Silicone Oil Removal Research Articles

Zespół Sticklera – opis przypadku i analiza literatury

PurposeTo present a case of patient with Stickler syndrome and retinal detachment with crystalline lens subluxation.Material and MethodsRetrospective case report.ResultsA 9-years-old patient approached Ophthalmology Department with retinal detachment in her right eye and proliferative vitreoretinopathy stage D2. Her medical history revealed previous cryotherapy of her right eye, high myopia (-14.5 D), bilateral glaucoma, bilateral posterior subcapsular cataracts and subluxated crystalline lens in her righteye. Further clinical examination of her right eye revealed best corrected visual acuity of light perception without localization, intraocular pressure 45 mmHg. Patient underwent pars plana vitrectomy with subluxated crystalline lens facoaspiration and silicone oil injection of her righteye. After 2 months pars plana vitrectomy was repeated with removal of silicon oil and further SF6 endotamponade. During control examination 6 months later right’s eye best corrected visual acuity was 5/16, intraocular pressure 23 mmHg. In USG of her right eye remains of silicon oil were noticed with retina attached.ConclusionsPars plana vitrectomy with silicon oil injection is effective method of treatment of retinal detachement in patients with Stickler syndrome. Those operations might be followed by many complications. Early diagnosis is essential in prevention of ocular complications in patient with Stickler syndrome.

Outcomes of Secondary Intracapsular Intraocular Lens Implantation in Patients following Rhegmatogenous Retinal Detachment.

This study reports the outcomes of a secondary IOL implantation technique in patients that suffered from rhegmatogenous retinal detachment combined with a cataract, which included reopening the capsular bag, enabling secondary intracapsular intraocular lens (IOL) implantation. We included consecutive cases with rhegmatogenous retinal detachment (RRD) treated with vitrectomy and silicone oil tamponade, and subsequent secondary IOL implantation during silicone oil removal between September 2019 and June 2022. Demographics, pre- and postoperative clinical data, and complications were collected. Visual and refractive outcomes and IOL position were evaluated. Thirty eyes were included and followed up for a mean of 24.2 ± 5.06 months. Compared with the preoperative values, no significant changes were observed in the intraocular pressure (p = 0.170) and endothelial cell density (p = 0.336); however, the best-corrected visual acuity (Snellen: 20/83 vs. 20/38; logMAR: 0.66 ± 0.23 vs. 0.37 ± 0.32; p < 0.001) and spherical equivalent (p < 0.001) improved significantly. The mean prediction error (ME) was -0.45 ± 0.68 D (-1.9-0.54 D), and the mean absolute prediction error (MAE) was 0.62 ± 0.52 D (0.01-1.9 D). The macula-on subgroup demonstrated significantly better refractive outcomes than the macula-off subgroup (ME, p = 0.046; MAE, p = 0.008). The IOL was well positioned, with a mean horizontal and vertical tilt and decentration of 0.53 ± 0.49° and 0.21 ± 0.16 mm, and 0.54 ± 0.45° and 0.22 ± 0.16 mm, respectively. Secondary intracapsular IOL implantation provided a good and stable IOL position and satisfactory refractive outcomes, and is a feasible treatment option for patients with RRD.

Use of 30 gauge needle to prevent hypotony during silicone oil removal.

Silicone oil (SO) is used as an intraocular tamponade after complex vitreoretinal surgeries because of its properties such as transparency, inertness, high surface tension, and interfacial tension with water. The only disadvantage of SO tamponade is the need for a second surgery for its removal. However, there is a risk of ocular hypotony soon after the removal of the infusion cannula, especially in retinal vascular conditions, such as diabetic retinopathy. We hereby present a silicone oil removal (SOR) technique using a 30 G needle that prevents intraocular hypotony during SOR.

Алгоритм лечения далеко зашедшей пролиферативной диабетической ретинопатии

Purpose. To develop an algorithm for the treatment of patients with advanced proliferative diabetic retinopathy with the determination of the stages of laser and surgical methods and evaluate its effectiveness. Material and methods. The study group included 38 patients (38 eyes) with type 1 diabetes mellitus (21 patients) and type 2 diabetes mellitus (17 patients, 16 of them with the insulin-requiring form of the disease). Patients age ranged from 24 to 75 years (41±8.6 years) old. All patients underwent staged treatment. Primary subtotal three-port 27 G vitrectomy was performed. Transpupillary patterned panretinal laser coagulation was performed at 1,5–2 months after the first stage of treatment. Panretinal laser coagulation was performed with a hexagonal matrix pattern with a laser spot diameter of 300 µm, exposure time of 30 ms on an Integre Pro Scan laser device (Ellex, Australia) with a wavelength of 561 nm using a panfundus lens. In cases of gas-air tamponade, panretinal laser coagulation was performed according to the same parameters in two sessions with an interval of 1–2 months between them, the average number of coagulates per session was 1053±107 applications. As the third stage of treatment, 1,5–2 months after panretinal laser coagulation, those patients whose vitreal cavity was tamponed with silicone oil underwent vitrectomy with the removal of silicone oil and it's replacement with a balanced solution. Results. The total number of treatment steps in the observation group (n=34) ranged from 1 to 5 and averaged 3±0.97. The time from primary vitrectomy followed by patterned panretinal laser coagulation to silicone oil removal was at average 3.7±0.48 months. Performing primary subtotal vitrectomy as the first stage of combined treatment made it possible achieve retinal attachment and its visualization throughout, to perform surgical intervention without massive endolaser coagulation, which reduced the duration of surgery and accelerated postoperative rehabilitation. The subsequent transpupillary panretinal laser coagulation of the retina in the pattern mode provided a dosed precision effect on the retina and made it possible perform the laser stage of treatment in one session. Conclusion. A step-by-step algorithm, including primary subtotal vitrectomy followed by simultaneous transpupillary pattern laser coagulation of the retina, is effective and safe in the treatment of proliferative diabetic retinopathy complicated by hemophthalmos. Key words: proliferative diabetic retinopathy, treatment algorithm, surgical treatment, laser treatment, vitrectomy, pattern laser coagulation

Silicone oil insulation effects on flash electroretinogram and visual evoked potential in patients with retinal detachment

BackgroundSilicone oil is used as endotamponade following vitreoretinal surgery to maintain the retina reattached when indicated. This study investigates the hypothesis that silicone oil causes insulation effects on the retina by affecting its response to light. MethodsElectrophysiological responses to a flash stimulus were recorded using full-field electroretinography (ERG) and visual evoked potentials (VEP). Recordings were performed in 9 patients who underwent surgery for retinal detachment, before (1–2 days) and after (2–3 weeks) silicone oil removal (SOR) in both the study and the control eye. Flash ERG and VEP recordings were performed according to the ISCEV standard protocol. ResultsStatistically significant differences were found in the study eye in the amplitudes of the ERG responses and their corresponding ratios, i.e. the amplitude after SOR over the amplitude before SOR, in all conditions tested. No differences were observed in the control eye. The mean ratio of photopic ERG response was 3.4 ± 2.4 for the study and 1.0 ± 0.3 for the control eye (p<0.001). The mean ratio of ERG flicker response was 3.1 ± 2.4 and 1.0 ± 0.3, respectively (p = 0.003). Scotopic flash ERG ratio was 5.0 ± 4.4 for the study and 1.3 ± 0.6 for the control eye (p = 0.012). No differences were observed for the amplitude and latency of flash VEP response after SOR. ConclusionsSilicone oil causes a reduction in flash ERG responses; no effect was found on flash VEP responses. ERGs in eyes filled with silicone oil should not be considered representative of retinal functionality, in contrast to VEPs, which are not affected by silicone oil presence.

Хирургическое лечение рецидивирующего массивного субмакулярного кровоизлияния путем механического удаления через ретинотомию

Purpose. To present a variant of surgical treatment of recurrence of extensive submacular hemorrhage (SMH) with the background of active agerelated macular degeneration (AMD). Methods. To the patient with a history of operated SMH and a recurrence of the disease, a three-port revision of the vitreal cavity with mechanical removal of subretinal clots through a retinotomy hole was performed on the basis of the N.I. Pirogov National Medical Surgical Center. The vitreal cavity was tamponed with silicone oil at the end of the operation. There was a standard ophthalmological examination before and after the operation. The second stage of treating the patient was the removal of silicone oil 2 months later. Results. according to the examination data, visual acuity was correct light projection at the time of admission to the hospital. Postoperative measurement of visual acuity showed an increase to 0.02, the patient describes an improvement in the quality of vision. As a result of surgery, a change in the morphological parameters of the retina was noted. Conclusion. It managed to treat the patient with recurrent SMH with a two-stage operation and mechanically eliminate the subretinal clot through retinotomy. The use of this method of treatment is appropriate in the case of recurrent massive SMH with the background of an active macular neovascularization (MNV). Key words: submacular hemorrhage, age-related macular degeneration, macular neovascularization, paramacular retinotomy

Retinal detachment following lightning injury mimicking acute retinal necrosis: A case report

A 16-year-old male presented with a diminution of vision after 1 month of lightning injury. Fundus examination showed inferior retinal detachment with multiple sieve-like breaks. After pars plana vitrectomy, he developed mutton fat keratic precipitates and anterior segment inflammation. Sieve-like breaks and mutton-fat keratic precipitates (MF-KPs) led to the diagnostic dilemma of viral etiology. The patient responded well to treatment with steroids and antivirals, showing good visual recovery after silicone oil removal. Lightning strike injury–related retinal detachment can rarely mimic an acute retinal necrosis (ARN)-related retinal detachment (RD).

Accuracy of Intraocular Lens Power Estimation in Aphakic Eyes Filled with Silicone Oil

Purpose: To compare preoperative refractive power estimation and actual postoperative refraction after combined silicone oil removal and intraocular lens (IOL) sulcus implantation in silicone oil-filled aphakic eyes.Methods: Records of patients with silicone oil-filled aphakic eyes who received simultaneous silicone oil-removal and IOL sulcus implantation (Group1) and aphakic patients who received vitrectomy combined with IOL implantation (Group 2) were reviewed. Optical biometry including axial length measurements were obtained using IOL master&lt;sup&gt;®&lt;/sup&gt; 700 and predicted refractive errors, actual postoperative refractive errors were examined retrospectively.Results: Predicted refractive errors, calculated by subtracting 1 diopter (D) from myopic lens power closest to plano based on sulcus implantation, were 0.50 ± 0.12 D in Group 1, 0.45 ± 0.20 D in Group 2. Six months after operation, mean refractive errors measured -0.76 ± 0.49 D in Group 1, -0.23 ± 0.49 D in Group 2, showing significant myopic shift (&lt;i&gt;p&lt;/i&gt; &lt; 0.001, &lt;i&gt;p&lt;/i&gt; &lt;0.001). Group 1 showed larger significant myopic shift compared to Group 2 (&lt;i&gt;p&lt;/i&gt; = 0.001), especially in 3 eyes with insufficient filling of intravitreal silicone oil showing -1.5 D myopic shift.Conclusions: Ocular biometry of silicone oil-filled aphakic eyes undergoing simultaneous silicone oil removal and IOL sulcus implantation are difficult to measure, showing postoperative myopic shift compared to control. Incomplete intravitreal silicone oil filling showed larger refractive errors needing additional compensations.

New approaches to explanting high-viscosity silicone oil in retinal surgery—polyimide cannulas vs extraction sleeves vs a luer-trocar

BackgroundThe removal of high-viscosity silicone oil in retinal surgery is time-intensive. In this laboratory and porcine eye study, we evaluated the efficiency of novel extraction techniques, namely shortened polyimide-cannulas, an extraction sleeve and an experimental luer-trocar system, for commercially available silicone oils.MethodsThe volume of silicone oil after a 5-min removal time was quantified. The feasibility of all studied techniques was additionally tested in vitrectomized porcine eyes. Siluron 1000, 2000, 5000 and Xtra, as well as Densiron 68 and Densiron Xtra were examined.ResultsShortening the 23G-polyimide-cannula from 6 mm up to 1.5 mm led to a significantly higher mean aspirated volume (e.g., 1 ml/min to 1.7 ml/min for Siluron Xtra). The extraction sleeve and luer-trocar increased the flow threefold compared to the shortest polyimide cannulas at 23G (5.2 ml/min and 5.2 ml/min vs 1.7 ml/min for Siluron Xtra, respectively). The extraction sleeve and luer-trocar system reached a similar flow at 27G as the best performing 23G-cannula. Angulation and movement of the eye was possible with the 2 mm-cannula, no angulation was possible when using the extraction sleeve. Stability and control were not impaired with the experimental luer-trocar setup.ConclusionShorter polyimide-cannulas and extraction sleeves increase the extraction flow but may decrease stability during surgery. The luer-trocar system facilitates rapid removal while offering great stability and control. Small 27G silicone oil removal is possible and time efficient.

Marfan’s syndrome with rhegmatogenous retinal detachment: a case report and literature review

Background: Marfan’s syndrome is known to be a rare, multisystem disorder of connective tissue typically affecting cardiac, skeletal and ocular system. The only definitive diagnosis is by gene testing for autosomal dominant mutation of FBN1 gene encoding the regulation of fibrillin 1 located on chromosome 15q.3. Ocular manifestations appear early in life with most of the abnormalities being sight threatening. These incude ectopia lentis, high myopia, rhegmatogenous retinal detachment , open angle glaucoma etc. Ophthalmological examination plays vital role in early diagnosis and visual preservation. Case report: A 16 year old male presented with chief complaints of curtain like shadow in temporal visual field with present glasses for past 7 days. He had bilateral ectopia lentis with rhegmatogenous retinal detachment sparing the macula in the left eye. General examination of patient revealed physical features suggestive of Marfan’s syndrome. Although genetic testing was not possible, all features were suggestive of Marfan’s syndrome according to revised Ghent criteria. Pars plana vitrectomy with lens extraction with silicone oil injection was the treatment of choice. After an eventful post-operative period with silicone oil induced rise in intraocular pressure and 360 degrees peripheral anterior synechiae, early removal of silicone oil led to a good final visual outcome. Thus, with early detection and prompt treatment we were able to restore his visual quality of life. Conclusion: Although serious and vision threatening manifestations may occur in the eye in cases of Marfan’s syndrome, early diagnosis and prompt treatment may be able to salvage vision. It is necessary to keep patients on regular follow up and inform them of possible vision threatening ocular manifestations in the eye for early diagnosis and prompt management.

The Emulsification of Silicone Oil 5000 cs in Patients With Retinal Detachment.

Background The emulsification of silicone oil is a significant concern for those with rhegmatogenous retinal detachment (RRD) following surgery. The aim of the study was to assess the frequency of emulsification in the patients who underwent primary vitrectomy and were administered 5000 cs silicone oil. Methodology The Layton Rahmatullah Benevolent Trust in Lahore conducted an ophthalmology study from January 2022 to March 2023. The patients who had primary vitrectomy for RRD with silicone oil tamponade were included regardless of age or gender. Those on anti-inflammatory or steroid medications prior to surgery were excluded. Retinal attachment was examined 8-12 weeks post operation to assess silicone oil removal eligibility. Emulsification occurrence was reported. Data on emulsification time, visual acuity (pre- and post-removal), mean intraocular pressure (IOP), and clinical outcomes were collected and analyzed using the Statistical Package for Social Sciences (SPSS) software (IBM SPSS Statistics, Armonk, NY). The results were graphically presented with mean, standard deviations, frequencies, and proportions. Results A total of 158 patients underwent silicone oil removal after undergoing primary vitrectomy for RRDwith silicone oil. The mean age of the patients was 45.90 ± 17.8 years. The mean preoperative intraocular pressure (IOP) among the patients was 16.28 ± 2.97 mmHg. Post removal of silicone oil, the IOP was reduced to 12.66 ± 3.02 mmHg. In 11 out of 158 cases (6.9%) of RRD, emulsification had occurred with silicone oil 5000 cs. We found that out of 11 cases of emulsification, eight (72.73%) were 40 years or older in age. Seven (63.64%) patients had tamponade duration of 10 weeks or longer. However, the difference was not statistically significant. Conclusion In conclusion, our study found that the incidence of emulsification of 5000 cs silicone oil in the patients who underwent primary vitrectomy for the treatment of RRD was 6.9%. We observed that emulsification was more frequent in patients aged 40 years or older and those with a tamponade duration of 10 weeks or longer, although the difference was not statistically significant. Further investigation with bigger sample sizes and extended follow-up periods is required to verify our findings and explore potential factors that could lead to emulsification in this group of patients.

Accuracy of New Intraocular Lens Calculation Formulae in eyes undergoing Silicone Oil Removal/Pars Plana Vitrectomy-cataract surgery.

To investigate the performance of novel intraocular lens (IOL) calculation formulae (Barrett Universal II [BUII], Emmetropia Verifying Optical [EVO], and Kane) and conventional formulae (Haigis, Hoffer Q, Holladay 1, and SRK/T) in patients who underwent pars plana vitrectomy (PPV) or silicone oil removal (SOR) combined with cataract surgery. In total, 301 eyes from 301 patients underwent PPV/SOR with concomitant cataract surgery were enrolled and divided into four groups according to preoperative diagnosis: silicone oil-filled eyes after PPV, epiretinal membrane, primary retinal detachment (RD), and macular hole. BUII exhibited the smallest mean absolute error (MAE) (0.65 diopters [D]) and median absolute error (MedAE) (0.39 D) in total. In patients with RD, each formula exhibited the worst refractive outcomes in diverse vitreoretinal pathologies (P<.01), and no difference in accuracy between the seven formulas was observed (P=.075). For long eyes, the second linear (WK2) version of the Wang-Koch adjustment significantly reduced the MedAE for Holladay 1 and SRK/T (P<.001 and P=.019). In combined surgery, both new and conventional formulas using WK2 adjustment demonstrated satisfactory performance, with BUII exhibiting the best overall performance. However, in patients with RD, all seven formulas showed less favorable performance.

Simplifying biometry in oil-filled eyes: A novel formula for axial length calculation in eyes with 1000 cSt silicone oil.

To derive a formula for accurate axial length (AL) assessment using routine ultrasound in silicone oil-filled eyes, where optical biometry is unavailable or not possible. This was a prospective, consecutive, nonrandomized study of 50 eyes of 50 patients conducted in a tertiary care hospital in North India. AL measurements were taken using both manual A-scan and IOL master, both in silicone oil-filled status and 3 weeks after silicone oil removal. A correction factor of 0.7 was used for AL adjustment in oil-filled eyes. The corrected AL (cAL) was compared with IOL master values in oil-filled eyes. Agreement analysis was carried out using Bland Altman plot. Linear regression analysis was done using uncorrected manual AL to find a new equation. Data was analyzed using Stata 14. A P value <0.05 was taken as significant. The study included 40 males and 10 females, with an age range of 6-83 years (mean 41.9 years). The mean AL of the oil-filled eye as measured by manual A-scan was 31.76 mm ± 3.09 and by IOL master was 24.7 mm ± 1.74. Linear regression analysis was performed in randomly selected 35 eyes of the observed data to obtain a new equation: predicted AL (PAL) = 14 + 0.3 × manual AL. The mean difference between PAL and optically measured AL with silicone oil in situ was 0.98 ± 1.67. We propose a new formula for better prediction of the correct AL in silicone oil-filled eyes using ultrasound-based AL measurement.

Clinical Characteristics of Patients with Intraocular Lens Calcification after Pars Plana Vitrectomy.

To determine the clinical risk factors that may increase the occurrence of intraocular lens (IOL) calcification in patients who had undergone pars plana vitrectomy (PPV). The medical records of 14 patients who underwent IOL explantation due to clinically significant IOL opacification after PPV were reviewed. The date of primary cataract surgery, technique and implanted IOL characteristics; the time, cause and technique of PPV; tamponade used; additional surgeries; the time of IOL calcification and explantation; and IOL explantation technique were investigated. PPV had been performed as a combined procedure with cataract surgery in eight eyes and solely in six pseudophakic eyes. The IOL material was hydrophilic in six eyes, hydrophilic with a hydrophobic surface in seven eyes and undetermined in one eye. The endotamponades used during primary PPV were C2F6 in eight eyes, C3F8 in one eye, air in two eyes and silicone oil in three eyes. Two of three eyes underwent subsequent silicone oil removal and gas tamponade exchange. Gas in the anterior chamber was detected in six eyes after PPV or silicone oil removal. The mean interval between PPV and IOL opacification was 20.5 ± 18.6 months. The mean BCVA in logMAR was 0.43 ± 0.42 after PPV, which significantly decreased to 0.67 ± 0.68 before IOL explantation for IOL opacification (p = 0.007) and increased to 0.48 ± 0.59 after the IOL exchange (p = 0.015). PPV with endotamponades in pseudophakic eyes, particularly gas, seems to increase the risk for secondary IOL calcification, especially in hydrophilic IOLs. IOL exchange seems to solve this problem when clinically significant vision loss occurs.

A Cone beam CT Evaluation of the Efficacy of Essential Oils in removing Silicone Oil based Calcium hydroxide Intra canal medicament from the Root canal

A Cone beam CT Evaluation of the Efficacy of Essential Oils in removing Silicone Oil based Calcium hydroxide Intra canal medicament from the Root canal

Отдаленные результаты применения вискодиссекции с контрастированием в хирургии пролиферативной диабетической ретинопатии

Purpose. To evaluate long-term results of surgery for proliferative diabetic retinopathy using contrast-enhanced viscodissection. Material and methods.The study involved 30 patients with type 1 diabetes mellitus (DM) and PDR with traction retinal detachment (TRD). All patients were divided into two groups. In the main group, viscodissection with contrast was performed; in the control group, segmentation and membrane removal were performed using a vitreotome and endovitreal forceps. The observation period was 12 months. Results. During dynamic observation, all patients showed a positive dynamics of morphofunctional parameters. In patients of the control group, in the vast majority of cases, it was necessary to resort to tamponade with silicone oil (60%) or gasair mixture (33%), while in the main group, the main postoperative media were sterile BSS solution (73%) and gas-air mixture (27%). 60% of patients in the control group required a reoperation to remove silicone oil. In patients of the control group in the late postoperative period, IOP values were significantly higher (main group 14.3 ± 1.1; control group 18.7 ± 1.5; p &lt; 0.05), and late postoperative vitreous hemorrhage developed more often (2.3 ± 0.5 in the main group, 4.1 ± 0.6 in the control group; p &lt; 0.05). Conclusion. In the long-term follow-up, the use of this method reduces the need for repeated endovitreal intervention, reduces the risk of developing late postoperative vitreous hemorrhage, and has a positive effect on IOP by reducing the need for endotamponade with silicone oil. Keywords: diabetes mellitus, proliferative diabetic retinopathy, vitreoretinal surgery, contrastenhanced viscodissection

Severe anterior persistent fetal vasculature: the role of anterior retinal elongation on prognosis.

This study aims to investigate surgical outcomes of eyes with severe anterior persistent fetal vasculature (PFV) and the role of associated anatomical anomalies on prognosis. This is a retrospective, comparative case series of 32 eyes of 31 patients who underwent vitreoretinal surgery for severe anterior PFV, defined as fibrovascular tissue totally covering the back of cataractous lens. Based on the degree of anterior retinal elongations, cases were classified as follows: group 1, eyes with well-developed pars plana and minor/no abnormalities (n = 11, 34%); group 2, eyes with partially developed pars plana and broad-based elongations (n = 9, 28%); and group 3, eyes with no visible pars plana and fibrovascular membrane having 360° continuity with peripheral retina (n = 12, 38%). Complications and functional and anatomical outcomes were investigated. The median surgical age was 2 (1-12) months. The median follow-up was 26 (6-120) months. Seventy-three percent in group 1 achieved finger counting or better vision with a single surgery and without any pupillary/retinal complication. Groups 2 and 3 required 2.1 ± 0.9 and 2.6 ± 1.2 surgeries on average. Pupillary obliteration and RD occurred in 33% and 22% in group 2 and 58% and 67% in group 3. Retina remained attached after silicone oil removal in 89% of group 2 and 25% of group 3. Phthisis developed in 50% in group 3. Peripheral retinal anomalies are common in severe anterior PFV and have a major impact on prognosis. Prognosis is favorable in cases with mild-to-moderate anomalies with appropriate management of possible retinal tears. In eyes with 360° retinal elongations, severe fibrous proliferation and eventual eye loss are common.

Safe Removal of Sticky Silicone Oil Using Perfluorocarbon Liquid Injection and Emulsification with a Fragmatome.

We examine the safe removal of a sticky silicone oil (SO) with an inconspicuous perfluorocarbon liquid (PFCL) layer. In the first experiment, we injected PFCL into the SO bubble on the bottom of a transparent container or into the chili oil layer of an immiscible droplet composed of PFCL and chili oil on the posterior retina of a vitrectomized pig eye, in order to release the SO bubble or the chili oil layer from the downward adhesion. In the second experiment, we sucked out the SO layer of an immiscible droplet composed of PFCL and SO on the bottom of a transparent container or on the posterior retina of a vitrectomized pig eye using a fragmatome. In the first experiment, the PFCL injection caused the SO bubble to move from the bottom of the transparent container and the chili oil to move from the posterior retina of the pig eye. In the second experiment, when the suction pressure was high, this made it easy and possible to remove the SO layer in the transparent container or the vitrectomized pig eye when emulsification was done by a fragmatome. Moving the SO layer of a sticky SO from the posterior retina after a PFCL injection followed by sucking out of the relocated SO layer using emulsification and high suction pressure through the utilization of a fragmatome can safely remove sticky SO with an inconspicuous PFCL layer.

Predisposing characteristics of optical coherence tomography for patients with persistent subretinal fluid after successful repair of rhegmatogenous retinal detachment.

To investigate the predisposing clinical parameters and characteristics of fundus imaging of patients with persistent subretinal fluid (PSF) after successful repair of rhegmatogenous retinal detachment. A retrospective study recruiting 57 patients was conducted. All patients underwent pars plana vitrectomy with silicone oil tamponade. Patients were divided into two groups: patients presenting PSF by the time of silicone oil removal (PSF group), and patients presenting no PSF by the time of silicone oil removal as control group. All patients were followed up for three months or longer after primary surgery. Ophthalmic examinations, including fundus photography and optical coherence tomography (OCT) were performed. There were significant differences between the two groups in terms of average age, durations of preoperative symptoms, and type of retinal breaks (P<0.05). These clinical parameters showed statistical correlations with PSF (P<0.05). The proportions of patients presenting distinctive boundaries of the detached retina on fundus photograph and patients showing a hyperreflective line underlying the detached retina on OCT in the PSF group were both significantly higher than the control group (P<0.05). The macular detachment heights on OCT in PSF group were significantly lower than control group (P<0.05). These imaging characteristics also showed strong correlations with PSF (P<0.05). This study suggests that patients with PSF have younger age, longer symptom duration, and higher incidence of retinal holes. The distinctive detachment boundary on fundus photograph, lower macular detachment height, and hyperreflective line underlying detached retina on OCT may be the predisposing characteristics of PSF.

Persistent Intraocular Pressure Elevation after Silicon Oil Removal in Patients with Post-Pars Plana Vitrectomy

Background: It is well-known that silicon oil (SO) injection into the vitreous cavity after pars plana vitrectomy is usually associated with high intraocular pressure. Objectives: To determine the influence of silicon oil (SO) removal on IOP level after pars plana vitrectomy for spontaneous rhegmatogenous retinal detachment (RRD) Subjects and Methods: A prospective study was conducted at Ibn Al-Haitham eye teaching hospital, Baghdad- Iraq. Intraocular pressure (IOP) was measured pre and post SO removal in patients who have underwent retinal detachment surgery with SO injection of 1000 centistokes (cSt) viscosity. Baseline IOP was measured for all the patient before the SO removal. Follow-up was performed at 1, 4, and 8 weeks after SO removal. IOP was measured by Goldman applanation tonometer. Patients with IOP &gt; 21 mm Hg at 8 weeks post-operatively with or without anti-glaucoma mediations were considered as persistent IOP elevation after SO removal. Result: Sixty eyes of 60 patients were included. Twenty eyes had persistent IOP elevation after SO removal on first week postoperative. It decreased to 14 eyes on 4th week after SO removal and further decreased to 12 eyes on 8th week af-ter SO removal. The percentage of persistent IOP elevation following SO remov-al was about 20% on 8th week of SO removal. Conclusion: Persistent IOP elevation sometimes happens after SO removal. Therefore, removing SO does not simply treat the elevated IOP happened during SO injection. Patients after SO removal should be followed up for IOP for several weeks and should be treated medically or surgically as required.