Measuring Anterior Chamber Inflammation After Cataract Surgery: A Review of the Literature Focusing on the Correlation with Cystoid Macular Edema

Incidence and Remission of Post-Surgical Cystoid Macular Edema Following Cataract Surgery in Eyes With Intraocular Inflammation

PURPOSE

To evaluate the incidence, remission, and relapse of post-surgical cystoid macular edema (PCME) following cataract surgery in inflammatory eye disease.

METHODS

A total of 1859 eyes that had no visually significant macular edema prior to cataract surgery while under tertiary uveitis management were included. Standardized retrospective chart review was used to gather clinical data. Univariable and multivariable logistic regression models with adjustment for inter-eye correlations were performed.

RESULTS

PCME causing VA 20/50 or worse was reported in 286 eyes (15%) within 6 months of surgery. Adults age 18-64 years as compared to children (adjusted odds ratio [aOR] = 2.42, for ages 18 to 44 years and aOR = 1.93 for ages 45 to 64 years, overall P = .02); concurrent use of systemic immunosuppression (conventional aOR 1.53 and biologics aOR = 2.68, overall P = .0095); preoperative VA 20/50 or worse (overall P < .0001); cataract surgery performed before 2000 (overall P = .03) and PMCE in fellow eye (aOR = 3.04, P = .0004) were associated with development of PCME within 6 months of cataract surgery. PCME resolution was seen in 81% of eyes at 12 months and 91% of eyes at 24 months. CME relapse was seen in 12% eyes at 12 months and 19% eyes at 24 months.

CONCLUSIONS

PCME occurs frequently in uveitic eyes undergoing cataract surgery; however, most resolve within a year. CME recurrences likely are due to the underlying disease process and not relapses of PCME.

Self-assembled coating with a metal-polyphenolic network for intraocular lens modification to prevent posterior capsule opacification

Posterior capsule opacification (PCO) is a main complication after cataract surgery and intraocular lens (IOLs) implantation and is attributed to residual lens epithelial cells (LECs) migrating to the IOL surface and posterior capsules. IOL surface modification has been a newly-developing research filed in recent years; however, the applicability and economical acquisition of modified materials remain unsolved. In this study, we first applied a metal-polyphenolic network coating with a self-assembly technique on the IOL surface by using tannic acid (TA) combined with AlCl3, which are easily acquire and applying on the IOL surface to solve the IOL transmittance affair. Using wound healing and Transwell assay to verify AZD0364 inhibits cell migration (P< 0.05), the lipopolysaccharide-induced macrophage inflammation model to verify pterostilbene (PTE) inhibits the inflammatory reaction (P< 0.01). By optimizes its self-assembly coating parameters and calculating its drug release kinetics, we successfully loaded these two drugs on the coating, named TA (AZD0364/PTE) IOL. Its surface morphology characteristics were analyzed by scanning electron microscope, x-ray photoelectron spectrometer and water contact angle. The optical performance was carefully investigated by optical instruments and equipment (n= 3). Thein vitroresults showed that TA (AZD0364/PTE) IOL can significantly inhibit cell adhesion and acute inflammation (n= 3,P< 0.0001). Importantly, afterin vivoimplantation for 28 d with eight rabbits PCO models in two groups, the TA (AZD0364/PTE) IOL group maintained clear refracting media and decreased the inflammatory reaction compared with the original IOL group (P< 0.05). This study provides a new applicable and economical strategy for preventing PCO and offers a reference for the next generation of IOLs that benefit cataract patients.

Blood-Aqueous Barrier Disruption in Penetrating and Posterior Lamellar Keratoplasty: Implications for Clinical Outcome

BACKGROUND

The blood-aqueous barrier (BAB) separates immunoprivileged tissue of the eye from the blood circulation. Disruption of the BAB is therefore a risk factor for rejection after keratoplasty.

PURPOSE

The present work provides a review of the work of our group and others on BAB disruption in penetrating and posterior lamellar keratoplasty and its implications for clinical outcome.

METHODS

A PubMed literature search was performed to generate a review paper.

RESULTS

Laser flare photometry provides an objective and reproducible method to assess the integrity of the BAB. Studies of the flare after penetrating and posterior lamellar keratoplasty demonstrate a mostly regressive disruption of the BAB in the postoperative course, which is influenced in extent and duration by multiple factors. Persistently elevated flare values or an increase in flare after initial postoperative regeneration may indicate an increased risk of rejection.

DISCUSSION

In case of persistent or recurrent elevated flare values after keratoplasty, intensified (local) immunosuppression may potentially be useful. This could become important in the future, especially for the monitoring of patients after high-risk keratoplasty. Whether an increase of the laser flare is a reliable early indicator of an impending immune reaction after penetrating or posterior lamellar keratoplasty has to be shown in prospective studies.

The Blood-ocular Barriers and their Dysfunction: Anatomy, Physiology, Pathology

Complex barriers comprise the blood-aqueous (BAB) and the blood-retinal barrier (BRB), and separate anterior and posterior eye chambers, vitreous body, and sensory retina from the circulation. They prevent pathogens and toxins from entering the eye, control movement of fluid, proteins, and metabolites, and contribute to the maintenance of the ocular immune status. Morphological correlates of blood-ocular barriers are tight junctions between neighboring endothelial and epithelial cells, which function as gatekeepers of the paracellular transport of molecules, thereby limiting their uncontrolled access to ocular chambers and tissues. The BAB is composed of tight junctions between endothelial cells of the iris vasculature, endothelial cells of Schlemm's canal inner wall, and cells of the nonpigmented ciliary epithelium. The BRB consists of tight junctions between endothelial cells of the retinal vessels (inner BRB) and epithelial cells of the retinal pigment epithelium (outer BRB). These junctional complexes respond rapidly to pathophysiological changes, thus enabling vascular leakage of blood-derived molecules and inflammatory cells into ocular tissues and chambers. Blood-ocular barrier function, which can be clinically measured by laser flare photometry or fluorophotometry, is compromised in traumatic, inflammatory, or infectious processes, but also frequently contributes to the pathophysiology of chronic diseases of the anterior eye segment and the retina, as exemplified by diabetic retinopathy and age-related macular degeneration.

Changes in Macular Thickness after Cataract Surgery in Patients with Open Angle Glaucoma

BACKGROUND

The purpose of this study was to examine the changes in IOP, total macular and RNFL, ganglion cell layer (GCL) thickness, and aqueous humour flare in open angle glaucoma (OAG) patients before and 6 months after cataract surgery.

METHODS

This was a prospective observational case-control age- and gender-matched study. Groups: 40 subjects in a controlled OAG (OAG_c) group, 20 subjects in an uncontrolled OAG (OAG_u) group, and 60 control group subjects.

EXAMINATION

complete ophthalmic evaluation, IOP measurement, anterior and posterior segment Optical Coherence Tomography (OCT), and laser flare photometry before and 6 months postoperatively.

RESULTS

Six months postoperatively IOP decreased in all groups. An increase in macular thickness was found postoperatively in all groups. Preoperative aqueous humour flare was higher in the OAG_c group than in the control group. After cataract surgery, aqueous humour flare was higher in the control group compared to the preoperative result.

CONCLUSIONS

Changes in IOP following cataract surgery were strongly negatively correlated with preoperative IOP. An increase in macular thickness was observed 6 months postoperatively in all groups. Aqueous humour flare did not differ in OAG_c and OAG_u groups pre- and postoperatively but significantly increased in the control group postoperatively.

Management of inflammation after the cataract surgery

PURPOSE OF REVIEW

To review most recent studies and clinical trials regarding pathogenesis, treatment, and prevention of inflammation after the cataract surgery.

RECENT FINDINGS

FLACS gave opportunity to evaluate inflammatory cytokines in the aqueous humour right after the laser procedure, which led to acknowledging the inflammation pathogenesis during the phacoemulsification. Although there is still a lack of evidence, which would prove the long-term benefit of NSAIDs, they are indicated and effective when risk factors for PCME are present. PREMED studies showed that combination of NSAID and steroids after the surgery for healthy subjects is cost-effective. The triamcinolone injection together with topical steroids and NSAIDs for diabetic patients after the cataract surgery was the most cost-effective in preventing PCME according to the PREMED. Dropless cataract surgery is another emerging topic: dexamethasone implants and suspensions look promising as we await more clinical trials with drug-loaded IOLs.

SUMMARY

Inflammation after the cataract surgery can be prevented, and these methods are one of the most essential topics with growing phacoemulsification rate. Topical NSAIDs are cost-effective not only for patients with risk factors for PCME but also for healthy subjects. New dropless techniques are being successfully introduced in the clinical practice.

Small Nucleolar RNAs in Pseudoexfoliation Glaucoma

Small nucleolar RNAs (snoRNAs) are small non-coding regulatory RNAs that have been investigated extensively in recent years. However, the relationship between snoRNA and glaucoma is still unknown. This study aims to analyze the levels of snoRNA expression in the aqueous humor (AH) of patients with pseudoexfoliation glaucoma (PEXG) compared to a control group and identify hypothetical snoRNA-dependent mechanisms contributing to PEXG. The AH was obtained from eighteen Caucasian patients, comprising nine PEXG and nine age-matched control patients. RNA was isolated, and a microarray system was used to determine the snoRNA expression profiles. Functional and enrichment analyses were performed. We identified seven snoRNAs, SNORD73B, SNORD58A, SNORD56, SNORA77, SNORA72, SNORA64, and SNORA32, in the AH of the PEXG and control group patients. Five snoRNAs showed statistically significantly lower expression in the PEXG group, and two snoRNAs had statistically significantly higher expression in the PEXG group compared to the control group. In addition, we identified two factors-CACNB3 for SNORA64 and TMEM63C for SNORA32, similar to PEX-related genes (CACNA1A and TMEM136). The enrichment analysis for four genes targeted by snoRNAs revealed possible mechanisms associated with glaucoma and/or PEX, but the direct role of snoRNAs in these biological processes was not proven.

Liposomal drug delivery system for anti-inflammatory treatment after cataract surgery: a phase I/II clinical trial

Liposomes as a drug delivery system may overcome the problems associated with non-compliance to eyedrops and inadequate control of inflammation after cataract surgery. We evaluated the safety and efficacy of a single subconjunctival injection of liposomal prednisolone phosphate (LPP) for the treatment of post-cataract surgery inflammation. This is a phase I/II, open-label non-comparative interventional trial of patients undergoing cataract surgery. All patients received a single injection of subconjunctival LPP intraoperatively. The primary outcome measure was the proportion of eyes with an anterior chamber cell count of 0 at postoperative month 1. Ocular and non-ocular adverse events, including elevated intraocular pressure, rebound iritis and pseudophakic macular edema were monitored. Five patients were enrolled in this study. The mean age was 66.6 ± 6.2 and 4 (80%) were male. The proportion of patients with AC cell grading of 0 was 0%, 80%, 80%, and 100% at day 1, week 1, month 1, and month 2 after cataract surgery, respectively. Mean laser flare photometry readings were significantly elevated at week 1 after cataract surgery (48.8 ± 18.9, p = 0.03) compared with baseline, decreasing to 25.8 ± 9.2 (p = 0.04) at month 1 and returned to baseline by month 2 (10.9 ± 5.1, p = 1.0). No ocular or non-ocular adverse events were observed. Liposomal prednisolone phosphate, administered as a single subconjunctival injection intraoperatively, can be a safe and effective treatment for post-cataract surgery inflammation. The delivery of steroids with a liposomal drug delivery system could potentially replace eyedrops as anti-inflammatory therapy following cataract surgery.

Preoperative Care for Cataract Surgery: The Society for Ambulatory Anesthesia Position Statement

Cataract surgeries are among the most common procedures requiring anesthesia care. Cataracts are a common cause of blindness. Surgery remains the only effective treatment of cataracts. Patients are often elderly with comorbidities. Most cataracts can be treated using topical or regional anesthesia with minimum or no sedation. There is minimal risk of adverse outcomes. There is general consensus that cataract surgery is extremely low risk, and the benefits of sight restoration and preservation are enormous. We present the Society for Ambulatory Anesthesia (SAMBA) position statement for preoperative care for cataract surgery.

KPI-121 1% for pain and inflammation in ocular surgery

Pain and inflammation are common experiences following ocular surgery and, if uncontrolled, can compromise patients' vision, functioning and quality of life. Corticosteroid drugs are available to manage inflammation and discomfort but have limitations in penetrating the ocular mucus barrier to reach the target ocular tissues. KPI-121 1% (INVELTYS^®) is a novel formulation of loteprednol etabonate that employs innovative proprietary technology to deliver nanoparticle-sized mucus-penetrating particles to the cornea. Results from clinical trials demonstrate that KPI-121 1% is effective and well tolerated. KPI-121 1% uses mucopenetrative technology for ophthalmic use and is the only US FDA-approved twice-daily ocular corticosteroid indicated for the treatment of inflammation and pain after ocular surgery.

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.

Fellow-Eye Comparison between Phaco-Microhook Ab-Interno Trabeculotomy and Phaco-iStent Trabecular Micro-Bypass Stent

The aim of this study is to compare the surgical efficacy and safety between microhook ab-interno trabeculotomy (µLOT) and iStent trabecular micro-bypass stent implantation when both were combined with cataract surgery in both eyes of patients. Sixty-four glaucomatous eyes (32 participants; mean age, 75.9 ± 7.6 years; 15 men, 17 women) were included retrospectively. Intraocular pressure (IOP), number of antiglaucoma medications, best-corrected visual acuity (BCVA), anterior chamber flare (ACF) and corneal endothelial cell density (CECD) were evaluated preoperatively, as well as 2, 3, 6, and 12 months postoperatively. Surgical complications and interventions were compared between the procedures. The preoperative IOP and medications with µLOT (18.8 ± 5.7 mmHg and 3.0 ± 1.2, respectively) were higher than with the iStent (15.5 ± 3.4 mmHg and 2.7 ± 1.2, respectively) (p = 0.0001 and p = 0.0437, respectively). At 12 months, the µLOT values (12.6 ± 2.3 mmHg and 2.3 ± 0.9, respectively) were identical to iStent (12.8 ± 2.5 mmHg and 2.3 ± 0.9, respectively) (p = 0.0934 and p = 0.3251, respectively). At 12 months, the IOP decreased more with µLOT (6.2 mmHg, 29.5%) than iStent (2.7 mmHg, 15.6%) (p = 0.0003). The decrease in medications was greater with µLOT (0.7) than iStent (0.4) (p = 0.0437). Survival rate of IOP control ≤15 mmHg and IOP reduction ≥20% was significantly higher after µLOT (40.6% at 12 months) than iStent (18.8%) (p = 0.0277). The frequency of layered hyphema was significantly greater with µLOT (8 eyes, 25%) than iStent (0 eyes, 0%) (p = 0.0048). The increase in the ACF at 2 weeks postoperatively was significantly greater with µLOT than iStent (p = 0.0156), while changes in the BCVA and CECD were identical between groups. The fellow-eye comparison showed that the IOP reduction was greater with µLOT than iStent when combined with cataract surgery.

Therapeutic Efficacy of Difluprednate 0.05% Versus Prednisolone Acetate 1% in Controlling Inflammation and Macular Oedema Following Phacoemulsification: An Optical Coherence Tomography-Based Study

BACKGROUND

Topical corticosteroids have been the cornerstone in the management of postoperative inflammation following cataract surgery. Due to potential side effects of the older topical steroids like prednisolone acetate and dexamethasone or betamethasone, newer potent steroids preparation like difluprednate, loteprednol or fluorometholone are now being used at lesser dose and frequency to control inflammation. There is scanty literature on the efficacy of these drugs in preventing inflammation and macular oedema in the Indian population.

PURPOSE

The purpose of this study was to compare the efficacy of difluprednate 0.05% against prednisolone 1% eye drops for control of inflammation following phacoemulsification. The adverse effects of both drugs were also evaluated in this retrospective study.

METHODS

This retrospective cohort study included 181 patients operated for age-related cataracts by a single surgeon at a tertiary referral eye hospital between December 2018 and March 2019. Patients received either difluprednate 0.05% emulsion (n=90 eyes) or prednisolone acetate 1% (n=91 eyes) after phacoemulsification with the same brand intraocular lens (IOL) and same phaco machine. The topical medication was initiated one day postoperatively and continued for six weeks in tapering dosage. Pain score (Visual Analogue Scale, VAS), conjunctival hyperemia, anterior chamber (AC) cell grading, corneal oedema, central retinal thickness, subclinical cystoid macular oedema (SCME), intraocular pressures (IOP) and best-corrected visual acuity (BCVA) were examined after one week and six weeks of cataract extraction.  Results: There was no statistically significant difference observed with regards to pain score (no pain in any patients after six weeks), conjunctival hyperemia (no hyperemia in any patients after six weeks), AC inflammation (no reaction in any patients), central retinal thickness (234.44 ± 35.75µ vs. 234.8 ± 34.99µ, p-value 0.946), SCME (16.67% vs. 13.19%, p-value 0.511), IOP (16.8 vs. 15.47 mmHg, p-value 0.101) and BCVA (BCVA 6/6 in 57.7% vs. 70.32%, p-value >0.05) between both groups. The mean change in IOP in both the groups at one week (0 ± 4.4 vs. 1.87 ± 3.54, p-value 0.0007) and six weeks (-0.01 ± 5.53 vs. 1.88 ± 4.01, p-value 0.004) was significant.  Conclusion: Both the groups were equivalent with regards to their therapeutic efficacy in controlling postoperative inflammation and restoration of vision following phacoemulsification.

Effect of anti-inflammatory regimen on early postoperative inflammation after cataract surgery

PURPOSE

To investigate whether a combination of topical nonsteroidal anti-inflammatory drugs (NSAIDs) and steroids were superior in controlling early postoperative inflammation after cataract surgery compared with topical NSAIDs alone and with dropless surgery where a sub-Tenon depot of steroid was placed during surgery.

SETTING

Department of Ophthalmology, Rigshospitalet-Glostrup, Denmark.

DESIGN

Prospective randomized controlled trial with masked statistical analyses.

METHODS

Patients undergoing phacoemulsification for age-related cataract were randomized to 1 of 5 regimens: ketorolac and prednisolone eyedrops combined (Pred+NSAID-Pre [control group] and Pred+NSAID-Post group) vs ketorolac monotherapy (NSAID-Pre and NSAID-Post groups) vs sub-Tenon depot of dexamethasone (dropless group). Drops were used until 3 weeks postoperatively, starting 3 days preoperatively in the Pre groups and on the day of surgery in the Post groups. Aqueous flare was measured at baseline and 3 days postoperatively.

RESULTS

Four hundred fifty-six participants, with a mean age of 72.1 (SD 7.0) years and 283 (62%) women, were included. Flare increased significantly more in the dropless group compared with the control group (Pred+NSAID-Pre), but none of the other groups differed significantly from the control group. Intraocular pressure decreased in all groups but significantly less in groups receiving prednisolone eyedrops (Pred+NSAID-Pre and Pred+NSAID-Post groups) compared with NSAID monotherapy and dropless groups. No differences in postoperative visual acuity were found compared with the control group.

CONCLUSIONS

No differences were found between groups randomized to NSAID monotherapy or combination of NSAID and steroid in controlling early inflammation after cataract surgery, but sub-Tenon depot of dexamethasone was less efficient. Initiating prophylactic eyedrops prior to surgery did not influence early postoperative anterior chamber inflammation.

Persistence of Inflammation After Uncomplicated Cataract Surgery: A 6-Month Laser Flare Photometry Analysis

PURPOSE

To evaluate, by laser photometry, the persistency of anterior chamber flare after uneventful phacoemulsification in asymptomatic patients with no signs of inflammation on slit lamp examination.

METHOD

Seventy-five patients previously enrolled in a randomized clinical trial that evaluated inflammation after uneventful phacoemulsification in eyes treated with dexamethasone 0.1% ophthalmic suspension (group 1) or bromfenac 0.09% ophthalmic solution (group 2) for 2 weeks. Anterior chamber inflammation was investigated by laser flare photometry. At 30 days after surgery, laser flare showed persistently elevated values. For this reason, patients were further analyzed at 3 and 6 months. Additionally, optical coherence tomography was used to measure the central macular thickness (CMT) and to assess for postoperative pseudophakic macular edema.

RESULTS

When compared to preoperative values, laser flare photometry demonstrated persistent ocular inflammation at postoperative days 90 and 180 in group 1, but not in group 2. Laser flare values showed a significant reduction in group 2 compared to group 1 throughout all the follow-up (p < 0.001). The increase in mean CMT at days 90 and 180 with respect to baseline was statistically significant in group 1 but not in group 2, in which it decreased to levels similar to preoperative value. Group 1 showed a higher increase in mean CMT compared to group 2 throughout all the follow-up (p < 0.001). The proportion of patients that developed pseudophakic cystoid macular edema (CME) was 14% (n = 5) and 0% (n = 0) in group 1 and group 2, respectively (p = 0.02). The bivariate analysis demonstrated a positive correlation between laser flare and CMT values in group 1 but not in group 2.

CONCLUSION

Anterior chamber inflammation persists for more than 30 days in a significant proportion of patients after uncomplicated cataract surgery and may be responsible for late onset of cystoid macular edema cases.

TRIAL REGISTRATION

ClinicalTrials.gov identifier, NCT03317847.