Background diseases and the number of previous intravitreal aflibercept injections on immediate intraocular pressure increase and vitreous reflux rate in phakic eyes

●AIM:To evaluate the effect of background diseases and number of previous intravitreal aflibercept injections(IVAIs)on immediate intraocular pressure(IOP)increase and vitreous reflux(VR)rate and to evaluate the correlation of both age and axial length with immediate IOP increase and VR rate.●METHODS:This study included 105 patients with cystoid macular edema secondary to retinal vein occlusion,35 patients with diabetic macular edema,69 patients with neovascular age-related macular degeneration(nAMD),and 12 patients with myopic choroidal neovascularization,which underwent first-time IVAI.The correlation of immediate IOP increase and VR rates with the four background diseases was investigated.Moreover,the correlation of age with immediate IOP increase and VR rate as well as correlation of axial length with immediate IOP increase and VR rate were evaluated.Further,54 patients with nAMD were treated with IVAI>10 times(multiple IVAIs).Moreover,the correlation of immediate IOP increase and VR rates with first-time and multiple IVAIs in nAMD was determined.●RESULTS:The immediate IOP increase(P=0.16)and VR rates(P=0.50)were almost similar among the four background diseases.The immediate postinjection IOP and age,VR rate and age,immediate postinjection IOP and axial length,or VR rate and axial length were not correlated in the four background diseases.The immediate IOP increase(P=0.66)and VR rates(P=0.28)did not significantly differ between first-time and multiple IVAIs in nAMD.●CONCLUSION:Background diseases and number of previous IVAIs have no effect on immediate IOP increase and VR rate.Further,age and axial length have no correlation on immediate IOP increase and VR rate.

Immediate intraocular pressure rise after intravitreal injection of ranibizumab and two doses of triamcinolone acetonide

AIM: To evaluate prospectively immediate intraocular pressure (IOP) changes after the intravitreal injection of ranibizumab, 2 and 4mg triamcinolone acetonide. METHODS: Patients who underwent intravitreal injection of 0.1mL (4mg) triamcinolone acetonide (TA, Group T4), 0.05mL (2mg) TA (Group T2) and 0.05mL (0.5mg) ranibizumab (Group R) comprised the study population. Overall, 229 eyes of 205 patients were injected. Fifty-four eyes (23.6%) were in Group T4, 69 eyes (30.1%) in Group T2 and 106 eyes (46.3%) in Group R. If IOP was less than 26mmHg immediately after the injection no further measurement was performed. If IOP was ≥26mmHg, IOP was remeasured till the reading was below 26mmHg at 5, 15 and 30 minutes. RESULTS: Immediately after the injection, the IOP of 28 eyes (51.9%) in Group T4, 22 eyes (31.9%) in Group T2 and 51 eyes (48.1%) in Group R were over 25mmHg. At 30 minutes, IOP of one eye (1.9%) in group T4, two eyes (2.9%) in group T2 and two eyes (1.9 %) in Group R were over 25mmHg. Immediate post-injection IOP was significantly higher in Group T4 and Group R when compared to Group T2 (P <0.001 and P <0.001, respectively). IOP was significantly higher in eyes without vitreous reflux when compared to those with vitreous reflux in all groups (P <0.001). CONCLUSION: IOP may remarkably increase immediately after the intravitreal injection of 2 or 4mg triamcinolone acetonide, and 0.5mg ranibizumab. Absence of vitreous reflux is the most important predicting factor for immediate IOP rise after the injection.

Intraocular pressure elevation after intravitreal triamcinolone acetonide injection: a Meta-analysis

AIM：To report on intraocular pressure（IOP）after intravitreal injections of triamcinolone acetonide.·M ETHODS：Systematic literature review of studies that investigated the effects of an injection of triamcinolone Intravitreal triamcinolone acetonide on IOP was conducted according to the Cochrane Collaboration methodology and the reported effects have been analyzed with Meta-analysis.·RESULTS：We found that the IOP follows an inverted-U shape pattern over time starting with an average value of14.81±1.22 mm Hg before the injection,rising to a maximum of 19.48±2.15 mm Hg after one month of injection and falling down to 16.16±1.92 mm Hg after6mo.Moreover,country of study,age,previous history of glaucoma and gender compositions matter for crossstudy were different in reported IOP changes.·CONCLUSION：Our findings may be helpful in determining pressure elevation risk of intravitreal triamcinolone acetonide therapy as well as comparing it with those of more recent therapies such as the antivascular endothelial growth factor agents.

Role of bevacizumab intraocular injection in the management of neovascular glaucoma

AIM:To assess the long-term effects of intraocular bevacizumab(Avastin)injections as an adjunctive drug to manage patients with neovascular glaucoma(NVG).METHODS:A retrospective study was conducted consisting of 34 eyes with secondary NVG caused by proliferative diabetic retinopathy(n=25),ischemic central retinal vein occlusion(n=8),and retinal ischemia resulting from persistent detachment(n=1)were managed by intraocular injections of bevacizumab(1.25 mg/0.05 m L),in addition to other treatments.The main outcome measure was the change in the degree of iris neovascularization.Secondary outcomes included intraocular pressure and the number of additional interventions or antiglaucoma medications administered after injection.RESULTS:All patients were followed-up for at least 12 mo.At the last follow-up,complete regression of rubeosis irides was detectable in 13(38.2%)eyes and incomplete regression in 21 eyes(61.8%).The mean intraocular pressure was 45.32±7.185 mm Hg at baseline and significantly decreased to 26.15±5.679 mm Hg at the last follow-up visit(P=0.000005).Patients received an average of 4.97 injections.As additional treatments,12 eyes(35%)received laser photocoagulation and 6 eyes(18%)underwent retinocryopexy.No further treatment was needed in 16 eyes(47.1%).CONCLUSION:Intravitreal bevacizumab injection can have a favorable effect in controlling intraocular pressure and pain control in patients with NVG because it decreases the angiogenesis and helps to augment the results of conventional procedures.The primary cause of retinal ischemia should be always targeted.

Effect of different lens status on intraocular pressure elevation in patients treated with anti-vascular endothelial growth factor injections

AIM: To assess the effect of lens status on sustained intraocular pressure(IOP) elevation in patients treated intravitreally with anti-vascular endothelial growth factor(VEGF) agents. METHODS: Data were retrospectively collected for all patients treated with intravitreal injections of anti-VEGF medication at a tertiary medical center in July 2015. Findings were analyzed by lens status during 6 months' follow-up. The main outcome measure was a sustained increase in IOP(≥21 mm Hg or change of ≥6 mm Hg from baseline on ≥2 consecutive visits, or addition of a new IOPlowering medication during follow-up). RESULTS: A total of 119 eyes of 100 patients met the study criteria: 40 phakic, 40 pseudophakic, and 39 pseudophakic after Nd:YAG capsulotomy. The rate of sustained IOP elevation was significantly higher in the postcapsulotomy group(23.1%) than in the phakic/pseudophakic groups(8.1%;P=0.032), with no statistically significant differences among the 3 groups in mean number of injections, either total(P=0.82) or by type of anti-VEGF mediation(bevacizumab: P=0.19;ranibizumab: P=0.13), or mean follow-up time(P=0.70). CONCLUSION: Nd:YAG capsulotomy appears to be a risk factor for sustained IOP elevation in patients receiving intravitreal anti-VEGF injections. This finding has important implications given the growing use of anti-VEGF treatment and the irreversible effects of elevated IOP.

The Effect of Intraocular Pressure Lowering Medications on the Pressure Spike Associated with Intravitreal Injection

Aim: This study investigates whether the post intravitreal injection intraocular pressure (IOP) spike is modifiable with the use of prophylactic apraclonidine and dorzolomide. Methods: The study design was a prospective, randomised controlled trial. 80 eyes undergoing intravitreal injection of anti-VEGF agent were studied. A control group (n = 42) received no IOP lowering drops, and a study group (n = 38) received guttae apraclonidine and dorzolamide 30 to 40 minutes before the intravitreal injection. IOP measurements were taken in both groups using the Perkins tonometer at baseline, immediately before and after the injection, 5 minutes post-injection, and 15 minutes post-injection. Results: Mean IOP immediately post injection in the study group was 26.71 mmHg, and in the control group was 32.73. The main outcome measure was the area under the curve (AUC)—reflecting the trend of IOP post injection. The AUC was lower in the study group compared to the control group (Mann-Whitney U test, p = 0.046). Conclusions: The use of prophylactic apraclonidine and dorzolamide is effective in modifying the post-injection IOP spike. IOP lowering prophylaxis may be considered in patients with a high baseline IOP.

Effects of multiple intravitreal anti-VEGF injections on retinal nerve fiber layer and intraocular pressure: a comparative clinical study

Dear Sir,Ifound the article by Sobac1etal[1]very interesting.The authors concluded that repeated intravitreal injection(IVI)of ranibizumab or bevacizumab didn’t seem have adverse effects on retinal nerve fiber layer(RNFL)thickness in wet age-related macular degeneration(AMD)patients.

Filtering bleb area and intraocular pressure following subconjunctival injection of CTGF antibody after glaucoma filtration surgery in rabbits

AIM: To study the role of connective tissue growth factor (CTGF) antibody in inhibiting bleb scarring after glaucoma filtration surgery (GFS) in rabbit model. METHODS: GFS was performed on both eyes in five rabbits. One eye of each rabbit was chosen randomly as antibody group and received subconjunctival injection of 0.1mL CTGF antibody (50mg/L) immediately after GFS applied and on the 5 th day after GFS. The other eye of each rabbit as control group was received subconjunctival injection of 0.1mL PBS at the same time as antibody group. On postoperative days 1, 3, 5, 7, 10, and 14, the appearance of filtrating blebs was observed under slit lamp, the area and the intraocular pressure (IOP) were measured with micrometer and applanation tonometer, respectively. RESULTS: On postoperative days 1, 3, 5, 7, 10, and 14, areas of filtrating blebs in antibody group were all larger comparing with the control group (P<0.05) and IOPs of antibody group were lower than the control group(P<0.05). CONCLUSION: Subconjunctival injection of CTGF antibody can maintain larger bleb area and lower IOP after GFS in rabbit.

Effect of dorzolamide-timolol fixed combination prophylaxis on intraocular pressure spikes after intravitreal bevacizumab injection

AIM: To evaluate the effect of topical dorzolamide-timolol fixed combination prophylaxis on short term intraocular pressure(IOP) changes in patients who had intravitreal bevacizumab injection.METHODS: One hundred and fifty one eyes of 151 patients which were followed up in retina clinic in Ulucanlar Eye Training and Research Hospital were evaluated in this study. Patients were divided into two groups. Group 1 consists of 75 patients who had topical dorzolamid-timolol medication two hours before injection;while Group 2 consists of 76 patients without prophylaxis. Demographic data, IOP measurements prior to the injection and one, thirty and sixty minutes and twenty-four hours after the injection were recorded. The data were analyzed using SPSS software version 15.0(SPSS Inc., Chicago, IL, USA).RESULTS: There were no significant difference between two groups in age, gender distrubition and indications for injections. The mean IOPs in Groups 1 and 2 prior to the injection(T0) were 17.84±0.43 and 18.15±0.43 mm Hg,one minute after the injection(T1) were 29.75 ±1.6 and34.44 ±1.59 mm Hg, 30 minutes after the injection(T30)were 20.06 ±0.6 and 21.71 ±0.59 mm Hg respectively. The mean IOPs were 18.26 ±0.56 mm Hg in Group 1 and19.78 ±0.56 mm Hg in Group 2 sixty minutes after the injection(T60). All IOP values after the injection were compared between two groups, there was a significant difference between two groups only on T1; one minute after the injection(P =0.04). There were a statisciallysignificant difference between the baseline values and other recorded values; except on T60, in Groups 1 and 2(P 【0.05).CONCLUSION: After intravitreal bevacizumab injection;we observe a transient IOP elevation which normalizes about one hour after intravitreal injection. In patients who had topical dorzolamid-timolol combination prophylaxis before injections, a significant decrease is seen in IOP spikes due to this injection. The appropiate approach will monitor IOP after intravitreal injection and evaluate the using prophylactic antiglaucomatous drugs before the injection in patients with ganglion nerve cell damage.

Effects of multiple intravitreal anti-VEGF injections on retinal nerve fiber layer and intraocular pressure: a comparative clinical study

AIM: To determine the effect of multiple injections of ranibizumab or bevacizumab on retinal nerve fiber layer (RNFL) and intraocular pressure (IOP) in patients with age-related macular degeneration (AMD). ·METHODS: This retrospective study includes 35 eyes of 35 patients treated with intravitreal bevacizumab (IVB, 1.25mg/0.05mL) and 30 eyes of 30 patients with intravitreal ranibizumab (IVR, 0.5mg/0.05mL) who had Fast RNFL analysis (Stratus TM ); IOP measurements were taken 30 minutes and 24 hours after each injection. RESULTS: The mean ages were 68.0±7.5 and 69.1±7.7 years in the IVR and IVB groups, respectively (P =0.55). They underwent (6.3±1.9) and (5.1±1.3) injections (P = 0.07) over (13.6±2.1) and (14.05±2.6) months (P =0.45) in the IVR and IVB groups, respectively. Changes in overall and temporal RNFL thickness in IVR-treated eyes (105.3± 6.9μm and 74.4±11.2μm) were not different from those in untreated eyes in the IVR group (104.6±8.4μm and 75.1±12.6μm) (P =0.57 and P =0.41, respectively). Similarly, overall and temporal RNFL thickness in IVB-treated eyes (105.8±8.1μm and 74.5±11.8μm) were not different from those in untreated eyes in the IVB group (104.6±8μm and 74.8±12.9μm) (P=0.42 and P=0.80, respectively). The frequencies of IOP rise (P=0.60) and changes in RNFL thickness from baseline (P =0.16) were comparable between groups. CONCLUSION: Repeated intravitreal injection of ranibizumab or bevacizumab does not seem have adverse effects on RNFL thickness or IOP in wet AMD patients.

Ocular hypertension and severe intraocular pressure elevation after posterior subtenon injection of triamcinolone acetonide for various diseases

AIM:To evaluate and compare the incidences of ocular hyper tension and severe intraocular pressure(IOP)elevation after posterior subtenon injection of triamcinolone acetonide(PSTA)for various diseases.METHODS:Totally 179 eyes that had received PSTA for diabetic macular edema(n=108),pseudophakic cystoid macular edema(n=20),branch retinal vein occlusion(n=16),central retinal vein occlusion(CRVO,n=14),choroidal neovascularization(n=14)or noninfectious uveitis(n=7)were retrospectively enrolled.The primary outcomes included ocular hypertension defined as an IOP>21 mm Hg,and severe IOP elevation defined as a rise of 10 mm Hg or more in IOP compared with baseline.Cox regression models were used to analyze the hazard ratios(HRs)among different diseases.RESULTS:After PSTA,the mean IOPs from month 1 to month 6 all significantly increased(P<0.05).Ocular hypertension occurred in 30.7%of eyes(median time:8 wk),and severe IOP elevation occurred in 16.2%of eyes(median time:9 wk).Patients receiving PSTA for CRVO or uveitis had a significantly higher risk for ocular hypertension(HR=3.049,P=0.004 for CRVO;HR=5.464,P=0.019 for uveitis)and severe IOP elevation(HR=2.913,P=0.034 for CRVO;HR=7.650,P=0.009 for uveitis).CONCLUSION:IOP significantly increases within 6 mo after PSTA,with the onset of ocular hypertension happening mostly at 2 to 3 mo.Patients of CRVO or noninfectious uveitis have a higher risk of ocular hypertension or severe IOP elevation after PSTA and should be monitored for IOP more carefully.

INTRACAMERAL INJECTION OF PLATELET ACTIVATING FACTOR AS A MEDIATOR OF INTRAOCULAR INFLAMMATION IN RABBIT EYES

Objective To evaluate platelet activating factor (PAF) induced aqueous liare, corneai edema, pupillary constriction and btphasic intraocular pressure (IOP) changes in the rabbit eyes. Methods PAF was delivered into anterior chamber by intracameral injection, other antagonists were administered systemically. Results PAF induced responses in a dose - dependent manner. All of the responses to PAF were inhibited by the PAF receptor antagonist, BN 52021 (20mg/kg, i.p.). The cyclooxygenase inhibitor, indomethacin (30mg/kg, i.P.) caused signofcant inhibition of the early phase PAF- induced aqueous flare, pupillary constriction and intraocular hypertension, but did not alfect PAF- induced corneal edema or intraocular hypotension. Nordihydroguaiaretic acid (NDGA) (10mg/kg, ip.), a lipoxygenase inhibitor, did not inhibit the inflammatory effects of PAF. Conclusion These data suggest that PAF may be an important mediator of intraocular inllammation and that some PAF- induced effects are prostaglandin dependent, while others may be independent of eicosanoid synthesis and release.

Corneal injection track: an unusual complication of intraocular lens implantation and review

Phacoemulsification is the main gold standard for cataract operation in the developed world together with foldable intraocular lens(IOL) implantation by injection,allowing for stable wound construction and less postoperative astigmatism. It is a safe procedure with high success rate with the advancement in machines,improvement of IOL injection systems and further maturation of surgeons’ techniques. Despite the large number of operations performed every day, foldable IOL injection leading to an intra-stromal corneal track is a very rare complication. We report a case of this unusual finding in a 70-year-old gentleman who has undergone cataract operation in November 2011 in our hospital and will review on the complications related to foldable IOL injection.

Refractory intraocular hypertension after dexamethasone-implant intravitreal injection treated with Preserflo MicroShunt implantation

Dear Editor,Herein,we report a case of a patient who presented with refractory ocular hypertension(OHT)after a dexamethasone implant(DEX-I)injection.Intraocular pressure(IOP)was finally managed after Preserflo Micro Shunt implantation,allowing the continued use of dexamethasone implant.

Clinical Analysis of Early and Mid-late Elevated Intraocular Pressure after Silicone Oil Injection

Purpose:.To discuss the incidence and clinical features of early and mid-late elevated intraocular pressure after pars plana vitrectomy and silicone oil injection, and to evaluate the clinical management of eyes with secondary glaucoma.Methods:.This was an observational consecutive case series of 691 eyes in 679 patients who were treated with pars plana vitrectomy and silicone injection...The diagnostic criteria of early elevated intraocular pressure after silicone oil injection was ≥21 mmHg two weeks after surgery, while mid-late elevated intraocular pressure was ≥21 mmHg after two weeks.The incidence and clinical management of elevated intraocular pressure were analyzed.Results: In total, 211 of 691 eyes(30.54%) developed elevated intraocular pressure two weeks after pars plana vitrecto my and silicone injection. Of the 211 eyes, 101 eyes(47.87%)had ocular inflammation, 64 eyes(30.33%) showed hyphema,35 eyes(16.59%) had silicone oil in the anterior chamber, 6eyes.(2.84%).had excess silicone oil injected,.and 5 eyes(2.37%).had rubeosis irides..Eighty three of 691 eyes(12.01%).developed elevated intraocular pressure after two weeks..Of these 83 eyes, 25 eyes(30.12%) had rubeosis irides,.16 eyes(19.27%) had issues related to topic steroid therapy,.13 eyes.(15.66%).had a papillary block,.silicone oil in the anterior chamber,10 eyes(12.05%) had a silicone emulsion,.10 eyes(12.05%).had peripheral anterior synchiae,.and 9 eyes(10.84%).had silicone oil in the anterior chamber..All eyes with elevated intraocular pressure were treated with antiglaucoma medications and surgeries.Conclusion:.The reasons for elevated intraocular pressure differed between early and mid-late after pars plana vitrectomy and silicone oil injection. The elevated intraocular pressure can be controlled effectively by immediate diagnosis and proper treatment with medicine and operation.

Triamcinolone Intravitreal Injection and Intraocular Pressure in Macular Edema Associated with Retinal Vein Occlusion

Purpose:To study the risk factors of increased intraocular pressure (IOP) response to triamcinolone acetonide intravitreal (IVTA) injection in eyes with macular edema associated with retinal vein occlusion. Methods:Eighty-nine eyes with macular edema associated with retinal vein occlusion first received periocular injection of 40 mg triamcinolone acetonide (TA) and were followed for one month. According to the diversity of IOP after periocular TA (PTA) injection, they were divided into the elevation IOP group (group A, 26 eyes) and the normal IOP group (group B,63 eyes).They then received 4 mg TA intravitreal injection.IOP measurements were recorded after PTA and IVTA injections, and were followed for six months. Results: Both PTA and IVTA injections caused a rise in IOP, but it was higher in the IVTA injection (40.45%) than in the PTA injection (29.21%). The mean rise in IOP was more significant in eyes with IVTA injection (28.08 ± 8.24 mmHg) than in eyes with PTA injection (20.87 ± 4.07 mmHg). Patients with an elevation IOP above 6 mmHg after PTA injection had a 73.08% chance of developing a pressure of 24 mmHg or higher,whereas only 12.70% of those with an elevation IOP below 6 mmHg after PTA injection experienced pressure elevation. Conclusion:IOP response to PTA injection is a good way to judge IOP response to IVTA. If the patient is highly sensitive to corticosteroid, treatments other than IVTA injection are used to avoid the increased risks associated with intravitreal corticosteroid injection.

Short-term fluctuation of intraocular pressure and influencing factors following intravitreal injection in patients with retinal vascular diseases

AIM:To investigate the patterns of short-term intraocular pressure(IOP)fluctuations and identify the contributing factors following intravitreal injection in patients with retinal vascular diseases.METHODS:Totally 81 patients were enrolled in this case control study.Eyes were categorized into 7 groups,including age-related macular degeneration(AMD),polypoidal choroidal vasculopathy(PCV),idiopathic choroidal neovascularization(CNV),proliferative diabetic retinopathy(PDR),diabetic macular edema(DME),macular edema secondary to branch(BVOME)and central(CVOME)retinal vein occlusion.IOP was measured in all patients using rebound tonometer at 7 preset time points perioperatively.Additionally,based on the administered medication,the eyes were classified into three treatment groups,including dexamethasone intravitreal implant(IVO),intravitreal conbercept(IVC),and intravitreal ranibizumab(IVR).To compare IOP values at various time points across groups,we employed one-way ANOVA,independent sample t-test or χ^(2) test and multivariate logistic regression analysis.RESULTS:Peak IOP values across all groups were observed at 40s,and 5min after intravitreal injection.Statistical differences in IOP were detected at the 5min among the 7 indication groups(F=2.50,P=0.029).When examing the impact of medications,the IVO group exhibited lower average IOP values at both 40s and 5min compared to the IVC and IVR groups(P<0.001;P=0.007).The IOP values at 40s and 5min were significantly higher in BVOME and CVOME group compared to non-retinal vein occlusionsecondary macular edema(RVOME)group(P<0.001).Multivariate logistic regression analysis further confirmed that IOP measurement at 40s was significantly higher in CVOME group than in non-RVOME group(OR=1.64,95%CI:1.09-2.47;P=0.018).CONCLUSION:Needle size plays a crucial role in the transient changes of IOP following intravitreal injection.Before administering intravitreal injection to patients with central retinal vein occlusion,it is essential to exclude any underlysing causes of increased IOP.

Refractory lipoatrophy treated with autologous whole blood injection:A case report

BACKGROUND Intramuscular corticosteroid injection may cause adverse effects such as dermal and/or subcutaneous atrophy,alopecia,hypopigmentation,and hyperpigmentation.Although cutaneous atrophy can spontaneously resolve,several treatment options have been suggested for this condition.CASE SUMMARY In this paper,we report a case of corticosteroid injection induced lipoatrophy treated with autologous whole blood(AWB)injection,as the condition had been unresponsive to fractional laser therapy.A 29-year-old female patient visited the dermatology clinic complaining of skin depression on her right buttock area,which had appeared six months earlier.There had been only subtle improvement at the margins after fractional CO2 laser treatment;therefore,after obtaining informed consent from the patient,AWB treatment was initiated.One month after the first AWB injection,the size and depth of the lesion had noticeably improved,and a slight improvement was also observed in discoloration.CONCLUSION Close observation is the initial treatment of choice for steroid induced skin atrophy;however,for patients in need of immediate cosmetic improvement,AWB injection may be a safe and cost-effective alternative.

Sutured scleral fixation of existing subluxated/dislocated acrylic one-piece intraocular lenses

AIM:To evaluate the visual and refractive outcomes in cases after sutured scleral fixation of existing subluxated or dislocated acrylic one-piece intraocular lenses(IOLs).METHODS:This study retrospectively enrolled a consecutive series of patients who underwent a surgery of sutured existing subluxated or dislocated IOLs from October 2018 to June 2020.All patients underwent comprehensive preoperative and postoperative ophthalmologic examination,and data were collected including age,sex,surgical indications,best-corrected visual acuity,refractive error,intraocular pressure.Presence of intraoperative and postoperative surgical complications was documented.RESULTS:A total of 20 consecutive cases were enrolled for analysis with mean final follow-up period 9.8±5.3mo.Visual acuity improved from a mean of 0.35(0.46±0.32 logMAR)preoperatively to 0.61(0.21±0.18 logMAR)at the 3-month follow-up(P=0.002).The mean amount of preoperative keratometric astigmatism and total postoperative refractive astigmatism was-1.24±0.80 diopters(D)and-1.42±0.97 D,respectively.There was no statistically significant difference between preoperative and postoperative astigmatism(P=0.156).The mean IOL-induced astigmatism was-0.23±0.53 D.The mean spherical equivalent at the 3-month follow-up was-0.1±0.94 D.No major complications were noted during the follow-up period.CONCLUSION:Surgical techniques using sutured scleral fixation of existing subluxated or dislocated acrylic one-piece IOLs result in favorable visual and refractive outcomes without major complications.

Numerical Simulation of Asphaltene Precipitation and Deposition during Natural Gas and CO_(2) Injection

Asphaltene deposition is a significant problem during gas injection processes,as it can block the porous medium,the wellbore,and the involved facilities,significantly impacting reservoir productivity and ultimate oil recovery.Only a few studies have investigated the numerical modeling of this potential effect in porous media.This study focuses on asphaltene deposition due to natural gas and CO_(2) injection.Predictions of the effect of gas injection on asphaltene deposition behavior have been made using a 3D numerical simulation model.The results indicate that the injection of natural gas exacerbates asphaltene deposition,leading to a significant reduction in permeability near the injection well and throughout the reservoir.This reduction in permeability strongly affects the ability of gas toflow through the reservoir,resulting in an improvement of the displacement front.The displacement effi-ciency of the injection gas process increases by up to 1.40%when gas is injected at 5500 psi,compared to the scenario where the asphaltene model is not considered.CO_(2) injection leads to a miscible process with crude oil,extracting light and intermediate components,which intensifies asphaltene precipitation and increases the viscosity of the remaining crude oil,ultimately reducing the recovery rate.