Nuclear sclerotic cataract after vitrectomy in patients younger than 50 years of age

Understanding cataract development in axial myopia: The contribution of oxidative stress and related pathways

Myopia is an evolving global health challenge, with estimates suggesting that by 2050 it will affect half of the world's population, becoming the leading cause of irreversible vision loss. Moreover, myopia can lead to various complications, including the earlier onset of cataracts. Given the progressive aging of the population and the increase in life expectancy, this will contribute to a rising demand for cataract surgery, posing an additional challenge for healthcare systems. The pathogenesis of nuclear and posterior subcapsular cataract (PSC) development in axial myopia is complex and primarily involves intensified liquefaction of the vitreous body, excessive production of reactive oxygen species, impaired antioxidant defense, and chronic inflammation in the eyeball. These factors contribute to disruptions in mitochondrial homeostasis, abnormal cell signaling, lipid peroxidation, protein and nucleic acid damage, as well as the induction of adverse epigenetic modifications. Age-related and oxidative processes can cause destabilization of crystallins with subsequent protein accumulation, which finally drives to a lens opacification. Moreover, an altered redox status is one of the major contributors to the pathogenesis of PSC. This review aims to summarize the mechanisms known to be responsible for the accelerated development of cataracts in axial myopia and to enhance understanding of these relationships.

Vision degrading myodesopsia from vitreous floaters in the young: An important aspect of myopia

Vitreous floaters are visual phenomena resulting from floating opacities inside the eye that disturb vision. The opacities consist of microscopic collagen fibers that aggregate in myopia and during aging. These collagen fibers are then seen as irregular, sometimes worm-like shadows or structures of a translucent to black color. Because of the floating aspect, they tend to follow the movements of the eye, causing distress and having a negative impact on a patient's quality of life due to degradation in contrast sensitivity function. This is referred to as vision degrading myodesopsia (VDM). The overall importance of floaters and their effect on quality of life gained attention in recent years. While the existence of floaters alone is labeled as harmless, there is an increasing group of young people suffering from VDM. This coincides with the growing prevalence of myopia. Indeed, myopia and myopic vitreopathy are the major causes of VDM in the young. This aspect of myopia, however, is often overlooked. We review the current research status in floater formation, quality of life impact, symptom assessment, localization and therapeutic options for vitreous floaters from the perspective of a myopic, potentially younger patient group.

Navigating Retinal Complications and Refractive Outcomes in High Myopia: A Case Report With Multi-surgical Interventions

Refraction through the ocular system is the process of bending light rays within the eye's optical system, which includes the cornea, anterior chamber, lens, and vitreous body. These structures work together to ensure precise focusing of light on the retina, enabling clear vision. Dysfunction or pathology at any level of the optical system can significantly affect the quality of vision, leading to changes in refractive status and visual acuity disturbances. A 58-year-old female patient presented to the Ophthalmology Clinic for a follow-up evaluation of her visual system after multiple previous surgeries, including radial keratotomy, multiple pars plana vitrectomies (PPV) due to recurrent retinal detachments, cataract phacoemulsification with intraocular lens implantation, and bilateral YAG-capsulotomy. Visual acuity was 0.004 in the right eye (OD) and 0.01 in the left eye (OS), with intraocular pressure of 20 mmHg in the OD and 18 mmHg in the OS. Autorefractor measurements were OD: +1.25/-4.0 ax 110° and OS: +1.25/-4.75 ax 130°. Pachymetry showed a central corneal thickness of 532μm in the OD and 518μm in the OS. Refraction measured by the WASCA (Wavefront Aberration Supported Cornea Ablation; (Carl Zeiss Meditec, Oberkochen, Germany)) wavefront aberrometer was +5.36/-2.43 ax 129° in the OD and +1.34/-4.08 ax 110° in the OS. Biometry results were 31.02 mm for the OD and 31.87 mm for the OS. High myopia presents complications that contemporary ophthalmology is capable of managing, even in its most severe stages. Advances in modern treatment methods often enable specialists to maintain functional visual acuity, ensuring patients can achieve a meaningful level of vision despite the challenges posed by advanced myopic conditions.

Challenges and outcomes of cataract surgery after vitrectomy

PURPOSE OF REVIEW

This review examines the challenges and outcomes of cataract surgery after pars plana vitrectomy (PPV), focusing on surgical techniques, timing, and complication management.

RECENT FINDINGS

Cataract formation remains the primary complication post-PPV, affecting approximately 80-100% of patients within two years. Nuclear sclerotic cataracts are most common, occurring in 60-100% of patients over 50, followed by posterior subcapsular cataracts (4-34%), which primarily affect younger and diabetic patients. PPV disrupts the normal oxygen gradient in the vitreous, resulting in a more uniform oxygen distribution and accelerating cataract formation.Post-PPV eyes present unique surgical challenges due to anatomical alterations, including zonular instability and capsular changes characterized by increased fragility, the potential for tears, and altered elasticity. Newer intraocular lens power calculations show promise, but unexpected refractive outcomes may occur. The choice between combined phacovitrectomy and sequential surgeries remains debated, with patient-specific factors guiding the approach. Visual outcomes vary depending on preexisting vitreoretinal pathologies and baseline vision before PPV. Further randomized controlled trials are needed to establish treatment guidelines and improve predictive models.

SUMMARY

Post-PPV cataract surgery presents unique challenges, including anatomical alterations and an increased risk of capsular complications. These necessitate careful consideration of the surgical approach and highlight the need for further research to optimize outcomes and establish treatment guidelines.

In Vivo Assessment of an Antioxidant Hydrogel Vitreous Substitute

The vitreous humor undergoes liquefaction with age, resulting in complications that may require a vitrectomy, or surgical removal of the vitreous from the eye. Silicone oil, a common vitreous substitute, lacks properties similar to the natural vitreous. In particular, it lacks antioxidants that may be necessary to reduce oxidative stress in the eye. The purpose of this study was to evaluate antioxidant-loaded hydrogel vitreous substitutes in a pilot in vivo study. Ascorbic acid and glutathione were loaded into synthesized PEGDA hydrogels. Following vitrectomy, experimental antioxidant hydrogels or silicone oil were injected into one eye of rabbits, while the other eye served as untreated or sham control. Ophthalmic assessments, including electroretinography, were performed. Levels of glutathione and ascorbic acid were higher in the eyes treated with the antioxidant-loaded hydrogel vitreous substitute, although this was not found to be significant after 28 days. There were no statistically significant differences between groups with respect to clinical examination, and ocular health scores, electroretinograms, and histology were normal. These results indicate minimal concerns for the hydrogel formulation or high levels of antioxidants. Future research will assess the capability of vitreous substitutes to prolong antioxidant release, with the goal of minimizing cataract after vitrectomy.

Vitrectomy for diabetic retinopathy: A review of indications, techniques, outcomes, and complications

Diabetic retinopathy is one of the most severe forms of retinopathy and a leading cause of blindness all over the world. Of a greater concern is proliferative diabetic retinopathy which leads to vitreous haemorrhage and tractional retinal detachment in such cases. A majority of these cases require a surgical intervention to improve vision and prevent further vision loss. Surgical manouevers in these cases require a complex combination of vitrectomy, membrane dissection, judious usage of endodiathermy, endolaser, vital dyes, bimanual dissection and usage of intraoperative and post-operative tamponades. Each case presents a unique challenge and necessitates an appropriate combination of the steps mentioned above. In the current review we present the current understanding of the need for surgery in diabetic retinopathy, various surgical approaches and a summary of current literature on the same. Multiple surgical video clips demonstrating these steps are also included in this review.

Posterior synechia formation after phacovitrectomy - Predicting factors and the role of short-acting mydriatics

PURPOSE

To evaluate the influence of topical short-acting mydriatics on the formation of posterior synechia after phacovitrectomy surgery of pars plana vitrectomy and phacoemulsification with intraocular lens implantation.

METHODS

A prospective randomised controlled trial. Fifty-seven adult (>18 years old) patients (57 eyes) who underwent phacovitrectomy surgery at a single tertiary hospital, were randomly divided into two groups. The control group (29 eyes) received standard postoperative treatment (topical antibiotics and steroids). The study group (28 eyes) received short-acting mydriatics together with standard therapy. Patients were followed until 24 months after surgery. The primary outcome measure was the formation of posterior synechia during the follow-up period.

RESULTS

A total of 7 patients developed posterior synechia during the follow-up period (12%), 3 in the study group (11%) and 4 in the control group (14%). There was no statistical difference between the groups. Significant associations for the development of posterior synechia were surgery for retinal detachment, longer surgery duration (>93 min) and the use of tamponade, in particular silicone oil.

CONCLUSIONS

The use of topical short-acting mydriatic drops after phacovitrectomy surgery, in addition to standard post-operative treatment, did not reduce the formation of posterior synechia. However, we identified several factors that may influence or act as predictors for the development of posterior synechia: surgery for retinal detachment, using silicone oil tamponade and a longer surgery duration. Our findings may aid in the standardisation of post-phacovitrectomy surgery treatment and define potential at-risk patients who should be monitored more closely.

Desired properties of polymeric hydrogel vitreous substitute

Vitreous replacement is a commonly employed method for treating a range of ocular diseases, including posterior vitreous detachment, complex retinal detachment, diabetic retinopathy, macular hole, and ocular trauma. Various clinical substitutes for vitreous include air, expandable gas, silicone oil, heavy silicone oil, and balanced salt solution. However, these substitutes have drawbacks such as short retention time, cytotoxicity, high intraocular pressure, and the formation of cataracts, rendering them unsuitable for long-term treatment. Polymeric hydrogels possess the potential to serve as ideal vitreous substitutes due to their structure-mimicking to natural vitreous and adjustable mechanical properties. Replacement with hydrogels as the tamponade can help maintain the shape of the eyeball, apply pressure to the detached retina, and ensure the metabolic transport of substances without impairing vision. This literature review examines the required properties of artificial vitreous, including the optical properties, rheological properties, expansive force action, and physiological and biochemical functions of chemically and physically crosslinked hydrogels. The strategies for enhancing the biocompatibility and injectability of hydrogels are also summarized and discussed. From a clinical ophthalmology perspective, this paper presents the latest developments in vitreous replacement, providing clinicians with a comprehensive understanding of hydrogel clinical applications, which offers guidance for future design directions and methodologies for hydrogel development.

Cataract progression after primary pars plana vitrectomy for uncomplicated rhegmatogenous retinal detachments in young adults

BACKGROUND

Scleral buckling is typically implemented to repair rhegmatogenous retinal detachments (RRD) in young patients. Therefore, there is limited data on post-pars plana vitrectomy (PPV) cataract formation in this cohort. We report the rates and risk factors of cataract progression after PPV for RRD repair in young eyes.

METHODS

Retrospective single-center cohort study. Medical records of patients between the ages of 15 to 45 undergoing PPV for uncomplicated RRD between 2014 and 2020 were reviewed.

RESULTS

Twenty-eight eyes from 26 patients met inclusion criteria. Cataracts developed in 20/28 (71%) eyes after PPV. After PPV, nuclear sclerotic cataract (NSC) rates were higher in patients above 35 (65%) compared to below 35 years (18%) (p = 0.024). Cataracts developed more frequently after macula-off RRDs (88%) compared to macula-on RRDs (50%) (p = 0.044) with NSC more common in macula-off detachments (p = 0.020). At postoperative month 2, all eyes with C3F8 gas developed cataracts compared to 59% of eyes with no gas (p = 0.040).

CONCLUSIONS

Cataract formation was common and frequent after PPV. After PPV, young eyes and macula-on detachments developed cataracts less frequently than older eyes and macula-off detachments. If appropriate, a shorter acting gas tamponade should be considered in young eyes to minimize cataract formation.

Cataract Formation Following Pars Plana Vitrectomy in the Pediatric Population

PURPOSE

To analyze post-vitrectomy cataract formation in the pediatric population to elucidate the number of phakic children requiring cataract surgery following vitreous surgery and the perioperative factors affecting cataract development in these patients.

METHODS

Eyes of pediatric patients that underwent phakic pars plana vitrectomy (PPV) with no prior cataract in a 10-year period were included. Analyses evaluated relationships between patient age and time to cataract surgery, as well as contributing factors for cataract formation. Final visual outcomes were also examined. Outcomes were collected for patient age at first vitrectomy, indication for vitrectomy, use of tamponade agents, history of ocular trauma, cataract status, and time to cataract surgery from first vitrectomy.

RESULTS

Of 44 eyes analyzed, 27 (61%) were noted to have some degree of cataract formation. Of these, 15 (56%; 34% of total eyes) underwent cataract surgery. Use of octafluoropropane (P = .04) or silicone oil (P = .03) positively correlated with the need for cataract surgery in the total study group. Patients requiring cataract surgery had worse endpoint visual acuities than those who did not undergo surgery (P = .02), although this difference becomes less significant in follow-up over 2 years (P = .30). Patients who had cataracts but did not need cataract surgery showed an improvement in visual acuity (P = .04), but this was not demonstrated in patients who did need cataract surgery (P = .90).

CONCLUSIONS

Pediatric eye care providers should be aware of the significant risk of cataract formation following a phakic PPV. [J Pediatr Ophthalmol Strabismus. 2023;60(6):421-426.].

Pars Plana Vitrectomy Alone or Combined with Phacoemulsification to Treat Rhegmatogenous Retinal Detachment: A Systematic Review of the Recent Literature

Pars plana vitrectomy is today a common first-line procedure for treatment of rhegmatogenous retinal detachment (RRD). Removal or preservation of the natural lens at the time of vitrectomy is associated with both advantages and disadvantages. The combination of cataract extraction (i.e., phacoemulsification) with pars plana vitrectomy (PPVc) enhances visualization of the peripheral retina and the surgical management of the vitreous base. However, PPVc prolongs the surgical time and is associated with iatrogenic loss of the accommodation function in younger patients, possible postoperative anisometropia, and unexpected refractive results. Performance of pars plana vitrectomy alone (PPVa) requires good technical skills to minimize the risk of lens damage, and quickens cataract development. We retrieved all recent papers that directly compared PPVc and PPVa using parameters that we consider essential when choosing between the two procedures (the success rate of anatomical RRD repair, postoperative refractive error, intra- and postoperative complications, and costs). PPVa and PPVc were generally comparable in terms of RRD anatomical repair. PPVc was associated with fewer intraoperative, but more postoperative, complications. Macula-off RRD PPVc treatment was often associated with undesirable myopic refractive error. PPVa followed by phacoemulsification was the most expensive procedure.

Microperimetric evaluation for different methods of epiretinal membrane surgery

PURPOSE

To investigate the anatomic and functional outcomes using microperimetry for the surgical methods for idiopathic epiretinal membranes (ERM).

METHODS

This retrospective study included 41 eyes from 41 patients. All patients underwent combined epiretinal membrane and cataract surgery. Best-corrected visual acuity (BCVA), optical coherence tomography, and microperimetry were performed before and 6 months and 1 year after surgery. The patients were divided into 3 groups; "ERM removal only without indocyanine green (ICG) staining", "ERM and internal limiting membrane (ILM) removal without ICG staining", and "ERM and ILM removal with ICG staining".

RESULTS

Preoperatively, the ages, BCVAs, central macular thickness (CMT), and mean retinal sensitivities of central 6° (MRSs) of the groups were not significantly different (p > 0.05). Postoperatively, the MRSs of the "ERM removal only without ICG staining" and "ERM and ILM removal without ICG staining" groups were not significantly different (p > 0.05). The MRSs of the "ERM and ILM removal without ICG staining" and "ERM and ILM removal with ICG staining" groups were not significantly different (p > 0.05). However, the MRSs of the "ERM and ILM removal with ICG staining" group significantly reduced than "ERM removal only without ICG staining" group (p < 0.05).

CONCLUSION

This retrospective study found reduced retinal sensitivity in ERM and ILM removal with ICG staining group compared to ERM removal only without ICG staining. Further studies with larger sample sizes are required.

Simplifying biometry in oil-filled eyes: A novel formula for axial length calculation in eyes with 1000 cSt silicone oil

Purpose

To derive a formula for accurate axial length (AL) assessment using routine ultrasound in silicone oil-filled eyes, where optical biometry is unavailable or not possible.

Methods

This was a prospective, consecutive, nonrandomized study of 50 eyes of 50 patients conducted in a tertiary care hospital in North India. AL measurements were taken using both manual A-scan and IOL master, both in silicone oil-filled status and 3 weeks after silicone oil removal. A correction factor of 0.7 was used for AL adjustment in oil-filled eyes. The corrected AL (cAL) was compared with IOL master values in oil-filled eyes. Agreement analysis was carried out using Bland Altman plot. Linear regression analysis was done using uncorrected manual AL to find a new equation. Data was analyzed using Stata 14. A P value <0.05 was taken as significant.

Results

The study included 40 males and 10 females, with an age range of 6-83 years (mean 41.9 years). The mean AL of the oil-filled eye as measured by manual A-scan was 31.76 mm ± 3.09 and by IOL master was 24.7 mm ± 1.74. Linear regression analysis was performed in randomly selected 35 eyes of the observed data to obtain a new equation: predicted AL (PAL) = 14 + 0.3 × manual AL. The mean difference between PAL and optically measured AL with silicone oil in situ was 0.98 ± 1.67.

Conclusion

We propose a new formula for better prediction of the correct AL in silicone oil-filled eyes using ultrasound-based AL measurement.

Outcomes of Retinectomy without Lensectomy in Rhegmatogenous Retinal Detachments with Proliferative Vitreoretinopathy

PURPOSE

To report the anatomic and functional outcomes of retinectomy without lensectomy in eyes with rhegmatogenous retinal detachment (RRD) and proliferative vitreoretinopathy (PVR).

DESIGN

Retrospective, noncomparative, and interventional case series.

SUBJECTS

One hundred twelve eyes of 112 patients with RRD complicated by PVR who underwent retinectomy without lensectomy.

METHODS

Retrospective review of patients treated with vitrectomy and retinectomy without lensectomy from January 1, 2015, to January 1, 2020.

MAIN OUTCOME MEASURES

The primary outcome was the final attachment rate and single surgery anatomic success (SSAS) at 3 and 6 months after retinectomy. Secondary outcomes included predictors of final visual acuity (VA), the mean number of subsequent operations required for complete retinal reattachment, cataract surgery, and the number of eyes that ultimately had successful silicone oil removal.

RESULTS

Complete final retinal reattachment was achieved in 111 of 112 (99.1%) patients, with a mean (standard deviation [SD]) follow-up of 29 (14) months (range, 8-62 months) after retinectomy. The SSAS was achieved in 84 of 112 (75%) patients at 3 months and 73 of 112 (65.2%) patients at 6 months. The final VA improved or stabilized in 76 of 112 (67.9%) eyes. Silicone oil removal was performed in 72 of 112 patients (64.3%) at a mean (SD) of 6.6 (3.3) months, and cataract surgery was performed on 101 (90.2%) eyes before the last follow-up visit.

CONCLUSIONS

Retinectomy without lensectomy to repair RRDs complicated by PVR showed acceptable anatomic and functional results. This study suggests that removing the lens when there is no significant cataract may not be necessary in these cases to obtain reasonable outcomes.

Prospective comparison of accuracy of intraocular lens calculation formulas in phacovitrectomy: a pilot study in a real-world clinical practice

PURPOSE

To compare the accuracy of intraocular lens (IOL) power calculations among IOL formulas after phacovitrectomy.

METHODS

We prospectively enrolled 206 eyes of 206 patients who underwent 25-gauge phacovitrectomy, without gas tamponade, for macular pathology. Pre-operative optical biometry used the IOLMaster 700 to calculate the IOL power with the new formulas, i.e. the Barrett Universal II (BU II), Emmetropia Verifying Optical version 2.0, Hill-Radial Basis Function (RBF) version 3.0, Kane, and Ladas Super Formula, and conventional formulas, i.e. Haigis, Hoffer Q, Holladay 1, Holladay 2, and Sanders-Retzlaff-Kraff/T (SRK/T). A single-piece foldable IOL was implanted in all cases. Manifest refractions were measured before and 3 months after surgery.

RESULTS

The BU II formula showed the lowest standard deviation and mean and median absolute errors and had the highest percentage of eyes with a refractive prediction error within ± 0.25 D. The absolute error was significantly lower with the four new formulas, except the Hill-RBF, than with the Hoffer Q (all p =  ≤ 0.010) and Holladay 1 formulas (all p =  < 0.010). The absolute error with the BU II formula was also lower than that with the Holladay 2 (p = 0.012) and SRK/T (p = 0.024) formulas.

CONCLUSION

Overall, the new IOL formulas, except the Hill-RBF, were superior to some of the conventional formulas for calculating IOL power in phacovitrectomy.

Cataract progression following lens-sparing pars plana vitrectomy for rhegmatogenous retinal detachment

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

Three-year results of combined pars plana vitrectomy and phacoemulsification in diabetic vitreous hemorrhage

Aim: The purpose of this study was to evaluate the efficacy and safety of complications following combined pars plana vitrectomy and phacoemulsification surgery of the eyes for the management of vitreous hemorrhage due to proliferative diabetic retinopathy as well as pronounced cataracts. Material and Method: Phacoemulsification and 23G pars plana vitrectomy procedures were performed for the management of vitreous hemorrhage and cataracts. Age, gender, best-corrected visual acuity before and after surgery, and intra- and post-operative complications were recorded in patients with cataracts who underwent surgery due to vitreous hemorrhage. Results: A total of 40 eyes of 40 patients, 22 females (55%) and 18 males, were included in the study. The mean age was 58.7±7.1 (44–76) years. Logmar visual acuity changed from a mean of 2.82±0.5 preoperatively to a mean of 0.7±0.6 postoperatively. Visual acuity increased in 38 eyes (95%) postoperatively. No reduction in visual acuity was observed in any eye. Complications associated with surgery included transient intraocular pressure increase (12 eyes), hyphema (2 eyes), posterior capsule rupture (1 eye), anterior chamber fibrin exudation (4 eyes), neovascular glaucoma (1 eye), vitreous hemorrhage (4 eyes), retinal detachment (1 eye), and posterior capsule opacification (2 eyes). Conclusion: It was found that combined phacoemulsification and PPV surgery was safe and effective in patients with proliferative diabetic retinopathy. Combined phaco-vitrectomy is a reliable method with a minimum complication profile and prevents the need for subsequent cataract surgery.

Predicting speed of progression of lens opacification after pars plana vitrectomy with silicone oil

Purpose

An increasing number of posterior segment disorders is routinely managed with pars plana vitrectomy (PPV). In older, phakic patients cataract formation is expected within the first two years after surgery. For younger patients its progression is individually fluctuating. This study uses an objective quantitative measurement for lens-status-monitoring after PPV with silicone oil to derive predictions for progression and severity of post-operative lens opacification evaluated in patients with rhegmatogenous retinal detachment (RRD).

Methods

Data acquisition was performed prospectively between March 2018 and March 2021. PentacamHR® Nucleus Staging mode (PNS) was used to objectively gather data about nuclear cataracts after PPV at different time points. Data was grouped into training and test sets for a mathematical prediction model. Via backward variable selection method a mathematical formula was set up by means of which predictions about lens densitometry (LD) can be calculated.

Results

20 males [58.8%] and 14 females [41.2%] matched the inclusion criteria (mean age 50.6 years [23–75; ±12.3]). Average follow-up was 8.1 months (3,4–17.4; ±3.4). Mean baseline LD of the treated and fellow eye before surgery was 11.1% (7.7%-17.6%; ±2.0) and 11.2% (7.7%-14.8%; ±1.5), respectively. Predicted LD values by the model for five pre-selected patients closely match the observed data with an average deviation of 1.06%.

Conclusions

Using an objective parameter like LD delivered by the PentacamHR® PNS mode additionally to the patient’s age allows us to make an individual prediction for any time after PPV with silicone oil due to RRD for all ages. The accuracy of the model was stronger influenced by baseline LD as cofactor in the equation than patient’s age. The application for the prediction lens opacification [which can be accessed for free under the following link (https://statisticarium.com/apps/sample-apps/LensDensityOil/)] can help vitreoretinal surgeons for patient consultation on the possibility to combine PPV with cataract surgery.

Longitudinal Change in Retinal Nerve Fiber Layer Thickness and Its Association With Central Retinal Sensitivity After Epiretinal Membrane Surgery

PURPOSE

To investigate the longitudinal changes in the peripapillary retinal nerve fiber layer (pRNFL) thickness after epiretinal membrane (ERM) vitrectomy with internal limiting membrane (ILM) peeling, examine associations between pRNFL thickness and central retinal sensitivity, and identify predictors of postoperative pRNFL thickness.

DESIGN

Prospective, observational, cohort study.

METHODS

This study enrolled 82 eyes of 82 Japanese patients that underwent surgery for unilateral idiopathic ERM, with their fellow eyes as controls. pRNFL thickness was measured in 4 (superior, temporal, inferior, and nasal) quadrants preoperatively and at 1, 3, 6, and 12 months postoperatively. Microperimetry was performed at 12 months postoperatively to evaluate central retinal sensitivity. Regression tree analysis was performed to predict pRNFL thickness at 12 months postoperatively.

RESULTS

The temporal quadrant showed continuous pRNFL thinning after surgery, reaching statistical significance at 3, 6, and 12 months postoperatively (all P < 0.001). The pRNFL thicknesses in the fellow eyes significantly increased at all postoperative time points (all P < 0.001). At 12 months postoperatively, the average central retinal sensitivity was significantly correlated with the temporal pRNFL thickness in the eyes with ERM (r = 0.372, P < 0.001); no significant correlation was found in the fellow eyes. Regression tree analysis showed that the preoperative pRNFL thickness in the temporal quadrant and patient age were the main determinants of the temporal pRNFL thickness at 12 months postoperatively.

CONCLUSIONS

The risk of deterioration of central retinal sensitivity after ERM vitrectomy with internal limiting membrane peeling should be considered for patients with thin temporal pRNFLs and older adults.

Visual outcomes following cataract surgery with intraocular lens implantation in vitrectomized eyes among children

Purpose:

To assess the visual outcomes and associated factors in pediatric patients undergoing cataract surgery following pars plana vitrectomy (PPV).

Methods:

A total of 52 eyes of 52 children who underwent cataract surgery and intraocular lens (IOL) implantation in previously vitrectomized eyes between January 2008 and December 2017 were included in this retrospective study. Descriptive and inferential statistical measurements (Chi-square test, Fisher's exact test, odds ratio, multiple logistic regression) were done.

Results:

The mean age at PPV was 11.3 ± 2.9 years. The most common indication for PPV was retinal detachment in 43 eyes (82.69%) and vitreous hemorrhage in 6 eyes (11.53%). The mean preoperative and postoperative best-corrected visual acuity (BCVA) was 1.31 ± 0.48 logMAR (logarithm of the minimum angle of resolution) units (20/400) and 0.69 ± 0.45 logMAR units (20/100), respectively; P < 0.001. The final visual outcome was good in 37 eyes (71.15%) and poor in 15 eyes (28.85%). In mean follow-up of 4 years, 42.3% developed posterior capsular opacification, 13.5% developed glaucoma, and 3.8% had retinal redetachment after cataract surgery. In the presence of macular pathology, the visual outcome was poor (aOR [adjusted odds ratio] = 4.26, P = 0.002).

Conclusion:

Cataract surgery with IOL implantation in vitrectomized eyes among children is a safe procedure and can improve visual acuity and quality of life. However, the extent of improvement is limited by macular pathology.

Lens densitometry for assessment and prediction of cataract progression after pars plana vitrectomy with C3F8-gas for retinal detachment

Purpose

Lens opacification is a common complication after pars plana vitrectomy (PPV) and knowing its progression would facilitate consulting patients. The purpose of this study was to evaluate a quantitative model for lens-status-monitoring after PPV with C3F8 gas. Our model was evaluated in rhegmatogenous retinal detachment (RRD) patients of various age and lens densitometry (LD).

Methods

Data between March 2018 and March 2020 were evaluated retrospectively. LD measurements of the PentacamHR® Nucleus Staging mode (PNS) were used to quantify lens opacification over time. A mixed-effect regression model was designed, to enable LD predictions at any time postoperatively. Calculations were based on patient’s age and baseline LD as dependent variables. Six patients were randomly excluded during model development, to be used for testing its power afterwards.

Results

34 patients (male 19 [55.9%], female 15 [44.1%]) matched the inclusion criteria. Average age was 58.5 years (32–77;±4.3) and average follow-up was 7.2 months (3,4–23.1;±1,8). Mean baseline LD of the treated and fellow eye before surgery were 10.9% (8.7%-14.8%;±0.8) and 10.7% (8.5%-14.1%;±0.6), respectively. Using our prediction model, LD values for the six pre-selected patients closely match the observed data with an average deviation of 1.07%.

Conclusions

Evaluation of age and baseline LD using a mixed-effect regression model might predict cataract progression in RRD patients treated with PPV and C3F8-gas. Such a tool could be considered during cataract surgery consultation in these patients.

Cataract Following Pars Plana Vitrectomy: A Review

Introduction: The indications for pars plana vitrectomy (PPV) have increased over the years. The vitreous is no longer considered an inert ocular structure and it is well known that its removal has anatomical and physiological consequences. The vitreous is no longer considered an inert ocular structure. The vitreous plays a key role as an intraocular physiologic oxygen regulator. In order to maintain its transparency, the crystalline lens needs protection from an excessive oxygen exposure. PPV leads to progression of nuclear sclerosis in most eyes.Methods: A systematic review of the literature was conducted using Embase and Medline databases. Articles studying the physiology, pathogenesis and surgical treatment of cataract after PPV were included in this review.Results: The pathogenesis of cataract formation after PPV remains unclear. Predisposing factors include advanced patient age, preexisting nuclear sclerosis, light toxicity, intraoperative oxidation of lens proteins, use of silicone oil or intravitreal gas, mechanical trauma and the duration of exposure to an irrigating solution.Conclusion: Cataract surgery in vitrectomized eyes presents with more technical difficulties, is more challenging and often has a higher risk of intraoperative and postoperative complications than in non vitrectomized eyes. There is no standardized technique or management in these cases; therefore, it requires more precautions during surgery.

Prediction of Visual Prognosis after Epiretinal Membrane Surgery Using Regression Tree Analysis

Background and Objective: Confounding factors should be considered when predicting visual prognosis after epiretinal membrane (ERM) surgery. We aimed to predict visual acuity after ERM surgery using regression tree analysis.Patients and Methods: We retrospectively reviewed 343 eyes of 343 patients who underwent vitrectomy for idiopathic ERM. Regression tree analysis was performed to predict best-corrected visual acuity (BCVA) at 6 months postoperatively.Results: Patients were first divided into two groups based on preoperative BCVA. Age, central macular thickness, and axial length were associated with visual prognosis in patients with specific preoperative BCVAs. When patients were subdivided into groups 1-8, BCVA was significantly better in group 1 than in groups 4-8 (p≤0.001), and in groups 2-5 and 7 than in groups 6 and 8 (p≤0.002).Conclusion: Surgical prognosis in eyes with ERM should be evaluated based on a comprehensive assessment of preoperative characteristics.

Accuracy of Intraocular Lens Power Calculation in Children With Vitrectomized Eyes Undergoing Cataract Surgery

PURPOSE

To assess the predictability of desired postoperative refractive outcomes using the SRK-II formula for intraocular lens (IOL) power calculation in children undergoing cataract surgery in eyes with a previous pars plana vitrectomy (PPV).

METHODS

In this retrospective study, 68 eyes of 66 children who underwent cataract surgery and IOL implantation in eyes that had previous vitrectomy between January 2008 and December 2017 were included. Data were collected on preoperative and postoperative characteristics. The Mann-Whitney test, Kruskal-Wallis test, and multinominal logistic regression were used for comparing the results.

RESULTS

Absolute prediction error (APE) in the cohort was 1.29 ± 1.13. Desirable refractive outcome with insignificant prediction error of less than 0.50 diopters (D) was found in approximately one-third of the children. Patients were further subdivided by magnitude of APE as ≥ 0.50 to ≤ 1.00 D and > 1.00 D. Age at the time of surgery, axial length, mean keratometry, silicone oil removal, IOL position, scleral buckle, and corneal suture did not affect APE and there was no significant difference between the groups (P > .05).

CONCLUSIONS

The mean APE of the SRK-II formula for IOL power calculation in pediatric eyes that had vitrectomy is comparable to that reported in the literature for routine pediatric cataract surgeries. Factors such as age, axial length, corneal power, IOL position (bag/sulcus), scleral buckle, corneal suture, and silicone oil removal done prior to surgery or along with cataract surgery did not affect the APE. [J Pediatr Ophthalmol Strabismus. 2021;58(2):126-131.].

Surgical repair of primary non-complex rhegmatogenous retinal detachment in the modern era of small-gauge vitrectomy

OBJECTIVE

To report anatomic and visual outcomes of pars plana vitrectomy (PPV), as well as scleral buckling (SB) and PPV/SB as surgical treatments for the management of primary, non-complex rhegmatogenous retinal detachment (RRD).

METHODS AND ANALYSIS

Data from 751 eyes that underwent PPV, SB or combined PPV/SB as a surgical treatment for primary non-complex RRD with at least 3 months of follow-up were analysed to determine rates of single surgery anatomic success (SSAS) and final anatomic success (FAS). Patients or the public were not involved in the design, conduct or reporting of this research.

RESULTS

PPV accounted for 89.0% (n=668), PPV/SB for 6.8% (n=51) and SB for 4.2% (n=32) cases. Overall SSAS (91.2% PPV, 84.3% PPV/SB, 93.8% SB; p=0.267) and FAS (96.7% PPV, 94.1% PPV/SB and 100.0% SB; p=0.221) were reported for the three surgical groups. SSAS and FAS were similar for lens status, macular detachment status and the presence or absence of inferior retinal breaks for each of the PPV, PPV/SB and SB groups.

CONCLUSIONS

In this large, single institution, retrospective case series, we report surgical outcomes for patients with primary non-complex RRD managed with PPV, SB or PPV/SB in the modern era of small-gauge vitrectomy. We demonstrate that primary PPV without adjunct SB provides excellent anatomic and visual outcomes irrespective of lens status, macular involvement or pathology location.

Prognostic Factors Associated with Ocriplasmin Efficacy for the Treatment of Symptomatic Vitreomacular Adhesion and Full-thickness Macular Hole: Analysis from Four Studies

Purpose

To assess the effect of patient baseline characteristics on the efficacy of ocriplasmin treatment for symptomatic vitreomacular adhesion (VMA) with full-thickness macular hole (FTMH) from phase 3/4 studies.

Methods

Patients with symptomatic VMA and FTMH at baseline and receiving ocriplasmin treatment 125 μg were pooled from the MIVI-TRUST, OASIS, and ORBIT studies. Multivariable logistic regression analysis was used to evaluate whether patient baseline characteristics were predictors of having VMA resolution by Day 28 and FTMH closure by Month 6.

Results

Two hundred and seventy-four patients receiving ocriplasmin treatment were assessed. Overall, 22.6% (62/274) of the patients experienced both VMA resolution by Day 28 and non-surgical FTMH closure by Month 6. Patients with FTMH ≤250 µm at baseline had a significantly higher success rate compared to those with FTMH >400 µm (29.9% [41/137] vs 2.2% [1/48]; P = 0.009). In patients with VMA resolution by Day 28, both small FTMH size (P = 0.001) and FTMH width at RPE (P = 0.012) were significantly associated with a higher FTMH closure rate. Patients with VMA resolution had higher rates of FTMH closure. Previously identified baseline predictive factors, including age, lens status, or presence of epiretinal membrane (ERM) were not found to be predictive of both VMA release and FTMH closure.

Conclusion

The analysis revealed that FMTH ≤250 µm was the only factor predictive for achieving both pharmacological VMA resolution by Day 28 and nonsurgical FTMH closure by Month 6; neither lens status or presence of ERM, previously identified baseline characteristics favoring VMA resolution, showed statistically significant predictive power for both outcomes.

Combined versus Sequential Phacoemulsification and Pars Plana Vitrectomy: A Meta-Analysis

TOPIC

It is unclear whether differences exist in efficacy and safety between combined versus sequentially performed phacoemulsification and pars plana vitrectomy (phaco-PPV).

CLINICAL RELEVANCE

This meta-analysis aimed to compare the efficacy and incidence of complications between these surgical methods.

METHODS

Ovid MEDLINE, EMBASE, and Cochrane CENTRAL were searched for articles reporting the efficacy and safety of combined versus sequential phaco-PPV for any indication. The primary outcomes were postoperative best-corrected visual acuity (BCVA) and mean absolute refractive error from target (RET). Secondary outcomes included efficacy outcomes and postoperative complications. Meta-analysis was conducted using a random effects model in all cases. Risk of bias assessment was performed using the Cochrane risk of bias assessment tool for randomized trials and ROBINS-I tool for observational studies.

RESULTS

Of the 5410 articles identified, 1 randomized controlled trial and 14 comparative studies were included, with 1407 and 951 eyes in the combined and sequential surgery groups, respectively. Mean age was 62.71 ± 6.16 years and 44% (range, 32.1%-70%) of eyes were from men. The mean baseline BCVA was 0.88 ± 0.59 logarithm of the minimum angle of resolution units (Snellen equivalent, 20/152). The meta-analysis showed no significance between groups in postoperative mean BCVA (P = 0.76) and mean absolute RET (P = 0.46). The risks of synechiae formation (risk ratio [RR], 2.74; 95% confidence interval [CI], 1.83-4.11; P < 0.001), fibrin formation (RR, 2.81; 95% CI, 1.84-4.30; P < 0.001), and intraoperative or postoperative retinal detachment (RR, 2.65; 95% CI, 1.08-6.47; P = 0.03) were significantly higher after combined surgery. However, the risks of posterior capsular tear (RR, 0.43; 95% CI, 0.25-0.73; P = 0.002) and macular hole nonclosure or reopening (RR, 0.18; 95% CI, 0.03-0.93; P = 0.04) were significantly lower in the combined group.

DISCUSSION

No significant differences were found in visual and refractive outcomes between combined and sequential phaco-PPV, whereas differences existed in certain safety outcomes. These conclusions remain preliminary, as most evidence is derived from low- to moderate-quality retrospective studies. Given the variability in outcome reporting and associated heterogeneity, future randomized controlled trials are needed.

Incidence and Factors of Postoperative Lens Opacity after Lens-Sparing Vitrectomy for Retinopathy of Prematurity

PURPOSE

To determine the incidence and factors associated with lens opacity after lens-sparing vitrectomy (LSV) for retinopathy of prematurity (ROP).

DESIGN

Retrospective, comparative case series.

PARTICIPANTS

Among the 141 eyes of 94 patients who underwent LSV for ROP between 2006 and 2019, 108 eyes of 71 patients with a minimum follow-up of 12 months after LSV were investigated.

METHODS

Data were collected from patients' charts, including gender, gestational age at birth, birth weight, stage of ROP, postmenstrual age (PMA) at LSV, surgical procedure, preoperative injection of anti-vascular endothelial growth factor (VEGF) agents, subsequent retinal surgeries, and lensectomy during follow-up.

MAIN OUTCOME MEASURES

Lens status at last visit, incidence and timing of lensectomy, and risk factors for lens opacity requiring lensectomy.

RESULTS

Stages of ROP at LSV were 4A, 4B, and 5 in 92 eyes, 13 eyes, and 3 eyes, respectively. The median PMA at LSV was 40.6 weeks. Thirty-two eyes received anti-VEGF therapy before LSV. Lens opacity was found in 17 eyes (15.7%), of which 10 eyes (9.3%) underwent lensectomy. The period between LSV and lensectomy ranged from 21 days to 131.9 months (median, 21.1 months). Eleven other eyes (10.2%) underwent lensectomy as part of a reoperation for worsening of ROP. A total of 80 eyes (74.1%) preserved clear lenses at the latest follow-up examination after surgery (median, 6.8 years; range, 1-14 years). The Kaplan-Meier estimate showed that the proportion of patients with phakia at 5 and 10 years was 92.4% and 89.0%, respectively. Multivariate Cox regression analysis revealed that eyes with the use of tamponade at LSV (P = 0.005; odds ratio [OR], 25.68; 95% confidence interval [CI], 4.187-157.5) and young PMA at LSV (P = 0.033; OR, 1.047; 95% CI, 1.012-1.099) were associated significantly with lens opacity requiring lensectomy. However, anti-VEGF therapy was not associated with lens opacity requiring lensectomy.

CONCLUSIONS

Nearly 10% of eyes required lensectomy because of lens opacity after LSV for ROP. The development of lens opacity requiring lensectomy seems to be associated with the use of tamponade and young PMA at LSV.

Vitreoretinal surgeons' experience and time interval from pars-plana vitrectomy to cataract extraction

AIM

To identify the association of the vitreoretinal surgeons' experience with the time interval between pars-plana vitrectomy (PPV) and cataract extraction (CE).

METHODS

Eyes with prior PPV and following CE were included in this retrospective cohort study. The years of practice and the annual case volume were used to describe the surgeons' experience. Multivariable linear regression analysis was used to investigate the relationship between surgeons' experience and the time interval adjusted for the patients age, gender, intraocular tamponade, and case complexity.

RESULTS

Of 132 430 eyes, 1445 eyes were included in this study. In multivariable linear regression analysis, cases performed by surgeons with >20 practice years had longer time intervals compared with surgeons with <10 practice years after adjusted for other variables (β=0.329, 95%CI: 0.113 to 0.549, P=0.003). No difference in time interval was detected for comparing the lowest with the highest volume groups (β=0.089, 95%CI: -0.164 to 0.343, P=0.343). The surgeons' practice years were not directly with the volume. For complicated surgery, the higher-practice-year surgeons had longer time interval than lower-practice-year surgeons.

CONCLUSION

The time intervals from PPV to CE is longer in higher-practice-year surgeons. The surgeons' practice years may have a greater effect on the time interval than annual case volume in high-complexity cases. Matching the complexity of vitreoretinal diseases with the surgeons' practice year should be considered.

Predictive Risk Factors for Retinal Redetachment Following Uncomplicated Pars Plana Vitrectomy for Primary Rhegmatogenous Retinal Detachment

Purpose: To investigate clinical and surgical factors influencing the outcome after primary rhegmatogenous retinal detachment surgery. Methods: A retrospective, single-centre, case-control study of 1017 eyes of 1017 consecutive patients with primary rhegmatogenous retinal detachment (RRD) who underwent pars plana vitrectomy (PPV), were included in the study. Analysed surgical factors were: combined procedure with phacoemulsification, type of retinopexy (cryocoagulation, endolaser, combined), type of tamponade (gas, silicone oil), and anatomical factors: primary proliferative vitreoretinopathy (PVR) and macular detachment at the time of surgery. Results: Overall retinal re-detachment rate was 10.1%. The main reason for re-detachment was an insufficient retinopexy in 53.6%, followed by PVR (37.3%), and retinal detachment occurred at a different location caused by another break in 9.1%. No significant difference in the rate of re-detachment was found if a phacoemulsification with simultaneous IOL implantation was performed (p = 0.641). No significant difference between the various retinopexy techniques was found (p = 0.309). Risk factors re-detachment were primary PVR (p = 0.0003), silicone oil as initial tamponade (p = 0.0001) as well as macula off detachments (p = 0.034). Conclusions: The present study showed no significant difference between the types of retinopexy and if additional phacoemulsification was performed or not. Factors associated with a higher risk for re-detachment were detached macula at surgery, primary PVR and primary oil-filling.

Vitamin C and the Lens: New Insights into Delaying the Onset of Cataract

Cataracts or clouding of the lens is the leading cause of blindness in the world. Age and diabetes are major risk factors, and with an increasing aging and diabetic population, the burden of cataracts will grow. Cataract surgery is an effective way to restore vision; however, alternatives to cataract surgery are required to reduce the looming cataract epidemic. Since it is well established that oxidative damage plays a major role in the etiology of cataracts, antioxidants have been promoted as therapies to delay and/or prevent cataracts. However, many antioxidant interventions including vitamin C have produced mixed results as anti-cataract therapies. Progress has been made towards our understanding of lens physiology and the mechanisms involved in the delivery and uptake of antioxidants to the lens which may guide future studies aimed at addressing some of the inconsistencies seen in previous animal and human studies. Of interest is the potential for vitamin C based supplements in delaying the onset of cataracts post vitrectomy which occurs in up to 80% of patients within two years. These targeted approaches are required to reduce the burden of cataract on hospitals and improve the quality of life of our aging and diabetic population.

Glutathione Improves the Antioxidant Activity of Vitamin C in Human Lens and Retinal Epithelial Cells: Implications for Vitreous Substitutes

PURPOSE

Tissues in the eye are particularly susceptible to oxidative damage due to light exposure. While vitamin C (ascorbic acid) has been noted as a vital antioxidant in the vitreous humor, its physiological concentration (1-2 mM) has been shown to be toxic to retinal and lens epithelial cells in in vitro cell culture. We have explored adding vitamin C to hydrogel vitreous substitutes as a potential therapeutic to prevent oxidative damage to intraocular tissues after vitrectomy. However, vitamin C degrades rapidly even when loaded at high concentrations, limiting its long-term effectiveness. Glutathione, another antioxidant found abundantly in the lens at concentrations of 2-10 mM, was proposed to be used in conjunction with vitamin C.

METHODS

Cell viability and reactive oxygen species activity of human retinal and lens epithelial cells treated with various combinations of vitamin C, glutathione, hydrogen peroxide, and a hydrogel vitreous substitute were determined using CellTiter-Glo luminescent cell viability assay and dichlorofluorescein assay, respectively. The vitamin C remaining in hydrogel vitreous substitute or glutathione-vitamin C solutions was determined using a microplate reader at 265 nm wavelength, compared against standard solutions with known concentrations.

RESULTS

Glutathione protected the lens and retinal cells from the negative effect of vitamin C on cell viability and prolonged the antioxidant effect of vitamin C in vitro. While the detected reading of pure vitamin C solution decreased rapidly from 100% to 10% by 3 days, glutathione provided a significant extension to vitamin C stability, with 70% remaining after 14 days when the glutathione was used at physiological concentrations found in the lens (2-10 mM).

CONCLUSIONS

These results indicate glutathione might be an effective addition to vitamin C in intraocular implants, including potential vitreous substitutes, and warrants additional studies on the effectiveness of the vitamin C - glutathione combination in preventing oxidative stress post-vitrectomy.

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.

The Influence of Diabetes Status on the Rate of Cataract Surgery Following Pars Plana Vitrectomy

PURPOSE

We aimed to evaluate the association between diabetic status and the rates of cataract extraction (CE) following pars plana vitrectomy (PPV).

DESIGN

Retrospective cohort, multicenter database study.

PARTICIPANTS

Patients were selected from an insurance claims database (PharMetrics LifeLink) that included persons who had filed claims between 2006 and 2015 in the United States.

METHODS

We analyzed the records of 22 146 patients who underwent PPV performed by 2705 retina physicians. The vitrectomy group included patients ≥18 years of age who had undergone PPV. The control group included patients who were matched to the vitrectomy group 1:2 based on sex, diabetes mellitus (DM) status, region of the United States, and Charleston Comorbidity Index.

MAIN OUTCOME MEASURES

Hazard ratios (HRs) and rates of cataract surgery in patients with and without diabetes who had undergone prior PPV.

RESULTS

The hazard ratio for post-PPV CE was lower among patients with diabetes (3.307; 95% confidence interval [CI], 3.051-3.583) than among patients without diabetes (4.889; 95% CI, 4.670-5.119). This association was significant for all subgroups of patients with diabetes except in patients with diabetes and without retinopathy (4.086; 95% CI, 3.511-4.754). There was a significantly longer time between PPV and CE in patients with diabetes (537 days; 95% CI, 459-677 days) compared with those without diabetes (295 days; 95% CI, 278-312 days). The type of DM (type 1 vs. type 2) did not influence the rate of post-PPV cataract surgery. In persons with diabetes who underwent PPV, we observed a trend for a lower HR of cataract surgery in eyes with proliferative retinopathy (0.903; 95% CI, 0.725-1.124), and nonproliferative retinopathy (0.965; 95% CI, 0.721-1.290) compared with eyes with no retinopathy.

CONCLUSIONS

Eyes of patients with diabetes had a significantly decreased risk of undergoing CE after PPV surgery compared with eyes of patients without diabetes.

Effect of Pars Plana Vitrectomy With or Without Cataract Surgery in Patients with Diabetes: A Systematic Review and Meta-Analysis

INTRODUCTION

Pars plana vitrectomy (PPV) is considered to be an essential and effective surgical approach for the management of complications of diabetic retinopathy. Given the high rate of accelerated cataract progression after PPV, PPV combined with cataract surgery appears to be an attractive treatment option for patients with diabetes. However, this combined surgical approach remains controversial in terms of effectiveness and safety. We have therefore conducted a meta-analysis to evaluate the treatment outcome of PPV with or without cataract surgery.

METHODS

A systematic search of three electronic databases (PubMed, Web of Science, and the Cochrane Library) was performed to identify relevant articles, using the key words "pars plana vitrectomy," "cataract," and "diabetic retinopathy." Main outcome measures included the final visual acuity and postoperative complications. The incidence of postoperative complications was pooled using odds ratio (OR) with 95% confidence intervals in a random effect model.

RESULTS

Ultimately, one randomized controlled trial (RCT) and four high-quality retrospective studies met the inclusion criteria and were included in the meta-analysis. In four of these studies, final visual acuity did not vary significantly between patients undergoing PPV alone and those undergoing PPV combined with cataract surgery (combined surgery). Only one study reported better visual improvement in the combined treatment group. Our analysis also showed that most phakic eyes after PPV had cataract progression with varying degrees. In addition, patients receiving PPV alone had a lower risk of neovascular glaucoma (OR 0.36; P  < 0.05), iris synechias to anterior capsule (OR 0.36; P  < 0.05), and iris rubeosis (OR 0.26; P  < 0.05) compared with those receiving combined surgery.

CONCLUSION

Overall, our findings show that PPV combined with cataract surgery achieved good outcomes without a substantial increased risk to visual acuity or most complications. Given the high rates of cataract progression after PPV, combined surgery may be the more appropriate treatment for patients with diabetes and coexistent visually significant cataract.

Combined pars plana vitrectomy with phacoemulsification for rhegmatogenous retinal detachment repair

Purpose

To investigate the outcome after combined phaco-vitrectomy in rhegmatogenous retinal detachment (RRD) repair.

Patients and methods

In this retrospective study, we included all patients who underwent pars plana vitrectomy (PPV) for RRD between January 2013 and December 2017. The main outcome measure was the retinal re-detachment rate after combined phaco-vitrectomy.

Results

Overall, 1017 eyes with RRD were included. All eyes received PPV, while in 516 eyes additional phacoemulsification was performed. A retinal re-detachment occurred in 103 patients (10.1%). No significant difference in the rate of re-detachment was found if additional phacoemulsification was performed (p=0.641). Subgroup calculations showed a significant higher rate of re-detachment in patients with a PVR (p=0.0003) and in patients where silicone oil was used as primary tamponade (p=0.0001) as well as in macula off RRDs (p=0.034).

Conclusion

Additional phacoemulsification during vitrectomy for RRD is not associated with higher rate of retinal re-detachment.

Idiopathic epiretinal membrane surgery: safety, efficacy and patient related outcomes

This review aims to give to the reader an overview selectively oriented on safety and efficacy of surgery, providing concise and direct answers about crucial questions of trainees and experts. Surgery for idiopathic epiretinal membrane (ERM) is a safe and effective procedure that can achieve long-term stable postoperative visual and anatomical improvement, with an overall low recurrence and complication rate. Young patients, with a short onset of symptoms and with better initial visual acuity achieve higher levels of visual outcome. The preoperative degree of metamorphopsia is the prognostic factor for their postoperative degree. Successful results may be obtained in eyes with specific optical coherence tomography criteria, such as thin ganglion cell layers, thin internal plexiform layer, longer photoreceptors outer segment, regular ellipsoid zone and cone outer segment tips line, and without ectopic inner foveal layer. Internal limiting membrane peeling demonstrates positive anatomical and functional outcomes, but final positions about its safety remain controversial.

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.

Intraocular Oxygen and Antioxidant Status: New Insights on the Effect of Vitrectomy and Glaucoma Pathogenesis

PURPOSE

The purpose of this study was to investigate correlations of partial pressure of oxygen (pO₂) in the ocular anterior segment of human eyes and aqueous humor antioxidant levels of ascorbate (AsA) and total reactive antioxidant potential (TRAP) with glaucoma and vitreous status.

METHODS

This prospective, cross-sectional study stratified patients (n = 288 eyes) by lens and vitreous status and the presence of primary open-angle glaucoma for statistical analyses. Intraocular pO₂ concentrations were measured using a fiberoptic probe in patients at the beginning of planned glaucoma and/or cataract surgery. Aqueous humor specimens were obtained for antioxidant analysis of AsA and TRAP.

RESULTS

Following prior pars plana vitrectomy, pO₂ levels were significantly higher than in the reference group of cataract surgery in the anterior chamber angle (16.2 ± 5.0 vs. 13.0 ± 3.9 mm Hg; P = .0171) and in the posterior chamber (7.6 ± 3.1 vs. 3.9 ± 2.7 mm Hg; P < .0001). AsA and TRAP levels were significantly lower (1.1 ± 0.4 vs. 1.4 ± 0.5 mM, respectively; 403.3 ±116.5 vs. 479.0 ± 146.7 Trolox units, respectively; P = .004 and P = .024, respectively) in patients after vitrectomy. In patients with an intact vitreous, neither pO₂ nor antioxidant status correlated with lens status or glaucoma.

CONCLUSIONS

Increased pO₂ and antioxidant depletion following vitrectomy suggests an alteration of the intraocular oxidant-antioxidant balance. Our study links physiologic factors such as increased pO₂ in the anterior chamber angle and the posterior chamber to decreased antioxidant levels in aqueous humor following vitrectomy. Oxidative stress/damage to the trabecular meshwork in such post-vitrectomy cases may contribute to intraocular pressure elevation and increased risk of glaucoma. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Anatomical and functional changes in paravascular abnormalities after epiretinal membrane removal

PURPOSE

To investigate the anatomical and functional changes in areas containing paravascular abnormalities (PVA) in eyes with epiretinal membrane (ERM) after surgery.

METHODS

Twenty-eight eyes with concurrent idiopathic ERM and PVA were enrolled in this prospective study. Best-corrected visual acuity (BCVA), central macular thickness (CMT), and areas of PVA in the superficial and deep capillary levels detected on en face optical coherence tomography were measured preoperatively and 1, 3, and 6 months postoperatively. Retinal sensitivity in selected PVA lesions was evaluated by microperimetry preoperatively and 1 and 6 months postoperatively.

RESULTS

The areas of PVA at the superficial capillary level before and 1, 3, and 6 months after surgery measured 1.65 ± 1.27, 0.44 ± 0.62, 0.40 ± 0.64, and 0.38 ± 0.62 mm², respectively, while those at the deep capillary level measured 0.27 ± 0.57, 0.10 ± 0.26, 0.09 ± 0.29, and 0.05 ± 0.15 mm², respectively. The areas of PVA in the superficial and deep capillary levels were significantly smaller postoperatively (all p < 0.001 at the superficial capillary level and p = 0.010 at the deep capillary level). Average retinal sensitivity values in the PVA lesions before and 1 and 6 months after surgery were 11.2 ± 3.5, 12.9 ± 3.2, and 13.2 ± 2.7 dB, respectively; the values at postoperative months 1 and 6 were significantly improved (p = 0.045 and p < 0.001, respectively). BCVA and CMT were significantly improved postoperatively.

CONCLUSION

PVA not only improves anatomically but also functionally after ERM surgery. Vitrectomy can improve not only central vision but also retinal sensitivity in areas of PVA.

Effects of Collagenase Type II on Vitreous Humor—An In Situ Rheological Study

The purpose of this study is to quantify the impact of enzyme activity on the vitreous humor structure over time to understand the mechanical characteristics of the vitreous humor gel. Changes in the mechanical behavior of the vitreous occur due to many reasons including aging, which may lead to many vitreoretinal diseases. The degeneration process of the vitreous has been studied; however, in situ experimental procedures to validate the existing hypotheses are limited. We examined thirty-eight porcine eyes using in situ rheological creep tests to measure the mechanical properties of the vitreous humor of the eyes prior to, 1 h and 24 h after the intravitreal injection. Eyes in one group were injected with collagenase type II solution and eyes in the control group were injected with phosphate buffered saline solution (PBS) with calcium and magnesium chloride. Prior to the injection, viscosity and creep compliance intercept values between both groups were not statistically different. At 1 h and 24 h after the injection, vitreous properties in the eyes from the first group showed a statistically significant increase in the J intercept values (representing the inverse of elasticity) compared to the control group. In addition, 1 h and 24 h after the injection, vitreous viscosity was lower in the eyes from the first group than in the eyes from the control group. These findings are a foundation for future studies on the effectiveness of intravitreal drugs that modify the mechanical properties of the vitreous humor.

A Randomized Controlled Clinical Trial Comparing 20 Gauge and 23 Gauge Vitrectomy for Patients with Macular Hole or Macular Pucker

Introduction

To compare the transconjunctival sutureless 23 gauge (G) pars plana vitrectomy (PPV) with 20 G PPV regarding inflammation, safety, visual outcome and patient comfort.

Methods

We included 103 patients with symptomatic macular hole or macular pucker, scheduled for vitrectomy in this prospective, randomized, controlled, mono-center clinical trial. Patients were randomized 1:1 to either 20G PPV (n = 51) or 23G PPV (n = 52). All eyes underwent standard 20G or 23G PPV with membrane peeling. Primary outcome measure was change in aqueous humor flare 3 weeks after surgery compared with baseline. Secondary outcome measures were flare values 2 days and 26 weeks after surgery, subjective discomforts measured with a visual analog scale, best-corrected visual acuity, duration of surgery, intraocular pressure (IOP) and adverse events.

Results

There was no significant difference in change of flare 3 weeks after PPV [− 1.7, 95% CI (− 6.3 to 2.9), p = 0.466]. Both groups showed a significant increase in flare 2 days after surgery (20G: p < 0.001, 23G: p = 0.002), but only the 20G group after 3 weeks (p = 0.011). The gain in visual acuity after 3 weeks was higher after 23G PPV (4.2 95% CI (0.4–8.0, p = 0.029), but without a difference after 6 months. The duration of surgery was shorter in the 23G group (p < 0.001). Patient comfort 3 weeks after surgery was greater after 23G PPV (foreign body sensation p = 0.002; itching: p = 0.021). However, the rate of complications did not differ between the groups.

Conclusion

The primary aim, showing the superiority of the 23G group regarding the change of flare value from baseline to 3 weeks after surgery, was not met, but the level of inflammation decreased faster after 23G PPV. Clear advantages of the 23G PPV were a lower risk of postoperative IOP elevation, a shorter surgery time, faster visual recovery and greater patient comfort in the early postoperative phase.

Clinical Trial Registration Number

ClinicalTrials.gov NCT01969929.

Electronic supplementary material

The online version of this article (10.1007/s12325-018-0826-6) contains supplementary material, which is available to authorized users.

Visual outcome and complications of cataract extraction after pars plana vitrectomy

Purpose

To evaluate the visual outcomes and complications of phacoemulsification in previously vitrectomized eyes.

Patients and methods

A retrospective analysis of 87 consecutive vitrectomized eyes (87 patients) which had undergone phacoemulsification with intraocular lens implantation between 2013 and 2016.

Results

The mean interval from pars plana vitrectomy (PPV) to cataract surgery (CS) was 18.8 months. Mean age at CS was 61.5 years. Intraoperative complications included anterior rhexis tear (1 eye) and hyphema (1 eye). Postoperative complications included macular edema (17.2%, mean 42 days), posterior capsule opacification (13.8%, mean 14 months), ocular hypertension (11.5%), and anterior uveitis (1.1%). Preoperative mean best-corrected visual acuity improved from 20/50 to 20/25. Ninety-one percent of the eyes gained 2 or more lines, and 95% achieved visual acuity ≥20/40 after CS. Preoperative mean spherical equivalent improved from -4.35 to -0.17. Eyes with clear lens prior to the PPV had later CS (clear lens 27.1 vs no clear lens 9.7 months; p=0.016). Patients >55 years with clear lens at PPV (n=21) had earlier CS than younger ones with clear lens (n=24) (11.8 vs 40.5 months; p=0.033). Mean follow-up was 14.5 months.

Conclusion

Phacoemulsification is a safe procedure in vitrectomized eyes, with substantial gains in vision in most cases. Patients of advanced age and eyes without clear lens prior to the PPV had earlier CS.

The quantitative assessment of alterations in lens transparency after transconjunctival 27-gauge microincision vitrectomy surgery

PurposeTo evaluate the baseline and post-vitrectomy lens densitometry values by a Scheimpflug camera in eyes with epiretinal membrane that were treated with 27-G microincision vitrectomy surgery (MIVS) without tamponade and to compare the results with those in fellow healthy eyes.Patients and methodsProspective case series. The lens densitometry measurements of 24 patients, who underwent 27-G MIVS without any tamponade for the treatment of epiretinal membrane, were taken preoperatively and on the first week, first month, and third month postoperatively with Pentacam HR-Scheimpflug imaging system.ResultsThe mean lens densitometry values at Zone 1 and average lens densitometry values significantly increased in the study eyes on the first month when compared with the preoperative values (P=0.011, P=0.033, respectively). Additionally, there were statistically significant differences regarding the mean lens densitometry values of Zone 1 and Zone 2, and also average lens densitometry values between the preoperative and third month postoperative values (P=0.003, P=0.021, P=0.009, respectively). However, the densitometry values of fellow eyes were similar at preoperatively and all the postoperative follow-up periods (P>0.05 for all).ConclusionsThis study suggests that 27-G MIVS might cause post-surgical lens density changes even in early postoperative months and vitreous may play an important role in protecting the transparency of the lens.