Characteristics of Silicone Oil Emulsification After Vitrectomy for Rhegmatogenous Retinal Detachment: An Ultrasound Biomicroscopy Study

Purpose: To investigate the characteristics of silicone oil (SO) emulsification after vitrectomy for rhegmatogenous retinal detachment (RRD) and possible correlations with clinical factors.Methods: Patients who underwent primary pars plana vitrectomy with SO injection for RRD followed by SO removal at the Eye and ENT Hospital of Fudan University between January 2016 and January 2020 were included. Ultrasound biomicroscopy (UBM) images of the anterior segment were taken before SO removal. Eight signs of SO emulsification in the UBM images were graded as 1 (present) or 0 (not present) and the grades for all signs in each eye were summed. Correlations between SO emulsification grade and clinical factors were determined.Results: A total of 118 patients (118 eyes) were enrolled in this study. Emulsified SO particles were found in all 118 eyes (100%). The eight signs were more frequently detected in the superior part of the eye. The mean total SO emulsification grade was 19.99 ± 12.98 (range: 1–36). Younger age and male (both P < 0.05) were associated with higher total SO emulsification grade. Patients with intraocular pressure (IOP) > 21 mmHg or the use of antiglaucoma medications at the time of SO removal had a higher total SO emulsification grade, were younger, and were more frequently male (all P < 0.05) than patients without ocular hypertension.Conclusions: UBM could play an important role in the diagnosis and grading of SO emulsification. Younger patients and males are more prone to SO emulsification, which may lead to elevated IOP.

Plasma Rich in Growth Factors in Macular Hole Surgery

The aim of this study was to evaluate the use of PRGF (plasma rich in growth factors) as an adjuvant to PPV (pars plana vitrectomy) in recurrent, persistent, or poor prognosis MH (macular hole). Patients with MH were treated with PPV plus adjuvant therapy (PRGF membrane (mPRGF) and injectable liquid PRGF (iPRGF)). The anatomical closure of MH and postoperative BCVA (best-corrected visual acuity) were evaluated. Eight eyes (eight patients) were evaluated: myopic MH (MMH, n = 4), idiopathic MH (IMH, n = 2), iatrogenic n = 1, traumatic n = 1. The mean age was 53.1 ± 19.3 years. Hence, 66.7% (n = 4) of patients previously had internal limiting membrane peeling. Five patients (62.5%) received mPRGF and iPRGF, and three patients (37.5%) received iPRGF. Gas tamponade (C3F8) was placed in seven cases and one case of silicone oil. Anatomic closure of MH was achieved in seven eyes (87.5%) and BCVA improved in six cases. In the MMH group, visual acuity improved in two lines of vision. Follow-up time was 27.2 ± 9.0 months. No adverse events or MH recurrences were recorded during follow-up. The use of PRGF as an adjuvant therapy to PPV can be useful to improve anatomical closure and visual acuity in MH surgery.

Identification of Interphotoreceptor retinoid-binding protein in the Schisis cavity fluid of a patient with congenital X-linked Retinoschisis

Background This case report describes the surgical outcome in a patient with congenital X-linked retinoschisis (CXLRS) and the results of proteomic analysis of surgically extracted samples from both vitreous and intraschisis cavities by mass spectrometry. Case presentation A 3-month-old boy presented with extensive retinoschisis involving macula and retinal periphery in both eyes. Genetic analysis confirmed retinoschisin 1 mutation (c.554C > T), and an electroretinogram showed significant reduction of b-wave and decreased cone and rod responses, which led to a diagnosis of CXLRS. By performing pars plana vitrectomy, including inner wall retinectomy, clear visual axes with stable retinal conditions and functional vision in both eyes were obtained during the 4 years of follow-up. Proteomic analysis of surgically retrieved fluid from the intraschisis cavity revealed a higher expression of interphotoreceptor retinoid-binding protein (IRBP) than that from the vitreous humor. However, both samples showed equal levels of albumin, transferrin, and pigment epithelium-derived factor. Conclusions Cellular adhesive imperfection in CXLRS may cause IRBP diffusion from the interphotoreceptor matrix, resulting in the strong expression of IRBP in the intraschisis cavity. An impaired retinoid cycle caused by an absence of IRBP in the retina may potentially underlie the pathology of CXLRS.

Role of intraretinal cysts in the prediction of postoperative closure and photoreceptor damages of the idiopathic full-thickness macular hole

Background To determine whether it would be effective in predicting the results of the postoperative full-thickness macular hole (FTMH) closure when intraretinal cyst (IRC) is present. Methods Case-control study. Patients with idiopathic FTMH who underwent pars plana vitrectomy with internal limiting membrane peeling were retrospectively reviewed. Preoperative spectral-domain optical coherence tomography was undertaken in all patients. The new parameter, macular hole closing factor (MHCF) was defined as the base diameter - (arm length + IRC height) by adding IRC to the existing parameter. After surgery, patients were classified and analyzed according to the type of hole closure and the damage of photoreceptor. Results Of the 35 patients, 28 (80.00%) had type 1 closure and seven (20.00%) had type 2 closure. There was a significant difference in postoperative BCVA (P < 0.01), base diameter (P = 0.037), arm length (P = 0.045), and IRC height (P = 0.011) between the two groups. In the type 1 closure, they were further divided into two subgroups according to photoreceptor damage, and it was confirmed that there were significant differences in postoperative BCVA (P = 0.045), hole height (P = 0.048), and IRC height (P = 0.046) in the two subgroups. As for the new parameters, a significant difference between the three groups was confirmed (P < 0.01). Conclusion IRC may help predict hole closure along with the known horizontal parameters. Therefore, the new parameter containing both two factors can help predict not only hole closure but also damage to photoreceptors that affects postoperative visual prognosis.

Trabeculectomy with mitomycin C for glaucoma secondary to emulsified silicone oil after pars plana vitrectomy: three-years follow up

Background/Aim: To evaluate the efficacy of trabeculectomy with mitomycin C (MMC) for lowering intraocular pressure (IOP) in patients with open angle glaucoma (OAG) secondary to emulsified silicone oil (SO) after pars plana vitrectomy. Methods: A single-center, prospective study was conducted, from December 2014 to December 2019, on 56 consecutive patients with an uncontrolled elevation of IOP after SO removal. The primary end-point was the IOP at the three-years follow-up visit. Complete surgical success was defined as an IOP ranging from 7 mmHg to 18 mmHg without glaucoma medication. Qualified success was defined as IOP ? 21 mmHg with one or two topical medications. Results: Fifty-six patients with mean (standard deviation) age of 56.6 (13.1) years had a mean baseline IOP of 42.3 (39.3 to 45.3) mmHg, which reduced to 18.6 (17.9 to 19.3) mmHg at 3 years after surgery (P < 0.0001). 17 (30.4%) eyes were classified as complete success, 21 (37,5%) as qualified success, and 18 (32.1%) as failure. In all treated patients, the number of antiglaucoma medications was significantly reduced from 2.85 (0.77) to 1.63 (0.62), p<0.0001. Conclusion: Trabeculectomy with MMC may be an option for lowering IOP in patients with OAG secondary to emulsified SO which was not controlled with maximum antiglaucomatous medical treatment.

Vitrectomy in Congenital Vitreous Pathologies

Congenital vitreous diseases are the result of embryological development defects of the vitreous. These diseases have a wide spectrum including congenital vitreous disorders and genetically impaired vitreous structure. Also, these diseases are the first diseases that should come to mind in vitreous and retinal pathologies seen in the early age group. In many of them, pars plana vitrectomy has an important role in the treatment. Due to the disease pathophysiology and age of the patients, they differ from the standard pars plana vitrectomy. In this review, congenital vitreous pathologies and the vitrectomy method applied in the treatment of these pathologies will be discussed.

Vitrectomy in Lens and Glaucoma Pathologies

Pars plana vitrectomy (PPV) is currently used as an effective method in many posterior segment pathologies. Although the most common indication is retina and vitreous pathologies, PPV is also preferred in some cases associated with lens and glaucoma. In case the crystalline lens or artificial intraocular lens, which is a product of industrial development, falls into the vitreous, it is essential to remove it mostly with the PPV approach. In some types of secondary glaucoma, especially malignant glaucoma, successful results are obtained in terms of visual prognosis and complications with vitreoretinal surgery techniques.

Vitrectomy for Vitreous Opacities

Pars plana vitrectomy (PPV) surgery in vitreous opacities is an effective treatment method that increases patient satisfaction. However, due to the risks associated with PPV surgery, its application in vitreous floaters is controversial. Instead, performing sutureless, minimally invasive PPV surgery with 25 gauge trocars on floaters may reduce the risks. For surgical treatment, it is important to select appropriate patients, evaluation of the risk and benefit balance of PPV, and application the treatment.

Vitrectomy in Endophthalmitis

Developing due to infectious and noninfectious causes, endophthalmitis is a serious condition requiring urgent intervention which can lead to eye loss. In recent years, medical and surgical approaches had great improvement in the treatment of endophthalmitis. Early diagnosis and therapy are very important in endophthalmitis. By prompt and accurate treatment, good outcomes are established. In order to get successful results, the combination of intravitreal antibiotic and pars plana vitrectomy approach is the best treatment modality. Early pars plana vitrectomy eliminates infective agents, suitable media, and toxins while amplifying the action of intravitreal antibiotics.