Mechanisms of intraocular pressure elevation after pars plana vitrectomy

Combined phacovitrectomy versus sequential surgery for idiopathic macular holes: systematic review and meta-analysis

OBJECTIVE

To compare the best-corrected visual acuity (BCVA) change, idiopathic macular (IMH) closure, and complications in IMH patients receiving combined phacovitrectomy and sequential surgery (vitrectomy followed by phacoemulsification).

DESIGN

Systematic review and meta-analysis.

METHODS

PubMed, Ovid EMBASE, and Cochrane Library databases were searched from their inception through February 2022. Randomized, controlled trials and observational studies that presented results of BCVA change, IMH closure, and surgery-related complications were included. A random-effects meta-analysis was conducted to calculate effect estimates with 95% CIs.

RESULTS

One randomized, controlled trials and 7 cohort studies with 585 patients were included. Overall, the meta-analyses of BCVA change (mean difference, -0.03; 95% CI, -0.10-0.04) and IMH closure (risk ratio = 1.04; 95% CI, 0.96-1.13) revealed no significant differences between combined phacovitrectomy and sequential surgery. The pooled risk ratios for various surgical complications such as postoperative retinal detachment, inflammation, and intraocular pressure elevation showed no significant differences between the 2 groups.

CONCLUSIONS

Similar visual gain and IMH closure rates were achieved after both combined phacovitrectomy and sequential surgery, with similar complication risks. The anatomic and functional outcomes of combined surgery were not better than those of sequential surgery. These results could serve as a reference for future trials.

A Multicenter Prospective Randomized Controlled Study of a New Corneal Wetting Agent During Ophthalmologic Surgery

INTRODUCTION

A multicenter prospective randomized controlled study was used to investigate the effect and safety of a new corneal wetting agent called the Corneal Surface Viscoelastic Protector (CsVisc, Success Bio-Tech Co., Ltd, China), on the corneal epithelium during ophthalmic surgery by comparison with the commercially available Cornea Protect (CP, Valeant Med Sp. zo. o. Leobendorf, Austria).

METHODS

This multicenter prospective randomized controlled study comprised patients scheduled for cataract surgery and pars plana vitrectomy. The patients were randomly assigned to receive either a new corneal wetting agent (CsVisc) or Cornea Protect (CP, Valeant Med Sp. zo. o. Leobendorf, Austria). Optical clarity during surgery, application frequency, duration of effect, diffusion time of corneal wetting agents, fluorescein staining, intraocular pressure (IOP), tear-film break-up time (TBUT), and Schirmer I test (SIT) were assessed. Adverse events were noted on the designated patient case report forms.

RESULTS

A total of 149 eyes (149 patients, mean age 62 years; range 25-80 years) were included in the study. There were 74 eyes in the control group and 75 eyes in the study group. In patients who underwent vitrectomy, the frequency of application was 1.62 ± 1.03 in the study group and 1.39 ± 0.66 in the control group, with no significant difference (P = 0.399), and the duration of effect was 19.16 ± 6.94 min in the study group and 19.06 ± 7.22 min in the control group, with no significant difference (P = 0.835). The optical clarity of the study group was not significantly different from that of the control group (P = 0.485). In patients who underwent cataract surgery, the frequency of application was 1.10 ± 0.38 in the study group and 1.07 ± 0.26 in the control group, and the difference was not significant (P = 0.950). The difference between the duration of effect in the study group (8.32 ± 2.50 min) and the control group (7.63 ± 2.52 min) was not significant (P = 0.310). The difference in optical clarity scores between the two groups was not statistically significant (P = 0.600). Among all patients in this study, the diffusion time of the corneal wetting agent was 14.97 ± 10.07 s in the control group and 11.23 ± 8.41 s in the study group, with a statistically significant difference (p = 0.008). The frequency of adverse events was 20.00% (15/75) in the study group and 14.86% (11/74) in the control group, with no statistically significant difference (P = 0.409). There were no serious adverse events related to the test medical device or causing patients to withdraw from the study.

CONCLUSIONS

The CsVisc is safe and effective in preventing intraoperative corneal epithelial damage due to corneal dryness and can be comparable to the CP. In addition, the CsVisc has a shorter diffusion time.

Eyewatch adjustable drainage device in vitrectomized eyes with refractory glaucoma

BACKGROUND

To describe the efficacy and safety of the adjustable system eyeWatch in vitrectomized glacomatous eyes.

METHODS

Prospective, non-comparative, small case series of 2 patients who underwent glaucoma drainage device implant with the eyeWatch system. Intraocular pressure, number of medications and early and late complications were evaluated.

RESULTS

None of the operated eyes developed early or late complications. After 1 week post operatively, the IOP raised at 28 mmHg in the first eye and 25 mmHg in the second one. The eyeWatch Pen was used to open and set the device into position 3 (that means implant half opened) After waiting for 30 min, IOP was 15 mmHg and 11 mmHg, respectively. Thirty days after surgery we set the EyeWatch into position 0 (that means implant full opened) even though the IOP was under control. A new IOP measurement was done and we registered that IOP was 14 mmHg and 10 mmHg respectively, and it remained stable after six months of follow up.

CONCLUSION

In conclusion, in our case series the use of eyeWatch adjustable system allows a safe and gradual regulation of the flow during post-operative management also in vitrectomized eyes. Considering the percentage of hypotony related complications in vitrectomized eyes this system is an effective and safe technique to handle glaucoma in post vitreoretinal surgery eyes.

Evaluation of Schlemm Canal Parameters Using Swept-Source Optical Coherence Tomography in Eyes That Underwent Keratoplasty

OBJECTIVES

In this study, we aimed to evaluate Schlemm canal parameters using anterior segment swept-source optical coherence tomography in eyes that underwent keratoplasty and compare them with keratoconus and healthy control groups.

METHODS

The study included 32 patients who underwent penetrating keratoplasty or deep anterior lamellar keratoplasty once due to keratoconus and age-matched and sex-matched 20 keratoconus patients and 30 healthy controls. In all the patients, a single horizontal image centered on the central cornea was obtained from the nasal and temporal quadrants with low-intensity scanning to visualize Schlemm canal.

RESULTS

There was no statistically significant difference between the groups for age and gender ( P ˃0.05). In the keratoplasty group, the area and diameter of Schlemm canal were 2.266±1.141μm 2 and 160.77±65.08 μm, respectively, in the nasal quadrant and 2.623±1.277 μm 2 and 158.81±68.05 μm, respectively in the temporal quadrant, which were statistically significantly lower compared with other groups ( P <0.001 for all). There was no significant difference between the penetrating and deep anterior lamellar keratoplasty subgroups for Schlemm canal parameters.

CONCLUSION

This is the first study to report anterior segment optical coherence tomography after surgery shows SC parameters that are, on average, less than age-matched and keratoconus controls.

Functional and anatomic changes between early postoperative recovery and long-term follow-up after combined epiretinal and internal limiting membrane peeling

OBJECTIVE

To evaluate short- and long-term changes in best-corrected visual acuity (BCVA) and retinal layer thicknesses after combined epiretinal membrane (ERM) and internal limiting membrane (ILM) peeling for macular holes and symptomatic ERMs.

DESIGN

Retrospective observational case series.

PARTICIPANTS

Patients with ERMs or with macular holes and ERMs treated with combined ERM and ILM peeling.

METHODS

Study eyes (n = 36) and healthy fellow eyes (n = 17) were evaluated using the automated segmentation of retinal layers performed by SPECTRALIS software that automatically calculated the average central retinal thickness and the average thickness in each of the individual retinal layers. The analysis was performed at 6-18 months after surgery and after 60 months.

MAIN OUTCOME MEASURES

Changes in BCVA and retinal layer thicknesses determined by automated segmentation at the first and last follow-up visits.

RESULTS

BCVA improved from a baseline 0.48 ± 0.25 logMAR (20/60 Snellen) to 0.18 ± 0.18 logMAR (20/30 Snellen) at the short-term postoperative examination (p < 0.0001). Between first and last follow-up visit, 5 eyes (14%) were classified as better, 28 (78%) as stable, and 3 (8%) as worse. BCVA of the control fellow eyes remained stable during the follow-up. The thicknesses of retinal layers decreased significantly (p < 0.009). At the last follow-up, the ganglion cell layer was thinner and the inner nuclear layer was thicker in the operated eyes compared with the healthy fellow eyes.

CONCLUSION

Combined ERM and ILM peeling may improve BCVA in some patients. However, over a long follow-up period, it can be associated with progressive ganglion cell layer thinning that could affect BCVA stability.

Pupillary block glaucoma due to anterior migration of nonemulsified silicone oil in a phakic patient: A case report and review of literature

This report describes a case of acute pupillary block glaucoma related to migration of nonemulsified silicone oil into the anterior chamber (AC) in a young phakic patient. A 24-year-old male diabetic patient underwent uneventful left eye pars plana vitrectomy (PPV) with silicon oil endotamponade for diabetic macula-off tractional retinal detachment. Two weeks after discharge, he presented with severe left eye pain. Examination revealed hand motion vision, high intraocular pressure (IOP) of 67 mmHg with ciliary injection, corneal edema, and two large nonemulsified silicone oil bubbles in the AC at the pupillary margin. Medical management with topical antiglaucoma medications (AGMs) and intravenous acetazolamide and mannitol failed to reduce the IOP. The patient underwent left eye PPV, silicone oil removal, and AC wash. IOP was eventually controlled after the operation without AGM. Pupillary block glaucoma after silicone oil injection is well recognized in aphakic patients, but ophthalmologists should be aware that it can occur in phakic and pseudophakic patients, particularly in complicated cases and patients with a weakness of the iris-lens diaphragm.

Two Year Randomized Prospective Comparison of Ahmed Valve Versus Baerveldt Implant in Vitrectomized Eyes

PRCIS

Ahmed Valve and Baerveldt shunt are efficacious options in vitrectomized eyes. Baerveldt implant achieves a lower mean intraocular pressure (IOP) at 2 years, with fewer medications and a higher percentage of medication-free patients.

PURPOSE

To investigate and compare the efficacy and complications between Ahmed FP7 Glaucoma Valve (AGV) and Baerveldt 101-350 Glaucoma Implant (BGI) in vitrectomized eyes.

MATERIALS AND METHODS

In this single-center randomized clinical trial, 43 vitrectomized eyes (39 patients) underwent glaucoma drainage device implantation. Eyes were randomized to receive either an AGV (FP7) or a BGI (101-350) and were followed for 2 years. Surgical success was defined as an IOP measurement≤18 mm Hg and≥5 mm Hg with or without glaucoma medication at 2 or more sequential visits after 3 months. The primary outcome was the comparison of the success rate at 2 years, while mean IOP, mean number of medications, and number of complications were considered secondary outcomes.

RESULTS

Kaplan-Meier estimates of the 2-year success rates in IOP control after GDD implantation were similar between the 2 groups; AGV group 81.8% (95% CI: 67.2%-99.6%) and BGI group 85.7% (95% CI: 72.0%-100.0%), (log-rank test P value = 0.74). Patients in the BGI group had a statistically significant lower mean IOP compared with the AGV group in all follow-up visits at 2, 6, 12, and 24 months (11.62 vs. 17.45 mm Hg at the latter P value <0.001). The BGI group required a significantly lower number of medications for IOP control at the 2-year visit compared with the AGV group (0.76±0.99 vs. 1.5±1.06 P value = 0.02) but had a higher number of complications (62% vs. 41%, respectively).

CONCLUSIONS

GDDs provide a viable solution for IOP control in vitrectomized eyes. Based on our prospective comparison, both Ahmed FP7 Glaucoma Valve and Baerveldt 101-350 Glaucoma Implant are efficacious options.

Outcomes of Anterior Chamber, Sulcus, and Pars Plana Glaucoma Drainage Device Placement in Glaucoma Patients

Purpose

To assess outcomes of anterior chamber (AC), sulcus, and pars plana (PP) glaucoma drainage device (GDD) placement in glaucoma patients. Patients and Methods. Retrospective evaluation of glaucoma patients who underwent GDD insertion in the AC, sulcus, or PP at Massachusetts Eye and Ear between November 2016 and May 2021. Patients who received AC, sulcus, and pars plana tubes were selected using simple random sampling, and the first 40 patients meeting inclusion criteria were analyzed. Main outcome measures were cumulative success probabilities from Kaplan-Meier (KM) analyses, intraocular pressure (IOP), medication burden, and complication rates.

Results

The PP group had a larger proportion of Ahmed GDDs and was younger on average with less severe glaucoma compared to patients with AC or sulcus tubes. The PP group had a higher proportion of mixed-mechanism glaucoma and lower proportion of primary open-angle glaucoma. With success defined as IOP reduction ≥20% and 5 < IOP ≤ 21 mm Hg, the Kaplan-Meier cumulative success probabilities for all three GDD locations were not significantly different. No significant differences were found in complication rates between all groups after 3 months. Patients with PP GDD had significantly lower medication burden than those with AC or sulcus GDDs up to 1.5 years postoperatively (1.7 ± 1.1, 3.0 ± 1.4, and 2.8 ± 1.2 for PP, AC, and sulcus, respectively; P=0.017).

Conclusion

PP GDDs may be more effective in lowering medication burden than AC or sulcus tubes without compromising long-term safety.

Therapeutic Vitrectomy in the Management of Uveitis: Opportunities and Challenges

PURPOSE

Pars plana vitrectomy (PPV) has been traditionally used for diagnostic tapping or for management of posterior segment complications, in uveitis. The anti-inflammatory potential of therapeutic PPV, independent of its role in managing uveitis complications, is yet to be realised completely. In this narrative review, we have described the indications, surgical technique, and outcomes of therapeutic PPV in the management of uveitis.

METHODS

Literature review of PubMed database for articles relating directly or indirectly, to the anti-inflammatory effect of therapeutic PPV in the management of uveitis. Of the 876 articles retrieved on initial review, only 37 articles were found to be relevant for the purpose of this review.

RESULTS

Therapeutic PPV is effective in controlling vitreous inflammation, improving visual outcomes and reducing the need for immunosuppressive medications in a wide range of infectious and non-infectious uveitis. Careful patient selection and meticulous surgical handling are mandatory. Post-operative complications include cataract progression, raised intraocular pressure, hypotony, retinal breaks, and worsening of cystoid macular edema. Despite being introduced more than 40 years ago, most data on therapeutic PPV remain retrospective. The possibility of therapeutic PPV replacing conventional medical therapy remains unknown.

CONCLUSIONS

Therapeutic PPV can control intraocular inflammation, independent of its role in managing posterior segment complications of uveitis. However, its exact place in the anti-inflammatory armamentarium against uveitis remains uncertain.

Accuracy of Intraocular Pressure Measurements of Eyes with Therapeutic Contact Lenses after Vitrectomy

Purpose: To evaluate the accuracy of intraocular pressure (IOP) measurements obtained by a rebound and non-contact tonometer in eyes with a therapeutic contact lens (CL) after vitrectomy.Methods: In 60 eyes of 60 patients who underwent vitrectomy for vitreoretinal disease, IOP was measured using a rebound tonometer (iCare ic200®; IOPRT) and non-contact computerized air puff tonometer (CT-80, IOPNCT), before and after wearing a CL (Purevision2®, +0.0 diopter). The mean IOP of three consecutive measurements were analyzed, and a comparative analysis with IOP measured by a Goldman applanation tonometer (IOPGAT) was performed.Results: The mean IOPRT without and with the CL was 12.55 ± 5.43 and 13.12 ± 5.13 mmHg, respectively, showing a statistically significant difference (p = 0.02) and strong positive correlation (r = 0.90, p < 0.001). The mean IOPNCT with and without the CL was 12.18 ± 3.24 and 12.17 ± 3.14 mmHg, showing no statistically significant difference (p = 0.17). The consistency with IOPGAT (12.57 ± 5.22 mmHg) was highest in IOPRT without the CL, followed by IOPRT with the CL, IOPNCT without the CL, and IOPNCT with the CL (intraclass correlation coefficients = 0.955, 0.945, 0.856, and 0.850, respectively). In addition, the rebound tonometer successfully measured IOP, regardless of whether the CL was worn; however, the non-contact tonometer failed to measure IOP in seven eyes without the CL and nine with the CL. No difference was observed according to intraocular tamponade type.Conclusions: A rebound tonometer can be used as an alternative IOL measuring method in eyes for which it is difficult to use a Goldman applanation tonometer due to the postoperative presence of a therapeutic CL.

Pars Plana Ahmed Valve Implantation for Vitrectomized Eyes With Refractory Glaucoma

This study aimed to analyze the surgical outcomes of pars plana Ahmed valve implantation in vitrectomized eyes with refractory glaucoma. We performed a retrospective case review of consecutive patients with refractory glaucoma after undergoing pars plana vitrectomy who underwent pars plana Ahmed valve implantation between July 2019 and December 2020 at the glaucoma unit of the Affiliated Changshu Hospital of Xuzhou Medical University (Changshu, China). All the patients were followed up for ≥12 months postoperatively. We recorded pre- to postoperative changes in best-corrected visual acuity (BCVA), intraocular pressure (IOP), number of anti-glaucoma medication, corneal endothelial count, and surgical complications, if any. There was a significant improvement in the median BCVA from 2.30 (0.87, 2.30) logMAR preoperatively to 1.70 (0.70, 2.30) logMAR at discharge and 1.0 (0.52, 1.85) at final examination (p = 0.011, p = 0.001). Compared with the preoperative IOP level, there was a significant decrease in the postoperative IOP at each postoperative time point (p < 0.001). There was a significant reduction in the median number of anti-glaucoma drugs (including postoperative ocular massage), from 3.00 (2.00, 3.00) preoperatively to 0.00 (0.00, 1.00) at the last follow-up postoperative examination (p < 0.001). A 29-year-old woman with proliferative diabetic retinopathy who underwent surgical treatment at 5 months postoperatively for fibrous wrapping formed around the plate of the Ahmed valve showed an IOP of 14 mmHg at the last follow-up. Our findings indicated that pars plana Ahmed valve implantation can be safely performed for managing vitrectomized eyes with refractory glaucoma.

Gas Expansion Three Days after Pars Plana Vitrectomy with Sulfur Hexafluoride 20% Tamponade following Carbon Monoxide Toxicity and Oxygen Therapy

Purpose

To report an unusual case of gas expansion following oxygen therapy in a patient with sulfur hexafluoride (SF₆) 20% tamponade after pars plana vitrectomy. Case Report. A 40-year-old man came to the clinic with severe ocular pain and redness and also vision decrease in his left eye three days after uncomplicated 23-gauge pars plana vitrectomy, internal limiting membrane peeling combined with phacoemulsification, and using 20% SF₆ injection as a tamponade agent due to significant cataract and a full-thickness macular hole. In ophthalmic examinations of his left eye, high intraocular pressure (approximately 70 mmHg), a flat anterior chamber, and a gas-filled vitreous cavity were found. The patient had been hospitalized the day before due to carbon monoxide poisoning and had undergone oxygen therapy with a pure 100% mask for three hours.

Conclusion

It seems that oxygen therapy or carbon monoxide poisoning increases the volume of gas in the patient's vitreous cavity and the nonexpansile percentage of SF₆ expands.

Scleral Buckling Alone or in Combination with Pars Plana Vitrectomy for Rhegmatogenous Retinal Detachment Repair: A Meta-Analysis of 7212 Eyes

PURPOSE

The efficacy and safety of scleral buckling (SB) versus combination SB and pars plana vitrectomy (SB+PPV) for rhegmatogenous retinal detachment (RRD) repair remains unclear.

METHODS

A systematic review and meta-analysis was conducted to identify comparative studies published from Jan 2000-Jun 2021 that reported on the efficacy and/or safety following SB and SB+PPV for RRD repair. Final best-corrected visual acuity (BCVA) represented the primary endpoint, while reattachment rates and ocular adverse events were secondary endpoints. A random-effects meta-analysis was performed, and 95% confidence intervals were calculated.

RESULTS

Across 18 studies, 3912 SB and 3300 SB+PPV eyes were included. Final BCVA was non-significantly different between SB and SB+PPV (20/38 vs. 20/66 Snellen; WMD=-0.11 LogMAR; 95%CI [-0.29,0.07]; P=0.23). Primary reattachment rate was similar between procedures (P=0.74); however, SB alone achieved a significantly higher final reattachment rate (97.40% vs. 93.86%; RR=1.03; 95%CI [1.00,1.06]; P=0.04). Compared to SB+PPV, SB alone had a significantly lower risk of postoperative macular edema (RR=0.69; 95%CI [0.47,1.00]; P=0.05) and cataract formation (RR=0.34; 95%CI [0.12,0.96]; P=0.04). The incidence of macular hole, epiretinal membrane, residual subretinal fluid, proliferative vitreoretinopathy, elevated intraocular pressure, and extraocular muscle dysfunction were similar between SB and SB+PPV.

CONCLUSIONS

There was no significant difference in final BCVA between SB+PPV and SB alone in RRD. SB alone offers a slightly higher final reattachment rate along with a reduced risk of macular edema and cataract. Primary reattachment rate and the incidence of other complications were similar between the two procedures.

Ahmed glaucoma valve implantation for secondary glaucoma post-vitrectomy

BACKGROUND AND OBJECTIVE

Ahmed glaucoma valv (AGV) implantation is one of the successful surgical methods in secondary glaucoma that develops after pars plana vitrectomy (PPV). In our study, we aimed to evaluate the 1-year results of AGV implantation in patients with a history of PPV.

STUDY DESIGN

A total of 26 patients who underwent AGV implantation after PPV were included in our retrospective study. Fourteen of 26 patients had AGV implantation due to neovascular glaucoma (NVG) and 12 of them had secondary refractory galucoma. Data of these two groups of patients were evaluated in terms of IOP reduction, number of medication use, surgical complete and qualified success, surgical failure, and complications.

RESULTS

The mean IOP was 29.54 ± 4.87 mmHg at the preoperative of AGV implantation and 12.88 ± 4.17 at the twelfth month visit in overal group. There was no statistically significant difference between two groups in terms of IOP in preoperative and all postoperative visits (p > 0.05). The mean intervals between PPV and AGV implantation were 67 ± 34 days in NVG and 391 ± 500 days in non-NVG group (p = 0.017). In overall group, 91.7% of patients had improvement in BCVA at the twelfth month visit. Complete and qualified surgical success rates were 75%, 83.3% in NVG group and 50%, 91.7% in non-NVG group, respectively. There was no devastating complication in both groups.

CONCLUSION

AGV implantation is a safe and effective surgical method in uncontrolled IOP elevations after PPV. While surgical success and failure rates were similar between etiologies, the time required for AGV implantation after PPV was shorter in NVG etiology.

Examining the Necessity of Postoperative Day-1 Review After Pars Plana Vitrectomy: A Meta-Analysis

BACKGROUND AND OBJECTIVES

This study aimed to evaluate the necessity of the postoperative day-1 (POD1) review after pars plana vitrectomy.

PATIENTS AND METHODS

The analysis included available literature that documented medical and surgical interventions performed on POD1 review after pars plana vitrectomy. A meta-analysis of proportions was conducted using a binomial-normal model to analyze three data sets consisting of all interventions, medical interventions, and surgical interventions. Heterogeneity and publication bias analyses were performed.

RESULTS

POD1 reviews of 2,262 patients across 14 studies were examined to yield a total POD1 intervention rate estimate of 4.7% (95% confidence interval [CI], 3.0-13.9). When stratified by medical or surgical intervention, the intervention rate estimates were 4.1% (95% CI, 1.4-11.6) and 0.7% (95% CI, 0.3-1.3), respectively. The most common complication requiring postoperative intervention was elevated intraocular pressure.

CONCLUSION

Given the wide confidence intervals of the estimated intervention rates, variability in postoperative practices, and range of interventions performed, the POD1 review cannot be discarded in its entirety. [Ophthalmic Surg Lasers Imaging Retina. 2021;52:513-518.].

Slow Coagulation Transscleral Cyclophotocoagulation for Postvitrectomy Patients With Silicone Oil-induced Glaucoma

PRECIS

Slow coagulation transscleral cyclophotocoagulation (TSCPC) is an effective and safe glaucoma surgery in patients with medically uncontrolled silicone oil (SO)-induced glaucoma.

PURPOSE

The purpose of this study was to report the outcomes of slow coagulation continuous wave TSCPC in patients with medically uncontrolled secondary glaucoma following pars plana vitrectomy (PPV) and intravitreal SO injection.

PATIENTS AND METHODS

This retrospective study enrolled patients with medically uncontrolled glaucoma secondary to PPV with SO injection who underwent TSCPC using slow coagulation TSCPC settings (power of 1250 mW and duration of 4 s). The primary outcome measure was surgical success at 12 months. Surgical success was defined as an intraocular pressure 6 to 21 mm Hg and reduced ≥20% from baseline, no reoperation for glaucoma, and no loss of light perception vision. Secondary outcome measures included number of glaucoma medications, visual acuity changes, and surgical complications.

RESULTS

A total of 18 eyes of 18 patients were included in the study. The mean age and follow-up of the patients were 51.94±14.5 years and 16.3±3.5 months, respectively. The mean intraocular pressure decreased from 29.7±9.6 mm Hg preoperatively to 14.6±6.5 mm Hg at 12 months postoperatively (P<0.001). Glaucoma medications were reduced from 4.2±0.9 at baseline to 1.9±1.3 at 12 months after TSCPC (P<0.001). A nonsignificant change of logarithm of the minimum angle of resolution visual acuity was observed at 12 months (P=0.722). The success rate at 12 months was 72.2%. No major complications were reported during the first year of follow-up.

CONCLUSION

Slow coagulation TSCPC had high efficacy and minimal complications when used as an initial glaucoma surgical procedure in patients with SO-induced glaucoma.

Corneal endothelial changes induced by pars plana vitrectomy with silicone oil tamponade for retinal detachment

Silicone oils are effective intraocular tamponade agents in the treatment of severe retinal detachments, because they maintain the adhesion between neurosensory retina and retinal pigment epithelium, thanks to their ability to remove aqueous humor from the surface of the retina. To understand their effectiveness, it is important to know the characteristics of silicone oils. Patients should be closely monitored due to many complications associated with intraocular silicon oil, such as inflammatory reaction, raised intraocular pressure, refraction disorders, cataract, and emulsification. This study presents corneal endothelial changes and some intraocular complications caused by silicone oil used as an intraocular tamponade agent in the case of vitrectomy for complex retinal detachments. The aim of the study was to demonstrate the damage of corneal endothelial cells after the use of silicone oil in patients with retinal detachment surgery. Endothelial specular microscopy measurements were performed and the changes of the following parameters demonstrated the corneal damage: Mean cell density, coefficient of variation, average cell area, percentage of hexagonal cells, and corneal thickness. Three months postoperatively, a statistically significant decrease was observed in the following analyzed parameters: Mean cell density (P=0.04), and percentage of hexagonal cells (P=0.002); the remaining parameters also had a linear decrease (coefficient of variation, average cell area), but were statistically insignificant. Three months postoperatively, the corneal thickness presented a slight increase. Silicone oils are powerful tools when used wisely and within the limits of their use. These are often recommended in cases of severe detachment of the retina in patients at high risk of experiencing intraoperative complications.

[Intraocular pressure elevation after vitrectomy-Goldmann applanation tonometry measures lower intraocular pressure than dynamic contour tonometry]

Hintergrund

Das dynamische Konturtonometer PASCAL (DCT) ist ein digitales, der natürlichen Hornhautgeometrie angepasstes Kontakttonometer. Verglichen wurde das DCT mit dem Goldmann-Applanationstonometer (GAT).

Methodik

In einer prospektiven Querschnittstudie wurden 100 Augen vor und nach Pars-plana-Vitrektomie (ppV) vergleichend mit dem GAT und DCT gemessen. Verwendete Endotamponaden waren verschiedene Gase und Silikonöle. Erfasst wurden der präoperative intraokulare Druck (IOD), postoperative Druckveränderungen und die Intertonometerdifferenz.

Ergebnisse

Präoperativ lag der mittlere IOD mit dem GAT gemessen bei 15,8 ± 5,2 mm Hg und dem DCT bei 17,5 ± 5,9 mm Hg. Am ersten postoperativen Tag stieg bei Augen, die mit Gas versorgt wurden, der Druck im Mittel um 2,5 mm Hg (p = 0,035) an. Das DCT erfasste 18 Augen (19,1 %) mit einem postoperativen IOD von ≥ 25 mm Hg. Postoperativ maß das GAT den IOD im Schnitt 2,5 mm Hg niedriger und bei expansiver Gasendotamponade im Mittel um 3,0 mm Hg niedriger als das DCT. Bei IOD-Werten von postoperativ über 20 mm Hg lag das GAT im Mittel 4,7 mm Hg unter dem DCT. Zehn von 18 Augen mit IOD ≥ 25 mm Hg wurden mit dem GAT nicht als hypertensiv (≥ 25 mm Hg) erkannt. Bei 13 % maß das DCT am 1. postoperativen Tag einen um mindestens 6 mm Hg höheren IOD als das GAT. In einem Extremfall wurde der IOD mit dem GAT bei Gasendotamponade um 12 mm Hg unterschätzt.

Schlussfolgerung

Postoperative Druckanstiege nach ppV sind gefürchtete Komplikationen und können zu irreversiblem Visusverlust führen. Abhängig von der verwendeten Endotamponade misst das GAT den IOD niedriger als das DCT – besonders bei Druckspitzen durch expansive Gase. Die postoperative IOD-Messung nach ppV ist bedeutend und die Messwerte von GAT und DCT können abweichen.

Pars Planectomy: Preliminary Report of a New Glaucoma Filtering Technique in Vitrectomized Eyes

Purpose

To propose a new filtering technique in vitrectomized eyes with glaucoma and report its clinical results and safety.

Methods

The medical records of 13 eyes that developed glaucoma following pars plana vitrectomy and underwent pars planectomy, from 2011 to 2018, at Songklanagarind hospital, Hatyai, Songkhla, Thailand were retrospectively reviewed. The main outcome measures were visual acuity (VA), intraocular pressure (IOP), number of glaucoma medications, and postoperative complications. Surgical success was defined as IOP value at the last visit of 6-21 mmHg, regardless of anti-glaucoma medication usage, and without further glaucoma surgery.

Results

The mean follow-up duration was 47.7 ± 32.1 months (range, 0.3-101.1 months). Preoperative BCVA increased from LogMAR 1.01 ± 0.85 to 1.2 ± 0.91 at the last visit (p = 0.233). The mean preoperative IOP was 28.15 ± 9.17 mmHg with an average of 3.46 ± 0.52 anti-glaucoma medications. At the final visit, the mean IOP was 14.08 ± 4.89 mmHg (p = 0.006) and the mean number of anti-glaucoma medications decreased to 1.31 ± 1.38 (p = 0.000). The probability of surgical success was 58.3%, 50%, and 37.5% at 1, 2, and 6 years after pars planectomy, respectively. Postoperative complications included vitreous hemorrhage in 1 eye (7.7%). No retina and pars plicata associated complications were found.

Conclusion

Pars planectomy is efficient and safe as well as requires a short learning curve. It should be considered as an alternative filtering surgery in glaucoma after vitrectomy, especially with an extensive limbal scar that might be a limitation in trabeculectomy and GDDs techniques and outcomes.

Long-Term Intraocular Pressure Changes after Pars Plana Vitrectomy: An 8-Year Study

Purpose:

To investigate the long-term changes of intraocular pressure (IOP) after pars plana vitrectomy (PPV).

Methods:

This was a retrospective historical cohort study. Patients with a history of vitrectomy in one eye by a single surgeon were enrolled. IOP of the operated eye was compared to the fellow eye. Previous scleral buckling, IOP rise due to surgical/anatomic complications, silicone oil (SO) emulsification, and contralateral ocular hypertension/glaucoma at recruitment were exclusion criteria. “Significant IOP rise” (>6.0 mmHg) and development of open angle glaucoma (OAG) were the main outcome measures.

Results:

Two hundred and twenty-five eyes were included. Mean and median follow-up duration were 20.6 and 9.0 months, respectively. Mean baseline IOP and mean final IOP were 13.53 ± 3.75 mmHg and 16.52 ± 6.95 mmHg, respectively (P < 0.001). Forty-three patients developed “significant IOP rise” with no statistically significant relation to the indication of vitrectomy, the postoperative lens status, and number of vitrectomies (P = 0.410, P = 0.900, and P = 0.160, respectively). SO injection raised the probability of IOP rise in the long-term (P = 0.028). OAG occurred in 17 patients (7.5%) with no association to SO tamponade (P = 0.840). “Significant IOP rise” and OAG occurred in 3 and 1 control eyes, respectively, significantly lower than the rates in study eyes (P < 0.001).

Conclusion:

Mean IOP slightly rose in the long-term after PPV. SO tamponade was associated with IOP rise in the long-term but not with the incidence of OAG. Both IOP rise and OAG were more probable after vitrectomy.

Pars Plana Vitrectomy and the Risk of Ocular Hypertension and Glaucoma: Where Are We?

Purpose is to review the pathogenic mechanism for ocular hypertension and glaucoma development after pars plana vitrectomy. Both acute and chronic causes are considered, and special attention is paid to the theories and clinical evidence on the risk of developing Open Angle Glaucoma (OAG) after Pars Plana Vitrectomy (PPV). Most existing scientific literature on the issue agree on the role of ascorbate as an oxygen scavenger within the vitreous chamber. Oxygen tension in the vitreous and anterior chamber is maximum inn proximity of the retinal surface and endothelium, respectively and steeply decreases toward the lens, on both sides, and trabecular meshwork. Vitreous removal and, to a lesser extent, liquefaction, greatly reduces oxygen tension gradient in vitreous chamber while cataract extraction has similar effects on anterior chamber oxygen gradients. Oxygen derivatives originated from the cornea and retina are actively reduced by the vitreous gel and/or the crystalline lens. Vitreous removal and cataract extraction reduce drastically this function. Most reported clinical series confirm this hypothesis although protocol difference and follow-up length greatly impact the reliability of results.

Surgical Treatment of Idiopathic Macular Hole Using Different Types of Tamponades and Different Postoperative Positioning Regimens

Purpose

To compare the effect of different types of intraocular tamponade and different types of postoperative positioning on the closure of idiopathic macular hole (IMH).

Methods

Prospective randomized clinical trial enrolling 104 eyes of 100 patients (age, 57–87 years) undergoing MH surgery. All patients were operated on by an experienced surgeon using 25-gauge pars plana vitrectomy (PPV) and internal limiting membrane (ILM) peeling. Patients were randomized according to the type of intraocular tamponade and postoperative positioning into the following four groups: SF6 + nonsupine reading position (n = 26) (group 1), air + nonsupine reading position (n = 25) (group 2), air + prone position (n = 26) (group 3), or SF6 + prone position (n = 27) (group 4). The follow-up period was 6 months.

Results

MH closure was achieved in 87 eyes (83.7 %) in the overall sample after the first surgery, with closure rates of 100%, 56%, 84.6%, and 92.6% in groups 1, 2, 3, and 4, respectively. The group 2 was significantly less successful compared to the other three groups (p < 0.05). MH of sizes ≤400 µm was closed in 97.2% of cases after the first surgery, with no significant differences between groups (p = 0.219). MH with sizes over 400 µm was closed in 70.9% of cases after the first surgery, with both groups with air tamponade being significantly less successful than group 1. The nonsupine reading position was subjected to a better subjective evaluation in terms of postoperative comfort and quality of sleep, with no differences between air and SF6 tamponade tolerance.

Conclusion

PPV with ILM peeling, intraocular tamponade, and positioning remains the basic surgical approach in the treatment of IMH. For MH ≤ 400 µm, a high closure rate can be achieved by combining air tamponade and nonsupine reading position. For macular holes >400 µm, the greatest anatomical success can be achieved by using the SF6 tamponade in combination with the nonsupine reading position.

Intraocular pressure change with face-down positioning after macular hole surgery

This study evaluated changes in intraocular pressure (IOP) with face-down positioning (FDP) following surgical treatment of idiopathic macular hole. We retrospectively reviewed the records of 130 patients diagnosed with idiopathic macular hole who underwent pars plana vitrectomy (PPV) with intravitreal gas injection after fluid-gas exchange. We analyzed IOP changes in both eyes following FDP over the course of 7 days. The mean IOP of the operated eyes was 14.98±2.95 mmHg preoperatively and 16.82±3.12 and 15.57±6.10 mmHg on postoperative days 2 and 7, respectively. In contralateral eyes, the mean IOP changed from 14.78±3.15 mmHg preoperatively to 16.27±1.87 and 14.40±4.14 mmHg on postoperative days 2 and 7, respectively. On postoperative day 2, the IOP increased in both eyes compared to the preoperative values, but the increase was significant only in operated eyes (p = 0.039). In contralateral eyes, the IOP on postoperative day 7 was significantly decreased compared with that on postoperative day 2 (p = 0.021) and in eyes with an axial length ≥ 23.0 mm, compared with the preoperative values (p = 0.042). The IOP of the operated eyes on postoperative day 7 was higher than that of the contralateral eyes (p = 0.039). Based on a short-term follow-up, FDP after PPV with intravitreal gas tamponade for the treatment of idiopathic macular hole may cause IOP elevation not only in the operated, but also in the contralateral eyes; the IOP increase in contralateral eyes was not as significant as that in operated eyes and was not maintained over 7 days after surgery; the IOP change seems to be affected by axial length and lens status.

Influence of pars plana vitrectomy for macular surgery on the medium term intraocular pressure

Purpose

To evaluate the long-term effect of 20 and 23 gauge pars plana vitrectomy (PPV) on intraocular pressure (IOP).

Methods

Study type: Monocentric retrospective cohort study. 249 eyes of 249 patients undergoing PPV due to epiretinal membrane (EM), idiopathic macular hole (IMH) or vitreoretinal traction (VT) were included. The fellow eye served as control. Exclusion criteria were factors known to influence the IOP, such as cataract surgery during follow-up, extended use of steroids, cryotherapy and silicone oil endotamponade. The relative change of IOP (operated vs. fellow eye) at 6–12 months after surgery was defined as primary endpoint. Secondary endpoints were the relative change of IOP at 3–6 and 12–24 months. Possible influencing cofactors were analysed using ANCOVA.

Results

The primary endpoint did not show a significant IOP reduction of the operated eye relative to the fellow eye (P = 0.089, n = 84). However, the IOP of the operated eye alone was significantly reduced at 6–12 and 12–24 months after surgery (-0.75 ± 2.80 and -1.22 ± 3.29 mmHg, P = 0.008 and 0.007, respectively). The IOP of the fellow eye was also significantly reduced at the 12–24 months period (-0.75 ± 2.73 mmHg, P = 0.008). In the subgroup analysis, sclerotomy size was a significant influencing cofactor, leading to lower IOP after 20G compared to 23G vitrectomy (P = 0.04).

Conclusion

Pars plana vitrectomy did not induce a significant long-term IOP reduction relative to the contralateral eye. However, we observed a IOP lowering potential in 20G vitrectomy.

[Distinctive features of phacoemulsification in previously vitrectomized eyes]

The review presents the main pathogenetic mechanisms of cataract development in an avitic eye as well as anatomical and functional changes of the eye in the state of avitria. The authors have also analyzed distinctive behavior of such eyes during phacoemulsification and surgical techniques used to answer specific avitreal phenomena.

Intraocular pressure changes during and after silicone oil endotamponade (Review)

Silicone oil (SIO) has rapidly become an indispensable adjunct in vitreoretinal surgery. Constant improvements in purity and also in viscosity have not totally prevented specific complications that may occur during endotamponade. Results of in vitro studies that suggested that higher viscosity silicone oil might be superior in terms of stability and safety are confirmed in real life only if endotamponade lasts for more than 6 months. Intraocular pressure changes induced by the silicone oil endotamponade or oil extraction are documented from its very first use and are potentially threatening vision. The purpose of this review is to update current knowledge on the incidence, risk factors, pathogenesis, and management of secondary silicone oil glaucoma. Also, in a retrospective evaluation on cases with complex retinal detachments that underwent 23G vitrectomy and high viscosity SIO endotamponade, we have noticed that a considerable number of cases developed significant intraocular pressure changes during SIO endotamponade and after SIO removal, especially in early postoperative period.

Rhegmatogenous retinal detachment: a review of current practice in diagnosis and management

Rhegmatogenous retinal detachment (RRD) is a common condition with an increasing incidence, related to the ageing demographics of many populations and the rising global prevalence of myopia, both well known risk factors. Previously untreatable, RRD now achieves primary surgical success rates of over 80%-90% with complex cases also amenable to treatment. The optimal management for RRD attracts much debate with the main options of pneumatic retinopexy, scleral buckling and vitrectomy all having their proponents based on surgeon experience and preference, case mix and equipment availability. The aim of this review is to provide an overview for the non-retina specialist that will aid and inform their understanding and discussions with patients. We review the incidence and pathogenesis of RRD, present a systematic approach to diagnosis and treatment with special consideration to managing the fellow eye and summarise surgical success and visual recovery following different surgical options.

Outcome of Surgical Management of Glaucoma Following Complex Retinal Detachment Repair With Silicone Oil Tamponade: Drainage Implant Versus Cyclophotocoagulation

PRéCIS:: Glaucoma drainage devices (GDDs) are effective for the management of silicone oil-induced glaucoma. Although cyclophotocoagulation (CPC) has the advantage of shorter operative time and repeatability, it carries a higher risk of failure, blindness, and phthisis.

BACKGROUND/AIMS

To compare the surgical outcome of GDD implantation and diode laser CPC in the management of refractory glaucoma following vitrectomy with silicone oil (SO) injection.

MATERIALS AND METHODS

In total, 56 eyes with refractory glaucoma after SO tamponade that underwent either CPC or GDD implantation were retrospectively evaluated. All patients underwent a complete ophthalmic examination and intraocular pressure (IOP) measurement at baseline and 1 day, 1 week, 1, 3, 6, and 12 months postoperatively. The rates of complete success and qualified success (for IOP between ≥5 and ≤21 mm Hg) were analyzed.

RESULTS

A total of 17 eyes underwent GDD implantation and 39 eyes underwent CPC. The preoperative IOP was 35.7±7.9 mm Hg and 27.8±8.4 mm Hg for the CPC and GDD groups, respectively (P=0.001), with a worse baseline visual acuity (P=0.01) and a higher proportion of SO-filled eyes in the CPC group (P<0.01). The IOP at 1 year postoperatively was 23.5±11.5 mm Hg and 15.3±5.9 mm Hg for the CPC and GDD group, respectively (P=0.01). Both groups achieved a reduction in IOP and number of medications at 1 year (P<0.001). The success rate in the GDD group was 94.1% (16/17), and 53.8% (21/39) in the CPC group at 12 months (P<0.005). Five eyes and 1 eye lost light perception vision in the CPC and GDD groups, respectively.

CONCLUSIONS

GDD implantation may carry a higher surgical success rate than CPC. However, CPC retains the advantage of being technically easier and repeatable.

Intraocular Pressure Rise Linked to Silicone Oil in Retinal Surgery: A Review

Silicone oil represents the main choice for intraocular tamponade in cases of complicated retinal detachment surgery. The intraocular pressure of an eye filled with silicone oil could increase, driven by a variety of different forces, according to several mechanisms. Two main conditions have been highlighted, depending on the onset: early hypertension or late glaucoma. The different types of silicone oils and their physico-chemical properties are varied and may play a role in the determination of intraocular pressure rise. The current body of literature allows for the illustration and categorization of the incidence and risk factors, as well as the pathogenesis and the management of the early postoperative hypertension subtended by an open- and closed-angle, along with the late onset silicone oil-induced glaucoma. Understanding the leading actors on the stage of ocular pressure elevation concurrently with silicone oil application for retinal surgery could help in guiding the timely and appropriate course of treatment.

Retinal Tamponades: Current Uses and Future Technologies

Purpose of Review

In this article, the current use and limitations of existing retinal tamponades are discussed. Potential novel developments that address those limitations are subsequently highlighted, along with areas of future improvements.

Recent Findings

While retinal tamponades have existed for decades and improved the treatment of retinal detachments, many problems still exist with their use, including inadequate tamponade of the inferior retina, toxicity from retained heavy liquids, glaucoma, and keratopathy, among others. New advancements in the components of heavy liquids and vitreous substitutes aim to mitigate those issues.

Summary

Existing retinal tamponades, including perflurocarbon heavy liquids, fluorinated gases, and silicone oil, have specific limitations that cause potentially avoidable morbidity. New developments, such as heavy silicone oil, novel vitreous gels, and future avenues of approach, such as potentially reabsorbing heavy liquids may help increase our ability to treat retinal detachments with fewer complications.

Tube Length Adjustment and Tube Trimming Technique in Refractory Glaucoma

Secondary glaucoma may develop after vitreoretinal surgery as it is a known risk factor for its development. When the risk factors are more than one, for instance along with neovascular glaucoma (NVG), the secondary glaucoma may become recalcitrant and very difficult to manage. Surgical intervention is often warranted to control intraocular pressure (IOP) and prevent progressive glaucomatous damage in patients with refractory glaucoma, and glaucoma drainage implant may be preferred as the primary choice. We describe a patient who develop secondary glaucoma after vitrectomy and silicone oil (SO) injection due to unresolved vitreous hemorrhage in proliferative diabetic retinopathy (PDR) and subsequent NVG. Baerveldt glaucoma implant (BGI) was carried out and placed in the superotemporal quadrant with longer anterior chamber tube placement to prevent escape of SO through the tube. Qualified success was achieved with additional one fixed-drug combination (FDC). However, 3 years later, the tube was blocked by the iris tissue at the inferior edge of the pupil. Tube trimming was performed efficiently using a simple technique. The distal end of the tube was pulled out of the anterior chamber through a paracentesis just next to the tube entrance and trimmed to the appropriate length. More than a year after the surgery, IOP was still well controlled with the same FDC. Unfortunately, the visual acuity could not be recovered due to advanced PDR.

First postoperative day review in eyes undergoing pars plana vitrectomy, encirclement and endotamponade to check intraocular pressure: Is it necessary?

PURPOSE

To assess the proportion of patients with raised intraocular pressure (IOP) (≥ 30 mmHg) on the first postoperative day following pars plana vitrectomy (PPV), encirclement and endotamponade and assess the number requiring alteration in management to address elevated IOP. To establish whether review on day one is required.

METHODS

Retrospective case note review of consecutive patients who underwent 23-gauge PPV, 276-encirclement and endotamponade under the care of a single surgeon. All patients as standard received prophylactic anti-glaucoma medication post-surgery (eye drops) to take home but initiate only after day-one review. Statistical analysis was carried out using student t tests and Fisher's exact tests.

RESULTS

Sixty-six patients were examined over a 2-year period. Mean day-one IOP was 22.2 mmHg (SD 7.3, 95% CI 20.4-24.0). Eleven patients (16.7%) had IOP ≥ 30 mmHg. Five patients (7.6%) had management changing decisions made at the day-one postoperative visit. Lens status, endotamponade, preoperative IOP, surgeon grade, cryopexy versus laser retinopexy or preoperative administration of once only 500 mg dose of intravenous acetazolamide did not influence IOP, with no significant difference between these subgroups. No cases of hypotony occurred.

CONCLUSIONS

A significant minority of patients had elevation of IOP above 30 mmHg, a number of whom required treatment changes to address this. No preoperative risk factors were identified indicating those at risk of high IOP. It is important to identify these potentially harmful IOP elevations, and therefore day-one review is imperative and should be continued.

Anatomic and functional results of idiopathic macular epiretinal membrane surgery

AIM

To assess the impact of macular surgery on the functional and anatomic outcomes in patients with grade 2 epiretinal membrane (ERM), and the effect of internal limiting membrane (ILM) peeling on visual acuity and to analyze the long-term effect of pars plana vitrectomy (PPV) on intraocular pressure (IOP).

METHODS

Pseudophakic eyes (62 eyes) diagnosed as idiopathic grade 2 ERM with at least 6mo postoperative follow-up were included in this retrospective study. The fellow eye was nonvitrectomized. Patients were divided into two groups: group 1 (29 eyes) treated with ERM and ILM peeling and group 2 (33 eyes) with only ERM peeling. Preoperative and postoperative best corrected visual acuity (BCVA), slit-lamp, and a dilated fundus examination was performed. IOP was measured with Goldman applanation tonometer before, day 1 and first week and each visit after surgery. The incidence of significant IOP elevation was compared between vitrectomized eyes and nonvitrectomized fellow eyes.

RESULTS

Visual improvement was statistically significant and similar in both groups (P=0.008 in group 1, P=0.002 in group 2, P=0.09 inter-group). The amount of decrease in central macular thickness was statistically significant and similar in both groups (P=0.005 group 1, P=0.008 group 2, P=0.37 intergroup). At the final follow-up (14.1±9.6mo) the incidence of significant IOP elevation was 4% in vitrectomized eyes (three eyes) and 3% (two eyes) in the nonvitrectomized fellow eyes (P=0.12). Four eyes (12.1%) had recurrent ERM after a mean follow-up of 8.6±1.1mo in group 2, there was no recurrence in group 1 (P=0.01).

CONCLUSION

Recurrence of ERM may be decreased by ILM peeling during ERM surgery. However, it seems that ILM peeling do not affect the functional outcome and 23-gauge PPV alone do not have a significant effect on IOP.

Incidence and risk factors for intraocular pressure rise after transconjunctival vitrectomy

Purpose

To study the incidence and risk factors of raised intraocular pressures (IOPs) in the follow-up of transconjunctival sutureless vitrectomy (TSV).

Methods

A retrospective observational study was performed on 635 patients who underwent TSV under a single surgeon. The IOPs were recorded using a calibrated non-contact tonometer at seven postoperative visits, viz., day 1, 7 and 1, 3, 6 months, and 1 day and 1 month following silicone oil removal.

Results

IOP rise was seen in 24.25% (154) out of the 635 eyes studied. Among patients under 50 years of age, 37.73% had an IOP rise, compared to 21.55% above 50 years (Odds Ratio 2.206). Among males, 30.32% had an IOP rise, as compared to 15.98% females (OR 2.287). In eyes with retinal detachment, 49.16% had raised IOP (OR 5.435), and 24.05% with proliferative diabetic retinopathy (OR 1.780), as opposed to 15.38% with macular hole and 12.32% with epiretinal membrane. This was statistically significant (P < 0.001). In eyes with silicone oil, 34.9% developed a rise in IOP (OR 2.738) as compared to 11.94% of other surgeries (OR 0.697). This was statistically significant (P < 0.001).

Conclusion

We observed an increase in IOP postoperatively, more in those under 50 years, males and patients undergoing surgery for RD and PDR.

Measurement of the volume of the vitrectomized space during vitrectomy in myopic patients with retinal detachment

PURPOSE

We present a novel technique for measuring volume of space replaced by air during fluid-air exchange in vitrectomy (vitrectomized space) for intravitreal gas injection. To confirm the feasibility of this technique, we assessed postoperative intraocular pressure (IOP) and the duration of injected gas. Using this technique, we found remarkable differences in volume between high myopic eyes with retinal detachment caused by peripheral break (PB-RD group) and those with macular hole retinal detachment (MH-RD group). We studied the relationships between the volume and biometric values, axial length (AL) and corneal curvature radius (CCR) in both PB-RD and MH-RD group.

STUDY DESIGN

Retrospective study.

METHODS

During fluid-air exchange, the aspirated fluid accumulates in the measuring cup between the infusion needle and vitrectomy instrument. Vitrectomized space volume is obtained by subtracting the volume of the tube between the infusion needle and the 3-way stopcock from the aspirated fluid volume. We performed phaco-vitrectomies by measuring the vitrectomized space volume and then injected pure SF6 at 15% of the volume into the vitreous cavity in 156 myopic eyes (AL > 26 mm) with RD consisting of 144 eyes in PB-RD group and 12 in MH-group.

RESULTS

The IOP (mean ± SD) was 13.5 ± 3.4 mmHg preoperatively, 23.4 ± 10.4 mmHg on day 1, 18.2 ± 7.4 mmHg on day 2, and 16.1 ± 4.5 on day 7. The gas disappeared in 16.1 ± 1.9 days. Axial length was longer in the MH-RD group but the volume of vitrectomized space was larger in the PB-RD group. AL and volume were significantly correlated in both groups (P < 0.01), but the fitting lines differed. The CCR and volume significantly correlated in the PB-RD group (P < 0.01) but not in the MH-RD group.

CONCLUSION

Our novel technique for measuring the volume of vitrectomized space can achieve target gas concentration in the vitreous cavity. The difference in the shape of eyeballs may explain discrepancies in relationship between volume and the biometric factors.

Incidence and outcomes of ocular hypertension from rhegmatogenous retinal detachment surgery in the acute postoperative setting

Purpose

To determine the incidence of ocular hypertension following surgery for rhegmatogenous retinal detachment in the first 3 months postoperatively and to determine their outcomes in terms of visual acuity, control of IOP, and changes in cup:disc ratio.

Patients and methods

A single center prospective cohort study was done involving patients who underwent retinal surgery for rhegmatogenous retinal detachment. The patients were followed up for 3 months postoperatively and were monitored for development of ocular hypertension. The primary outcome measures were changes in IOP, visual acuity, and cup:disc ratio.

Results

Of the 52 eyes enrolled in the study, 19 eyes developed ocular hypertension in the first 3 months postoperatively, giving an incidence rate of 36.5% (95% CI, 48.9-76.0%). Analysis of mean IOP trends shows that most cases of IOP elevations occur in the first day postoperatively with a sustained elevation up to the first month and then returning to normal levels by the 3rd month. There is a significant increase in mean cup:disc ratio among patients who developed ocular hypertension (p=0.047). Visual acuity trends show that mean visual acuity significantly improved from baseline among cases who maintained normal IOP (p=0.002) as compared to those who developed ocular hypertension (p=0.97), although the difference in final visual acuity at the end of 3 months between groups was not statistically significant (p=0.30).

Conclusion

Ocular hypertension may complicate retinal reattachment surgery. Control of IOP in the acute setting is essential to prevent development of secondary glaucoma.

The effect of multiple vitrectomies and its indications on intraocular pressure

Background

To assess the relationship between different indications for trans pars plana vitrectomies (PPV’s) and the intraocular pressure (IOP), and the effect of multiple PPV’s on the IOP. We also examined whether there were differences in the number of IOP-lowering medications or surgeries before and after PPV.

Methods

A retrospective study including all patients that underwent at least one PPV in the period from 2001 till 2014 at our clinic. Medical records of all patients were reviewed and clinically relevant data were entered in a database. Generalized estimating equations models for repeated measurements were used to examine the effect of the number of PPV’s on the IOP and on the risk of undergoing glaucoma surgery, for each of the indications for PPV.

Results

Of 1072 PPV’s 447 eyes fulfilled the inclusion criteria. The IOP increased with 3.0 mmHg after a PPV with indication retinal detachment (p < 0.001), but remained stable after PPV for epiretinal membrane (p = 0.555), macular hole (p = 0.695), and vitreous hemorrhage (p = 0.787). At the end of the follow-up period the number of IOP-lowering medications was significantly higher compared to baseline, except in the macular hole group (p = 0.103). Also, the number of eyes that underwent glaucoma surgery was significantly higher compared to the fellow (not-operated) eyes (p < 0.001). There was a significant association between the number of PPV’s and the final IOP for the indication retinal detachment (p = 0.009), and between the number of PPV’s and glaucoma surgery (odds ratio [95% confidence interval]: 2.60 [1.62–4.15]).

Conclusions

The IOP rises significantly after PPV with indication retinal detachment. This association was not found for other indications for PPV. Also, the risk of IOP-lowering surgeries was higher after PPV, but not different between the PPV indications. The IOP should be monitored carefully after PPV, since there may be a higher risk of secondary glaucoma.

Changes in intraocular pressure after intraocular eye surgery-the influence of measuring technique

AIM

To investigate the changes in intraocular pressure (IOP) before and after intraocular surgery measured with Goldmann applanation tonometry (GAT) and pascal dynamic contour tonometry (PDCT), and assessed their agreement.

METHODS

Patients who underwent trans pars plana vitrectomy (TPPV) with or without cataract extraction (CE) were included. The IOP was measured in both eyes with GAT and PDCT pre- and postoperatively, where the non-operated eyes functioned as control.

RESULTS

Preoperatively, mean IOP measurements were 16.3±6.0 mm Hg for GAT and 12.0±2.8 mm Hg for PDCT for the operated eyes. Postoperatively, the mean IOP dropped to 14.3±5.6 mm Hg for GAT (P=0.011) and rose up to 12.7±2.6 mm Hg for PDCT (P=0.257). Bland-Altman analysis showed a poor agreement between GAT and PDCT with a mean difference of 2.9 mm Hg preoperatively and 95% limits of agreement ranging from -3.2 to 9.0 mm Hg. Postoperatively, the mean difference was 1.2 mm Hg with 95% limits of agreement ranging from -8.3 to 10.7 mm Hg. There were no significant differences between the TPPV and TPPV+CE group, except when measured with PDCT postoperatively (P=0.012).

CONCLUSION

The IOP is reduced after surgery when measured with GAT and remained stable when measured with PDCT. However, the agreement between GAT and PDCT is poor. Although PDCT may be a more accurate predictor of the true IOP, it seems less suitable for daily use in the clinical practice.

Three-Year Findings on Intraocular Pressure Changes in The Prospective Retinal and Optic Nerve Vitrectomy Evaluation (PROVE) Study

BACKGROUND AND OBJECTIVE

This paper reports 3-year intraocular pressure (IOP) outcomes of the Prospective Retinal and Optic Nerve Vitrectomy Evaluation (PROVE) study.

PATIENTS AND METHODS

The prospective, controlled, observational study included 80 eyes of 40 participants undergoing routine pars plana vitrectomy. Study patients underwent preoperative evaluation and multimodal testing of the study (surgical) and fellow (control) eye. This testing was repeated at 3 months postoperatively and then annually for 3 years.

RESULTS

Thirty-two of 40 patients (80%) completed 3-year follow-up. At 3 years postoperatively, there was no difference in IOP measurements in surgical eyes overall from baseline (P = .36). Subgroup analysis of pseudophakic eyes at baseline showed a significant elevation in IOP from 14.3 mm Hg ± 2.9 mm Hg at baseline to 16.8 mm Hg ± 3.2 mm Hg at 3-year follow-up (P < .029). Fellow eyes did not experience a significant change from baseline.

CONCLUSION

The authors' 3-year results show that IOP is consistently and significantly elevated in pseudophakic eyes compared to baseline following routine vitrectomy. [Ophthalmic Surg Lasers Imaging Retina. 2019;50:371-376.].

Comparison of intraocular pressure using Goldmann applanation tonometry versus non-contact tonometry in eyes with high-viscosity silicone oil

BACKGROUND

To compare intraocular pressure (IOP) measurements using Goldmann applanation tonometer (GAT) and air tonometer (non-contact tonometry [NT]) in vitrectomized eyes with high-viscosity silicone oil tamponade, as well as in normal eyes.

PATIENTS AND METHODS

In this prospective comparative study, 32 eyes with silicone oil tamponade of high viscosity (5700 CS) and 32 normal fellow eyes were included. IOP was measured by GAT and air tonometer 30 ± 12 days after vitrectomy, while measurements of central corneal thickness (CCT) were also obtained.

RESULTS

In eyes with silicone oil, IOP was 20.09 ± 4.91 mmHg and 16.75 ± 3.86 mmHg using contact tonometer and air tonometer, respectively (p < 0.0001). In normal eyes, IOP was 16.41 ± 2.15 mmHg and 16.31 ± 2.49 mmHg using the same tonometry techniques and this difference was not statistically significant (p = 0.598). In addition, no significant correlation was detected between IOP measurements using both techniques and age, gender, CCT, and type of lens.

CONCLUSIONS

It seems that GAT overestimates IOP in eyes with high-viscosity silicone oil compared with NT, while both IOP measurement techniques in normal eyes provide similar values. Further assessment of available IOP measurement methods could possibly establish the most accurate technique for IOP estimation in vitrectomized eyes with silicone oil tamponade.

Influence of Vitrectomy-related Factors on the Outcome of Ahmed Glaucoma Valve Implantation

Purpose

To evaluate the outcome of Ahmed glaucoma valve (AGV) implantation in eyes with refractory secondary glaucoma following pars plana vitrectomy (PPV) and the associated prognostic factors.

Methods

A total of 146 eyes in 146 patients who underwent AGV implantation after PPV (followed up for ≥1 year) were included. AGV implantation was considered successful when the intraocular pressure (IOP) was 6 to 21 mmHg regardless of using IOP-lowering medication. The hazard ratios (HRs) associated with surgical failure were determined with Cox proportional analysis.

Results

The most common cause for PPV was complications of proliferative diabetic retinopathy (50%). The mean and peak IOPs between PPV and AGV implantation were 26.9 ± 6.6 and 35.9 ± 10.2 mmHg, respectively. AGV implantation was performed on average 18.7 months after PPV, and its overall success rate was 80.1% during a mean follow-up period of 43.6 months. In multivariate analyses, rubeosis observed before AGV implantation (HR, 4.07; 95% confidence interval, 1.57 to 10.6; p = 0.004) and higher peak IOP before AGV (HR, 1.04; 95% confidence interval, 1.00 to 1.07; p = 0.034) were predictive of failure. However, no PPV-related factors were associated with the surgical outcome of AGV implantation.

Conclusions

The outcome of AGV implantation is good in refractory glaucoma following PPV. Rubeosis after PPV and higher peak IOP before AGV are risk factors for poor outcomes. Patients who undergo PPV should be followed for the development of rubeosis and IOP control.

Positional Intraocular Pressure of Vitrectomized and Normal Fellow Eyes

Purpose

To compare posture-induced intraocular pressure (IOP) changes in vitrectomized eyes and normal eyes of patients who had vitrectomy in one eye.

Methods

A total of 31 patients older than 20 years of age who underwent vitrectomy were enrolled in the study. At least six months after vitrectomy, we measured IOP in both eyes using a rebound tonometer 10 minutes after the patient assumed sitting, supine, right lateral decubitus, and left lateral decubitus positions. Patients with a history of ocular surgery (not including vitrectomy) or recent medication use associated with IOP were excluded. IOP and ocular parameters of vitrectomized and normal fellow eyes were compared. For the decubitus position, IOP values of dependent and nondependent eyes were compared.

Results

No significant difference was observed in IOP between vitrectomized and normal eyes in the sitting and supine positions. The IOP for dependent eyes (on the lower side in the lateral decubitus position) was significantly higher than the IOP for nondependent eyes in both right lateral decubitus (right vitrectomized eye 19.31 ± 4.20 vs. 16.71 ± 4.02 mmHg, p < 0.001; left vitrectomized eye 18.35 ± 1.75 vs. 16.04 ± 3.02 mmHg, p = 0.003) and left lateral decubitus (right vitrectomized eye 17.32 ± 4.63 vs. 19.15 ± 3.83 mmHg, p = 0.004; left vitrectomized eye 16.19 ± 1.81 vs. 18.12 ± 2.29 mmHg, p < 0.001) positions.

Conclusions

IOP was higher in the dependent than the nondependent eye in the lateral decubitus position, for both vitrectomized and nonoperated eyes.

Complications Associated with the Use of Expandable Gases in Vitrectomy

Intraocular gases have been used in vitreoretinal surgery for over 40 years. The aim of this study was to review the complications related to the use of expandable gases in vitrectomy and their management. A PubMed, Cochrane Library, and Embase search was conducted using the terms "intraocular gas" and "vitrectomy for retinal detachment." Of the articles retrieved by this method, all publications in English and abstracts of non-English publications were reviewed. Intraocular pressure elevation was reported in up to 58.9% patients after vitrectomy with expandable gas administration for retinal detachment. Vitreoretinal surgery is known to induce cataract development. With that, cataract progression is associated with lens exposure to intraocular gas, the duration of such exposure, patient's age, and the magnitude of vitreous removal. With intraocular gas, the posterior surface of the lens becomes a strongly refractive factor, resulting in high myopia and temporary vision impairment. Other complications related to the use of expandable gases include anterior chamber and subconjunctival gas displacement. Single reports on subretinal and cranial gas migration were published. In vitrectomy for uncomplicated retinal detachments, attempts to shift from expandable gases towards air are observed. Nevertheless, gas tamponade remains a reasonable choice for patients suffering from retinal detachment.

Ahmed Glaucoma Valve Implantation in Vitrectomized Eyes

Purpose

To evaluate the outcomes of Ahmed glaucoma valve (AGV) implantation in vitrectomized eyes.

Materials and Methods

The medical records of 13 eyes that developed glaucoma due to emulsified silicon oil or neovascularization following pars plana vitrectomy and underwent AGV implantation were retrospectively reviewed. The main outcome measures were intraocular pressure (IOP), best-corrected visual acuity (BCVA), number of antiglaucoma medications, and postoperative complications. Surgical success was defined as last IOP ≤21 mmHg or ≥6 mmHg and without loss of light perception.

Results

The mean follow-up duration was 11.7 ± 5.5 (range, 6–23) months. The mean IOP before the AGV implantation was 37.9 ± 6.7 mmHg with an average of 3.5 ± 1.2 drugs. At the final visit, the mean IOP was 15.9 ± 4.6 mmHg (p=0.001) and the mean number of glaucoma medications decreased to 2.3 ± 1.3 (p=0.021). At the last visit, 11 eyes (84.4%) had stable or improved VA and one eye (7.7%) had a final VA of no light perception. Surgical success was achieved in 11 of the 13 eyes (84.4%). Postoperative complications were bleb encapsulation (69.2%), early hypotony (38.5%), hyphema (23.1%), decompression retinopathy (23.1%), choroidal detachment (15.4%), intraocular hemorrhage (7.7%), and late endophthalmitis (7.7%). One eye (7.7%) was enucleated because of late endophthalmitis.

Conclusions

Despite complications necessitating medical and surgical interventions, vitrectomized eyes were effectively managed with AGV implantation.

AIR TAMPONADE COMBINED WITH NONSUPINE POSITIONING IN MACULAR HOLE SURGERY FOR PSEUDOPHAKIC EYES

PURPOSE

To investigate the closure rate of primary full-thickness macular hole, following intraocular air tamponade combined with a nonsupine positioning regimen.

METHODS

A prospective study of patients with full-thickness macular hole, who underwent pars plana vitrectomy with internal limiting membrane peeling and intraocular air tamponade followed by 3 days of nonsupine positioning. Outcome measures were primary full-thickness macular hole closure and improvement in best-corrected visual acuity after 6 months.

RESULTS

A total of 34 eyes were included. In the group of full-thickness macular hole ≤400 μm, primary closure occurred in 95% (19/20), whereas only 57% (8/14) of those >400 μm closed (P = 0.01). The mean gain in best-corrected visual acuity was 3.5 ETDRS (Early Treatment Diabetic Retinopathy Study) lines (SD = 1.5) (P < 0.01). The air bubble meniscus height at the first postoperative day was estimated to a mean of 59% (range, 50-70%), at the second postoperative day it was 46% (range, 40-55%), and the third day it was 39% (range, 30-45%). Mean intraocular air bubble duration was 10 days (range, 8-13 days).

CONCLUSION

The combination of air tamponade and nonsupine positioning regimen leads to high closure rates for small/medium macular holes (≤400 μm), but not for large macular holes (>400 μm).