Silicone Oil-filled Eye Research Articles

Post Pars Plana Vitrectomy Silicone Oil Related Endophthalmitis Caused by Citrobacter Koseri: A Case Report and Literature Review

Purpose: To present a rare case of a Citrobateri koseri endophthalmitis after pars plana vitrectomy silicone oil-filled eye. Case Report: A 64-year old male patient presented to our clinic for eye pain and decrease vision in the right eye. He had a history of diabetes mellitus, hypertension, and a cataract surgery in both eyes ten years before and surgery of retinal detachment in RE For a relapse of regmatogenous retinal detachment in RE a pars plana vitrectomy with silicone oil injection was performed. He received topical betamethasone, naphazoline and tetracycline 6 times a day. After one week the patient complained ocular pain and decreased vision. Examination revealed visual acuity deterioration, a severely injected conjunctiva. The cornea was edematous with Descemet’s membrane folds. The anterior chamber was hazy with cells and flare, and hypopyon was observed. A diagnosis of post vitrectomy endophthalmitis was made. Sampling of the aqueous fluid was obtained and he was empirically treated with intravitreal ceftazidime 2.0mg/0,1ml and sub-tenon injection of betamethasone (2mg). The microscopic examination of the aqueous fluid stained with Gram stain revealed the presence of numerous polymorphonuclear cells and of small gram-negative bacteria identified as C. koseri. The strain was susceptible to all the antibiotics tested. A high MIC value (16mg/L) was detected only for tetracycline. The therapy was changed to fortified ceftazidime 5%, fortified tobramycin 0.3%, atropine 1% and prednisone-eye drops administered every 2 hours along with systemic antibiotic (ceftriaxone 2g iv for 5days) and steroid treatment without any improvement. The patient underwent to a new pars plana vitrectomy, removal of the IOL, and silicone oil exchange. In this occasion silicon leakage from previous sclerotomy, pus filled vitreous cavity and some retinal hemorrhages were observed. Vancomycin and ceftazidime according to Endophthalmitis Vitrectomy Study protocol were injected in the vitreous cavity and previous topical and systemic therapy was continued, too. An improvement of visual acuity was obtained. Conclusion: Among cases of culture positive endophthalmitis, Citrobacter spp. is very rare, and this is the first report of a silicone oil related endophthalmitis caused by this microorganism.

Effectiveness of different silicone oil remove methods after vitrectomy and light silicone oil tamponade in elderly patients.

During the remove of oil from the silicone oil-filled eye after vitrectomy, perfusion fluid is often mistakenly aspirated when mechanical force is used to remove the oil. This leads to a sudden sharp drop in intraocular pressure and collapse of the eyeball, which may cause complications. The aspiration of perfusion fluid can be detected when the oil is removed manually, and the force of the hand and location of the aspiration can be adjusted to remove the silicone oil instead. In this study, we assessed the efficacy and safety of a manual 23-gauge (23G) silicone oil remove method and confirmed that this is a feasible, highly efficient, safe, simple and economical way to remove oil. We recruited 130 patients (130 affected eyes) 3-6 months after they had undergone vitrectomy and light silicone oil tamponade at our hospital. The patients/eyes were randomly divided into two groups (manual or vitrectomy system), with 65 eyes in each group. All eyes in both groups underwent 23G oil remove by the same physician. The following aspects of the two groups were compared: 1. Oil remove duration; 2. Average intraocular pressure at 1 day, 1 week and 1 month after the procedure; and 3. Postoperative complications, such as retinal redetachment, silicone oil residue, massive suprachoroidal hemorrhage and choroid detachment. The average oil remove durations of the manual group and the vitrectomy system group were 5.92±1.34 and 8.87±1.68 min, respectively (P<0.05); the duration for the manual group was significantly shorter than that for the vitrectomy system group (t=11.07, P=0). The average intraocular pressures at 1 day, 1 week and 1 month after operation of the manual group were 10.2±2.7, 15.2±3.5 and 17.2±3.1 mmHg, respectively, and those of the vitrectomy system group were 9.8±2.4, 15.5±3.1 and 16.8±3.4 mmHg, respectively; the differences between the two groups were not statistically significant at any time point (t=0.892, P=0.374 at 1 day; t=0.517, P=0.606 at 1 week; and t=0.701, P=0.485 at 1 month). The difference in the incidence of postoperative complications, including retinal redetachment, silicone oil residue, massive suprachoroidal hemorrhage and choroid detachment, between the two groups was statistically significant (χ 2 =4.2787, P=0.0386). None of the affected eyes were complicated with transient intraocular hypotension, vitreous hemorrhage or endophthalmitis. The manual 23G silicone oil remove method is highly efficient, safe, simple and economical and can be used conveniently and clinically by the majority of medical institutions.

Retinal Toxicity Following the Injection Ganciclovir into Silicone Oil-filled Eye to Treat Acute Retinal Necrosis

Retinal Toxicity Following the Injection Ganciclovir into Silicone Oil-filled Eye to Treat Acute Retinal Necrosis

Unplanned readmission after ocular trauma ambulatory surgery: A retrospective study of the Zhongshan Ophthalmic Center.

Ambulatory surgery (AS) has become common in recent years. This study explored the causes of unplanned readmission after AS and the trends in the rate of unplanned readmission in the Ocular Trauma Department of Zhongshan Ophthalmic Center. We collected information on patients who underwent AS from 1 January 2015 to 31 December 2017, summarized the causes of ambulatory hospitalization, and analysed the type of initial surgical procedure and the reasons for 31-day unplanned readmission. The Ocular Trauma Department started to perform AS in around mid-2015, and we collected information on patients who underwent ambulatory pars plana vitrectomy (APPV) from 1 January 2016 to 31 December 2017 to explore the predictive factors for the 31-day unplanned readmission of APPV patients. In 2015, 2016, and 2017, a total of 3443 patients underwent AS, among whom the three most common causes of ambulatory hospitalization were eye wall and appendages injury, aphakia, and silicone oil-filled eye. Of the 3443 patients, 32 returned for 31-day unplanned readmission, a readmission rate of 0.93%. The most common surgery (34.4%, 11/32) that resulted in unplanned readmission was pars plana vitrectomy (PPV). The major reasons for unplanned readmission were retinal detachment (RD) (34.4%, 11/32) and high intraocular pressure (HIP) (18.8%, 6/32). There were 860 patients who underwent APPV from 1 January 2016 to 31 December 2017, among whom 10 needed 31-day unplanned readmission, and the readmission rate of APPV for ocular trauma in 2016 and 2017 was 1.16%. Length of procedure (P<0.05) and use of silicone oil filling (P<0.05) were significantly related to the risk of unplanned readmission for APPV surgery. It is generally safe to perform AS on patients with ocular trauma. However, longer operative times and silicone oil filling increase the risk of unplanned readmission for APPV surgery.

Location of a Dexamethasone Implant at the Macula after Intravitreal Injection in a Silicone Oil-Filled Eye.

Here, we report a case with cystoid macular edema (CME) due to central retinal vein occlusion (CRVO) presented with a dexamethasone implant (Ozurdex) trapped at the macula in her silicone oil- (SO-) filled eye after injection. No additional complications such as intraocular pressure (IOP) rise or retinal damage were observed. The CME was resolved during the follow-up period. At the last visit, 3 months following the injection, Ozurdex implant was found to be mostly dissolved without any additional ocular complications.

Intravitreal bevacizumab (avastin) combined with vitrectomy for recurrences of proliferative vitreoretinopathy in von Hippel–Lindau disease

Intravitreal bevacizumab (avastin) combined with vitrectomy for recurrences of proliferative vitreoretinopathy in von Hippel–Lindau disease

Clinical results of ultrasound biometry in silicone oil-filled eye.

To evaluate a method of ultrasound biometry in silicone oil-filled eye and its clinical results. This was a series case study. According to the principle of measuring a distance with ultrasound, we compared the measured distance between a space filed with balanced salt solution and silicone oil at same height, to calculate a conversion factor (0.674) between them. A formula for corrective axial length in silicone oil-filled eye was established. The formula = ab + 0.674 x bc (a, b and c standing for the apex of the cornea, the posterior pole of the lens or the center of the capsular membrane and the anterior surface of the macular, respectively). The axial lengths of 150 silicone oil-filled eyes in 150 cases were then measured before and after silicone oil removal with Vivid 7 Dimension ultrasound. According to the axial length, they were divided into two groups, namely group 1 (the length < 25 mm) and group 2 (the length > or = 25 mm). In 76/150 eyes, before combined silicone oil removal and intraocular lens (IOL) implantation, the SRKT formula was used for intraocular lens calculation; the post-operative actual refraction was compared with the pre-operative predicted refraction and statistics analysis was made. The retinal condition of 150 silicone oil-filled eyes in 150 cases after 3 months' follow-up was stable after surgery. The results of the biometry were as follows. In the first group, the mean corrective axial lengths of 111 silicone oil-filled eyes before silicone oil removal was (22.77 +/- 1.00) mm (ranging from 21.10 to 24.90 mm); the mean axial lengths after silicone oil removal was (22.76 +/- 0.99) mm (ranging from 21.00 to 24.70 mm). The difference between them was not statistically significant (t = 0.518, P > 0.05). The vitreous cavity depth before and after silicone oil removal was (26.57 +/- 2.14) mm and (17.90 +/- 1.38) mm, respectively. The ratio of the latter to the former was 0.673 78. In the second group, the mean corrective axial lengths of 39 silicone oil-filled eyes before silicone oil removal was (26.52 +/- 1.31) mm (ranging from 25.00 to 30.58 mm); the mean axial lengths after silicone oil removal was (26.53 +/- 1.29) mm (ranging from 25.00 to 30.59 mm). The difference between them was not statistically significant (t = 0.109, P > 0.05). The vitreous cavity depth before and after silicone oil removal was (32.01 +/- 2.90) mm and (21.57 +/- 2.04) mm, respectively. The ratio of the latter to the former was 0.673 95. In 76 eyes with IOL, the post-operative actual refraction after at least 3 months follow-up was compared with the pre-operative predicted refraction (-1.50 DS) in both groups. The differences between them were not statistically significant (t(1) = 0.253, P(1) > 0.05; t(2) = 0.209, P(2) > 0.05) in each group. Ultrasound biometry in silicone oil-filled eye is accurate and simple, and has good results in clinical measurement.

Intraocular bevacizumab for iris neovascularization in a silicone oil-filled eye.

To report the effectiveness of intravitreal injection of bevacizumab for treatment of iris neovascularization in a silicone oil-filled eye. Case report. A 56-year-old man with recurrent retinal detachment associated with iris neovascularization. Iris neovascularization regressed after treatment with a 1.25-mg intravitreal injection of bevacizumab in the presence of silicone oil. Intraocular injection of bevacizumab is an effective short-term treatment of neovascularization caused by persistent retinal detachment even in the presence of silicone oil. The standard dose of 1.25 mg of bevacizumab may not require adjustment in an aphakic vitrectomized eye.

Pharmacokinetics of intravitreal 5‐fluorouracil prodrugs in silicone oil: experimental studies in pigs

To examine the in vivo pharmacokinetics of intravitreal 5-Fluorouracil (5-FU) following tamponade with 5-FU prodrug silicone oil formulations. Two different alkoxycarbonyl 5-FU prodrugs denoted C12 and C18 were synthesized and formulated as silicone oil suspensions. A total of 26 pigs underwent conventional three-port lens-sparing pars plana vitrectomy. Approximately 1.6 ml of the prodrug-silicone oil formulation was placed in the vitreous cavity. Operated eyes were enucleated between 20 min and 168 hours postoperatively, and analysed for their content of free 5-FU by high performance liquid chromatography. With the C12 prodrug silicone oil formulation, the concentration of free 5-FU in the vitreous water phase 1 hour after surgery was 3.30 +/- 1.62 microg/ml. After 4 hours this concentration had declined to 1 microg/ml. With the C18 prodrug, the concentration of free vitreal 5-FU never reached 1 microg/ml during the 7 days these experiments lasted. A mathematical model is presented that can explain the measured data if the clearance of 5-FU from the vitreous water phase follows first order kinetics with a half-life of 20 min. These experiments, and the model analysis, suggest that the elimination half-life of 5-FU in the vitreous cavity of a vitrectomized, silicone oil-filled eye is very fast. The model analysis indicates that an alkoxycarbonyl 5-FU prodrug with a specific release rate constant of 10.7 microg/square root h cm(2) can maintain an intravitreal 5-FU concentration above 1 microg/ml for 5 days in the porcine eye.

Reproducibility of Nerve Fiber Layer Thickness Measurements Using Optical Coherence Tomography in Silicone Oil-Filled Eyes

Purpose: To evaluate the reproducibility of nerve fiber layer (NFL) thickness measurements by optical coherence tomography (OCT) in individuals with silicone oil-filled eyes. Methods: Eighteen patients who had undergone pars plana vitrectomy and silicone oil tamponade for retinal detachment were enrolled in a prospective, case-controlled clinical study. Each patient underwent OCT measurement of NFL thickness. Five repetitions of a series of scans on five separate occasions within a 0.5-month period were performed. Each eye was scanned at two different nerve head programs [radius (R) = 1.5 and R = 1.73]. The contralateral healthy eye was used as control. For each option (R = 1.5 and R = 1.73) and region (superior, inferior, temporal, nasal and overall mean), variance components and intraclass correlation coefficients (ICCs) were determined using repeated-measures regression. In these models, NFL thickness, as measured by OCT, was considered to have three variance components: intersubject, intervisit (within subject, between dates), and intravisit (within subject, within date). The ICC (intersubject variance/total variance) was used as a measure of reliability. Results: The contralateral healthy eye provided a higher degree of reproducibility than the silicone oil-filled eye (p = 0.0001). Reproducibility was higher in a given eye on a given visit than from visit to visit. Reproducibility as measured by ICCs was as follows: R = 1.5, 0.54/0.30 (control eyes/silicone oil-filled eyes); R = 1.73, 0.51/0.30. Conclusions: Reproducibility results for OCT measurement of NFL thickness are different in healthy eyes and silicone oil-filled eyes. NFL thickness measurement is not reliable in silicone oil-filled eyes.

Biometry of the silicone oil-filled eye

The advent of silicone oil tamponade has resulted in improved success rates in complicated retinal detachment surgery. Its use, however, can induce cataract formation in phakic eyes. In selected patients, removal of silicone oil can be combined with phacoemulsification of the cataract and intraocular lens (IOL) implantation, thus avoiding a further operation. This, however, poses a problem when trying to decide the power of IOL to be used, since the echographically measured axial length (AL) of an eye is greater in the presence of silicone oil. We performed ultrasound examination in the presence of silicone oil of viscosity 1300 centistokes, in order to determine whether the measured AL varied from the true AL by a constant factor. The ALs of 7 phakic eyes were measured by A-mode echography, with and without silicone oil of viscosity 1300 centistokes in the posterior segment. The retina was attached in all cases. The control group consisted of 6 phakic eyes with attached retinae undergoing vitrectomy without the use of silicone oil. The ALs in the control group were measured before and after vitrectomy. The mean ratio of true AL to measured AL in the presence of silicone oil was 0.71 (standard deviation 0.01; range 0.70-0.73; median 0.71) in the 7 eyes in this study. In the control group, vitrectomy appeared to have no significant effect on AL. We have established a constant which corrects for the apparent increase in AL induced by silicone oil of viscosity 1300 centistokes. This conversion factor, when used in existing biometry formulae (SRK/T), allows estimation of the power of IOL required in eyes undergoing combined cataract extraction, removal of silicone oil and lens implantation.

Management of endophthalmitis in a silicone oil-filled eye

PURPOSE&nbsp; To describe the management of endophthalmitis in an eye filled with silicone oil for prolonged internal retinal tamponade. METHODS&nbsp; A patient with a silicone oil-filled eye developed endophthalmitis postoperatively. Results of clinical examination, diagnostic procedures, and surgical management are described. RESULTS&nbsp; Removal of the silicone oil, injection of antibiotics into the fluid-filled vitreous cavity, and reinjection of silicone oil resulted in resolution of the endophthalmitis and improvement in vision. CONCLUSIONS&nbsp; Aggressive management of endophthalmitis in an eye requiring silicone oil tamponade may salvage useful vision.

Injury prediction in female gymnasts.

In order to identify injury-proneness in female competitive gymnasts, 20 measures of flexibility, hypermobility, spinal posture and anthropometry were performed on 40 competitive gymnasts and injury scores were derived from the severity and extent of previous gymnastic injury and inherent hypermobility traits. Results were compared between contrasting groups of "low" and "high" injury gymnasts respectively (both N = 10). Nine variables demonstrated significant differences between the "low" and "high" injury risk status groups namely, weight (p less than 0.001), height (p less than 0.001), age (p less than 0.001), mesomorphy (p less than 0.01), Quetelet Index (p less than 0.01), shoulder flexion (p less than 0.05) and lumbar extension (p less than 0.05), standing lumbar curvature and total peripheral flexibility score (both p less than or equal to 0.05). Multiple regression analysis was applied to determine the relative contribution of these variables to the estimation of injury-proneness as evidenced by previous history of injury and hypermobility traits. Using 9 independent variables, multiple regression yielded a multiple correlation coefficient (R) = 0.840, accounting for over 70% of the observed variance (R2 = 0.706) in injury scores among the total group of gymnasts. However, a subset of five variables, (weight, mesomorphy, standing lumbar curvature, age and height) yielded a multiple correlation coefficient (R) = 0.834 accounting for almost 70% of the observed variance (R2 = 0.696). This was not significantly different from the larger subset. Using injury classification system of "low", "medium", and "high" risk categories, comparisons were made between predicted and observed injury scores in the respective risk categories. In "high" risk and "low" risk gymnasts, injury scores could be classified correctly with 70% and 79% accuracy respectively, so that relative risk status could be determined from simple physical tests which may be employed by practitioners in the field.