Surgery of cicatricial stage of choroidal neovascular membrane with autologous conditioned plasma

Purpose. To estimate the effectiveness of the cicatricial stage of choroidal neovascular membrane (CNM) surgery with retina fixation after retinotomy of paracentral areas with autologous conditioned platelet rich plasma (ACP) and without endolaser photocoagulation and silicone oil tamponade. Material and methods. 17 CNM patients aged 49 to 82 with visual acuity from 0.02 eccentric to 0.08 were operated. The operation consisted in 25-, 27+-gauge vitrectomy, removal of the posterior hyaloid membrane and the inner limiting membrane (in the presence of an epiretinal membrane), paracentral retinotomy, removal of the choroidal neovascular membrane via retinotomy, pneumoretinopexy, 2–3 layer instillation of ACP in the retinotomy area without endolaser photocoagulation and silicone oil tamponade, seamless closure of sclera- and conjunctivotomy with a layer of autologous conditioned plasma. Results. Full retinal reattachment and closure of the retinotomy opening in the late postoperative period was noted in all patients. No case of recurrent retinal detachment was recorded. Complete closure of sclera- and conjunctivotomy with no additional suture fixation was achieved in all cases. In the long-term period after the removal of the cicatricial choroidal membrane, visual acuity was 0.03–0.2. Conclusion. The modern surgery of the cicatricial stage of CNM using ACP to close the retinotomy defect after removal of cicatricial CNV without endolaser coagulation of the retina and silicone tamponade, followed by seamless blocking of the sclero- and conjunctivotomy with ACP produces excellent anatomical and functional results, minimizing the risk of postoperative complications.

Biometry in Silicone Oil Filled Eyes. A Review

The “gold standard” of modern vitreoretinal surgery is silicone oil tamponade of the vitreous cavity. The lens opacity development is in the list of complications of prolonged silicone oil eye filling (from 2 weeks to 2 years). Polydimethylsiloxanes hydrophobicity, direct contact with the front of the silicone bladder, macrophage and toxic reaction, trophic disturbances are the causes leading to the cataract initiation. This makes the problem of cataract surgery and preliminary intraocular lens calculation in silicone oil filled eyes before its removing very relevant as well as cloudy retina visualization and the necessity of minimization of number of operations through their combination. Certainly, the main error in IOL power calculation is associated with axial length measurement inaccuracy, as the most significant term of an equation. Silicone oil filled eyes biometry errors, and, consequently, postoperative refraction biases remain unresolved problem until now. To date authors report only 58 % of cases in which target refraction was achieved after combined surgery. Some researchers figure out that average calculation error after phacoemulsification with IOL implantation in avitreal eyes was 0.8 D despite of the optical biometry usage. Today it is represented by several methods: partial coherent interferometry, optical low-coherence reflectometry and optical coherence tomography, which are implemented in devices such as IOLMaster 500, Lenstar LS 900 and IOLMaster 700, which have their own characteristics and measurement accuracy. Their advantages as well as creation an accurate IOL calculation method for silicone oil filled eyes could reduce postoperative refraction error that outline significant medical and social problem.

Effect of Duration of Silicone Oil Tamponade on Retinal Structure after Rhegmatogenous Retinal Detachment Surgery

<b><i>Purpose:</i></b> The aim of the study was to investigate the effect of tamponade duration on retinal changes induced by silicone oil (SO) in patients who underwent successful rhegmatogenous retinal detachment (RRD) surgery. <b><i>Methods:</i></b> Retrospective comparative case series of 68 patients who underwent SO tamponade for RRD. Patients were divided into 2 groups based on timing of SO removal: &#x3c;6 months (group 1, <i>n</i> = 34) versus ≥6 months (group 2, <i>n</i> = 34). The main outcome measure was the change in central macular, inner, and outer retinal layer thickness (CMT, IRLT, and ORLT) before and after SO removal (SOR). <b><i>Results:</i></b> The median tamponade duration was 4 [Clin Ophthalmol. 2016;10:471–6, Zhonghua Yan Ke Za Zhi. 1997 Jan;33(1):39–41] months in group 1 and 8 [Arch Ophthalmol. 1994 Jun;112(6):778–85, Retina. 2004 Dec;24(6):871–7] months in group 2 (<i>p</i> &#x3c; 0.001). The mean CMT significantly increased from 245.3 ± 22.2 μm and 238.8 ± 41.6 μm under SO to 281.3 ± 60.2 μm and 259.0 ± 43.5 μm after SOR in group 1 (<i>p</i> = 0.009) and in group 2 (<i>p</i> = 0.007), respectively. Automated segmentation measurement revealed a significant increase in mean IRLT (<i>p</i> = 0.014 and <i>p</i> = 0.013) but no change in mean ORLT (<i>p</i> = 0.080 and <i>p</i> = 0.257) in both groups. After adjustment, there was no difference between the 2 groups in terms of mean final CMT, IRLT, and ORLT and mean retinal thickness changes after SOR. There was also no correlation between the tamponade duration and macular microstructural changes or visual recovery. <b><i>Conclusion:</i></b> SO tamponade causes a thinning of all retinal layers, mainly affecting the inner retinal layer. However, these changes resolved following SO extraction and were not affected by longer tamponade duration.

Cataract Progression Following Lens-Sparing Pars Plana Vitrectomy for Rhegmatogenous Retinal Detachment

Purpose: Lens-sparing pars plana vitrectomy (PPV) is often followed by cataract development. However, there have been few prospective studies evaluating the timing of cataract progression and potential associated factors.Methods: This was an observational study conducted at the Ophthalmology Unit of the University Hospital of Parma (Parma, Italy). Patients presenting with rhegmatogenous retinal detachment (RRD), who underwent PPV with preservation of the lens, were examined according to a scheduled follow-up (3, 6 and 12 months after PPV) and then preoperatively when cataract extraction surgery (CES) was indicated, or at the end of the study follow-up period (May 2021). The primary outcome was the interval between PPV and CES indication (based on predefined refractive criteria).Results: A total of 36 eyes of 36 patients (mean age: 52 ± 10 years) were included in the study. Nineteen eyes (53%) were indicated for CES a median of 14.5 months (IQR: 12.0–24.8) after PPV. The nuclear and posterior subcapsular forms of cataract progressed significantly starting at 6 months after PPV. Older age at the time of PPV, silicone oil tamponade and RRD without macular involvement were significantly and independently associated with an earlier indication for CES. Conclusions: Patient age and the use of silicone oil tamponade must be taken into consideration when evaluating the risk of cataract development after PPV.

Biometric changes after vitrectomy with silicone oil tamponade

Background: The Lenstar LS 900 (Haag-Streit AG, Koeniz, Switzerland) is an optical biometer, and its measurements are highly repeatable and precise in cataractous eyes. This study investigated changes in biometric parameters, including axial length (AL), anterior chamber depth (ACD), lens thickness (LT), vitreous cavity depth (VD), and central corneal thickness (CCT) before and after three-port 23-Gauge pars plana vitrectomy with silicone oil tamponade. Methods: This was a prospective follow-up study. Patients who were scheduled for surgery underwent a detailed slit-lamp examination and objective cycloplegic refraction preoperatively. In eligible cases, the Lenstar LS 900 was used to measure biometric parameters. At the 1-month postoperative follow-up, we repeated the same assessments for the silicone oil (SO)-filled eyes. Data were analyzed to assess the significance of changes and to test the possible correlation of values between the two time points. Results: Twenty-three patients with a mean ± SD age of 60 ± 12 years completed the study. Postoperatively, we found a significant increase in AL and a decrease in ACD and CCT (all P < 0.05), with no significant changes in LT and VD. A significant correlation was found for ACD, CCT, and cylinder values between the two time points (all P < 0.05). Postoperatively, the spherical and cylindrical components of refraction demonstrated a hyperopic shift, but did not change statistically significantly. Conclusions: The Lenstar LS 900 underestimated the ACD and overestimated the AL in SO-filled eyes when comparing pre- and postoperative values, in phakic as well as pseudophakic eyes. In planning for cataract surgery in this group of patients, it is more reasonable to calculate IOL power based on the biometric data of the fellow eye, although this may not eliminate possible errors. Further studies with a larger sample size, longer follow-up, and robust study design are necessary to confirm our preliminary results.

Results of improved vitreoretinal surgery at proliferative diabetic retinopathy

Purpose. To improve the technology of combined vitreoretinal intervention, including preliminary intravitreal injection of angiogenesis inhibitors followed by vitrectomy and a differentiated approach to internal limiting membrane peeling in patients with proliferative diabetic retinopathy (PDR). Material and methods. The research based on analysis of morpho-functional parameters 134 patient's eyes with PDR during type II diabetes mellitus. The patients were divided into 2 groups. The first group consisted of 30 patients (30 eyes), who were determined optimal period for vitrectomy. That patients underwent fundus photography and optical coherence tomography during 1 month after intravitreal injection of ranibizumab. Vitrectomy was performed within 1-3 months (38.4 ± 5.6 days). The second group consisted of 104 patients (104 eyes) who underwent vitrectomy with a differentiated approach to internal limiting membrane peeling and tamponade of the vitreous cavity. Results. The optimal period for vitrectomy in patients with PDR is 10-14 days after preliminary ranibizumab injection, which is due to the maximal regression of neovascularization and minimal traction on the retina (the risk of developing local traction retinal detachment decreases by 36.6%). Carrying out vitrectomy in optimal period helped to reduce the risk of intraoperative hemorrhagic complications by 4.2 times, the frequency of using perfluorocarbons by 3.7 times. At postoperative period, in patients without internal limiting membrane peeling on the silicone oil tamponade, the risk of epiretinal fibrosis increased 2.7 times compared with the data before treatment, and 1.8 times on air-gas mixture tamponade. Conclusion. The optimal surgical tactic for patients with PDR is preliminary intravitreal injection of angiogenesis inhibitors before vitrectomy, internal limiting membrane peeling at silicone oil tamponade (frequency of epiretinal fibrosis 96%) and individual approach to surgical correction of macular area at gas-air mixture tamponade (frequency of epiretinal fibrosis 36%), which allows to achieve a progressive improvement in morphological and functional results. Key words: proliferative diabetic retinopathy, preliminary anti-VEGF therapy, vitrectomy, internal limiting membrane peeling.