Corneal endothelial cell loss and corneal biomechanical characteristics after two-step sequential or combined phaco-vitrectomy surgery for idiopathic epiretinal membrane

One-year longitudinal study of corneal changes after different vitrectomy procedures using confocal microscopy

This study aimed to evaluate corneal stromal and endothelial alterations after vitrectomy using in vivo confocal microscopy (IVCM), focusing on the implications of different surgical techniques and tamponades. In this prospective cohort study, a total of 99 eyes from 98 consecutive patients scheduled for vitrectomy were initially enrolled. Each subject underwent a comprehensive ophthalmic evaluation, including fundus examination, intraocular pressure assessment, and IVCM imaging. These evaluations were conducted preoperatively, as well as at 1, 3, 6, 9, and 12 months following surgery. Data were analyzed to correlate corneal cellular alterations with vitrectomy techniques and tamponades. Data from 80 eyes of 79 patients were used in the final analysis stratified into six groups based on the combination of surgical approach and tamponade used. Postoperatively, compared to baseline, posterior stromal cell density (SCD) significantly increased in patients who underwent phacoemulsification (Phaco) and intraocular lens (IOL) implantation with C3F8 tamponade, while anterior SCD significantly decreased in patients treated with Phaco and silicone oil (SiO2). The prevalence of keratic precipitates, endothelial nucleation, and dark spots in the corneal endothelial layer significantly increased post-surgery and did not return to the preoperative baseline by the end of the follow-up period, especially in the group treated with Phaco and C3F8 tamponade. Endothelial cell loss was significantly higher at 3 months post-surgery, with rates of 9.16% for air tamponade, 8.86% for C3F8, 2.93% for SiO2, 9.24% for Phaco and C3F8, 11.58% for Phaco with IOL and C3F8, and 11.99% for Phaco with SiO2. By the end of the 12-month follow-up, losses were 8.12% for air, 9.39% for C3F8, 16.38% for SiO2, 3.39% for Phaco and C3F8, 10.65% for Phaco with IOL and C3F8, and 14.40% for Phaco with SiO2. Our IVCM-based study offers insights into the dynamic responses of corneal cells to vitreoretinal surgeries, focusing on the effects of Air, C3F8, and SiO2 tamponades, with and without Phaco. The distinct patterns of response observed in the C3F8 and SiO2 groups, both with and without Phaco, underscore the importance of carefully choosing the surgical procedure based on individual fundus conditions and implementing tailored postoperative care based on the tamponade used. Our findings lay the groundwork for further studies on the long-term effects of tamponade materials and the development of targeted therapies to mitigate corneal reactions related to vitrectomy.

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.

The corneal biomechanical changes of phacoemulsification in cataract patients: A systematic review and meta-analysis

PURPOSE

To evaluate the corneal biomechanical properties of phacoemulsification in the treatment of cataract patients.

METHODS

Pertinent studies were searched in PubMed, EMBASE, Web of Science and clinicaltrials.gov., as of November 05, 2024. The reference lists of related published reviews were included as well. This meta-analysis was performed with Stata Software and Review Manager, we used mean difference (MD) to evaluate the statistical consequence, using I2 statistic to assess the heterogeneity. Subgroup analysis were performed under the occurrences of high heterogeneity. We used eleven items to describe the characteristics of included studies, publication bias was performed with Egger's test. The quality assessment were evaluated with 3 items by Newcastle-Ottawa Scale (NOS) items.

RESULTS

Thirteen eligible studies were identified for data synthesis and assessment. According to the result of meta-analysis, the central corneal thickness(CCT) (MD = 10.50, 95% CI: [5.01, 15.98]; P<0.05) and intraocular pressure(IOPg)(MD = -0.73, 95% CI: [-1.26, -0.19]; P<0.05) of cataract patients after phacoemulsification was significantly higher than the control groups. The values of corneal hysteresis(CH) (MD = -0.43, 95% CI: [-0.62, -0.23]; P<0.05) and corneal resistance factor(CRF) (MD = -0.49, 95% CI: [-0.64, -0.33]; P<0.05) after phacoemulsification surgery were statistically lower than the control groups. While the values of IOPcc did not show statistically different (MD = -0.13, 95% CI: [-0.67, 0.41]; P = 0.64).

CONCLUSION

Included data analysis indicated that the values of CCT, CH, CRF and IOPg showed statistical change in cataract patients after phacoemulsification surgeries compared with control groups. There is a correlation between corneal biomechanics and phacoemulsification surgeries.

Corneal densitometry: an innovative method to quantitatively evaluate corneal changes after phacovitrectomy

BACKGROUND

To quantitatively investigate corneal changes and the correlation between corneal densitometry (CD) and endothelial parameters after phacovitrectomy.

METHODS

Thirty-eight eyes with idiopathic full-thickness macular holes (iFTMHs) and cataracts underwent phacovitrectomy. Examinations were conducted at baseline and Day 1, Day 7, Month 1, and Month 3 postoperatively. CD and central corneal thickness (CCT) were measured using Pentacam. Corneal endothelial cell density (ECD), coefficient of variation (CV), and hexagonality (HEX) were measured using specular microscopy.

RESULTS

ECD and HEX significantly decreased after surgery and the change in HEX occurred prior to CV. CCT increased immediately after surgery and recovered 3 months postoperatively. CD values increased significantly 1 day after surgery and then gradually decreased. For CD in the 0-2 mm zone, it took 1 month to recover in the central and posterior layers and 3 months in the anterior and total layers. For CD in the 2-6 mm zone, the central layer recovered at Day 7, the anterior and total layers recovered at 1 month, and the posterior layer did not recover until 3 months postoperatively. The CD within all layers in the 0-2 mm zone was positively correlated with CCT. Posterior CD in the 0-2 mm zone was negatively correlated with ECD and HEX.

CONCLUSIONS

CD is not only correlated with CCT, ECD, and HEX but also reflects the state of the whole cornea and each layer. CD can be an objective, rapid, and noninvasive tool that reflects corneal health and undetectable edema and monitors the process of lesion repair.

TRIAL REGISTRATION

This study was registered with the Chinese Clinical Trial Registry (31/10/2021, ChiCTR2100052554).

Early influence of endotamponade on corneal biomechanical parameters, central corneal thickness and accuracy of intraocular pressure measurement

To define the influence of air, SF6 gas and silicon oil 1000cs tamponade injection and oil tamponade removal on corneal biomechanics, central corneal thickness and intraocular pressure. 77 eyes referred to vitrectomy were divided into 4 groups: 19 to air tamponade, 21 to SF6 tamponade, 19 to oil tamponade, 18 to oil tamponade removal. Pre- and postoperative corneal hysteresis, corneal resistance factor, corneal thickness, Goldman intraocular pressure (GAT) and corneal compensated intraocular pressure (IOPcc) were analysed. GAT and IOPcc did not change after the air or SF6 tamponade. The oil tamponade injection caused increase in GAT and IOPcc, while the oil removal caused reduction in those parameters. In all groups, preoperative and postoperative values of GAT and IOPcc did not differ. There was no change in corneal thickness and biomechanics after air, SF6 or oil tamponade while after removal of oil those parameters are decreased. The air, SF6 and oil tamponade does not change the corneal thickness and corneal biomechanics. The removal of oil causes decrease in corneal thickness and biomechanics which can lead to bias in intraocular pressure measurement. GAT and IOPcc did not differ in eyes pre- and post-vitrectomy, being similarly reliable measure.

[Phacovitrectomy-Influence of the timing of intraocular lens implantation on the corneal endothelium]

BACKGROUND AND PURPOSE

In phacovitrectomy the cataract is usually operated on first including implantation of the intraocular lens (IOL) before beginning vitrectomy but the IOL can also be implanted following vitrectomy. This variation avoids optical impairments from corneal opacities and the lens rim, improves the visualization of the retina during surgery and might thereby reduce intraoperative complications, such as peripheral retinal tears or IOL subluxation. It might, however, increase stress on the corneal endothelium. The aim of this study was, therefore, to compare postoperative corneal endothelial cell loss for the standard procedure of phacovitrectomy and the surgical variation.

METHODS

In this retrospective study 41 eyes were each assigned to group I (standard phacovitrectomy) or group II (variation of phacovitrectomy). The primary endpoint was the absolute and relative corneal endothelial cell loss appearing 5 ± 1 weeks postoperatively with reference to the preoperative number of endothelial cells. Secondary endpoints included visual acuity, intraocular pressure, coefficient of variation of endothelial cell area (CV), proportion of hexagonal endothelial cell forms (6A), pachymetry, intraoperative and postoperative complications.

RESULTS

The absolute and relative endothelial cell loss in group I (-108 ± 146; -4.1 ± 5.7%) did not differ significantly from that in group II (-73 ± 122; -3.1 ± 5.3%, p = 0.299; p = 0.388). The secondary endpoints also showed no significant differences.

CONCLUSION

The presented variation of phacovitrectomy expands the surgical options and does not show a significantly different postoperative corneal endothelial cell loss compared to the standard procedure.

ENDOTHELIAL CELL LOSS AFTER PARS PLANA VITRECTOMY

AIMS

To analyse the changes in endothelial cell density (ECD) after pars plana vitrectomy (PPV) and to identify the factors implicated.

PATIENTS AND METHODS

This was a prospective, consecutive, and non-randomised, case-control study. All 23-gauge vitrectomies were performed by a single surgeon at a tertiary centre. ECD was measured at baseline before surgery and on postoperative Days 30, 90, and 180. The fellow eye was used as the control eye. The primary outcome was a change in ECD after PPV.

RESULTS

Seventeen patients were included in this study. The mean age of the patients was 65 years. The mean ECD count at baseline was 2340 cells/mm2. The median ECD loss in the vitrectomised eye was 3.6 %, 4.0 %, and 4.7 % at Days 30, 90, and 180, respectively, compared to +1.94 %, +0.75 %, +1.01 %, respectively, in the control eye. The relative risk of ECD loss after PPV was 2.48 (C.I. 1.05-5.85, p = 0.0247). The pseudophakic eyes lost more ECD than the phakic eyes, but this was not statistically significant. There were no significant differences in diagnosis, age, surgical time, or tamponade used after surgery.

CONCLUSIONS

Routine pars plana vitrectomy had an impact on the corneal endothelial cells until Day 180 post-op. The phakic status was slightly protective against ECD loss after PPV, although it was not statistically significant. The pathophysiology of corneal cell damage after routine PPV remains unclear. Further studies are required to confirm these findings.

Clinical Outcomes of Primary Posterior Continuous Curvilinear Capsulorhexis in Postvitrectomy Cataract Eyes

Purpose

To evaluate the safety and outcomes of primary posterior continuous curvilinear capsulorhexis (PPCCC) combined with phacoemulsification in postvitrectomy eyes.

Design

Retrospective case series.

Methods

Twenty-one postvitrectomy eyes of 21 patients with cataract between April 2017 and December 2019 were enrolled. PPCCC through the cornea incision was performed before in-the-bag intraocular lens implantation. All patients were followed up for at least 3 months postoperatively. The outcome measures were corrected distance visual acuity (CDVA), intraocular pressure (IOP), corneal endothelium cell counts (CECC), central macular thickness (CMT), the occurrence of intraoperative or postoperative complications, and the incidence of posterior capsular opacification (PCO).

Results

The mean age was 56.14 ± 9.76 years (ranging from 31 to 68). The mean Snellen CDVA was 20/400 preoperatively and improved to 20/67 postoperatively (P < 0.001). No significant differences were found between IOP (P = 0.96) and CMT (P = 0.42) preoperatively and postoperatively. The mean CECC was 2571.8 ± 319.3 cells/mm² preoperatively and 2498.2 ± 346.3 cells/mm² postoperatively (P < 0.05). Lens epithelium cells proliferation was confined to the peripheral capsular bag during a mean follow-up of 12.9 ± 10.5 months (ranging from 3 to 28 months). Intraoperative posterior capsule extension occurred in 1 eye (4%), although it did not affect the patient's vision. No serious complications, including retinal detachment or endophthalmitis, were detected in any of the 21 cases.

Conclusion

PPCCC through cornea incision combined with phacoemulsification may be a safe and practical alternative to prevent PCO in postvitrectomy eyes with cataract.

Changes in the anterior segment of the eye following uncomplicated pars plana vitrectomy. A review

Pars plana vitrectomy is currently the most common technique used in retinal surgery. Although primarily involving the posterior segment of the eye it also affects the anterior segment. As this is a less published topic, the aim of this paper was to review the literature on changes in the anterior segment after uncomplicated pars plana vitrectomy using data based literature search. The conclusions are that even in otherwise ophthalmologically healthy patients, complications may occur in the anterior segment. Surgeons need to pay utmost attention in glaucoma patients and in those with endothelial insufficiency who are at highest risk of complications. He/she must also correctly plan a potential cataract surgery if not already done earlier. From the literature, most of the changes in the anterior segment after uncomplicated PPV are found to be temporary.

Comparison of Three Intraocular Lens Implantation Procedures for Aphakic Eyes With Insufficient Capsular Support: A Network Meta-analysis

PURPOSE

To compare the clinical outcomes and main complications of transscleral-fixated (TSF), intrascleral-fixated (ISF), and iris-fixated (IF) intraocular lenses (IOLs).

DESIGN

Systematic review and network meta-analysis.

METHODS

The authors searched PubMed, EMBASE, and the Cochrane Library for relevant articles up to April 2017 with no language restrictions, and related studies meeting the eligibility criteria were included. A Bayesian framework was applied to compare the visual outcomes and complications of these 3 approaches.

RESULTS

A total of 14 studies with 845 eyes were included in the present report. There was no significant difference between any pair of surgical approaches in best-corrected visual acuity (BCVA) and in final BCVA achieving 20/40 or better (Snellen). ISF presented a lower risk of cystoid macular edema (CME) compared with TSF (risk ratio [RR], 0.45; 95% confidence interval [CI], [0.18, 1.0]). IF showed superiorities in less intraocular hemorrhage (IOH) than ISF (RR, 0.078; 95% CI [0.0095, 0.38]), as well as TSF (RR, 0.26; 95% CI, [0.09, 0.72]). IF had a lower risk of glaucoma escalation; the difference was slightly higher than the conventional level of significance (RR, 0.41; 95% CI, [0.16, 1.04]). Moreover, the surgical time in IF was shorter than TSF (standard mean difference [SMD], -2.98; 95% CI, [-4.32, -1.64]) and ISF (SMD, -2.60; 95% CI, [-3.71, -1.49]). However, IF was associated with a significantly higher risk of endothelial cell density (ECD) impairment (SMD, -0.54; 95% CI, [-1.02, -0.05]) and significantly greater postoperative corneal endothelial cell loss rate (ECLR, %) (SMD, 0.35; 95% CI, [0.08, 0.63]) compared with TSF.

CONCLUSIONS

Postoperative visual outcomes were comparable among TSF, ISF, and IF for eyes with insufficient capsular support. However, the risk of some complications differed among approaches. IF showed its superiorities in lower risk of IOH and glaucoma escalation as well as shorter surgical time, while IF was at a disadvantage in greater endothelial cell impairment. Since some patients might have a clear contraindication to one of the surgical approaches, the decision of surgical approach eventually depends on surgeon experience and the presenting pathology.