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.

Midterm visual outcome and progression of diabetic retinopathy following cataract surgery. Midterm outcome of cataract surgery in diabetes.

OBJECTIVE: To assess the influence of cataract surgery on progression of diabetic retinopathy and visual acuity. METHODS: 37 patient eyes with mild to moderate diabetic retinopathy at baseline underwent phacoemulsification and intraocular posterior chamber lens implantation. They were examined 3.3 +/- (SD) 0.7 years after surgery. RESULTS: 83.8% of the eyes showed a better final visual acuity, and 67.6% achieved a final visual acuity of 0.5 or better. The retinopathy remained unchanged in 83.8% and progressed in 16.2% of the eyes. No eye progressed to proliferative retinopathy. CONCLUSION: Phacoemulsification and implantation of a posterior chamber intraocular lens is a safe procedure for patients with mild to moderate diabetic retinopathy.

Ocular blood flow in patients infected with human immunodeficiency virus.

PURPOSE: Alterations of ocular blood flow may play a role in the pathophysiology of human immunodeficiency virus (HIV) related retinal microvasculopathy. In this study ocular blood flow was investigated in patients with HIV infection. DESIGN: In a prospective, cross-sectional study ocular blood flow was measured in 37 eyes of consecutive HIV- infected persons and compared with the data of age-matched healthy controls. This sample size was calculated based on an alpha-error of 0.5 and a beta-error of 0.8. METHODS: Macular white blood cell flow, fundus pulsation amplitude, and blood flow velocities in the retrobulbar vessels were measured with blue field entoptic technique, laser interferometry, and Doppler sonography, respectively. Immunologic and ophthalmologic status was evaluated from each patient. RESULTS: Mean CD4+ cell count of the HIV-infected persons was 206.8 +/- 145.6 cells/mm(3). In five patients HIV-related retinopathy was observed. A significant reduction in leukocyte density was seen in HIV infected persons (82.2 +/- 23.4) as compared with the control group (102.0 +/- 28.4; P =.019). The resistive index in the central retinal artery was higher in HIV infected patients (0.77 +/- 0.05) as compared with the controls (0.74 +/- 0.04; P =.04). The other hemodynamic parameters were not different between groups. No correlation of flow parameters and CD4+ cell count or HIV-related retinopathy was observed. CONCLUSIONS: Decreased macular leukocyte density was detected in HIV infected persons. Our study suggests that abnormal retinal hemodynamics in individuals infected with HIV may be involved in the pathogenesis of HIV-related microvasculopathy.

Inflammation after phacoemulsification in diabetic retinopathy. Foldable acrylic versus heparin-surface-modified poly(methyl methacrylate) intraocular lenses.

PURPOSE: To evaluate inflammation after cataract surgery in patients with nonproliferative diabetic retinopathy (NPDR) and compare results with 2 intraocular lenses (IOLs): a foldable hydrophobic acrylic and a heparin-surface-modified (HSM) poly(methyl methacrylate) (PMMA). SETTING: Department of Ophthalmology, University of Vienna, Vienna, Austria. METHODS: Patients with NPDR were randomized for implantation of an HSM PMMA IOL (811C, Pharmacia) through a 6.0 mm sclerocorneal incision (30 patients) or a foldable hydrophobic acrylic IOL (AcrySof, Alcon) through a 4.0 mm sclerocorneal incision (32 patients). Both IOLs had 6.0 mm optics. All patients were treated according to a standardized protocol. The degree of flare in the anterior chamber was measured with the Kowa 1000 laser flare-cell meter 1 day preoperatively and 1 day, 1 week, and 1 and 3 months postoperatively. RESULTS: In both IOL groups, flare was highest on the first postoperative day and decreased to preoperative levels by 3 months after surgery. There was no statistically significant difference in relative flare values between the 2 groups. CONCLUSION: There was no difference in postoperative inflammation in eyes with a foldable hydrophobic acrylic IOL implanted through a small incision and those with a rigid HSM PMMA IOL. Postoperative inflammation results indicate that the lenses are equally suitable for the use in patients with diabetic retinopathy.

Intravitreal injection of tissue plasminogen activator and gas in subretinal hemorrhage caused by age-related macular degeneration.

PURPOSE: To assess the efficacy and safety of intravitreal injection of recombinant tissue plasminogen activator and sulfur hexafluoride gas for displacement of subretinal hemorrhages in patients with age-related macular degeneration. METHODS: The authors injected 25 microg of recombinant tissue plasminogen activator and 0.5 mL sulfur hexafluoride gas intravitreally in 11 patients with subretinal hemorrhages of less than 3 weeks duration. Anatomic and functional results were evaluated. RESULTS: Displacement of subretinal blood was successful within the first week after surgery in 10 of 11 patients. This was accompanied by visual improvement in eight patients. After 1 year, visual acuity was better than before surgery in five patients. Diagnosis of a choroidal neovascularization by fluorescein angiography was possible in all patients, and was treated with laser photocoagulation in five. The authors observed no adverse effects of treatment. CONCLUSION: Recombinant tissue plasminogen activator and gas effectively displace subretinal blood in patients with age-related macular degeneration. Randomized studies are necessary to prove the benefit of this simple and safe method in patients with subretinal hemorrhage due to age-related macular degeneration.

Control of cytomegalovirus retinitis after combination antiretroviral therapy.

PURPOSE: To report on AIDS patients having combination antiretroviral therapy whose cytomegalovirus (CMV) retinitis remained inactive after discontinuation of anti-CMV maintenance therapy. METHODS: We describe the course of CMV-retinitis in 3 patients with AIDS after initiation of combination antiretroviral therapy. RESULTS: After cessation of anti-CMV therapy no relapse of CMV-retinitis has been observed for up to 18 months. Two of the patients developed new CMV-retinitis in the first months after initiation of combination therapy, nevertheless after further improvement of immunological parameters retinitis remained stable without anti-CMV therapy. CONCLUSION: The sustained immunological effects of combination therapy are possibly sufficient enough to provide protection against CMV-retinitis.

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.

Evaluation of cytomegalovirus retinitis management. Outcome of four years of cytomegalovirus therapy.

Cytomegalovirus (CMV) is the most common pathogen of opportunistic viral infections in patients with the acquired immunodeficiency syndrome. In this study, we assessed the therapeutic outcome of our treatment regimen of CMV retinitis by analysing retrospectively 33 consecutive patients. The clinical utility of CMV cultures from blood, urine and throat specimens obtained at the time of diagnosis was additionally evaluated. Treatment started with ganciclovir (GCV) therapy. In case of relapsing retinitis, re-induction therapy was initiated, and if unsuccessful, the patient was switched to foscarnet. Patients developing resistant retinitis despite foscarnet therapy were offered a GCV-foscarnet combination therapy. Under primary GCV therapy, the median first stable interval of the whole group was 202 days (mean 238 days). Twenty-five out of 33 CMV retinitis patients (76%) responded to initial GCV therapy. Eleven of these patients showed relapsing retinitis that could be stabilised in 3 patients solely with combination therapy. Eight patients did not respond to primary GCV therapy. Three of them improved with foscarnet, but 3 patients did not respond to either treatment. In 18 (56%) out of 32 patients, CMV cultures yielded positive results. Considering our series, we may conclude that in the majority of patients primary or secondary viral resistance can be overcome by dose increase, switching to the alternative drug or a combination therapy.

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 hemorrhage associated with dental implant surgery.

PURPOSE: To report a complication of dental implant surgery. METHOD: We examined a 44-year-old man with systemic hypertension who reported sudden loss of the central visual field in one eye that occurred during maxillar dental implant surgery. RESULTS: Subretinal, intraretinal, and intravitreal hemorrhages in the right eye were present on initial examination. Intraocular hemorrhage may have been caused by a Valsalva maneuver in combination with a rise of systemic blood pressure during treatment. CONCLUSION: Intraocular hemorrhages may occur as a complication of dental implant surgery.