Michaela Velikay

Experimental long-term vitreous replacement with purified and nonpurified perfluorodecalin.

Highly purified perfluorodecalin and non-purified perfluorodecalin were injected into 34 rabbit eyes after mechanical vitrectomy, to evaluate the retinal tolerance in long-term vitreous replacement and the effect of purification on the retina. Unpurified perfluorodecalin caused severe inflammation and retinal damage and eight of ten eyes had developed retinal detachment after four weeks. In the eyes injected with highly purified perfluorodecalin, we observed retinal changes of the rod and cone, outer nuclear, and ganglion-cell layers after two weeks, which progressed to a thinning of all layers of the retina by the fourth week and to localized areas of retinal atrophy by the eighth week in the lower part of the eyes. Retinal damage in the upper part occurred after four weeks. At the perfluorocarbon-aqueous interface we observed a band of retinal necrosis that was noticed in all eyes four weeks postoperatively regardless of the substance used.

The effect of chemical stability and purification of perfluorocarbon liquids in experimental extended-term vitreous substitution

Abstract• Background: To determine the importance of chemical stability and purification of perfluorocarbon liquids (PFCLs) in experimental retinal tolerance, we tested four different substances as long-term vitreous tamponade: purified and nonpurified perfluorodecalin (PFD) and perfluoro-octylbromide (PFOB) • Method: After mechanical vitrectomy we replaced the vitreous of 65 rabbit eyes. Five groups were formed; four of them received the four PFCLs, while one served as control and received Ringer solution. The eyes were observed clinically every week and examined histologically after 1, 2, 4 and 8 weeks • Results: After 1 week we observed foam cells and intraretinal macrophages in all eyes with PFCLs. Purified PFD caused retinal lesions in the photoreceptor, ganglion cell and outer nuclear layers after only 2 weeks in the lower part of the eyes. In eyes filled with purified PFOB we observed more pronounced damage of the same nature. Unpurified substances caused severe inflammation and retinal detachment • Conclusion: Our study demonstrates that purification and chemical stability are important factors in retinal tolerance of PFCLs for vitreous replacement. Although purified PFD was tolerated by the rabbit eyes for 1 week, we cannot recommend this substance for short-term clinical use as a vitreous substitute.

Intraocular silicone lenses in silicone oil : an experimental study

Abstract• Background: To evaluate a potential effect of silicone oil on flexible silicone intraocular lenses, four lenses (STAAR AA-4203) were stored in silicone oil under sterile conditions for periods between 1 month and 3 years.• Method: The edge and surface of the lenses were examined by scanning electron micrography and the findings compared with a lens of the same model which had been stored in Ringers solution for 2 years.• Results: After 1 year of silicone oil exposure, droplets of different sizes adherent to the surface of the lens were found. These changes proceeded to a wave-like appearance of the surface after 2 and 3 years of storage, so that a continuous layer of silicone oil polymers is probably covering the intraocular lens.• Conclusion: Optical interference has to be considered a possibility if it turns out that the droplets cannot be removed during silicone oil evacuation. Consequently silicone intraocular lenses without hydrophilic preparation of the surface should not be implanted in eyes undergoing combined anterior and posterior segment surgery with silicone oil tamponade or in eyes with high risk for vitreoretinal complications.

Ocular findings in asymptomatic amateur boxers

A group of 25 active, asymptomatic, amateur boxers were examined to evaluate the nature and incidence of ocular pathologic conditions in amateur boxing. An approximately age-matched group of 25 men who were not boxers was used as a control group. The number of fights varied from 1 to 220 (mean 39.4), and the number of spar rounds from 20 to 600 (mean 192.5). Visual acuity was 20/20 in all subjects of both groups, except for one boxer with kerato-conus. Intraocular pressure was below 20 mmHg in all eyes. In 19 (76%) boxers, pathologic anatomic findings were attributed to contusion trauma. Lesions of the anterior eye segment included injuries of the lid in 3 eyes (12%), angle abnormalities in 5 (20%), and slight lens opacities in 5 (20%). Posterior vitreous detachment was observed in 3 (12%) boxers and peripheral retinal scars were seen in 15 (60%). In 6 (24%) 3eyes, retinal tears or atrophic holes were detected. In the 7 (28%) boxers with lesions of the anterior eye segment, the posterior segment was also affected in 6 (85%). In the control group, an atrophic hole was found in one (4%) patient with no other ocular pathologic findings. It is strongly recommended that the following conditions be implemented in amateur boxing: (1) the use of head gear and thumbless boxing gloves even for short spars; (2) the use of thumbless gloves instead of thumb-attached gloves; (3) the use of the sparring head gear for bouts; and (4) dilated retinal examination before beginning amateur career and periodic ophthalmologic examinations, including a dilated vitreoretinal examination, as a mandatory part of the license examination.

Radiation therapy in proliferative vitreoretinopathy

In a prospective study of the effect of postoperative radiation therapy for the prevention of reproliferation of membranes and recurrent proliferative vitreoretinopathy (PVR) two similar groups of patients with retinal detachment and PVR grade D1 to D3 in one eye were compared. Half the eyes (30) received a total dose of 3000 cGy after surgery; the other half remained untreated. After a followup of 6 months and 14 months or more (maximum 36 months) the anatomical and functional results of each group were compared. After 6 months in the unirradiated group 57% (17/30) remained attached and 43% (13/30) had detached again. In the irradiated group 63% (19/30) were attached and 37% (11/30) had detached. However, there was no statistically significant difference between the two groups (P=0.479, Fishers Exact Test). After 14 months the number of cured and uncured eyes remained the same in the unirradiated group, while in four of the eyes in the irradiated group a later onset of reproliferation and detachment occurred (after 7, 8, 12 and 14 months, respectively). A final cure rate of 57% (17/30) was achieved in the unirradiated group and a 50% (15/30) cure rate in the irradiated group. Thus the failure rate was 43% (13/30) in the unirradiated group and 50% (15/30) in the irradiated group (P=0.473, Fishers Exact Test). No side effects from the radiation were observed in any case and no radiation retinopathy occurred during an observation period of up to 3 years. The visual acuity of the cured treated and cured untreated eyes was similar in the two groups. From these results we conclude that immediate radiation treatment does not improve the long-term results and does not reduce the number of reoperations. In a considerable number of treated eyes the onset of reproliferation was delayed from 7 to 14 months, whereas in the untreated group reproliferation was always observed during the first 6 months. A combination of various antiproliferative and antiinflammatory therapies are needed to suppress recurrent PVR after succesful vitreoretinal surgery and to minimize the side effects of these treatments.

Anterior segment changes in rabbits after experimental aqueous replacement with various amounts of different perfluorocarbon liquids

Abstract · Background: We evaluated biomicroscopic and histological effects on the anterior segment in the rabbit eye after temporary aqueous substitution with various amounts (0.2 cc and 0.025 cc) of perfluorodecaline (PFD) and perfluorophenanthrene (PFP). · Methods: A quantity of 0.2 cc of the two perfluorocarbon (PFC) liquids was exchanged simultaneously with about 50% of the aqueous in 15 rabbit eyes each for periods of 1, 2, or 4 weeks. At these points some eyes were enucleated for histological examination. After 2 and 4 weeks the substances were removed from the remaining eyes, which were then followed up for 8–10 weeks. In an additional 8 eyes, 0.025 cc PFD or PFP was injected and left for 8 weeks. Four eyes received balanced salt solution and served as controls. Beside biomicroscopic evaluation and measurement of the intraocular pressure, endothelial cell counts and corneal pachymetry were performed regularly during follow-up. · Results: The postoperative results were well comparable for PFD and PFP eyes. Within the first 2 weeks postoperatively corneal edema with endothelial cell loss was observed in both groups. Thereafter regression of the edema started independently of whether the substances were removed or not. IOP was not elevated at any time. At the end of follow-up central corneal thickness was the same as initially. In the inferior corneal endothelium cell density decreased to 45–50% of that in normals. Histologically, vacuoles in the iris and chamber angle were found inferiorly after 4 weeks. Chamber angle closures were present between 5 and 7 o’clock in those eyes where the PFC liquids had been removed after 2 and 4 weeks. Eyes with 0.025 cc PFD or PFP droplets showed vacuolization of the inferior trabecular meshwork 8 weeks postoperatively that was comparable with eyes which had a 50% aqueous replacement for 4 weeks. Control eyes remained unchanged in all aspects. · Conclusion: Anterior segment damage caused by PFC liquids is a contact-dependent effect seen in the early observation period. Experimentally there was no difference between the products used or between 2 and 4 weeks’ duration of the tamponade.

Die Behandlung der Konjunktivitis sicca mittels Akupunktur

ZusammenfassungHintergrundIn einer vorangegangenen Studie konnte gezeigt werden, daß nach Abschluß der Behandlung Beschwerden aufgrund einer Konjunktivitis sicca durch Akupunkturtherapie in 91% der behandelten Patienten reduziert, in 59% sogar Beschwerdefreiheit ohne Therapie erzielt werden konnte. Diese prospektive Arbeit soll die Objektivierbarkeit und die Dauer der Akupunkturwirkung bei Konjunktivitis sicca aufzeigen.Patienten und MethodeInsgesamt wurden 25 Patienten (22 Frauen/3 Männer) im Alter von 20 bis 71 Jahren (mittleres Alter: 51,5 Jahre) einer Behandlung mit Akupunktur unterzogen. Kriterien für die Aufnahme in die Studie waren: eine mindestens einjährige Dauer der Anamnese, trotz Tropftherapie fehlende Beschwerdefreiheit, wiederholte Schirmertestwerte unter 5 mm sowie Tränenfilmaufreißzeiten unter 5 Sekunden. Die Behandlungsdauer betrug 10 Wochen mit einer mindestens 30 Minuten dauernden Sitzung pro Woche. Zur Beurteilung des Behandlungserfolges wurden ein Beschwerden- und Tropfprotokoll sowie Schirmertest, Tränenfilmaufreißzeit und der Bengalrosatest verwendet. Die Nachuntersuchungen erfolgten eine Woche sowie vierteljährlich bis ein Jahr nach Abschluß der Akupunktur.Ergebnisse1 Woche nach Akupunktur waren 15 (60%) Patienten beschwerdefrei bei einer Tränenfilmaufreißzeit über 10 Sekunden und normaler Bengalrosafärbung, jedoch erniedrigten Schirmertestwerten. 13 (52%) davon benötigen keine Therapie. Bei allen übrigen Patienten wurde eine Reduktion der Beschwerden und Therapienotwendigkeit beobachtet. 12 Monate nach Akupunktur waren 13 (52%) Patienten ohne Therapie beschwerdefrei bei normaler Tränenfilmaufreißzeit und Bengalrosavitalfärbung sowie unveränderten Schirmertestwerten. 5 (20%) Patienten berichteten über gleich starke Beschwerden wie vor Akupunktur. Eine Abnahme des Therapieeffektes wurde erstmals nach 6 Monaten bei 6 (24%) und nach 12 Monaten bei 8 (32%) Patienten beobachtet.SchlußfolgerungenDie subjektive Besserung ist gut mit den Ergebnissen der Therapie sowie Bengalrosafärbung, nicht jedoch mit den Schirmertestwerten in Einklang zu bringen. Bei Patienten mit Konjunktivitis sicca erscheint ein Therapieversuch mit Akupunktur gerechtfertigt, wenngleich über mögliche Wirkmechanismen noch keine Aussagen getroffen werden können.SummaryBackgroundIn a previous study we have shown that complaints due to conjunctivitis sicca were reduced in 91% of patients treated with acupuncture. 59% of these patients had no complaints even without therapy. This prospective study was performed to prove the effect of acupuncture treatment and its duration with objective means.Patients and methodsIn total 25 patients (22 women/ 3 men) with an age ranging from 20 to 71 (mean 51.5) were treated with acupuncture. Inclusion criteria were: an anamnesis of at least one year, complaints despite therapy, repeated Schirmer’s test values below 5 mm and break up time measurements below 5 seconds. Acupuncture treatment was performed 30 minutes once a week for ten weeks. To evaluate the therapy effect a protocol of complaints and therapy frequency as well as Schirmer’s test, break-up time and bengalrose staining were used. Examinations were performed one week and every 3 months up to one year after acupuncture treatment.Results1 week after acupuncture 15 (60%) patients had no complaints. Break-up time exceeded 10 seconds and bengalrose staining was normal, yet the Schirmer’s test were low. 13 (52%) were on no therapy. In all other patients a reduction of complaints and therapy frequency was observed. At 12 months 13 (52%) patients still had no complaints without therapy. Break-up time and bengalrose staining were normal and Schirmer’s test values were unchanged. In 5 (20%) patients the severity of complaints was as severe as before acupuncture. A reduction of the therapy effect was observed at 6 months in 6 (24%) and at 12 months in 8 (32%) patients.ConclusionThere is a good correlation between subjective improvement and break-up time and bengalrose staining, but not with Schirmer’s test results. In patients with conjunctivities sicca a try with acupuncture therapy is justified although the mechanisms remain unclear.

The antiproliferative effect of fractionized radiation therapy: Optimization of dosage

Fractionized radiation therapy with high-energy electrons have proven to reduce retinal detachment rate from 85% to 5% in the fibroblast model using a dosage of 3000 rad, starting from the first postoperative day. The purpose of this study is to gain more information about the therapeutic range of fractionized radiation therapy in experimental PVR. We therefore investigated the efficacy of this therapy when the total dose is reduced to 2000 rad. Irradiation treatment started on the first postoperative day. Eight weeks after cell implantation 5 of 14 eyes (35%) in the irradiated group and 15 of 16 eyes of the control group (93%) showed traction detachment. The statistically significant result proves a broad therapeutic range of fractionized radiation therapy in experimental PVR. We believe that a combination with antiinflammatory drugs could lead to a dose reduction in both therapies in patients.

Akupunktur bei Konjunktivitis sicca

ZusammenfassungIn einer prospektiven Studie wurden 22 Patienten (4 Männer, 18 Frauen) mit Konjunktivitis sicca einem Therapieversuch mit Akupunktur unterzogen. Die Indikation für eine Akupunkturbehandlung wurde bei mindestens einjähriger Anamnese, unbefriedigender Tropftherapie sowie bei mehrmaligen Schirmertestwerten unter 5 mm und einer Tränenfilmaufreißzeit von unter 5 Sekunden gestellt. Zur Beurteilung eines Akupunktureffektes wurden die Kriterien Symptomhäufigkeit und -intensität, Tropfhäufigkeit, Schirmertest und Tränenfilmaufreißzeit herangezogen. Die Akupunkturbehandlung erfolgte einmal wöchentlich für über 30 Minuten an fixen und dem aktuellen Beschwerdebild angepaßten Punkten. Das Alter der Patienten schwankte zwischen 20 und 75 Jahren, die Nachbeobachtungszeit betrug 3 Monate. Nach Akupunktur waren bei den unter 50-jährigen Patienten (n = 10) 8/10 völlig beschwerdefrei und benötigten keine Therapie, während die übrigen 2/10 Patienten über eine Reduktion der Symptomatik und Therapie berichteten. Beim Schirmertest beobachteten wir ein Ansteigen der Werte auf über 10 mm in 3/10 Patienten, auf Werte zwischen 5 – 10 mm in 5/10 Patienten. Bei 2/10 blieb der Schirmertest unter 5 mm. Bei der Tränenfilmaufreißzeit wurde in 7/10 Patienten ein Anstieg auf über 10 Sekunden, in 3/10 ein Anstieg auf werte zwischen 5 und 10 Sekunden gemessen. In der Gruppe der über 50-jährigen Patienten (n = 12) kam es dagegen nur in 5/12 zu völliger Symptomfreiheit, und in 5/12 zu einer Reduktion. Die Tropfhäufigkeit wurde von allen Patienten reduziert, wobei 5/12 keine Therapie benötigten. Schirmertestwerte von über 10 mm erreichte 1/12, Werte zwischen 5– 10 mm 6/12 Patienten und 5/12 blieben unter 5 mm. Die Tränenfilmaufreißzeit überschritt 10 Sekunden in 3/12 Patienten. Ein Anstieg auf werte zwischen 5 und 10 Sekunden wurde in 7/12 Patienten beobachtet und 2/12 blieben unverändert. Diese vorläufigen Ergebnisse lassen den Schluß zu, daß bei Patienten mit Konjunktivitis sicca nach unbefriedigender konservativer Therapie ein Therapieversuch mit Akupunktur gerechtfertigt erscheint, wenngleich über mögliche Wirkmechanismen, Langzeitergebnisse und eine nach Ursachen differenzierte Erfolgsrate noch keine sicheren Aussagen getroffen werden können.SummaryIn a prospective study 22 patients (4 men, 18 women) with dry eye’s syndrome were treated with acupuncture. All patients fulfilled the following criteria: anamnesis of at least one year, unsatisfying drop therapy, repeated Schirmer test values below 5 mm and a break-up time of less than 5 seconds. The frequency and intensity of symptoms, the frequency of therapy necessity, Schirmer-test and breakup time were used to evaluate the effect of acupuncture. Acupuncture was performed 10 weeks once a week for more than 30 minutes using fix and variable points, which varied according to the patient’s actual complaints. The patients age ranged from 20 to 75, the follow-up was 3 months. In the group of patients with an age below 50 (n = 10) 8/10 patients had no symptoms and did not use any therapy whereas 2/ 10 reported a decrease in symptoms and therapy necessity. Schirmer-test values increased to 10 mm or more in 3/10 patients and to 5–10 mm in 5/10 patients. In 2/10 the Schirmer-test was still below 5 mm. The break-up time showed an increase in all patients. Values of 10 seconds or more were measured in 7/10 patients and values between 5 and 10 seconds in 3/10.In the group of patients aged 50 or more (n = 12) only 5/12 had no symptoms and 5/12 reported a decrease of symptoms. The therapy frequency was reduced by all patients and 5/12 were without any therapy at all. Schirmer-test results exceeding 10 mm was achieved by 1/12 and values between 5 and 10 mm by 6/12 patients. In 5/12 Schirmer-test results remained below 5 mm. The break-up time exceeded 10 seconds in 3/12 patients. In 7/12 the break-up time of 5 to 10 seconds was found and in 2/12 it remained unchanged. From this preliminary results we propose that acupuncture therapy seem to be justified in patients with dry eye’s syndrome if the conservative therapy is unsatisfying although statements concerning long-term results, possible mechanisms and success rates in the treatment of the different subtypes of dry eye’s syndrome cannot be drawn by now.

Experimental perforating injury with high energy electrons to inhibit intraocular proliferation

Abstract. Since 1980, the fibroblast model creating experimental proliferative vitreoretinopathy has been used to evaluate the antiproliferative effect of various drugs. In previous studies radiation therapy was found to reduce effectively intraocular proliferation in this model. We therefore investigated the effect of high energy electrons in a standard perforating injury model creating a traumatic proliferative vitreoretinopathy. In 36 eyes we performed a 8 mm pars plana incision and injected 0.4 ml of 80% fibronection solution intravitreally. Ten rabbits (20 eyes) received radiation therapy with a Betatron accelerator in a total dosage of 3000 cGy to each eye divided into 10 single fractions starting on the first postoperative day. Maximum concentration of the dose was focused to the posterior vitreous. The other 9 rabbits, 18 eyes, served as control. In our perforating injury model we observed a reduction of retinal detachment rate of 72% in the controls to 55% in the treated group. The effect of radiation therapy with high energy electrons and total dosage of 3000 cGy was not statistically significant in experimental traumatic proliferative vitreoretinopathy.