Adipose derived mesenchymal stem cells partially rescue mitomycin C treated ARPE19 cells from death in co-culture condition

Age-related macular degeneration is a retinal disease with important damage at the RPE layer. This layer is considered a target for therapeutical approaches. Stem cell transplantation is a promising option for retinal diseases. Adipose derived mesenchymal stem cells secret growth factors which might play a significant role in RPE maintenance. This study aimed to evaluate human AD-MSCs ability to rescue mitomycin C treated dying ARPE19 cells in co-culture condition. ARPE19 cells were treated with MMC (50 μg/ml, 100 μg/ml and 200 μg/ml) for 2 hours to induce cell death. These treated cells were co-cultured with hAD-MSCs in indirect co-culture system for 3 days and 3 weeks. Then the viability, growth and proliferation of these ARPE19 cells were evaluated by a cell viability/cytotoxicity assay kit and Alamar Blue (AB) assay. Untreated ARPE19 cells and human skin fibroblasts (HSF) were used as controls. MMC blocked ARPE19 cell proliferation significantly in 3 days and cells were almost completely dead after 3 weeks. Cell toxicity of MMC increased significantly with concentration. When these cells were co-cultured with hAD-MSCs, a significant growth difference was observed in treated cells compared to untreated cells. hAD-MSCs rescue capacity was also significantly higher than HSF for treated ARPE19 cells. This study showed that hAD-MSCs rescued MMC treated ARPE19 cells from death. It probably occurred due to undefined growth factors secreted by hAD-MSCs in the medium, shared by treated ARPE19 cells in co-culture conditions. This study supports further evaluation of the effect of hAD-MSCs subretinal transplantation over the RPE degeneration process in AMD patients.

Variations in Functional and Anatomical Outcomes and in Proliferative Vitreoretinopathy Rate along a Prospective Collaborative Study on Primary Rhegmatogenous Retinal Detachments: The Retina 1 Project-Report 4

Purpose. To analyse variations in the anatomical and functional outcomes and in proliferative vitreoretinopathy (PVR) rate of a prospective multicentric study that was primarily designed for identification of clinical risk factors for PVR. Methods. 1,046 retinal detachment (RD) cases were analysed. Cases were divided into two series based upon variation in PVR rate determined by logistic regression analysis. Series 1 (S1) included RD treated during 2004-2005 (n = 481) and Series 2 (S2) during 2006–2008 (n = 565). Pre-, intra-, and postoperative characteristics were recorded. Results. There were few differences in the preoperative characteristics. S2 had more vitrectomies and scleral bands and fewer explants and associated cataract extractions than S1. Anatomic reattachment improved from 87.9% to 92.9% in S1 and S2, respectively, (P = 0.006). Visual acuity at 3 months ≥20/40 increased from 36.5% of S1 to 44.2% in S2 (P = 0.049). PVR rate diminished from 14.1% in S1 to 8.1% in S2 (P = 0.002). Centres with higher rates of PVR in S1 showed the greatest reductions in S2. Conclusion. An improvement in anatomical and functional outcome and PVR rate occurred in participating centres cannot be attributed to the learning curve of surgeons. We speculated that it could be an effect of their participation in the study.

Detecting amblyogenic diseases with the photographic Bruckner test

The authors evaluated the photographic Brückner test for its ability to detect the main causes of amblyopia. One hundred four patients divided into four groups underwent this test: Group I, small deviation esotropia; Group II, large deviation esotropia; Group III, anisometropia; and Group IV, healthy controls. The results show high sensitivity (82%), specificity (91%), and accuracy (84%), indicating that this test could be a potential way to mass-screen pre-verbal and pre-school children to facilitate early detection of the main causes of amblyopia, when treatment is still possible.

Original papers: Prevalence of amblyogenic diseases in a preschool population sample of Valladolid, Spain

OBJECTIVES

Amblyopia is the leading cause of monocular vision loss in people under 40 years, and especially in children. The purpose of the present investigation is to determine the prevalence of amblyopia and ocular pathology, specially the most common causes of amblyopia, in a population of 3-to 6-year-old children.

PATIENTS AND METHODS

From a total of 8167 children, a geographically defined population of 3-to 6-year-old children, 2000 were randomly selected, and 1179 (58.9%) examined. Ophthalmologic examination included: Personal and familial history, visual acuity, extraocular motility, cover test at near distance, cycloplegic refraction with autorefractometer and fundus eye examination. Amblyopia was considered when corrected visual acuity was < 0.5 with Marquez optotypes and difference in visual acuity of 0.2 or more between eyes. Pathology considered as amblyogenic were strabismus, visual acuity asymmetry and anisometropia.

RESULTS

The family history showed amblyopia in 249 (21.1%), strabismus in 227 (19.2%), and refractive errors in 808 (65.5%). Cover test was positive in 78 children (6.7%). A visual acuity difference of 0.2 or more between eyes was present in 88 (7.5%) children, and anisometropia over 1.5 diopters (in spherical equivalent) was present in 17 (1.4%) subjects. One hundred and twenty-two (10.35%) children did not achieve a normal visual acuity: visual acuity in the better eye was less than 0.5 in 55 children under 5 years and less than 0.6 in 67 children over 5 years. The prevalence of amblyopia was 7.5%.

CONCLUSIONS

The data support the importance of early detection and treatment of amblyopia and the need for visual screening at an early age.

[Surgical therapy of lithiasis in horseshoe kidney]

OBJECTIVE

To present our centre's experience in the surgical treatment of lithiasis in patients with horseshoe kidney.

MATERIAL AND METHODS

From October 2007 to March 2011 we treated 10 patients with renal lithiasis in their horseshoe kidneys. Retrospectively, we reviewed the symptoms, medical and surgical history, the characteristics of the stones (size, location, composition) and treatments that were carried out. In all the cases, the study was carried out by CT, with volume reconstruction and with an angiographic study. A percutaneous nephrolithotomy (PCNL) or an endoscopic retrograde intrarrenal surgery (RIRS) was carried out, depending on the size and location of the stone.

RESULTS

Three percutaneous nephrolithotomies were carried out (2 on staghorn lithiasis stones, 1 pseudocoraliform stone) with a combined rigid and flexible single-access nephroscopy. In one case there was haemorrhage that required treatment by selective embolization. In the rest, RIRS was carried out, all with stones < 30 mm in their greatest diameter without any complications. The mean surgical times were 120 (60-180) minutes for the percutaneous route and of 105 (65-160) minutes for the retrograde route. In all the cases the treatment achieved a complete elimination of the stones or remains of less than 5 mm.

CONCLUSIONS

The treatment of renal lithiasis in horseshoe kidneys is complex, given their peculiar anatomy. The usual surgical techniques can be reproduced in these cases with good results. We opt for PCNL in complete staghorn stone and pseudocoraiform stones, whereas RIRS is a valid option in cases with stones < 3 cm.

Training and professional profile of retinologists in Spain: Retina 2 project, Report 4

Background:

Uniform postresidency systems to train medical specialists have not been developed in most European countries. Before developing a framework for such a system, we established the learning and professional profiles of Spanish ophthalmologists dedicated to medical retina and vitreoretina subspecialties.

Methods:

After identification of presumed subspecialists by experts from different autonomous regions, a self-administered questionnaire was mailed in 2006. A reminder was sent three weeks later. Postal mail was used. Nonresponder bias was determined.

Results:

Of 492 possible retina subspecialists, 261 replied to the questionnaires. While about 86% received specific retinal training, standardized fellowship programs were uncommon for both medical retina and vitreoretina (around 10%). Of the responders, 24.5% performed only medical retina, 11.8% vitreoretina, and 63.6% both. Most (60.5%) practiced anterior segment surgery, and 78.7% declared skills in vitrectomy.

Conclusion:

We have developed a database of Spanish ophthalmologists dedicated to retinal pathologies and identified some characteristics of their professional profile. Although most of them have received specific retinal training, standardized mastership programs are still uncommon. These data will be useful in creating a standardized Retina Mastership, an important goal of the European Higher Education Area.

A Brief Review and Re-thinking of Proliferative Vitreoretinopathy

Prevention of proliferative vitreoretinopathy (PVR) continues to be a challenge for retinologists despite almost 30 years of research history. New diagnostic tools, based on the genetic profiles of patients with retinal detachment (RD), are now available. In addition, clinical trials in humans are about to begin of new pharmacological approaches, based on so-called ‘biological agents’. Thus, it might be that, in the near future, it will be possible to reduce the incidence of PVR, which currently accounts for 8–10 % of all cases of RD.

[Training and clinical activity of Spanish retinologists: a preliminary approach. Retina 2 project. Descriptive analysis]

PURPOSE

To create a database of Spanish ophthalmologists mainly dedicated to retinal pathology care, describing their training period characteristics and their daily activity (clinical and surgical).

METHODS

A postal questionnaire was sent to 504 possible retinologists identified through the information supplied by the Spanish Ophthalmological Society and the Spanish Vitreous-Retina Society, with a minimum of 3 retinologists per Autonomous Region.

RESULTS

267 (52.9% of the sample population) responses were collected and processed. Most of the respondents had started their residency after 1980 (82.4%). Ninety-four percent had received specific training in retinal pathology, mostly during the residency period (82.1%) and from more experienced colleagues (62.9%). Official fellowships were held in a minority of cases (around 12%). Twelve percent of retinologists performed retinal surgery only, 14.6% performed anterior segment surgery, and 60.7% performed both types of surgery.

CONCLUSIONS

Despite not having taken into consideration non-response bias, this study provides the first reported data on the professional profile of Spanish retinologists.

Development of predictive models of proliferative vitreoretinopathy based on genetic variables: the Retina 4 project

PURPOSE

Machine learning techniques were used to identify which of 14 algorithms best predicts the genetic risk for development of proliferative vitreoretinopathy (PVR) in patients who are experiencing primary rhegmatogenous retinal detachment (RD).

METHOD

Data from a total of 196 single nucleotide polymorphisms in 30 candidate genes were used. The genotypic profile of 138 patients with PVR following primary rhegmatogenous RD and 312 patients without PVR RD were analyzed. Machine learning techniques were used to develop statistical predictive models. Fourteen models were assessed. Their reproducibility was evaluated by an internal cross-validation method.

RESULTS

The three best predictive models were the lineal kernel based on the Support Vector Machine (SMV), the radial kernel based on the SVM, and the Random Forest. Accuracy values were 78.4%, 70.3%, and 69.3%, respectively. The more accurate, although complex, algorithm uses 42 SNPs, whereas the simpler one uses only two SNPs, which makes them more suitable for routine diagnostic work. The radial kernel based on SVM uses 10 SNPs. The best individually predictor marker was rs2229094 in the tumor necrosis factor locus.

CONCLUSION

Genetic variables may be useful to predict the likelihood of the development of PVR. The predictive capabilities of these models are as good as those observed with clinical approaches. These results need external validation to estimate the true predictive capability and select the most appropriate ones for clinical use.

Non-complicated retinal detachment management: variations in 4 years. Retina 1 project; report 1

AIMS

To assess variations in the characteristics and management of two series of non-complicated rhegmatogenous retinal detachments (RD) carried out 4 years apart in Spain.

METHODS

Prospective, multicentric, non-randomised comparative study. 339 consecutive cases of RD treated in five hospitals were included. Group 1 (G1) (n = 186) included cases operated on from 1999 to 2001; group 2 (G2) (n = 153) included cases from 2004 to 2006. 83 variables related to preoperative characteristics of RD, surgical management and postoperative evolution were recorded. Surgeons were allowed to treat patients following their personal criteria. Differences in preoperative characteristics, rate of vitrectomy and anatomical outcome were studied. Quantitative variables were compared by Mann-Whitney U test and qualitative variables by standard contingency tables. Multivariate analysis was carried out by logistic regression analysis.

RESULTS

G1 showed a significantly longer delay in performing surgery, since the first symptoms appeared (G1: 29 (SD 50) days; G2: 22 (55); p<0.001) and more RD without visible retinal break than G2 (G1: 17.4%; G2: 9.2%; p = 0.028). In G2, cases with multiple retinal breaks (G1: 31.6%; G2: 44.6%) were more frequent (p = 0.022). No significant differences in other preoperative variables were observed. Vitrectomy was performed in 30.1% in G1 and in 78.4% in G2 as a primary surgical approach (p<0.001). Regardless of the characteristics of the RD, the rate of vitrectomy was higher in G2. The reattachment rate was over 94% in both groups (p = 0.833). Pseudophakic RD showed better anatomical outcomes in G2 (G1: 83.9%; G2: 96.4%; p = 0.028).

CONCLUSION

There is an increasing tendency to treat RD with primary vitrectomy, which is related to neither a higher complexity of cases nor better anatomical results.

[Urgent retinal detachment management by the National Health System of Spain. Project Retina 2]

OBJECTIVE

To identify problems in the urgent management of retinal detachments (RD) in hospitals of the Spanish National Health System (NHS).

METHODS

A questionnaire was submitted confidentially to the heads of Ophthalmic Departments of 217 hospitals of the NHS to obtain information on the management of urgent RD during the last year. Data was stored in a Microsoft Access database and statistically analyzed by Excel and Statgraphics. Qualitative variables were analyzed by Chi-Square and Fisher exact tests and quantitative variables by the Kruskall-Wallis test.

RESULTS

A global response rate of 54.8% was achieved with higher participation of the Teaching Hospitals (TH). District Hospital and non-Teaching Hospital responses were similar and grouped as non-TH. Eighteen percent of centers, mostly non-TH, had no ophthalmologist on duty. Thirty-six percent had a vitreoretinal specialist on call. Eighty percent of centres admitted to have problems handling urgent RD during weekends. Twenty-four had no ophthalmic surgical theatre available. Fifty percent referred to have problems having an anaesthesiologist available and only 22% had ophthalmic trained personnel (nurses) available. Sixty-four percent of centres performed pars plana vitrectomy (PPV) and 77% of those were able to perform an urgent PPV. Ninety percent admitted that a patient with a macula-threatening RD occurring at the beginning of the week-end would not be treated until at least 24 hours had elapsed, although 84% considered this to be inadequate.

CONCLUSION

Despite the methodological problems and bias of this questionnaire, we did identify several important problems in the management of urgent RD by NHS hospitals. The data obtained provides useful information to enable the quality of the NHS care of RD to be improved, particularly that available at the week-end.

[Correction of secondary anisometropia after retinal detachment and LASIK surgery]

CASE REPORT

A male with cylindrical anisometropia secondary to retinal detachment (RD) surgery in the right eye (OD) was referred for contact lens (CL) fitting. His refraction was OD -1.25 -2.75 x 60 degrees VA 1.0 and OS +0.25 VA 1.2. He was complaining of diplopia with spectacles. Seven years prior to the RD surgery, he had undergone LASIK without complications. The diplopia was eliminated after a CL was fitted according to his corneal topography.

DISCUSSION

RD surgery can cause anisometropic refractive changes. In patients with diplopia and asthenopia, spectacles are not well tolerated. CL fitting according to post-LASIK corneal geometry succeeded in refractive correction with less anisometropic symptoms.

[National survey on vitreo-retinal surgery and the management of rhegmatogenous retinal detachments in Spain. Project retina 2]

PURPOSE

To obtain information throughout Spain on the current management of vitreo-retinal surgical diseases, the number of ophthalmologists involved in retinal surgical diseases care, and the urgent management of retinal detachments.

METHODS

A 30 item questionnaire was sent by mail, on two separate occasions, to the heads of Ophthalmology Departments of 276 centers in Spain.

RESULTS

A total response rate of 48.2% was achieved, however the answers from private centers represented only 9.4% of the total so these were excluded from the analysis. The centers most likely to respond were those in Teaching Hospitals (TH) (52.3%). Of these, 64% of hospitals responded that, in the last year, they performed pars plana vitrectomies (PPV) and 70% performed more than 100 PPVs in the year. In all, 77% of the centers that performed PPVs had also performed them urgently. A total of 75% of hospitals indicated that they had ophthalmologists mainly dedicated to retinal diseases care, with a median of 2 specialists per center, with this representing 23% of their total staff. Retinal surgery was performed by general ophthalmologists in 11.5% of centres. Only 40.3% of hospitals audit their results (37.5% TH).

CONCLUSIONS

Despite the existence of a relatively low response rate, as well as some biases and methodological problems, data on the management of retinal surgical disease has been obtained for the first time at a national level. This data will facilitate later studies and must be taken into consideration in improving the planning and adequate management of these diseases in Spain.

Intraretinal immunohistochemistry findings in proliferative vitreoretinopathy with retinal shortening

To report the major intraretinal pathological changes in retinas with proliferative vitreoretinopathy (PVR) and retinal shortening, 13 human retinal samples from postoperative PVR after primary surgery for retinal detachment were immunostained for vimentin, glial fibrillary acidic protein (GFAP), cytokeratins, and CD68. One more sample was studied with electron microscopy. Retinal disorganization, neuronal loss, and gliosis were observed in 12 out of 13 samples, but all 13 were positive for GFAP. Muller cell processes showed different degrees of intermediate filament hyperplasia. CD68-positive cells were present in 11 of 13 retinal samples.

CONCLUSION

A gliotic response plays a major role in retinal shortening in PVR. In addition, the presence of macrophage-like cells in retinal tissues suggests a possible role of these cells in the pathogenesis of this variety of PVR.

[Cholesterol, alpha-tocopherol, and retinoid concentrations in silicone oil used as a vitreous substitute]

OBJECTIVE

To verify the existence of organic lipophylic compounds in silicone oil extracted from human eyes following its use for previous retinal detachment, and to determine the intraocular permanence time of these substances in the oil.

METHODS

Concentrations of retinoic acid, retinol, retinal, cholesterol and alpha-tocopherol were detected by HPLC in 23 samples of silicone oil extracted from patients with complicated retinal detachments. The time interval between the time of injection of the silicone oil and the subsequent assessment varied from 3 to 50 months (the permanence time).

RESULTS

All tested compounds were found in the samples, but these were most commonly cholesterol and less frequently alpha-tocopherol. There was an inverse relationship between retinoic acid concentration and age (p=0.023), and a direct relationship between cholesterol concentration and permanence time (p=0.0008) at least up to 20 months.

CONCLUSIONS

These findings confirm that silicone oil is not an inert substance but is capable of extracting lipophylic compounds from the intraocular tissues. There is a clear linear elevation of cholesterol levels with increased intraocular permanence time. This finding could be used to further establish a safe permanence time for intraocular silicone oil used in ophthalmologic surgery. More studies with larger samples are warranted to evaluate this further.

Interaction between surgical procedure for repairing retinal detachment and clinical risk factors for proliferative vitreoretinopathy

PURPOSE

To asses risk factors of proliferative vitreoretinopathy (PVR) and a model for predicting it.

METHODS

Observational, case-control. 335 patients with non-complicated retinal detachment (RD) were included: 134 developed PVR (Cases); 201 patients did not (Controls). Risk factors for PVR were identified by multivariate analysis. Influence of variables was assayed according to the surgical approach. By logistic regression analysis a model to predict the risk of developing PVR and odds ratio (OR) values for each clinical factor were estimated.

RESULTS

Risk was higher in patients > 70 years and with intraocular pressure lower than 14 (OR: 3.84; CI 95%: 2.04-7.30) and in retinal breaks larger than "1 clock hour" (OR: 2.54; CI: 1.28-5.05), extended retinal detachments (OR: 4.01; CI: 1.98-8.10) and reinterventions (OR: 1.55; CI: 1.14-9.22). Scleral surgery also was a risk factor (OR: 3.89; CI: 2.12-7.14) and aphakia/pseudophakia when scleral surgery is performed (OR: 3.33; CI: 1.54-7.22). A model to predict PVR was proposed with these results.

CONCLUSIONS

Surgical approach modifies risk factors of PVR, and should be taken into account to improve the models for predicting it.

[Retinal shortening: the most severe form of proliferative vitreoretinopathy (PVR)]

PURPOSE

To identify the clinical characteristics of patients developing retinal shortening due to intraretinal PVR.

METHODS

Observational and retrospective cohort study on 110 PVR patients operated on between 2000 and 2001. During surgery, after removing epiretinal membranes and ruling out the presence of subretinal membranes, a perfluorocarbon liquid was injected. Those cases in which retinal flattening was not accomplished, were considered intraretinal PVR (group 1). Those in which retinal flattening allowed endolaser application, were taken as the control group (group 2). Clinical features of both groups were compared by chi-square test.

RESULTS

60 cases (54.5%, CI 95%: 40.5-68.5) showed retinal shortening (group 1). In 24 cases (21.8%, CI 95%: 12.9-30.7) complete retinal flattening was accomplished (group 2). In 26 cases (23.6%), evaluation was inconclusive. In 9 out of the 60 cases of group 1 (15%) a retinectomy was necessary to reattach the retina. Differences between both groups were not statistically significant for any of the clinical variables. However, the number of retinal detachments of more than 60 days of evolution was significantly higher in retinectomized eyes (20.7%) than in group 1 (3.7%) (p=0.04).

CONCLUSIONS

Retinal shortening is a relatively frequent phenomenon in PVR. Further studies are necessary to characterize this clinical presentation of PVR and its pathogenesis.

Proliferative vitreoretinopathy: cytologic findings in vitreous samples

PURPOSE

To compare the cellularity of vitreous samples obtained from patients with rhegmatogenous retinal detachment complicated by proliferative vitreoretinopathy (PVR) and from patients with uncomplicated rhegmatogenous retinal detachment (RD) to detect possible variations in cellularity over time.

METHODS

One hundred and twenty-five vitreous specimens collected from patients with RD (n = 41) and PVR (n = 84) were processed through direct paraffin embedding and cytospin. Different cell types were identified by light-microscopy (hematoxylin-eosin and Papanicolaou stain) according to their morphologic features, and a scale of cellular density was established for each cell type. Student's t test was used to analyze differences in the cellularity of RD versus PVR. A quadratic model was used to identify variations in the density of each cellular type in the PVR group, based on its evolution time.

RESULTS

During the first months after surgery, more macrophages and fibroblast-like cells were observed in the PVR group, but at other times no differences were found.

CONCLUSIONS

There are some differences in vitreous cellularity in PVR specimens when compared with RD. Especially relevant could be the large number of macrophages in earlier stages and their constant presence over time in PVR samples. The cytology of vitreous samples may shed light on the chronology of PVR cell pathobiology.

[Clinical risk factors for postoperative proliferative vitreoretinopathy (PVR). A prospective study]

PURPOSE

To identify clinical risk factors for development of postoperative PVR, to determine the incidence of this complication and its time of onset by a prospective multicentric study.

METHODS

A multicentric and prospective study of 223 patients with rhegmatogenous retinal detachment (RD) was conducted. Logistic regression analysis was used to identify risk factors for PVR among 83 variables related to preoperative, intraoperative and postoperative characteristics.

RESULTS

22 out of 223 RD developed PVR (incidence 9.9%, confidence interval 95%: 5.9-13.9). After logistic regression analysis, four variables showed an odds ratio higher than 1.0 (RD affecting 4 quadrants, cryopexy, aphakia/pseudophakia and those RD in which an encircling band was implanted). None of these factors showed a <<p>> value lower than 0.05. Most of postoperative PVR (77.2%) appeared in the first month after surgery.

CONCLUSIONS

This study establishes the incidence of PVR, and its time of onset, but it was not effective to identify clinical risk factors with a high level of confidence.

[Ghost cell detection in vitreous cytology: clinico-pathological correlation]

PURPOSE

To determine the prevalence of detection of ghost cells (GCs) in vitreous hemorrhages (VHs) and correlate it with the development of ghost cell glaucoma. To compare our results with those previously reported.

METHODS

Retrospective analysis of clinical records and vitreous cytology reports (cytospin and direct paraffin embedding) from patients undergoing vitrectomy for VH at Instituto Universitario de Oftalmobiología Aplicada and University Hospital, Valladolid, for the last 2 years.

RESULTS

76 VHs have been analysed; 45 corresponded to proliferative diabetic retinopathy and the remainder to several pathologies. GCs have been detected in 18 cases (25%) (4 out of 76 specimens were excluded): 14 were phakic and 4 pseudophakic. Most of 76 VHs lasted more than 2 months. No case of ghost cell glaucoma was detected, neither previously nor after vitrectomy.

CONCLUSIONS

The frequency of detection of GCs in vitreous cytology may vary according to the cytologic technique. In contrast with the information previously reported, ghost cell glaucoma is an unfrequent disease, particularly after vitrectomy, probably because of a better removal of hemorrhagic debris from the vitreous cavity nowadays. Nevertheless, this diagnosis should not be overlooked.

[Glutathione-related enzymes activity during vitrectomy. Effect of BSS Plus(R) in retinal tissue]

PURPOSE

To determine changes in the retinal activity of two enzymes related to the glutathione metabolism (Glutathione synthetase -GSHS- and glutathione reductase -GSSGR-) after vitrectomy using BSS Plus(R).

MATERIAL AND METHODS

Forty-five pigmented rabbits were distributed in 6 groups: group I (GSHS control in retinal tissue); Group II (analysis of GSHS at 3 hours post-vitrectomy); Group III (determination of GSHS at 48 hours after vitrectomy); Group IV (GSSGR control in retinal tissue); Group V (measurement of GSSGR at 3 hours post-surgery) and Group VI (study of GSSGR at 48 hours post-vitrectomy). Statistical analysis was done by a parametric test (ANOVA of single factor) (p<0.05).

RESULTS

The activity of these enzymes was: Group I (n=5, basal GSHS). 2785,63 D.S. 419,51 U/g; Group II (n=4, GSHS at 3 hours). 6053,50 D.S. 2788,84 U/g; Group III (n=4, GSHS at 48 hours). 7424,30 D.S. 997,47 U/g; Group IV (n=10, basal GSSGR). 150,86 D.S. 24,40 mU/mL; Group V (n=7, GSSGR at 3 hours). 212,03 D.S. 53,30 mU/mL; Group VI (n=8, GSSGR at 48 hours). 210,84 D.S. 46,03 mU/mL.

CONCLUSIONS

At retinal tissue, BSS Plus(R) intraocular irrigating solution increases GSHS activity without modifications of GSSGR levels. It seems to be related to the <<novo>> synthesis of glutathione.