A. T. A. Liem

Levels of basic fibroblast growth factor, glutamine synthetase, and interleukin-6 in subretinal fluid from patients with retinal detachment.

PURPOSE To investigate the presence of basic fibroblast growth factor, glutamine synthetase activity, and interleukin-6 in subretinal fluid from patients with retinal detachment. METHODS In a prospective study we measured basic fibroblast growth factor, glutamine synthetase activity, interleukin-6, and total protein in subretinal fluid samples from 96 eyes from 94 consecutive patients with a retinal detachment corrected by a conventional scleral buckling operation in our clinical practice. As controls, vitreous fluid samples from eyes with a macular hole (n = 6) or pucker (n = 11) were used. Laboratory data of the patient group were compared with the control group and correlated with various clinical data. RESULTS Levels (median, range) of basic fibroblast growth factor, glutamine synthetase activity, interleukin-6, and total protein were significantly higher in patients than in controls (P <.0001). An increased level of glutamine synthetase and total protein correlated with a longer duration of the retinal detachment (r =.4, P =.002, and r =.34, P =.001, respectively). Interleukin-6 and basic fibroblast growth factor levels did not correlate with the duration of the detachment. After multivariate logistic regression analysis, no significant relation was found between any of the tested subretinal proteins and a low visual outcome or redetachment. CONCLUSIONS We found increased levels of basic fibroblast growth factor and glutamine synthetase in subretinal fluid from patients with retinal detachment. Basic fibroblast growth factor and glutamine synthetase may play a role in the pathogenesis and recovery after retinal detachment. The questions of whether the increased levels of basic fibroblast growth factor and glutamine synthetase result from leakage of dying glia cells (including Müller cells) and neurons and if basic fibroblast growth factor is actively produced to protect the photoreceptor cells need further research.

Balance of vascular endothelial growth factor and pigment epithelial growth factor prior to development of proliferative vitreoretinopathy.

Background: Pigment epithelium-derived factor (PEDF) and vascular endothelial growth factor (VEGF) are imbalanced in eyes with proliferative diabetic retinopathy or proliferative vitreoretinopathy (PVR). It is not known whether such an imbalance is already present in early PVR stages. We therefore analyzed VEGF and PEDF concentrations in subretinal fluids prior to PVR development. Methods: A large number (n = 137) of subretinal fluid samples were obtained at the time of scleral buckling surgery for rhegmatogenous retinal detachment (RRD). Thirty patients developed PVR within 6 months after surgery. One hundred and seven patients undergoing the same surgery but without complications served as controls. Furthermore, vitreous from 16 patients with macular hole or pucker (MHP) served as reference for baseline intraocular concentrations. PEDF and VEGF concentrations were measured by commercial ELISAs. Results: PEDF levels were substantially higher (9.6 µg/ml) compared to MHP vitreous (0.3 µg/ml, p < 0.001). VEGF levels were also higher (RRD: 0.07 ng/ml; MHP: 0.01 ng/ml, p < 0.05). Subretinal concentrations were not significantly different between PVR and control RRD patients. Conclusions: Although both VEGF and PEDF are increased at first surgery for RRD, they do not predict PVR development later on. The high PEDF concentrations and its known antiangiogenic activity suggest a protective role against neovascularization.

Persistent subfoveal fluid and increased preoperative foveal thickness impair visual outcome after macula-off retinal detachment repair.

Purpose: To investigate the influence of subfoveal fluid and foveal thickness on visual outcome in patients who underwent reattachment surgery for rhegmatogenous retinal detachment (RRD). Methods: This prospective study included 53 patients who were undergoing successful scleral buckling surgery for primary RRD. A thorough ophthalmologic examination including best-corrected visual acuity, slit-lamp biomicroscopy, binocular indirect ophthalmoscopy, and optical coherence tomography scanning was performed preoperatively and during all subsequent follow-up visits at 1, 3, 6, 9, 12, and 24 months postoperatively. Results: Preoperative foveal thickness was significantly higher in the macula-off group (n = 38) compared with the macula-on group (n = 15) (P < 0.0001), whereas postoperative measurements were normal in both the groups. Linear mixed-model analysis revealed that persistent subfoveal fluid (P = 0.0004) was an independent predictor of a worse visual outcome after scleral buckling surgery for primary macula-off RRD, although the effect on visual outcome was small (0.1 logarithm of the minimal angle of resolution units). Moreover, increased preoperative foveal thickness was associated with a worse visual prognosis in macula-off RRD (P = 0.010). Conclusion: Persistent subfoveal fluid and increased preoperative foveal thickness were associated with a worse visual prognosis in macula-off RRD patients, albeit the effect of persistent subfoveal fluid was small and temporary.

Risk factors for redetachment and worse visual outcome after silicone oil removal in eyes with complicated retinal detachment

Purpose The goal of this study was to identify risk factors for redetachment and/or a worse visual outcome after silicone oil removal (SOR) for complicated retinal detachment. Methods The authors retrospectively analyzed 287 consecutive eyes with SOR between January 1999 and December 2003. Results Anatomic success after SOR was achieved in 81% of the eyes. The overall anatomic success at the end of follow-up was 94%. Postoperative ocular hypertension was found in 8% of the eyes, hypotony in 6% of the eyes, and keratopathy in 29% of the eyes. After SOR 43% of the eyes had an improvement in visual acuity of at least two Snellen lines. After multivariate analysis, male sex, the presence of preoperative rubeosis, and proliferative diabetic retinopathy (PDR) were found to be risk factors for recurrent retinal detachment. Male sex, preoperative visual acuity of <0.1 Snellen lines, PDR, the performance of three more operations, any size of retinectomy, and hypotony were found to be associated with a poor visual outcome of Snellen visual acuity <0.1. Conclusions Retinal detachment after SOR in the current unselected series of eyes occurred in approximately 20%, which is comparable to the Silicone Oil Study reports, published approximately 20 years ago. However, preoperative selection was then made, and less than 50% of the silicone oil-filled eyes had SOR. The higher overall anatomic success in the current study may be due to improved vitreoretinal surgical techniques.

Decreased levels of cGMP in vitreous and subretinal fluid from eyes with retinal detachment

Background: Cyclic guanosine monophosphate (cGMP) is produced in different retinal cells, including photoreceptor cells, wherein cGMP mediates photo-transduction. CGMP is degraded by phosphodiesterases (PDE). The aim was to investigate whether retinal detachment alters intraocular cGMP levels in human eyes. Methods: cGMP and PDE were determined in vitreous fluid from 50 eyes with a retinal detachment (group I) and in 20 control samples (group II) of vitreous fluid from eyes without retinal detachment. Group III consisted of subretinal fluid samples from 70 eyes with retinal detachment. Results: cGMP in vitreous fluid from eyes with retinal detachment (6.5 (SD 1.7) nM) was decreased compared to controls (67.1 (10.0) nM) (p<0.0001). In subretinal fluid, the mean level of cGMP was 2.4 (0.2) nM. No PDE could be detected in any of the intraocular fluid samples of patients nor controls. A decrease in the mean level of cGMP in subretinal fluid of eyes with retinal detachment correlated with a longer duration of detachment (r = −0.45, p = 0.007). Conclusions: Retinal detachment was found to be associated with a decrease in vitreous cGMP concentration. In subretinal fluid, a low cGMP level correlated inversely with the duration of the detachment.

Corneal endothelial cell density after vitrectomy with silicone oil for complex retinal detachments.

Purpose: To evaluate the endothelial cell density changes in eyes with silicone oil tamponade after vitrectomy for complex rhegmatogenous retinal detachment. Methods: A prospective controlled study with 81 eyes with complex rhegmatogenous retinal detachment undergoing vitrectomy and silicone oil tamponade. Fellow eyes that fulfilled specific inclusion criteria served as controls. Endothelial cell density (in cells per square millimeter), coefficient of variance (standard deviation per mean cell area × 100), percentage of hexagonal cells, and corneal thickness were documented preoperatively and compared with values obtained at 3, 6, and 12 months postoperatively. For the purpose of the study analysis, all study eyes were divided into 5 groups, according to their lens status during the follow-up. Results: High endothelial cell density loss was found in Group 3, (eyes that underwent an additional phacoemulsification procedure) and Group 4 (eyes that underwent lens and/or intraocular lens removal during the follow-up) at 12 months with a mean cell loss of 19% and 39%, respectively (P < 0.001). Conclusion: An intact natural or artificial lens–iris diaphragm may provide a protective barrier against corneal endothelial cell damage from long-term silicone oil tamponade.

Diplopia was not predictable and not associated with buckle position after scleral buckling surgery for retinal detachment.

Purpose: The possibility of postoperative binocular diplopia is seen as an important drawback of conventional scleral buckling surgery for rhegmatogenous retinal detachment. The goal of this study was to evaluate the occurrence and pattern of binocular diplopia after scleral buckle procedures in patients with rhegmatogenous retinal detachment. Methods: In a retrospective study of 1,030 patients with primary rhegmatogenous retinal detachment who were treated by scleral buckle surgery between January 2001 and July 2008, the postoperative occurrence of binocular diplopia was retrieved from the medical charts. Results: Secondary strabismus developed in 39 subjects (3.8%) after scleral buckle surgery during a mean follow-up of 6.4 ± 6.3 months. Twenty-eight patients (2.7%) developed strabismus because of a mechanical restriction of one of the muscles. No association was found between the position of the buckle, that is, the muscle affected, and the incidence of diplopia. A moderate significant association was found when two muscles were affected with a higher incidence of diplopia. This was, however, not found for three or more muscles. In 28 of 39 patients, binocular single vision was restored at the end of the follow-up period. In the majority, this was accomplished with conventional prism treatment. Conclusion: Strabismus caused by a restriction of the muscles in scleral buckle surgery was not predictable based upon the buckle position. Patients with a minimal restriction of the muscles after scleral buckle surgery can often be well treated with prisms.