Visual evoked potentials (VEPs) were assessed in 50 adult type I (insulin-dependent) and 19 type II (noninsulin-dependent) diabetes mellitus patients and in 54 controls. P100 wave latency was significantly longer in diabetic patients (P less than .001). Twenty-eight percent of diabetic patients had P100 wave latencies above the normal range. There was no correlation between P100 latency and type or duration of diabetes mellitus, quality of metabolic control, or presence of degenerative complications. The significance of VEP abnormalities in diabetes mellitus remains speculative.

Background: A study of the characteristics and the results obtained in 99 consecutive eyes operated on for rhegmatogenous retinal detachment associated with aphakia or pseudophakia in order to find the predictive factors of poor anatomical and functional results. Methods: The authors retrospectively reviewed the files of 99 consecutive cases of aphakic and pseudophakic retinal detachment operated on by the same surgeon between January 1992 through July 1993 with a minimum follow-up of 6 months. Multivariate and chi square analysis were carried out. Results: Of the pseudophakic eyes, 25 had an anterior chamber lens and 48 had a posterior chamber lens. The posterior capsule was disrupted using a Yag laser in 58% of those with an posterior chamber lens but only 14% of them developed detachment within 6 months. The rate of vitreous loss was 27% with 5% in case of intracapsnlar extraction, 31% in case of extracapsular extraction and 54% in case of phacoemulsification. PVR was present in 30% of the patients and 51% of detachments occurred more than 24 months as a mean after cataract surgery. The overall anatomic reattachment rate was 88% with no significant difference between the aphakic and the pseudophakic patients, either with an anterior chamber of posterior chamber lens. Visual results were significantly worse in the anterior chamber lens group and in the aphakic eyes (P < 0.02). Negative prognostic indicators for reattachment included poor preoperative vision, extension of the retinal detachment to the macula (P < 0.05) and grades B, C or D proliferative vitreoretinopathy (P < 0.01). In addition to the above factors, eyes with vitreous loss, anterior chamber lens, aphakia and a larger extent of the retinal detachment had a poor visual outcome. Conclusion: Most aphakic or pseudophakic retinal detachment can now be reattached with either scleral or vitreo retinal surgery. The main difficulties are the localisation of the breaks and the treatment of PVR. Indirect ophthalmoscopy associated with vitrectomy does well in cases of an opacified posterior capsule. In cases of severe PVR long term internal tamponade either with C3F8 or silicone oil improves anatomical results but the functional results remain inferior.

The dichroic properties of in vitro sheep corneas were studied with a spectrophotometer in transmission mode for several angles of incidence of light beams. Several models of corneal anisotropy have been presented in the literature. The results presented here allow us to believe that the cornea behaves as a dichroic biaxial crystal. Furthermore, this dichroism is weak when the angle of incidence on the corneal surface stays small. The mathematical model that describes these optical properties of the cornea uses Mueller matrices.

This study was designed to improve the understanding of the mechanisms that govern the origin of retinal detachment (RD) by examining the quantitative composition of proteins in the subretinal fluid (SRF). Inflammation proteins and immunoglobulins (Ig) were titrated from SRF and sera in 25 patients with RD The following concentrations were found in SRF: total proteins 16 g/l, albumin 12.6 g/l; pre-albumin 0.37 g/l; transferin 1.8 g/l in 68% of cases; haptoglobin and alpha 2 macroglobin were present in only one SRF: alpha 1 antitrypsin 0.86 g/l in 48%; orosomucoid 0.57 g/l in 32%; IgG 2 g/l in 52%; IgA 0.17 g/l in 88% and IgM 15.9 mg/l in 56%. Correlations were found between the duration of detachment and the concentration of total proteins (p < 0.01). The extent of RD was correlated with the concentration of IgG or IgA in the SRF (p < 0.01). These findings suggest that the correlation between the Ig concentration and the extent of RD is an argument for the participation of choriocapillaris in the genesis of SRF.

This study evaluates the efficiency of fluid-air exchange on the reattachment of the retina and clarifies the possibility that a posterior retinotomy is a cause for intra- and postoperative complications. A consecutive series of 211 eyes with retinal detachments due to P.V.R. (47%), diabetic traction, perforating trauma, macular hole or giant tears is presented. All eyes underwent pars plana vitrectomy, fluid-air exchange, internal drainage of subretinal fluid, laser endophotocoagulation and scleral buckling of the tears; 56% of the eyes were phakic and 55% underwent a posterior retinotomy, 54% underwent tamponade with C3F8 and 46% with silicone oil. Intraoperatively the retina was completely flattened in 91% cases. The causes of incomplete reattachment were residual membranes (6.6%), poor visualization (1.4%) and suprachoroidal hemorrhage (1%). These complications were isolated as being the cause of the bad final results (p < 0.001). Postoperatively, the retina remained attached in 66% of cases after the first procedure and with further surgery in 81% (mean follow up 16 months). Best corrected visual acuity was improved in 73% of eyes, unchanged in 17%, and worse in 10%. Complications were retraction of the retinotomy site in 3 cases and peripheral choroidal hemorrhage in 4 cases. We concluded that fluid air exchange with internal subretinal fluid drainage was an efficient and safe technique even if a posterior retinotomy was necessary.