23-Gauge versus 20-gauge system for pars plana vitrectomy: a prospective randomised clinical trial.

AIM: To compare the sutureless 23-gauge system with a standard 20-gauge system in pars plana vitrectomy. METHODS: 60 patients in two randomised groups were included in this prospective clinical trial. Pars plana vitrectomy with either 23- or 20-gauge instruments was performed. The main outcome measures were postoperative conjunctival injection and pain. Secondary outcome parameters were time of surgery, intraocular pressure, visual acuity and complications. RESULTS: Conjunctival injection (p = 0.0003) and postoperative pain (p = 0.01) were significantly reduced following 23-gauge vitrectomy compared with the 20-gauge procedure. Opening (p = 0.006) and closure times (p<0.00001) were significantly shorter, and vitrectomy time (p = 0.001) significantly longer in the 23-gauge system compared with 20-gauge vitrectomy. However, retinal manipulation and overall surgery times did not differ significantly between both groups. The same applies for eye pressure, distance and reading acuity. Regarding complications, two choroidal haemorrhages and one flat serous choroidal detachment occurred in the 23-gauge group. CONCLUSION: The 23-gauge system for pars plana vitrectomy offers significantly higher patient comfort during the early postoperative period. Time of surgery is almost equal--a shorter time for wound closure is neutralised by a longer vitrectomy time in the 23-gauge group.

Long term results after transpupillary thermotherapy in eyes with occult choroidal neovascularisation associated with age related macular degeneration: a prospective trial.

AIM: To evaluate long term results after transpupillary thermotherapy (TTT) in eyes with exudative age related macular degeneration. METHODS: In a prospective clinical study eyes with occult or predominantly occult choroidal neovascularisation and no pretreatment were scheduled to have a TTT with a power of 630 mW. Visual acuity for far and near distances as well as contrast sensitivity were evaluated 6, 12, and 24 months postoperatively and statistically analysed. RESULTS: 47 eyes fulfilled the inclusion criteria. Overall, 70% of the patients showed an improved (14%) or had unchanged (56%) ETDRS vision after 24 months. Reading vision was stabilised (51%) or better (5%) in 56% of the eyes at this time. However, the increasing number of eyes with severe deterioration resulted in a significant decrease of both parameters over time (p = 0.0002 and p = 0.0003, respectively). Contrast sensitivity could be maintained (70%) or improved (9%) in 79%. Statistical analyses indicated a trend but no significant decrease over time (p = 0.056). CONCLUSION: Although in the majority of patients far and near distance acuity could be stabilised on average a significant decrease over time after TTT was observed. Statistical comparison of months 12 and 24 showed no further deterioration.

Optical coherence tomography guided retreatment of photodynamic therapy.

AIM: To evaluate the results of a retreatment modality of photodynamic therapy (PDT) based on optical coherence tomography (OCT) and fluorescein angiography (FA). To quantify the effect of PDT with the help of measurement of the retinal thickness. METHODS: Eyes with predominantly classic subfoveal choroidal neovascularisation (CNV) due to age related macular degeneration were included. PDT was performed every three months, when needed. OCT, FA, and measures of distance acuity were performed at baseline, after 6 weeks, 3 months, and from then on every 3 months. A control group of a consecutive series of eyes that had been retreated based only on FA results was installed. RESULTS: Forty eyes of 38 patients were included. The average age was 73 years. The maximum retinal thickness decreased from 404 mum at baseline to 281.6 mum at month 12. Furthermore there was a significant decrease of retinal thickness in both subgroups. The number of retreatments was reduced, when activity was diagnosed using OCT and FA. (2.4 v 4.0). The distance acuity correlated significantly with the maximum retinal thickness (p=0.0042). CONCLUSION: Information about the activity of a neovascular lesion can be obtained with the help of OCT. The retreatment modalities can be optimised by using OCT and FA and the number of retreatments can be reduced.

[Vitreoretinal traction syndrome in multiple sclerosis]. / Vitreoretinales Traktionssyndrom bei multipler Sklerose.

METHODS: From January to December 2001, 89 patients with multiple sclerosis (MS) were treated in our hospital; 24 of them were diagnosed for the first time. All patients underwent a complete ophthalmologic examination including a three-mirror contact lens examination when photopsias were found or the disease was diagnosed primarily. RESULTS: Two patients showed vitreoretinal tractions with signs of periphlebitis before clinical-neurological manifestation of multiple sclerosis. The third patient, in whom the disease had been known for years, showed distinct neovascularizations, vasculitis, and recurrent vitreous hemorrhages. High-dose steroid therapy resulted in stabilization of the retinal situation in one patient, but the tractions remained unchanged. Additional laser coagulation in the second patient achieved stabilization and reduction of the tractions. A pars plana vitrectomy led to stabilization of the retinal proliferation in the third patient. CONCLUSIONS: The vitreoretinal traction syndrome is associated with MS and can precede its clinical-neurological manifestation. The good results after argon laser coagulation and vitreoretinal surgery suggest a vascular pathogenesis of these tractions.

[Photodynamic therapy for severe myopia]. / Photodynamische Therapie bei hoher Myopie.

INTRODUCTION: In the modern western world quality of life depends on the ability of reading. Our study was designed to prove the possibility of stabilization of reading acuity, central visual field and multifocal electroretinogram (mERG) after photodynamic therapy (PDT) in cases of pathologic myopia. PATIENTS AND METHODS: In our study 20 eyes were included. At baseline, after 6 weeks,3 months and afterwards every 3 months we investigated distance acuity, reading acuity, 10 degrees static threshold perimetry, mERG, optical coherence tomography and fluorescence angiograophy. RESULTS: After 1 year 85% of eyes lost less than 1.5 lines of distance acuity, the reading acuity could be stabilized in 80%, the central visual field in 60% and the ERG in 55%. Patients less than 60 years old showed better results than older patients. DISCUSSION AND CONCLUSION: PDT was found to be very effective because the membranes were classic without any occult parts in 100%. They were small and superficially located and the scotomas were small. There was a good correlation between functional and morphological results.

[Corneal infiltrates and ulcers. A retrospective study of 239 eyes]. / Hornhautinfiltrate und Hornhautgeschwüre. Eine retrospektive Analyse von 239 Augen.

PURPOSE: In our outpatient service the number of corneal infiltrates and ulcers associated with contact lens wear in young patients increased during the last years. Therefore we evaluated all patients with keratitis regarding to the reason. PATIENTS AND METHODS: From January 1999 to August 2000 the medical charts of 210 consecutive patients and 239 eyes were reviewed. We evaluated the percentage of contact lens wearers. Patient age, localisation and number of infiltrates, bacteria and healing results were also evaluated. RESULTS: In 134 of 239 eyes (56%) keratitis was caused by contact lenses, 127 eyes (53%) with soft lenses. The mean age of soft contact lens wearing patients was 28,2 +/-13,0 years. Mean age in other reasons was 46,0 +/-22,5 years. 71% (170 eyes) had single central infiltrates, 19% (45 eyes) multiple peripheral infiltrates and 10% (24 eyes) corneal ulcers. Bacteria were found in 33% (78 eyes). The most frequent isolated bacteria in non contact lens induced keratitis was staphylococcus aureus (22 eyes). In those eyes with soft contact lenses we found mostly gram negative bacteria such as serratia spp. (6 eyes), pseudomonas spp. (6 eyes), stenotrophomonas maltophilia (6 eyes) and klebsiella oxytoca (5 eyes). 20% (26 of 127 eyes) of contact lens induced corneal infection healed with a scar. CONCLUSION: Our analysis shows, that the major part of keratitis was induced by soft contact lenses. One fifth of these very young patients retained a corneal scar. There is a higher risk to suffer a keratitis when using soft contact lenses. This should influence especially patients information regarding choice and use of soft contact lenses.

Erbium:YAG laser vitrectomy: clinical results.

PURPOSE: To evaluate the intraoperative use of a new erbium:yttrium aluminum garnet (YAG) laser vitrectomy system. METHODS: An erbium:YAG laser combined with an infusion-suction system (Wavelight Laser Technology, Erlangen, Germany), equipped with a flexible fiber optic and a hand piece with a 20-gauge end tip and a side opening of 0.6 mm was used. Cutting rates were 2 to 30 Hz, and energies were 20 to 40 mJ. Between January 1998 and January 1999 the erbium:YAG laser system was used in 67 consecutive patients (68 eyes) where vitrectomy was indicated. The patients had a complete eye examination before surgery and postoperatively at 1 to 3 days, 1 week, 3 weeks, and 6 weeks. During surgery, the total time needed for vitrectomy, the laser time itself, amount of energy used, cutting rate, suction, and perfusion, as well as manipulative difficulties and/or complications, were documented. RESULTS: The average laser time was 4.5 minutes for a basic vitrectomy with a setting of 20 mJ, 20 Hz, and suction 100 to 200 mm Hg. Hemorrhages, loose intravitreal, and preretinal membranes of different densities were cut well with adjustment of energy. After a minimal observation time of 6 months (median, 12.7 months) no laser-associated complications were found. CONCLUSIONS: The erbium:YAG laser, combined with an infusion-suction system, offers a new technology for vitreous surgery. Its advantages, compared with mechanical vitrectomy cutters, are higher cutting rates and the modulation of energy. Modifications of the end tip are needed to develop this system further.

New approaches in the management of choroidal neovascular membrane in age-related macular degeneration.

Age-related macular degeneration (AMD) is a leading cause of blindness in the elderly population. The prevalence is reported to be 1.2-1.4% in several population-based epidemiological studies. Currently 25-30 million people worldwide are blind due to AMD. With the aging world population it is bound to increase significantly, and could become a significant public health problem in next two decades, with serious socio-economic implications. Several strategies are today available to treat the wet form of AMD, which is responsible for significant visual loss. These were until recently confined to laser photocoagulation, and subretinal surgery, but today two other modalities, namely, radiation and photodynamic therapy, are available. These treatment modalities however, are aimed at preservation of vision only, and not at reversing the process of the disease. Further research on antiangiogenic drugs and gene therapy could significantly help AMD patients.

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

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.

[Etiology of non-penetrating corneal injuries]. / Atiologie nicht penetrierender Hornhautverletzungen.

BACKGROUND: Non-penetrating injuries of the cornea are frequent. Complications like corneal infiltrations, or corneal ulcera, may follow. MATERIAL AND METHODS: This prospective study included 144 patients with non-penetrating corneal injuries. Records contained epidemiological data, field of activity, profession, cause of the injury, and stress during the trauma. RESULTS: 97% of the patients were men, 78% of the injuries occurred during working hours, 41% of the patients were from metal working professions, 73% of the accidents happened with grinding machines and drilling machines. Only 6.9% of patients weared adequate glasses. The cause of trauma was deflection and working without glasses. In 32% of patients stress played a role in the cause of injuries. CONCLUSIONS: Most of the corneal, non penetrating injuries happened during the working hours by deflection, and by neglecting safety glasses. With the use of safety glasses the number of corneal non-penetrating injuries could definitely be reduced.

Experimental vitreous and aqueous replacement with perfluorophenanthrene. Clinical, histologic, and electrophysiologic results.

PURPOSE: Anterior and posterior segment changes of experimental vitreous and aqueous substitution with Perfluorophenanthrene were evaluated. METHODS: In 28 rabbit eyes that underwent vitrectomy, tamponades of 1.2 cc Perfluorophenanthrene remained as long as 8 weeks under clinical and electrophysiologic control. Histologic examinations of the eyes were done 1, 2, 4, and 8 weeks after insertion of the tamponade. In an additional 15 rabbit eyes, Perfluorophenanthrene was injected into the anterior chamber, and in some cases it was removed after 2 and 4 weeks, respectively. Follow-up examinations, which were done no later than 12 weeks after injection, included clinical appearance, endothelial cell counts, corneal pachymetry, tonometry, and histopathology. RESULTS: Histologically we found narrowing of the outer plexiform layer and single macrophages in the inferior retina after 2 weeks. Cell loss in the outer nuclear layer and wrinkling of the outer retinal layers were observed after 4 weeks, which lead to the development of irregularities of all layers inferiorly after 8 weeks. Electroretinograms showed unchanged b-wave amplitudes after maximal light stimulation at each examination, but separate interpretation of low light intensity responses showed a significant decrease in b-wave amplitudes 4 weeks after surgery. Anterior segment intolerance started with stromal edema on the second day after surgery; corneal vascularization and scar formation occurred subsequently. Inferior endothelial cell density decreased to about 50%. Histologically inflammatory reactions, vacuolization of the inferior trabecular meshwork, and closure of the chamber angle between 5 and 7 o'clock were observed. CONCLUSIONS: Perfluorophenanthrene is only suitable for very short-term vitreous replacement unless prolapsing into the anterior chamber. Damages to the retina were observed 2 weeks after surgery.

Intraocular silicone lenses in silicone oil: an experimental study.

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 Ringer's 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.

Use of perfluorocarbon liquids in proliferative vitreoretinopathy: results and complications.

BACKGROUND: The present study was set up to evaluate the influence of perfluorocarbon liquids on the postoperative anatomical and functional results as well as on the complication rates in eyes with proliferative vitreoretinopathy (PVR). METHODS: Sixty five consecutive eyes (64 patients) with PVR in different stages requiring surgical intervention where liquid perfluorocarbons were used were compared with 64 consecutive eyes (62 patients) operated without the help of perfluorocarbon immediately before this time. Both groups were similar with regard to severity of PVR, number of operations, and initial visual acuity. The observation period was shorter in the perfluorocarbon group because they were operated more recently (17.4 months as against 24.4 months). RESULTS: The anatomical as well as the functional success rates were not significantly higher in the perfluorocarbon group (69% v 61% and 65% v 53% respectively). However, in cases operated on without perfluorocarbons where reproliferation would occur it was of much greater severity than in cases where perfluorocarbons were used. The number of uncured cases with contraction of the retina at least in the inferior half was more than twice as high in the group operated on without perfluorocarbon. Combined with massive reproliferation secondary glaucoma and bullous or band keratopathy were more frequent in eyes treated before the use of perfluorocarbon. CONCLUSION: The intraoperative use of perfluorocarbon liquids in vitreoretinal surgery does not prevent postoperative reproliferation but does reduce its severity.

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

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-octyl-bromide (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.

Experimental perforating injury with high energy electrons to inhibit intraocular proliferation.

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% fibronectin 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 post-operative 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.

Radiation therapy in proliferative vitreoretinopathy. A prospective randomized study.

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 follow-up 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, Fisher's 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, Fisher's 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.(ABSTRACT TRUNCATED AT 250 WORDS)

Retinal detachment with severe proliferative vitreoretinopathy in Terson syndrome.

BACKGROUND: In several reports, early vitrectomy has been proposed for eyes with vitreous hemorrhage due to Terson syndrome as a means to hasten visual recovery. But the development of nuclear sclerosis and the neurologic problems arising from this disease encourage surgeons to wait for spontaneous resorption, especially with young patients. Although the formation of epiretinal membranes has been described, to the authors' knowledge retinal detachment with proliferative vitreoretinopathy in Terson syndrome never has been observed. METHODS: The authors report five eyes from four patients with Terson syndrome due to spontaneous aneurysm rupture, in whom retinal detachment with proliferative vitreoretinopathy developed. RESULTS: The early onset and the severe clinical course of proliferative vitreoretinopathy in these eyes showed parallels to traumatic proliferative vitreoretinopathy. The retina in all eyes could be reattached. CONCLUSION: The authors point out the necessity for accurate and close follow-up and early, extensive surgical treatment in Terson syndrome, especially in patients with a reduced general state of health.

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.

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.

Irradiation pretreatment before fibroblast implantation in experimental PVR.

Fibroblast injection into the vitreous body causes traction detachment in the rabbit's eye. Various working groups reported different results on the main causes of the development of experimental PVR. These contradictions encouraged us to investigate the main source of experimental PVR by irradiating the ocular tissues before fibroblast implantation thus suppressing cell proliferation originating from host tissue. Over a period of 3 weeks, 22 eyes received ten radiations in a total dosage of 3000 rad. After the last radiation, 250,000 fibroblasts were implanted into 22 eyes. In another 4 eyes, fibroblast implantation but no radiation was carried out. After 8 weeks, 59% of 22 eyes developed different stages of retinal detachment. Comparison with the group of unirradiated eyes, which developed retinal detachment in 85%, revealed no significant differences in the number of detachments.