severe chemical burn and its complications still are a serious threat to the afflicted eye, particularly in case of insufficient treatment. Rehabilitation of visual acuity can be achieved only in the minority of cases.

PATIENT

We present a 49-year-old female patient, who suffered a severe chemical burn in both eyes by alcaline detergent. Visual acuity was OD 20/50, OS light perception. After directly started acute treatment as well as peritomy, peridectomy, tenon plasty and application of a PMMA contact lens a stabilization was achieved. Complete rehabilitation of visual acuity was gained by EDTA abrasion, excimer treatment, penetrating keratoplasty and cataract surgery. Last examination showed a visual acuity of 25/20 in both eyes.

CONCLUSIONS

Even in severe chemical burn an optimal result can be achieved by using an adequate treatment conception. Immediate beginning of therapy is important as well as persistent and persevering application of the treatment. Repeated, if necessary daily, excisions of necrotic tissue associated with tenon plasty and application of a PMMA contact lens have special importance.

[Intraoperative skiascopy for determining the refractive value of an implantable intraocular lens]

BACKGROUND

Preoperative biometry for calculation of the refractive power of intraocular lenses is not sufficiently reliable in certain cases. Most frequently inaccuracies tend to occur in highly myopic eyes. Preceding refractive procedures can also impair IOL-calculation or even make it impossible.

PATIENTS

In a highly myopic patient IOL-power calculation was not possible with conventional calculation formulas due to a preexisting refractive silicone lens located between the cataractuous natural lens and the iris. In another myopic patient ultrasound measurement of axial eye length produced variable and unreliable results. Therefore retinoscopy was performed intraoperatively in the aphakic eye. Refractive power of the IOL was calculated using a new formula. For validation of the method retinoscopy was performed intraoperatively in a second group of 11 patients with unproblematic ultrasound biometry.

RESULTS

In 3 eyes IOL power was chosen according to intraoperative retinoscopy. A maximal deviation of 1.25 D from the aimed refraction resulted. In the second group, the retinoscopic method produced partially considerably inaccurate results as compared to the ultrasound biometry. Inaccuracies increased with the extent of hyperopia.

CONCLUSIONS

In cases of difficult or inaccurate preoperative ultrasound biometry IOL power can be estimated after intraoperative retinoscopy in the aphacic highly myopic eye. IOL power can be calculated instantly using computer programs or tables. This method additionally enables the surgeon to control the refractive result of intraocular lens implantation prior to wound closure. However this method lacks reliability in higher hyperopic eyes, as in these cases small changes in corneal vertex distance of the lens used for retinoscopy highly alter the result.

Effects of viscoelastics on bovine corneal endothelial cells in vitro

PURPOSE

To evaluate the possible toxic effects of sodium hyaluronate and hydroxypropyl methylcellulose on corneal endothelium.

METHODS

Cultured bovine corneal endothelial cells (BCEC) were treated with either original Healon (10 mg/ml) or Methocel (20 mg/ml) for 1 h, or with various dilutions of these substances in culture medium for up to one week. The toxicity of the viscoelastics was assessed in terms of lactate dehydrogenase (LDH) release into the supernatant and of cell density.

RESULTS

Neither Healon nor Methocel in a dilution of 2 mg/ml enhanced LDH release after 72 h incubation, when compared with the control in a confluent model. In a proliferation model neither diluted Healon nor Methocel showed apparent inhibitory or stimulatory effects on the growth of BCEC up to the highest concentration we tested. When a BCEC monolayer was covered for 1 h with either undiluted Healon or undiluted Methocel, a significant, though transient, higher LDH release was induced.

CONCLUSION

The results indicate that the diluted viscoelastics are safe for long time contact with BCEC, but undiluted they may temporarily interfere with the metabolism of the cytoplasm membranes of BCEC.

MRI of the nasal cavity, the paranasal sinuses and orbits in Wegener's granulomatosis

The purpose of this study was to evaluate diagnostic MRI criteria in Wegener's granulomatosis of the nasal cavity, the paranasal sinuses and orbits. Between March 1991 and January 1996, 62 patients with biopsy-proven Wegener's granulomatosis were studied with T1- and T2-weighted spin-echo (SE) sequences. In 32 patients coronal postcontrast T1-weighted images were obtained. Mucosal thickening of the nasal cavity and paranasal sinuses was demonstrated as high-intensity lesions on T2-weighted SE sequences in 57 patients (92%). Of this group, inflammatory granulomatous tissue was found on biopsy in 30 patients (48%) in the nasal cavity and in 4 patients (6%) in the paranasal sinuses. In 23 patients (37%) biopsy revealed unspecific inflammatory changes without evidence of granulomatous tissue. In 14 patients (23%) granulomas were depicted as low-signal intensity lesions on T1- and T2-weighted SE sequences in the paranasal sinuses and orbits. In 5 patients (8%) osseous destruction was found. After gadolinium injection, 12 of 14 granulomas showed inhomogeneous signal enhancement. In two granulomas no enhancement was found. The MRI technique is helpful in the diagnosis of patients with Wegener's granulomatosis. In the initial inflammatory process of Wegener's granulomatosis, it is not possible to differentiate between mucosal inflammation and granulomatous tissue in MRI. In the later stage of granulomatous transformation, granulomas can be depicted as low-signal-intensity lesions. Therefore, Wegener's granulomatosis should be included in the differential diagnosis of patients with low-signal-intensity lesions on T1- and T2-weighted SE sequences of the nasal cavity, paranasal sinuses and orbits.

Expression of adhesion molecule CD44 on human corneas

AIMS

This study was undertaken to confirm the distribution and expression of the molecule CD44 on human corneas under normal and pathological conditions.

METHODS

Fifty eight corneal buttons from adult patients suffering from various corneal diseases and four normal corneas were included in this study. Frozen sections were stained immunohistochemically with monoclonal antibodies against human CD44 using an APAAP method and observed under a light microscope.

RESULTS

In normal corneas CD44 was predominantly expressed on the membranes of basal epithelial cells and on the keratocytes, as well as on the vascular endothelial cells of the corneal limbi, but was not expressed on corneal endothelial cells. Enhanced expression of CD44 was observed on the epithelium of corneas with inflammation and allograft rejection. In a number of abnormal conditions including allograft rejection, corneal trauma, primary and secondary corneal endothelial decompensation the remaining endothelial cells stained positively for CD44. However, in some corneas of keratitis, keratoconus, and dystrophy the endothelium which appeared relatively integral in morphology and amount remained CD44 negative.

CONCLUSIONS

These results suggest that CD44, the hyaluronate receptor, may play an important role in corneal cell-cell and cell-matrix interactions. Its regulation is closely related to corneal inflammatory reactions. The induction of CD44 on corneal endothelium might play a potential role in compensatory processes when corneal endothelial cells are injured.

[New permanent humidity chamber in dry eye disorders]

BACKGROUND

In corneal lubrication or eyelid closure disorders it may be necessary to apply a monoculus to protect the eye from drying out. Changing the monoculus involves dermal irritation. Furthermore, because the monoculus is not completely airtight, the desired humidity is not achieved.

INSTRUMENT

We introduce a tape-free permanent humidity chamber fastened to a spectacle frame that achieves a relative humidity of more than 98% even over a long period of time. PATIENTS/TESTED PERSONS: Five test persons and two patients with lagophthalmus were treated with a monoculus and with the permanent humidity chamber. Comparative measurements of the humidity achieved with the two methods were done.

RESULTS

For both test persons and lagophthalmus patients the permanent humidity chamber is a good alternative to the monoculus, because it maintains a humidity of more than 98% r/H over a period of eight hours or longer. It consequently provides much better conditions for successful treatment and additionally minimizes skin irritation.

Adhesion molecule expression in bullous keratopathy

BACKGROUND

Adhesion molecules may play an important role in the pathogenesis of bullous keratopathy.

METHODS

The expression of the integrin VLA-beta 1, alpha-subunits of the beta 2-integrins LFA-1, Mac-1, and p150,95, the members of the immunoglobulin family ICAM-1 and VCAM-1, and the selectin ELAM-1 on corneas with bullous keratopathy (BK) secondary to intraocular surgery was studied immunohistochemically using an APAAP method.

RESULTS

In the corneas with BK (in contrast to normal corneas), a downregulation of VLA-beta 1 was observed throughout the corneal tissues, particularly on the epithelial layer where bullae occurred; ICAM-1 was induced on epithelial membranes in both BK and inflamed corneas; and the expression of beta 2-integrins, VCAM-1 and ELAM-1 was upregulated in some specimens with remaining endothelial cells.

CONCLUSION

The results show that the investigated adhesion molecules may participate in the pathogenesis of BK. The decrease in VLA-beta 1 in patients with BK may be an important factor in the occurrence and development of recurrent bullae; the induced ICAM-1 may recruit beta 2-integrin-positive leukocytes into the epithelial layer, thus aggravating epithelial damage; and beta 2-integrins and VCAM-1 may play a role in endothelial injury and decompensation.

Chloroquine-induced lipidosis in the rat retina: functional and morphological changes after withdrawal of the drug

BACKGROUND

The antimalarial and antirheumatic drug chloroquine is one of the most infamous amphiphilic cationic drugs in clinical ophthalmology. It is known to cause lipidosis and photoreceptor degeneration in the human and the rat retina.

METHODS

We treated female albino Wistar rats (mean weight 200 g) orally with chloroquine (95 mg/kg body weight) for 12 weeks, followed by a period of 4 months with normal feed. After initial electroretinography in all rats, measurements were made after 4 and 12 weeks of treatment and 16 weeks after withdrawal. The rats were prepared for histological examination.

RESULTS

Treatment of rats with chloroquine caused severe lipidosis in the neuroretina; photoreceptor cell degeneration was slight. After 12 weeks of treatment, the b-wave amplitude was reduced to 30% of the initial value; the a-wave amplitude was reduced, but remained within the range of normal values. After withdrawal of chloroquine the lipidosis remitted, but the degeneration of the photoreceptor cell layer continued to progress. Despite remission of lipidosis, electroretinography demonstrated functional disturbances, marked by reduction of the a- and b-wave amplitudes to 25% and 16% of initial values, respectively.

CONCLUSIONS

Seen from the point of view of function, it is doubtful whether lipidosis is the primary cause of changes in the electroretinogram or of receptor cell degeneration.

Cross-matches on donor cadaver retinal pigment epithelial cells in corneal risk patients

BACKGROUND

Allografts can be rejected either through the antibody-mediated or cellular pathways. The objective of this study was to look at the extent of antibody formation in patients awaiting re-keratoplasty using cross-matches on cadaver retinal pigment epithelial (RPE) cells.

METHODS

Cadaver RPE cells were derived by trypsin digestion from donor eyes (n = 1200). After 3 days of cell cultivation, the cells were adherent and began to lose their pigment. By day 7 most cells were clear and grew as a polygonal monolayer. MHC class I expression by RPE cells was studied by the W6/32 (anti-HLA-A, B, C) monoclonal antibody (MoAb) and that of class II (HLA-DR) by the 136 MoAb. Normal RPE cells express few class I and no detectable class II antigens. For the induction of MHC expression, cells were subsequently stimulated with 250 U/ml of recombinant gamma-interferon for 5 days. Cells were used for tissue typing and also for cross-matches with recipient serum. Cross-matches were subsequently performed and measured by flow cytometry.

RESULTS

Both class I and class II antigens were strongly enhanced, as could be shown by immunohistochemical staining. Some 20% of those patients awaiting rekeratoplasty (n = 60) were positive for anti-HLA antibodies. In one case anti-DR3 antibodies were detected in a recipient who had had several rejection episodes after keratoplasty.

CONCLUSIONS

RPE cells are not only useful for cadaver post-mortem HLA typing but also for donor-specific cross-matches. The degree of antibody formation after keratoplasty in rejecting patients was, however, low. This may imply that anti-HLA antibodies are not the major cause of corneal graft loss after keratoplasty.

Indirect immunofluorescence study of the cornea and the conjunctiva in a xenogeneic system: analysis of humoral reactivity in patients with Wegener's granulomatosis

BACKGROUND

Ocular involvement in patients with Wegener's granulomatosis (WG) can cause progressive loss of vision. The pathophysiological events leading to the WG-specific ocular inflammation are unknown.

METHODS

A method involving indirect immunofluorescence on bovine and porcine corneoconjunctival frozen sections was used to detect antibodies to corneal and conjunctival epithelium in serum samples from patients suffering from WG with ophthalmic involvement (orbital granuloma or ocular vasculitis, both active and inactive phase). Normal persons and WG patients without ophthalmic involvement served as control groups. Anti-human IgG, IgA and IgM were tested.

RESULTS

Five different immunofluorescence patterns could be distinguished in each species. There were differences in the reactivity with bovine and porcine tissue. Every pattern was caused mainly by human IgG. The antibodies were directed to the cell nuclei or to extranuclear structures. All patterns also occurred frequently in normal sera. No pattern was found that occurred specifically in the serum of patients with WG and ocular inflammation.

CONCLUSIONS

The results indicate that this immunofluorescence system does not detect a characteristic antibody profile that could be attributed to the serum of WG patients. Hence the approach lacks clinical usefulness as a diagnostic procedure.

Adhesion molecules in normal and pathological corneas. An immunohistochemical study using monoclonal antibodies

BACKGROUND

Adhesion molecules are cell surface receptors that are probably important in various cell-cell and cell-extracellular matrix interactions of the cornea.

METHOD

In this immunohistochemical light-microscopic study we analyzed the expression pattern of adhesion molecules in normal and pathological human corneas (cases of corneal inflammation and degenerative disorders). The analyzed molecules included the beta 1 integrin or VLA family VLA-1-6, the beta 2 integrins or leukocyte integrins LFA-1, Mac-1, and p150,95, the immunoglobulins LFA-3, CD2, ICAM-1 and VCAM-1 and the selectins ELAM-1 and GMP-140.

RESULTS

Inflamed cornea (in contrast to normal cornea). On corneal epithelium, increased expression of the alpha 2 subunit of VLA-2 was detected and ICAM-1 was induced on the basal epithelial cells. On corneal stromal keratocytes, LFA-3 was induced and expression of the alpha subunits of VLA-1-6 and ICAM-1 was increased. On vascular endothelium, VCAM-1 and ELAM-1 were induced and ICAM-1 and GMP-140 expression was increased. On corneal endothelium, ELAM-1 was induced and increased levels of the alpha 1 subunit of VLA-1 and GMP-140 were expressed. Degenerative disorders (in contrast to normal cornea): In corneas with degenerative disorders we found decreased expression of adhesion molecules.

CONCLUSION

Inflammatory cytokines increase the expression of the adhesion molecules. Increased expression of the VLAs probably promotes cell-extracellular matrix and cell-cell interactions. ICAM-1, VCAM-1, LFA-3, ELAM-1 and GMP-140 expression was increased on vascular endothelium in inflamed corneas. Corresponding receptors on leukocytes probably enable a selective recruitment of different leukocyte populations in inflammatory corneal diseases. The decreased expression of adhesion molecules in corneal degenerative disorders is probably a sign of reduced cell-cell and cell-extracellular matrix interactions.

Recognition performance of subjects with color-vision deficiencies on a polychromatic sonar screen for ship navigation

To facilitate differentiation between objects that are approaching, stationary, and moving away, these objects are represented in different colors on the screens of sonar locating devices used in ship navigation. Yellow represents stationary objects, and represents approaching objects, and green represents those objects moving away. A total of 46 subjects with normal color vision and 184 individuals with color-vision deficiencies, among them 29 deuteranopic, 100 deuteranomalous, 21 protanopic and 34 protanomalous individuals, were investigated for their ability to identify different signals. Ten different objects were presented for a period of 64 s each. As a minimal requirement it was established that 50% of the respective experimental group be capable of recognizing the objects within half of this time. Whereas 73.3% of the subjects with normal color vision could meet this requirement, none of the subjects in the different groups with color-vision deficiencies could do so. Only 16.1% of the deuteranopic subjects, 33.1% of the deuteranomalous individuals, 16.2% of the protanopic subjects, and 37.6% of the protanomalous individuals detected all objects within 32 s. No appreciable difference in the ability to recognize signals occurred among the different groups of subjects with color-vision deficiencies.

Chloroquine-induced lipidosis in the rat retina: a functional and morphological study

Corneal opacity, reversible retinal lipidosis and irreversible receptor cell degeneration are known to occur after long-term treatment with chloroquine. Female albino Wistar rats (initial age 6 weeks, weight between 100 and 150 g) were treated orally with chloroquine (40-60 mg/kg body weight) for 4 weeks and with 70-80 mg/kg body weight for the following 4 (group A) and 8 weeks (group B). The animals were submitted to electroretinography ERG, and the retinas were prepared for histological investigation. After treatment with chloroquine for 8 weeks, lipidosis-like inclusions could be seen in the rat retina. A deformation of the receptor cell layer was not observed by light microscopy. The a-wave amplitude decreased to 33% and the b-wave amplitude to 40% of the values before treatment. In contrast to group A, we found receptor cell degeneration and macrophage-like cells in the peripheral and central retina in rats treated for 12 weeks. These changes were probably responsible for a-wave and b-wave reductions of 50 and 79% of values before treatment, respectively. It can be assumed that changes in ERG parameters in the first period are caused by lipidosis. Later extremer deformation is induced by receptor cell degeneration and accompanying lipidosis.