Faster recovery after 25-gauge microincision vitrectomy surgery than after 20-gauge vitrectomy in patients with proliferative diabetic retinopathy

Differential distribution of fibrovascular proliferative membranes in 25-gauge vitrectomy for proliferative diabetic retinopathy

AIM

To analyze the distribution of fibrovascular proliferative membranes (FVPMs) in proliferative diabetic retinopathy (PDR) patients that treated with pars plana vitrectomy (PPV), and to evaluate the outcomes separately.

METHODS

This was a retrospective and cross-sectional study. Consecutive 25-gauge (25-G) PPV cases operated for PDR from May 2018 to April 2020. According to the FVPMs images outlined after operations, subjects were assigned into three groups: arcade type group, juxtapapillary type group, and central type group. All patients were followed up for over one year. General characteristics, operation-related variables, postoperative parameters and complications were recorded.

RESULTS

Among 103 eyes recruited, the FVPMs distribution of nasotemporal and inferiosuperioral was significantly different (both P<0.01), with 95 (92.23%) FVPMs located in the nasal quadrants, and 74 (71.84%) in the inferior. The eyes with a central FVPM required the longest operation time, with silicon oil used in most patients, generally combined with tractional retinal detachment (RD) and rhegmatogenous RD, the worst postoperative best-corrected visual acuity (BCVA) and the highest rates of recurrent RD (all P<0.05). FVPM type, age of onset diabetes mellitus, preoperative BCVA, and combined with tractional RD and rhegmatogenous RD were significantly associated with BCVA improvement (all P<0.05). Compared with the central type group, the arcade type group had higher rates of BCVA improvement.

CONCLUSION

FVPMs are more commonly found in the nasal and inferior mid-peripheral retina in addition to the area of arcade vessels. Performing 25-G PPV for treating PDR eyes with central FVPM have relatively worse prognosis.

DIAGNOSTIC YIELD OF IN VITRO VITREOUS BIOPSY FOR INTRAOCULAR LYMPHOMA AT VARIABLE VITREOUS CUTTER SPEEDS USING 25-GAUGE VITRECTOMY

PURPOSE

Primary vitreoretinal lymphoma is the most common intraocular lymphoproliferative disorder. We evaluated the diagnostic yield of pars plana vitrectomy, specifically using modern high cut rate dual-cycle cutters, on in vitro cell viability and diagnostic yield.

METHODS

Human Burkitt lymphoma cell line Namalwa at 2 x 10^5 cells/mL was aspirated by 25-gauge dual-blade guillotine-type vitrectomy at five speeds (500, 1,000, 4,000, 7,500, or 15,000 cuts per minute). Cell viability and diagnostic yield in each subtype group were determined using hemocytometry, viable cell count using Cell Counting Kit-8, and pathologist-guided manual count.

RESULTS

No significant deviation in cell count was identified in any cut rate by ANOVA ( P = 0.61), and no trends in the number of viable cells were identified across cut rates (R 2 = 0.188, P = 0.47). Among histologic cell counts per cut-rate, neither linear regression (R = 0.531, P = 0.16) nor ANOVA ( P = 0.096) were statistically significant.

CONCLUSION

There was no significant degradation in the number of viable cells with increasing cut speed. These results suggest that in contrast to previous findings using 20g or 23g vitrectomy for diagnostic vitrectomy, modern vitrectomy systems may be used at up to 15,000 cpm without compromising the viability of lymphoma cells.

A Systematic Review and Meta-Analysis of Clinical Outcomes of Small Gauge Vitrectomy with or without Intravitreal Anti-Vascular Endothelial Growth Factor Agents Pretreatment for Proliferative Diabetic Retinopathy

BACKGROUND

Proliferative diabetic retinopathy (PDR) is a common visual threatening ocular disease, patients with nonclearing vitreous hemorrhage (VH), tractional retinal detachment (RD), or extensive fibrovascular proliferation are always in need for surgical treatment. Although several studies reported better surgical outcome in patients underwent surgery after anti-VEGF injection, the effect of anti-VEGF pretreatment for small gauge vitrectomy in PDR patients remains to be elucidated.

OBJECTIVES

The objective of the study was to evaluate the benefits of preoperative anti-VEGF treatment in small gauge vitrectomy for PDR patients.

METHODS

A comprehensive literature search in PubMed, Embase, and the Cochrane Central Register of Controlled Trials was performed to identify relevant studies. Meta-analyses were performed for intraoperative (including intraoperative bleeding, endodiathermy, iatrogenic retinal breaks, surgical time, etc.) and postoperative outcome parameters (including best-corrected visual acuity (BCVA), postoperative VH, postoperative RD, etc.).

RESULTS

Ten randomized controlled trials were identified and used for comparing small gauge vitrectomy alone (344 eyes, control group) and small gauge vitrectomy with preoperative anti-VEGF injection (355 eyes). The intraoperative findings showed that the surgical time, the incidence of clinically significant intraoperative bleeding, iatrogenic retinal breaks, silicone oil tamponade, and the frequency of endodiathermy were significantly less in the anti-VEGF pre-treated group than in the vitrectomy alone group (p < 0.01). The postoperative findings showed that the incidences of early postoperative VH, postoperative RD were significantly less in the anti-VEGF pre-treated group than in the control group (p < 0.05). The pooled result of postoperative rubeosis iridis/neovascular glaucoma was borderline (p = 0.072) between cases and controls, while no statistically significant differences in BCVA at last follow-up and incidences of late postoperative VH were found between these two groups (p > 0.05).

CONCLUSIONS

Anti-VEGF injection prior to small gauge vitrectomy in PDR patients might facilitate easier surgical procedure and reduce intra- and postoperative complications. Further studies are needed to verify our findings and evaluate the optimal interval and dosage for preoperative anti-VEGF injection.

FLUIDIC PERFORMANCE OF A DUAL-ACTION VITRECTOMY PROBE COMPARED WITH A SINGLE-ACTION PROBE

PURPOSE

To assess flow rates, nearfield effects, and traction of a dual-cutting 20,000 cpm vitrectomy probe (HYPERVIT, Alcon) versus a single-cutting 10,000 cpm probe (Advanced ULTRAVIT, Alcon).

METHODS

Flow rates were evaluated for 25+ and 27+ gauge probes using balanced salt solution or porcine cadaver vitreous (biased open, 50/50, and biased closed duty cycles). Probes were suspended in an open beaker, and flow rates were calculated using a precision balance. Nearfield effects and flow pulsatility were assessed using a validated simulation model based on experimental microparticle image velocimetry. Traction was assessed by attaching vitreous to a cantilever beam and measuring the deflection of the beam.

RESULTS

For HYPERVIT probes, aqueous flow rates were similar across all cutting rates. Vitreous flow rates increased with increasing cutting rates. At maximum cutting rates, aqueous flow was 62%-67% greater (25+) and 63% greater (27+) with HYPERVIT versus Advanced ULTRAVIT ( P < 0.05); vitreous flow was 44%-47% greater (25+) and 26%-32% greater (27+) with HYPERVIT versus Advanced ULTRAVIT ( P < 0.05). Nearfield effects were reduced, and peak traction forces were significantly lower for HYPERVIT versus Advanced ULTRAVIT ( P < 0.05).

CONCLUSION

Significantly greater aspiration flow, reduced nearfield effects, and reduced traction were observed with dual-action versus single-action probes.

Potential bias of preoperative intravitreal anti-VEGF injection for complications of proliferative diabetic retinopathy

PURPOSE

Intravitreal anti-VEGF injection (IVI) is administered before vitrectomy to assist management of proliferative diabetic retinopathy (PDR)-related complications. In the clinical setting, retinal surgeons determine the use of preoperative IVI based on individual criteria. In this study, we investigated factors related to the potential bias of retinal surgeons in using IVI prior to vitrectomy for PDR-related complications, and evaluated the real-world outcomes of surgeon-determined preoperative IVI.

METHODS

Medical records of 409 eyes of 409 patients who underwent 25-gauge vitrectomy for PDR complications at seven Japanese centers (22 surgeons) were retrospectively reviewed. Ocular factors, demographic and general clinical factors, surgical procedures, and postoperative complications were compared between IVI group (patients who received preoperative IVI; 87 eyes, 21.3%) and non-IVI group (patients who did not receive preoperative IVI; 322 eyes, 78.7%). In addition, baseline HbA1c in IVI group and non-IVI group was compared between eyes with and without postoperative complications.

RESULTS

At baseline, IVI group was younger (P<0.001), had shorter duration of diabetes treatment (P = 0.045), and higher frequencies of neovascular glaucoma [NVG] (P<0.001) and tractional retinal detachment [TRD] (P<0.001) compared to non-IVI group. Although IVI group had higher frequencies of intraoperative retinal break and tamponade procedure, there were no significant differences in postoperative complications and additional treatments between two groups. Baseline HbA1c levels were also not correlated with postoperative complications of VH, NVG, and RD both in IVI group and non-IVI group. Logistic regression analysis identified age (P<0.001, odds ratio [OR] 0.95), presence of NVG (P<0.001, OR 20.2), and presence of TRD (P = 0.0014, OR 2.44) as preoperative factors in favor of IVI.

CONCLUSIONS

In this multicenter real-world clinical study, younger age and presence of NVG and TRD were identified as potential biases in using IVI before vitrectomy for PDR complications. Eyes that received preoperative IVI had more intraoperative retinal breaks requiring tamponade than eyes not receiving IVI, but postoperative outcome was not different between the two groups.

Outcomes of 25-gauge pars plana vitrectomy for cytomegalovirus retinitis-related retinal detachment

Purpose:

The purpose of this study is to evaluate the anatomical and functional outcomes of 25-gauge (G) pars plana vitrectomy (PPV) in patients with cytomegalovirus retinitis (CMVR)-related rhegmatogenous retinal detachment (RRD).

Methods:

Single-center retrospective consecutive case series of patients who underwent 25-G PPV for CMVR-related RRD repair with a minimum follow-up of 3 months. Complete anatomic success was defined as the complete attachment of retina including the periphery. Best-corrected visual acuity (BCVA) of ≥20/400 was defined as functional success.

Results:

Sixteen eyes of 15 patients were included in the study. Eleven patients were human immunodeficiency virus positive, three patients had hematological malignancies, and one patient suffered from dyskeratosis congenita. The mean follow-up was 20.5 ± 17.4 months (range 3–60 months). Complete anatomical success was seen in 15 eyes (93.75%). One eye had a residual inferior detachment with attached macula. Silicone oil was used as tamponade in 15 eyes and C₃F₈ gas in one eye. The mean change in BCVA was statistically significant, preoperative LogMAR BCVA was 2.05 ± 0.94 while the final follow-up postoperative LogMAR BCVA was 1.03 ± 0.61 (P < 0.001). Thirteen eyes (81.25%) had final BCVA ≥20/400.

Conclusion:

Microincision vitrectomy surgery can achieve excellent retinal reattachment rates in post-CMVR RRDs without significant intraoperative and postoperative complications. The visual outcome varies depending on the status of the optic disc and macula. Majority of the patients maintained functional vision.

Pars plana vitrectomy in uveitis in the era of microincision vitreous surgery

Pars plana vitrectomy (PPV) in uveitis is indicated for various diagnostic and therapeutic indications. With the advent of microincision vitreous surgery (MIVS), the use of PPV in uveitis has increased with a wider spectrum of indications due to shorter surgical time, less patient discomfort, less conjunctival scarring, and a decreased rate of complications as compared to standard 20G vitrectomy. Because of faster post-operative recovery in terms of visual improvement and reduction of inflammation, and reduced duration of systemic corticosteroids, MIVS has gained popularity in uveitis as an adjunctive therapy to the standard of care medical therapy. The safety and efficacy of MIVS is related to the emerging vitrectomy techniques with better and newer cutters, illuminating probes, and accessory instruments. Because of the instrumentation and fluidics of MIVS, PPV is emerging as a safe and useful alternative for diagnostic challenges in uveitis, aiding in earlier diagnosis and better outcome of inflammatory disease, even in the presence of severe and active inflammation, which was once considered a relative contraindication for performing vitreous surgery. However, for surgical interventions for therapeutic indications and complications of uveitis, it is advisable to achieve an optimum control of inflammation for best results. The increasing reports of the use of MIVS in uveitis have led to its wider acceptance among clinicians practicing uveitis.

Outcomes of 25-gauge pars plana vitrectomy with encircling scleral band for acute retinal necrosis-related rhegmatogenous retinal detachment

Purpose

The aim of this study was to evaluate the anatomic and functional outcomes of 25-gauge pars plana vitrectomy (25G PPV) with encircling scleral band (ESB) in patients with acute retinal necrosis (ARN)-related rhegmatogenous retinal detachment (RRD).

Methods

Single-center retrospective interventional case series of patients who underwent 25G PPV with ESB for ARN-related RRD. Complete anatomic success was defined as the complete attachment of retina after primary PPV. Functional success was measured by the final best-corrected visual acuity (BCVA) ≥20/400. Intraoperative and postoperative complications were also noted.

Results

14 eyes of 13 patients were included in the study. Six patients (46.1%) were immunocompromised. The mean follow-up was 23.64 ± 9.95 (range 6-42) months. Silicone oil was used as tamponade in 13 eyes and C3F8gas in one eye. After the primary PPV, complete anatomical success was seen in all eyes (100%), however, one eye developed phthisis bulbi after silicone oil removal (SOR). Statistically significant improvement of BCVA was seen, from LogMAR 2.03 ± 0.29 preoperatively to LogMAR 1.57 ± 0.63 postoperatively (p-value 0.014). Six eyes (42.9%) had functional success. Nine eyes (64.3%) had improvement in vision while 4 eyes (28.6%) maintained preoperative vision. 10 eyes (71.4%) underwent cataract surgery, nine eyes (64.3%) underwent SOR while 2 eyes (14.3%) had epiretinal membrane (ERM) under oil during follow-up.

Conclusion

25G PPV combines the advantages of minimally invasive vitrectomy surgery while offering improved anatomic outcomes in patients with ARN-related RRD. The functional outcome varies depending on the status of the optic disc and macula.

Recent trends in vitreoretinal surgery: a nationwide database study in Japan, 2010-2017

PURPOSE

We clarified recent trends in vitreoretinal surgery in Japan, which is a rapidly aging country.

STUDY DESIGN

Retrospective cohort study.

METHODS

We used the Diagnostic Procedure Combination database (2010-2017), a national inpatient database in Japan. Patients undergoing vitreoretinal surgery were included. We measured the number of surgeries stratified by procedures, diagnoses, age categories, and combined cases of cataract surgery per fiscal year. We also considered changes in the Japanese population.

RESULTS

From 2010 to 2017, the total number of vitreoretinal surgeries per fiscal year increased by 7.8% (from 36,988 to 39,873). Among the diagnoses categories, epiretinal membrane (ERM) increased by 71%, rhegmatogenous retinal detachment (RRD) with pars plana vitrectomy (PPV) by 50%, and macular hole (MH) by 12% throughout the observed period. Diabetic retinopathy (DR) decreased by 20%, RRD with scleral buckling (SB) by 40%, and vitreous hemorrhage (VH) by 10%. We observed remarkable increases in ERM among patients in their 60s and 70s, in MH in their 70s and 80s, and in RRD with PPV in their 50s and 60s. We observed remarkable decreases in RRD with SB in patients in their 20s-70s, in DR in their 60s, and in VH in their 60s and 70s. These findings did not change greatly when population changes were considered. All age groups from the 30 to 80s showed significant increases in the proportions of combined vitreoretinal and cataract surgery.

CONCLUSION

The total number of cases of vitreoretinal surgery per fiscal year increased throughout the period. The increases in ERM and RRD with PPV and the decreases in DR and RRD with SB were remarkable.

Prognostic factors of revitrectomy for complications in eyes with proliferative diabetic retinopathy: a retrospective multicentre study

PURPOSE

To identify prognostic factors for revitrectomy in patients who underwent vitrectomy for complications with proliferative diabetic retinopathy (PDR) in multicentre study.

METHODS

Consecutive 452 eyes of 452 patients with PDR undergoing 25-gauge microincision vitrectomy system (MIVS) in seven centres were retrospectivity reviewed. Preoperative ocular factors (baseline visual acuity [VA], vitreous haemorrhage [VH], tractional retinal detachment [TRD] and retinal photocoagulation), general factors (sex, age, diabetes duration, HbA1c level, hypertension, anti-coagulant medication and estimated glomerular filtration rate), surgical procedures (preoperative anti-vascular endothelial growth factor injection, internal limiting membrane peeling, combined cataract surgery, retinal break, and tamponade), postoperative complications for revitrectomy and postoperative VA at 6 months were evaluated.

RESULTS

In the follow-up period of 6 months, revitrectomy was performed in 56 eyes (26.3%), and postoperative complications for revitrectomy were VH in 31 eyes (15%), TRD in 13 eyes (6.2%) and membrane proliferation in 12 eyes (5.2%). The mean LogMAR improvement from baseline to 6 months in revitrectomy group (0.39) was significantly worse than in single vitrectomy group (0.74). Diabetic duration, low baseline VA, less simple VH, TRD and air tamponade were statistical risk factors of revitrectomy, and logistic regression analysis identified low baseline VA and air tamponade also as prognostic factors of revitrectomy.

CONCLUSION

Our results indicated that prognosis of VA was worse in PDR patients with revitrectomy and low baseline VA and air as the tamponade material were the potential prognostic factors of revitrectomy.

Prospective Comparison of Intraocular Lens Dynamics and Refractive Error between Phacovitrectomy and Phacoemulsification Alone

PURPOSE

To compare intraocular lens (IOL) dynamics and refractive prediction errors between eyes that underwent phacovitrectomy and eyes that underwent phacoemulsification alone.

DESIGN

Prospective, nonrandomized, comparative, observational study.

PARTICIPANTS

Sixty eyes of 60 patients who underwent 25-gauge phacovitrectomy without gas injection for macular pathology and 60 eyes of 60 patients who underwent phacoemulsification alone for cataract were enrolled.

METHODS

Preoperative optical biometry was performed using the IOLMaster 700 (Carl Zeiss Meditec, Inc, Dublin, CA) to calculate the IOL power with the Barrett Universal II formula. Monofocal, nontoric, single-piece foldable aspherical IOLs were implanted in each patient. Comprehensive ocular examinations, including CASIA2 (Tomey Corp, Nagoya, Japan) evaluations of the preoperative crystalline lens and postoperative IOL positions (i.e., decentration, tilt, and aqueous depth), were performed before and 3 days, 1 month, and 3 months after surgery.

MAIN OUTCOME MEASURES

Refractive prediction errors and IOL dynamics.

RESULTS

Mean refractive prediction errors at 3 days, 1 month, and 3 months after phacovitrectomy were 0.51±0.59 diopters (D), 0.11±0.40 D, and 0.05±0.41 D, respectively, whereas those after phacoemulsification alone were 0.43±0.38 D, 0.11±0.37 D, and 0.07±0.34 D, respectively. There was no significant difference in the refractive error between the 2 groups at any time point. A myopic shift of -0.50 D or more negative refractive error occurred in 4 (6.7%) of 60 eyes with phacovitrectomy and 3 (5.0%) of 60 eyes with phacoemulsification alone; there was no significant between-group difference. At 3 months postoperatively, refractive errors within ±0.50 D and ±1.00 D were achieved in 49 (81.7%) and 58 (96.7%) of 60 eyes in the phacovitrectomy group and 52 (86.7%) and 60 (100.0%) of 60 eyes in the phacoemulsification alone group, again without any significant between-group differences. There were no significant differences in the preoperative lens and postoperative IOL positions between the 2 study groups, except for a significantly deeper mean aqueous depth at 3 days after surgery in the phacovitrectomy group.

CONCLUSIONS

Neither myopic shift nor IOL displacement occurs after 25-gauge phacovitrectomy with a single-piece IOL without gas injection for macular pathology compared with phacoemulsification alone.

Outcomes of 25-Gauge Vitrectomy for Tractional and Nontractional Diabetic Macular Edema with Proliferative Diabetic Retinopathy

The benefit of pars plana vitrectomy with internal limiting membrane peeling for tractional macular edema and diffuse nontractional macular edema in diabetic retinopathy has been reported. Although these studies had included various stages, use of conventional 20-gauge vitrectomy system, small number of cases, single-center study, and lack of retinal structure measurements were limitations. We compared one-year outcomes of 25-gauge vitrectomy for refractory diabetic macular edema with or without the tractional proliferative membrane in proliferative diabetic retinopathy (PDR) eyes and examined the prognostic factors for postoperative visual acuity. A total of consecutive 116 PDR eyes of 116 patients that underwent 25-gauge vitrectomy for tractional macular edema (TME group: 56 eyes) or nontractional macular edema (nTME group: 60 eyes) at six centers were retrospectively reviewed. Visual acuity (VA), central macular thickness (CMT), complications, and postoperative treatments before and 12 months after vitrectomy were compared. Mean VA improved significantly in each group (both P < 0.01), and mean CMT decreased significantly in each group (both P < 0.01). Thirteen eyes underwent additional vitrectomy, six eyes developed neovascular glaucoma, six eyes received intravitreal anti-VEGF injection, and thirteen eyes received subtenon triamcinolone acetonide injection. Multiple linear regression analysis showed that baseline VA and CMT in the TME group and kidney function in the nTME group were the predictable factors of the 12-month postoperative VA. Twenty-five-gauge vitrectomy effectively improved VA and macular structure both in TME and nTME groups. Baseline VA, CMT, and kidney function are important factors affecting postoperative VA.

Surgical Factors Affecting Changes in Ocular Surface Dynamics in the Early Postoperative Period After 25-Gauge Vitrectomy

OBJECTIVES

Because vitrectomy-associated postoperative ocular surface changes are not well known, we evaluated such changes before and after vitrectomy in eyes with posterior segment diseases and investigated their associations with patients' characteristics and surgical procedures.

METHODS

Thirty-five eyes of 32 consecutive patients (16 women; average age 66.6±11.1 years) were included in this prospective, noncomparative case series from tertiary care university hospital. Contact lens wearers and patients with history of ocular surgery or regular use of topical eyedrops were excluded. Patients had undergone primary 25-gauge vitrectomy at Osaka University Hospital in Japan between July and December 2016. Tear break-up time (TBUT), corneal and conjunctival fluorescein staining score (FSS), and tear meniscus height (TMH) were evaluated before, 1 week after, and 1 month after vitrectomy.

RESULTS

Conjunctival FSS and TMH were significantly higher at 1 week after vitrectomy than preoperatively. However, they decreased significantly 1 month after. Changes in TBUT and corneal FSS showed a similar course at 1 week, but this was not statistically significant. Multiple linear regression analysis showed no significant correlation between significantly increased ocular parameters and patients' characteristics. By contrast, surgical time and combined cataract surgery significantly contributed to increased and decreased conjunctival FSS, respectively (P=0.011 and 0.033, respectively). Sclerotomy site suturing significantly contributed to increased TMH (P=0.025).

CONCLUSIONS

We showed associations between ocular surface changes and specific surgical procedures. Caution should be exercised to minimize the effect of surgical procedures on the ocular surface during vitrectomy.

Surgical management of diabetic tractional retinal detachments

Tractional retinal detachment is an end-stage form of diabetic retinopathy that occurs when contractile forces in the vitreous and neovascular tissue lead to the detachment of the neurosensory retina. We review the literature related to the management of this disease. Preoperative planning includes appropriate patient selection, diagnostic and prognostic imaging, and medical optimization with reduction of systemic risk factors. Use of antivascular endothelial growth factor for preoperative treatment has had significant benefits for tractional retinal detachment repair in improving surgical efficiency and outcomes. Advances in microsurgical instrumentation are discussed, with attention to small-gauge vitrectomy with improved flow dynamics, viewing strategies, and lighting allowing bimanual surgery. Special emphasis is placed on bimanual surgical technique, choice of tamponade, and the avoidance of iatrogenic damage. Complications and special considerations are further explored. Based on our compilation of relevant literature, we propose a surgical algorithm for the management of these complex patients.

Application of Laser Flare Photometry in the Quantification of Blood-Aqueous Barrier Breakdown after Micro-incision Vitrectomy

Purpose: The purpose of the study is to quantify aqueous flare using laser flare photometry (LFM) in patients undergoing 25-G pars plana vitrectomy (PPV) and assess the need for postoperative topical corticosteroid administration . Methods: Prospective evaluation of 50 eyes (50 patients) was performed using LFM until day 30 postoperative. Duration of surgery, indication of PPV, and use of laser and/or cryotherapy were noted. Topical corticosteroids were used if mean LFM values were >50, or if there was anterior chamber fibrin. Results: Mean age of the subjects was 48.62 ± 10.07 years. The preoperative LFM value for 50 subjects was 17.42 ± 25.20. Topical corticosteroids were initiated in only 22 patients. The LFM values of subjects were not different from baseline at 1 month whether or not the subjects received corticosteroids (p > 0.106). Conclusions: With 25-G PPV, there is minimal breakdown of blood-aqueous barrier. LFM helps in monitoring postoperative inflammation, obviating the need for topical corticosteroids in significant number of patients.

Soloist performance of vitrectomy probe in proliferative diabetic retinopathy

Purpose:

To evaluate the feasibility and outcomes of the sole use of 23g pars plana vitrectomy in cases with diabetic vitreous hemorrhage with vitreoretinal traction.

Methods:

Prospective interventional case series involving patients between January 2013 and January 2018. All eyes underwent 23g pars plana vitrectomy with internal tamponade. Intraoperative parameters including ancillary instruments, the methods used for hemostasis and complications were all recorded. Postoperative parameters including anatomic success rate, functional success, and postoperative complications were recorded and analyzed. Patients were followed up for at least 12 months.

Results:

A total of 68 eyes of 66 patients were included. Intraoperative ancillary instruments were required in 5 (7.4%) eyes. None of the cases required the use of chandelier illumination, endodiathermy, or scissors. Mean best-corrected visual acuity improved significantly from LogMAR 1.67 ± 0.63 preoperative to 1.22 ± 0.38 at 1-year follow-up (P = 0.005). Functional success was achieved in 37 (54.4%) eyes at 1-year follow-up. Iatrogenic breaks occurred in 3 (4.4%) eyes, vitreous hemorrhage in 4 (5.9%) eyes, and epiretinal membranes in 3 (4.4%) eyes. Repeated vitrectomy was done in 3 (4.4%) eyes.

Conclusion:

The 23g vitrectomy probe proved to be a safe, effective, and beneficial single tool that could accomplish the diabetic vitrectomy mission exclusively with minimal aid from other instruments in cases with vitreous hemorrhage associated with vitreoretinal traction.

Dellen formation as a complication of subconjunctival silicone oil following microincision vitrectomy

Purpose

To study the subconjunctival silicone oil (SCSO) parameters associated with dellen formation following microincision vitrectomy (MIV).

Patients and methods

This was a case-control study of 20 eyes with SCSO following MIV. Ten of them suffered postoperative dellen formation. Dellen occurrence, their sizes, number of loci, and distance between SCSO and the limbus were recorded. The outcome after silicone-oil removal was evaluated.

Results

The SCSO was at 3.1±1.2 mm from the limbus. All cases with dellen had SCSO within 2 mm of the limbus (P<0.001). No other factors were found to be associated with dellen formation (age, P=0.414; sex, P=0.656; laterality, P=1; indication for pars plana vitrectomy, P=0.655; instrument gauge, P=0.211; circumference involved by SCSO, P=0.252). All the dellen healed after surgical evacuation of SCSO (P<0.001), leaving scars.

Conclusion

Dellen can be associated with MIV secondary to SCSO near the limbus. Resolution with scarring occurred following SCSO evacuation. Therefore, SCSO should be evacuated as early as possible to avoid long-term peripheral corneal morbidity.

Characteristics of cases with postoperative vitreous hemorrhage after 25-gauge vitrectomy for repair of proliferative diabetic retinopathy

PURPOSE

The purpose of this study was to compare ocular and systemic parameters between proliferative diabetic retinopathy (PDR) cases with postoperative vitreous hemorrhage (PVH) and those without PVH after 25-gauge vitrectomy, and to investigate the predictors of PVH.

METHODS

The medical records of 106 eyes of 78 consecutive patients who underwent primary 25-gauge vitrectomy were reviewed.

RESULTS

The incidences of early and late PVH were found to be 18.9 % (20/106 eyes) and 17.9 % (19/106 eyes) respectively. On multiple logistic regression analysis, intraoperative bleeding from new vessels on the disc was identified as the most important factor, with the greatest odds ratio, for the development of early PVH (odds ratio = 3.395, P = 0.134), while the HbA1c level was identified as the most important significant factor, with the greatest odds ratio, for the development of late PVH (odds ratio = 1.403, P = 0.014).

CONCLUSIONS

Early PVH tends to occur in severe PDR cases, while late PVH tends to occur in cases with poor diabetic control.

Hydraulic Resistance of Vitreous Cutters: The Impact of Blade Design and Cut Rate

Purpose

To measure the hydraulic resistance (HR) of vitreous cutters equipped with a Regular guillotine Blade (RB) or double edge blade (DEB) at cut rates comprised between 0 and 12,000 cuts per minute (CPM) and compare it with vitreous fragment size. This was an in vitro experimental study; in vivo HR measure and vitreous sampling.

Methods

HR, defined as aspiration pressure/flow rate, was measured in balanced salt solution (BSS; Alcon, Fort Worth, TX) (in vitro) and during pars plana vitrectomy of 20 consecutive patients aged 18 to 65, undergoing macular surgery. HR was recorded at increasing cut rates (500–6000 CPM for the RB and 500–12,000 CPM for the DEB; 5 mL/min flow). Vitreous samples were withdrawn and analyzed with Western and collagen type II and IX immunostaining to evaluate protein size. The main outcome measures were hydraulic resistance (mm Hg/ml/min [±SD]) and optic density for Western blot and immunostaining.

Results

RB and DEB showed identical HR in BSS between 0 and 3000 CPM. Above 3000 CPM, RB HR steadily increased, and was significantly higher than DEB HR. Vitreous HR was also similar for the two blades between 0 and 1500 CPM. Above 1500 CPM, RB offered a significantly higher resistance. Western blot and immunostaining of vitreous samples did not yield a significant difference in size, regardless of blade type and cut rate.

Conclusions

DEB is more efficient, offering a lower HR than RB over 1500 CPM in human vitreous. There is no viscosity reduction as a function of cut-rate between 1500 and 12,000 CPM, as HR does not vary.

Translational Relevance

Future vitreous cutters will benefit of a DEB; optimal cut rate needs to be defined, and the simple increase of cut rate does not provide benefits after a certain limit to be assessed.

Visual outcome of 25-gauge microincision vitrectomy surgery in diabetic vitreous haemorrhage

Objective:

To assess the visual outcome and complications of 25-gauge micro incision vitrectomy surgery (MIVS) in diabetic vitreous haemorrhage.

Methods:

This Quasi Experimental study was conducted at LRBT, Tertiary eye care hospital Karachi, from February 2012 to January 2013. Sixty eyes of sixty patients with uncontrolled type II diabetes mellitus (DM) were included. There were 43 (71.7%) males and 17 (28.3%) females. Age range was 40 – 60 years. All randomly selected patients underwent 25-gauge sutureless micro incision vitrectomy surgery for diabetic vitreous haemorrhage. Main outcomes measured were best corrected visual acuity (BCVA) assessed with logMAR and post-operative complications. Follow ups were at one day, one week, one month, three months and six months post-operatively.

Result:

Best corrected visual acuity (BCVA) gradually improved in majority of subjects in each subsequent follow up visit. Preoperative visual acuity was 1.023 ±0.226 logMAR, which was improved after final follow up to 0.457±0.256 and P-value was < 0.001. Five patients developed recurrent vitreous haemorrhage during study period, one patient developed cataract (1.7%), one (1.7%) had ocular hypotony defined as intraocular pressure < 5 mmHg and one (1.7%) developed endophthalmitis.

Conclusion:

25-gauge micro incision vitrectomy surgery (MIVS) is an effective sutureless parsplana vitrectomy surgery which has good visual outcome in diabetic vitreous haemorrhage with minimum manageable complications.

Surgical outcomes of 25-gauge pars plana vitrectomy for diabetic tractional retinal detachment

PURPOSE

To evaluate the outcomes and complications of 25-gauge (G) pars plana vitrectomy (PPV) for repair of diabetic tractional retinal detachment (TRD).

METHODS

Retrospective review of consecutive, single-surgeon 25-G PPV cases between July 2007 and July 2014. Seventy eyes from 55 patients were operated on for diabetic TRD; all eyes were tamponaded with sulfur hexafluoride, octofluoropropane, silicone oil, or balanced salt solution. Mean age at surgery was 47.7 years (range 23-76 years), and mean length of follow-up was 713 days (range 90-2368 days; median 671 days). Primary outcomes included best-corrected visual acuity (BCVA), intraocular pressure (IOP), anatomic success, redetachment, and endophthalmitis.

RESULTS

Preoperatively, 49 eyes (70%) had a concurrent rhegmatogenous component (8 of which also had proliferative vitreoretinopathy (PVR)). Mean BCVA improved from logarithm of the minimal angle of resolution 1.59 (20/800, SD 0.88) to 0.68 postoperatively (20/100, 0.77), P-value<0.001. Mean IOP increased from 15.9 to 20 mm Hg 1 day after surgery. Elevated postoperative IOP (≥ 22 mm Hg) occurred in 25 eyes, and low IOP (≤ 5 mm Hg) occurred in 2 eyes. Primary reattachment was achieved in 63 eyes (90%), and final anatomical success occurred in 69 eyes (99%). There were no cases of endophthalmitis.

CONCLUSIONS

Twenty-five-G PPV repair was safe and effective in the repair of diabetic TRD, including eyes with a combined rhegmatogenous detachment or PVR. Gas, silicone oil, and balanced salt solution tamponading agents all proved to be efficacious in this surgical population.

Evaluation of microincision vitrectomy surgery using wide-viewing system for complications with ocular sarcoidosis

We evaluate the outcomes of microincision vitrectomy surgery (MIVS) using wide-viewing system for complications with ocular sarcoidosis resistance to medical treatment.Consecutive clinical records of 24 eyes (19 patients) with complications of ocular sarcoidosis underwent MIVS between April 2010 and December 2013 were retrospectively reviewed. MIVS and phacoemulsification were performed in 18 eyes and MIVS only in 6 eyes. Best-corrected visual acuity (BCVA), inflammation scores in the anterior segment and in the posterior segment, and central retinal thickness (CRT) of eyes with cystoid macular edema (CME) before surgery and after 1 week, 1, 3, 6, and 12 months were evaluated.LogMAR (log of the minimum angle of resolution) converted from BCVA was improved in 83.3% after 12 months and 66.7% showed improvement of more than 2 lines. The mean LogMAR was significantly improved from 1.14 ± 1.18 to 0.36 ± 0.79 in all eyes and 0.83 ± 0.86 to 0.23 ± 0.41 in eyes with MIVS and phacoemulsification, although no improvement was observed in eyes with MIVS only. Significant decrease of the mean anterior inflammation score was observed after 1 month in eyes with MIVS only and after 12 months in eyes with MIVS and phacoemulsification, and the mean posterior inflammation scores decreased after 1 week in all eyes. In eyes with preoperative CME, mean CRT was significantly decreased from 1 week after surgery. There was no case in which ocular inflammation was exacerbated by surgical stress. Improvement of visual acuity and resolution of ocular inflammation could be achieved by MIVS using wide-viewing system for complications of ocular sarcoidosis.

23-gauge versus 25-gauge vitrectomy for proliferative diabetic retinopathy: a comparison of surgical outcomes

PURPOSE

This study compared clinical outcomes and complications between 23-gauge (23g) and 25-gauge (25g) transconjunctival sutureless vitrectomy in patients with proliferative diabetic retinopathy.

STUDY DESIGN

It was a retrospective study using data prospectively defined and collected. 80 eyes underwent 23g transconjunctival sutureless vitrectomy, and 80 eyes underwent 25g surgery using the same vitrectomy system by one surgeon. Primary outcome measures were best-corrected visual acuity, intraocular pressure (IOP), and incidence of intraoperative and postoperative complications.

RESULTS

Vision was significantly improved after intervention in both groups (p ≥ 0.0001). There was no significant difference in visual outcomes between the groups (p = 0.43) or in the type and frequency of retinal breaks occurring during surgery (p = 0.63). The 23g group had significantly more patients with a day 1 IOP of <6 mm Hg (p = 0.034) and significantly more patients requiring a sclerostomy suture postoperatively (p = 0.014).

CONCLUSION AND MESSAGE

Both gauges are equally effective for the treatment of proliferative diabetic retinopathy.

Advances in diabetic retinopathy

Diabetic retinopathy (DR) is a complication of long-term diabetes mellitus (DM). Over the last 2 decades lot of work has been on early diagnosis of DR and screening programs have been designed to help the masses. Large numbers of clinical studies have been done for patients of diabetes and DR wherein the role of blood sugar control, metabolic control, role of oral medicines for DR, role of imaging, fluorescein angiography, and retinal photocoagulation has been studied. Newer treatment modalities are being devised and studied for better patient care. We discuss these issues in our review highlight and newer advances over the last few years.

25-Gauge pars plana vitrectomy for ciliary block (malignant) glaucoma

To evaluate the efficacy of 25-ga pars plana vitrectomy (PPV) and 25-ga PPV combined with phacoemulsification surgery for managing ciliary block (malignant) glaucoma. The medical records of 11 eyes, in nine consecutive patients with malignant glaucoma were retrospectively reviewed to determine the efficacy of 25-ga PPV for alleviating this disease. All phakic eyes underwent phacoemulsification surgery during vitrectomy. Control of intraocular pressure (IOP), pre- and postoperative best-corrected visual acuity (BCVA), and development of intra- and postoperative complications were evaluated during follow-up. Malignant glaucoma was promptly resolved, and recurrence was not observed during a mean follow-up period of 12.7 ± 3.2 (range 6-18) months. The mean IOP decreased from 35.9 ± 2.9 mmHg, preoperatively, to 16.0 ± 1.4 mmHg, measured at last visit (P = 0.013). Although IOP control was achieved in all eyes after surgery, two eyes required long-term topical antiglaucoma medication. The mean logarithm of the minimum angle of resolution BCVA improved from +0.69 ± 0.11, preoperatively, to +0.29 ± 0.07, postoperatively (P = 0.027). No severe intraoperative complications were observed. Postoperative complications mostly occurred during the first week after surgery, including transient corneal edema and Descemet's membrane folds in three eyes, fibrotic exudation in 2, local iris posterior synechia in 1, and transient hypotony in 1, which were resolved spontaneously or with medication. The 25-ga PPV procedure seems to be safe and effective for treating malignant glaucoma. Combined vitrectomy with phacoemulsification surgery and a staged surgical approach may improve the success rate.

Surgical management of diabetic retinopathy

Surgery for late complications of proliferative diabetic retinopathy remains the cornerstone of management even in patients who have received optimal laser photocoagulation and medical therapy. With improvisation in the surgical techniques and development of micro-incision surgical techniques for vitrectomy, the indications for surgical intervention are expanding to include diabetic macular edema with a greater number of patients undergoing early intervention. This review describes the current indications, surgical techniques, adjunctive anti-vascular endothelial growth factor therapy, surgical outcomes, and postoperative complications of pars plana vitrectomy for proliferative diabetic retinopathy and macular edema.