Ralf Kuckelkorn

Perfluorohexyloctane as a long-term vitreous tamponade in the experimental animal

Background: Perfluorocarbon liquids are established tools for intraoperative hydrokinetic retinal manipulation. Because of their high specific gravity, however,they may well cause mechanical damage to the retina whenapplied as a long-term vitreous substitute.Perfluorohexyloctane, a semi-fluorinated liquid fluorocarbon of low specific gravity (1.35 g/cm3), was developed as a long-term vitreous substitute. The current study was performed to investigate intraocular tolerance to perfluorohexyloctane as a long-term vitreous substitute in the experimental animal. Methods: 34 vitrectomised eyes of pigmented rabbits underwent intravitreal injection of 1.0–1.2 ml perfluorohexyloctane or balanced salt solution. In 5 eyes the anterior chamber was filled. During the follow-up period of 3 months, the eyes were examined by slit lamp biomicroscopy, by fluorescein angiography and by electroretinography. The eyes were then enucleated and processed for light- and electron microscopy. Results: Perfluorohexyloctane depicted dispersion beginning between the first and third week. Over a period of 9 weeks no toxic effect on retina, lens and cornea was noticed. At 14 weeks ERG showed a slight decrease in amplitude and early morphological changes in the retina.Conclusion: Our findings suggest that perfluorohexyloctane is tolerated in the rabbit eye for 9 weeks. Since avascular rabbit retina is more susceptible to mechanical and toxic damage than vascularized primate retina, we suggest proceeding from here, and investigating tolerance and quality of tamponade of perfluorohexyl octane in man for up to 9 weeks.

Poor prognosis of severe chemical and thermal eye burns: the need for adequate emergency care and primary prevention.

The epidemiology and wound healing following medical and surgical treatment of 101 patients with 131 severely burnt eyes due to chemical or thermal agents have been analyzed. Most of the accidents occurred at work (72.3%); the majority of the burns were chemical (84.2%), of which 79.8% were caused by alkalis. The long average duration of treatment on ward (5.2 ± 4.1 months) and the high number of surgical interventions (8.0 ± 8.0) indicate the difficulties in treatment and the delayed recovery of the affected eyes. Despite improved possibilities of immuno-suppression after keratoplasty (cyclosporin A) and new methods of surgery (Tenon plasty), the possibilities of an optical rehabilitation are still limited. A visual acuity of 6/60 or better was achieved in 39 eyes (32.2%). Immediate irrigation was reported in 56.1% of accidents at the place of work and in 42.8% of accidents sustained at home. There was a significant difference with respect to the extent of damage, the treatment on ward and the number of surgical interventions. The visual prognosis for eyes which received immediate irrigation was significantly improved. Eye protection was not used in any of the 101 cases. Spread of information is necessary for adequate emergency care for eye burns as well as for permanent employment of protective glasses in high-risk occupations.

Retrospective study of severe alkali burns of the eyes

BACKGROUND Alkali burns are of special interest because of the rapid and deep penetration of alkali into the ocular tissues. PATIENTS AND METHODS This report examines the epidemiology, management and outcome of 42 cases of alkali burns of the eye admitted to the eye clinic of the RWTH Aachen from 1985 to 1992. Aspects examined were the nature of accident, type of alkali, treatment and complications. The intention was to use this information for improvement of prevention and treatment of these cases. RESULTS The age analysis showed the greatest at-risk population were the 20-40 year-old patients. 73.8% were industrial accidents, 30% happened to builders and labourers, 20% in the chemical industry and 20% in machine factories. At home most of the injuries were caused by lime and drain cleaners. Sodium and potassium hydroxide produced more extended and deeper damages than lime due to their rapid penetration through the ocular tissues. A delayed surgical intervention led to a longer time of stay in hospital and to a higher number of operations. All eyes could be prevented from melting, but an optical rehabilitation (visual acuity > 0.3) was achieved only in a few cases (14.5%). CONCLUSION There is a need to ensure adequate public awareness of the danger of alkali burns to the eye. Beside the primary prevention, adequate first aid with immediate and continuous irrigation is of paramount importance. A uniform concept for the management of these severe cases is necessary including an antiinflammatory medical and surgical treatment.

Investigation of enzyme activities in severe burns of the anterior eye segment

In severe burns of the anterior eye segment, including the cornea, limbus and adjacent conjunctiva, ischemia resulted from the necroses. While necrotic conjunctival and subconjunctival tissues may be removed to eliminate the toxic influence, the opaque cornea and ischemic sclera could not be removed. In the surrounding healthy tissues an inflammatory reaction developed, which brought about an infiltration of the damaged tissues by leukocytes and the release of lysosomal marker enzymes.N-Acetylglucosaminidase and cathepsin-d represent a number of other destructive enzymes involved with corneal and corneoscleral ulceration. Initially, their activities were low in the turbid, acellular cornea and increased 3 weeks after the burn. In the surrounding conjunctiva, these enzyme activities were normally higher than in the cornea and increased significantly after the burn. The elevated activites ofN-acetylglucosaminidase and cathepsin-d in the conjunctiva and cornea were related clinically to corneal and corneoscleral ulceration.

Tenonplasty: A New Surgical Approach for the Treatment of Severe Eye Burns

BACKGROUND AND OBJECTIVE In the acute stage of most severe eye burns, the primary goal is survival of the globe. Initial tissue destruction may lead to extensive necrosis of the conjunctiva and underlying tissue down to the fornices, with resulting ischemia. These circumstances may cause a polymorphonuclear cell response, with resulting corneo-scleral ulceration and early melting of the globe. To reestablish the ocular surface, Tenonplasty was performed as a plastic procedure to reconstruct the conjunctival matrix of the globe up to the limbus. PATIENTS AND METHODS Vital Tenons sheets from the orbital region were prepared and advanced up to the limbus to cover the ischemic or ulcerating sclera with healthy, vascularized tissue. Fifty-nine patients with 75 severely burned eyes were treated with this procedure between 1987 and 1994. A total of 243 Tenons flaps were prepared. RESULTS In all cases, scleral ulcerations were prevented or healed. Epithelialization of the advanced Tenons sheets was complete within 21 days in 80% of the cases and in all eyes within 54 days. Primary epithelialization of the burned cornea was achieved in approximately 31% of the cases. Fornices were sufficiently deep in about 74%, but severe symblepharon formation occurred in 26% of the cases. CONCLUSION Tenonplasty may be an alternative surgical procedure to transplantation of autologous conjunctival or mucous grafts in restoring the conjunctival surface of the globe in severely burned eyes.

Klinische Erfahrungen bei der Verwendung eines Irisdiaphragmas

ZusammenfassungHintergrund. Bei einem partiellen oder vollständigen Verlust des Irisdiaphragmas führt eine Silikonöltamponade häufig zu einer Keratopathie. Künstliche Irisdiaphragmata können eine solche Komplikation vermeiden.Bei hypotonen Augen ist dabei wegen der unzureichenden Kammerwasserzirkulation ein geschlossenes Diaphragma notwendig. Methoden. In dieser retrospektiven Studie wurden die Verläufe von 41 Patienten (41 Augen) untersucht, die im Zeitraum von 1996–2000 nach Silikonölchirurgie mit einem geschlossenen Irisdiaphragma versorgt wurden.Alle 41 Augen waren aphak. Die häufigsten Diagnosen waren Trauma (22 Augen, 54%), PVR-Amotio (12 Augen, 29%), schwere Uveitis (4 Augen, 10%) und schwere proliferative diabetische Retinopathie (3 Augen, 7%).Die Nachbeobachtungszeit beträgt im Mittel 12 Monate. Ergebnisse. Bei 25 Augen (61%) wurde das Silikonöl hinter dem Diaphragma zurückgehalten. Bei 14 Augen (34%) kam es zu einer Abflachung der Vorderkammer.Bei 2 Augen war,wegen der getrübten Hornhautsituation, eine Beurteilung des Silikonölstands nicht möglich.Eine Verschlechterung der Hornhautsituation insgesamt sah man bei 11 Augen (27%).Als Langzeitkomplikationen zeigten sich eine weiterhin bestehende Hypotonie (≤5 mm Hg) bei 29 Augen (71%),Fibrinreaktion bei 13 Augen (32%) bis hin zur Ausbildung von Fibrinmembranen (9 Augen, 22%).Der Visus blieb bei 39 Augen (95%) stabil, verbesserte sich bei keinem Patienten und verschlechterte sich in 2 Fällen (5%). Schlussfolgerung. Trotz aller Komplikationen stellt das künstliche Irisdiaphragma einen Fortschritt zum Erhalt schwersttraumatisierter Augen dar,wenngleich eine persistierende Hypotonie bei 29 Augen (71%) fortbesteht. Ein Silikonöl-Hornhautendothel-Kontakt wird in 25 Augen (61%) im Beobachtungszeitraum verhindert. Es trat keine Phthsis bulbi oder Enukleation ein. Die Entwicklung einer verbesserten Abdichtung am Übergang des Irisdiaphragmas zur Bulbuswand ist wünschenswert.AbstractBackground. As a result of a partial or complete loss of the natural iris diaphragm,longstanding silicone oil tamponade frequently causes keratopathy.An artificial iris diaphragm can avoid such a complication. In hypotony, with insufficient circulation of aqueous humor, the “closed” artificial iris diaphragm is used. Methods. In this retrospective study 41 patients (41 eyes) were reviewed. Each patient had a single aphakic eye, in which a closed iris diaphragm was implanted after silicone oil surgery.The underlying diagnosis included in these 41 cases included trauma (22 eyes, 54%), retinal detachment due to proliferative vitreoretinopathy (12 eyes, 29%), severe uveitis (4 eyes, 10%), and proliferative diabetic retinopathy (3 eyes, 7%).The mean follow-up time was 12 month. Results. In 25 eyes (61%) silicone oil was retained behind the diaphragm.In 14 eyes (34%), silicone oil prolapsed in the anterior chamber. In 2 eyes (5%) the silicone oil could not been assessed due to a corneal opacity.A deteriorated corneal situation after implantation of the diaphragm was observed in 11 eyes (27%). As a longstanding complication permanent hypotony (≤ 5 mmHg) developed in 29 eyes (71%), fibrous reaction in 13 eyes (32%) within fibrotic membranes (9 eyes, 22%) .The visual acuity remained stable in 39 eyes (95%), improved in none, and deteriorated in 2 eyes (5%). Conclusion. Despite all complications, the artificial iris diaphragm represents an important progress in the salvage of severely traumatized eyes though persistent hypotony remains in 29 eyes (71%).Contact of silicone oil with the endothelium was avoided in 25 eyes (61%).There was no phthisis bulbi or enucleation.Improvement of anterior-posterior separation is necessary.

Tarsoconjunctival advancement : A modified surgical technique to correct cicatricial entropion and metaplasia of the marginal tarsus

Severe eye burns and mucocutaneous cicatricial disorders frequently cause upper and lower lid entropion with metaplasia of the tarsal conjunctiva, dislocation of the meibomian gland orifices, trichiasis, and tarsal scars near the lid margin. Between 1985 and 1993, 26 patients (29 eyes, 36 lids) were treated by excision of pathologic tissue and advancement of the tarsoconjunctival layer. The presented procedure is used mainly in cicatricial entropion with keratinization of the marginal tarsus.

Glaukom nach schwersten Verätzungen und Verbrennungen Operative Möglichkeiten

ZusammenfassungHintergrund. Als alternative Verfahren bei späten Sekundärglaukomen aufgrund schwerer Verätzungen und Verbrennungen bieten sich Drainageimplantate oder eine Zyklophotokoagulation an. Patienten. In einer retrospektiven Studie wurden die Heilungsverläufe von 12 Patienten mit 14 schwerstverätzten oder verbrannten Augen untersucht: 9 Augen wurden mit einem Drainagesystem versorgt, bei 5 Augen wurde eine Zyklophotokoagulation vorgenommen. Ergebnisse. Der Augeninnendruck konnte bei den von-Denffer-Implantaten von 39±7 auf 23±6, bei den Ahmed-Implantaten von 38±3 auf 8±10 und bei der Zyklophotokoagulation von 33±8 auf 18±2 mmHg gesenkt werden. Der Visus verschlechterte sich bei 5 der 9 Augen mit Drainageimplantaten und blieb bei allen 5 Augen mit Zyklophotokoagulation gleich oder besserte sich. Schwere Komplikationen bei Drainageimplantaten waren bei 4 Augen eine wiederholte Zystenbildung, bei jeweils einem Auge eine expulsive Blutung und eine Phthisis bulbi. Bei 2 Augen musste die Zyklophotokoagulation wiederholt werden, Komplikationen wurden nicht beobachtet. Schlussfolgerung. Der drucksenkende Effekt der beiden Verfahren erscheint bei allerdings geringer Fallzahl vergleichbar. Aufgrund der niedrigen Komplikationsrate bevorzugen wir die Zyklophotokoagulation.AbstractBackground. Late secondary glaucomas after severe chemical or thermal eye burns are associated with diagnostic and surgical difficulties. Routine filtering surgery (trabeculectomy) has a low success rate. In these eyes aqueous shunt implantation and cyclophotocoagulation are alternative procedures. Patients. In our retrospective study, the records of 12 patients with 14 severe eye burns (grade IV) were analyzed. Nine eyes were treated with an aqueous shunt device (six von Denffer and three Ahmed implants). Diode laser cyclophotocoagulation (Iris Medical Instruments) was performed in five eyes. The mean time interval between surgery and accident was 88.3 months (aqueous shunt) and 32.8 months (cyclophotocoagulation). Results. The mean follow-up was 45±36 months (von Denffer implant), 38±5 months (Ahmed implant), and 11±8 months (cyclophotocoagulation). Intraocular pressure (IOP) was reduced from 39±7 to 23±6 (von Denffer implants) and from 38±3 to 8±10 (Ahmed implants). Mean IOP before treatment with cyclophotocoagulation was 33±8 and 18±2 after treatment. Systemic carbonic anhydrase inhibitors were stopped in all patients. Visual acuity deteriorated in five of nine eyes treated with aqueous shunt devices and was unchanged or better in all eyes treated with cyclophotocoagulation. Multiple re-operations were necessary after aqueous shunt implantation. Severe complications leading to failure in these eyes were encapsulated bleb in four eyes, expulsive hemorrhage in one eye, and phthisis in one eye. Cyclophotocoagulation was repeated in two eyes. Severe complications were not observed. Conclusion. IOP reduction was effective and comparable in both procedures. Because of the high incidence of severe complications after shunt surgery, we prefer cyclophotocoagulation for the treatment of intractable glaucoma after severe eye burns.