Dexamethasone 0.4mg Sustained-Release Intracanalicular Insert in the Management of Ocular Inflammation and Pain Following Ophthalmic Surgery: Design, Development and Place in Therapy

Dexamethasone Intracanalicular Insert versus Standard Topical Steroids for the Prophylaxis of Inflammation after Cataract Surgery

PURPOSE

To compare the efficacy of an intracanalicular dexamethasone intracanalicular insert (DII) to a topical prednisolone acetate 1% taper for preventing breakthrough inflammation (iritis or cystoid macular edema) during the first post-operative month (POM1) after cataract surgery DESIGN: Retrospective, non-randomized comparative interventional study METHODS: Patients received either DII or topical prednisolone acetate 1% eyedrops (control) during POM1. Exclusion criteria included history of iritis, glaucoma, intraoperative posterior capsular rupture or vitreous prolapse, immediate postoperative anterior chamber inflammation requiring treatment, or less than 1 month follow up post-operatively. Outcomes included development of breakthrough inflammation after >3 days postoperatively necessitating additional anti-inflammatory drops, cystoid macular edema, and increased intraocular pressure at POM1.

RESULTS

266 eyes of 174 patients were included in the DII group, and 258 eyes of 167 patients in the control group. Demographics, comorbidities, and baseline IOP were comparable between groups. The breakthrough inflammation rate was significantly higher in the DII group compared to control (9.0% vs 3.1%; p < .01); cystoid macular edema rates were similar between groups (4.9% vs 4.3%; p = .75). There were no cases of increased IOP >10mmHg at POM1 compared to baseline in either group.

CONCLUSION

After cataract surgery, DII demonstrated a higher rate of breakthrough inflammation than a standard topical steroid regimen with no significant differences in CME rate or IOP increase; however, overall, the rate of postoperative complications was low. DII can be a safe and effective alternative to topical corticosteroid therapy after cataract surgery.

Controlled Drug Delivery Device for Cornea Treatment and Novel Method for Its Testing

A new solution for local anesthetic and antibiotic delivery after eye surgery is presented. A contact lens-shaped collagen drug carrier was created and loaded by Levofloxacin and Tetracaine with a riboflavin crosslinked surface layer, thus impeding diffusion. The crosslinking was confirmed by Raman spectroscopy, whereas the drug release was investigated using UV-Vis spectrometry. Due to the surface barrier, the drug gradually releases into the corneal tissue. To test the function of the carrier, a 3D printed device and a new test method for a controlled drug release, which mimics the geometry and physiological lacrimation rate of the human eye, were developed. The experimental setup with simple geometry revealed that the prepared drug delivery device can provide the prolonged release profile of the pseudo-first-order for up to 72 h. The efficiency of the drug delivery was further demonstrated using a dead porcine cornea as a drug recipient, without the need to use live animals for testing. Our drug delivery system significantly surpasses the efficiency of antibiotic and anesthetic eyedrops that would have to be applied approximately 30 times per hour to achieve the same dose as that delivered continuously by our device.

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.

In Situ Forming Hydrogel as a Tracer and Degradable Lacrimal Plug for Dry Eye Treatment

Lacrimal plug is an effective and widely therapeutic strategy to treat dry eye. However, almost all commercialized plugs are fixed in a certain design and associated with many complications, such as spontaneous plug extrusion, epiphora, and granuloma and cannot be traced in the long-term. Herein, a simple in situ forming hydrogel is developed as a tracer and degradable lacrimal plug to achieve the best match with the irregular lacrimal passages. In this strategy, methacrylate-modified silk fibroin (SFMA) is served as a network, and a self-assembled indocyanine green fluorescence tracer nanoparticle (FTN) is embedded as an indicator to develop the hydrogel plug using visible photo-crosslinking. This SFMA/FTN hydrogel plug has excellent biocompatibility and biodegradability, which can be noninvasively monitored by near-infrared light. In vivo tests based on dry eye rabbits show that the SFMA/FTN hydrogel plug can completely block the lacrimal passages and greatly improve the various clinical indicators of dry eye. These results demonstrate that the SFMA/FTN hydrogel is suitable as an injectable and degradable lacrimal plug with a long-term tracking function. The work offers a new approach to the development of absorbable plugs for the treatment of dry eye.

In Clinic Optometrist Insertion of Dextenza (Dexamethasone Ophthalmic Insert 0.4mg) Prior to Cataract Surgery: The PREPARE Study

Purpose

Methods

Results

Conclusion

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Dexamethasone-loaded keratin films for ocular surface reconstruction

Amniotic membrane (AM) is often applied as a substitute material during ocular surface reconstruction. However, since AM has several disadvantages, alternative materials must be considered for this application. Keratin films made from human hair (KFs) have previously been presented as a promising option; they exhibited suitable characteristics and satisfactory biocompatibility in an in vivo rabbit model. Nevertheless, dexamethasone (DEX) eye drops are necessary after surgery to suppress inflammation. Since eye drops must be administered frequently, this might result in poor patient compliance, and the release of DEX at the transplant site would be clinically beneficial. Therefore, we aimed to incorporate DEX into KFs without hindering the positive film characteristics. Drug-loaded KFs were generated either by suspension technique or by the addition of solubilizing agents. The resulting specimens were analyzed regarding appearance, loading capacity, transparency, mechanical characteristics, swelling behavior and in vitro release. Furthermore, biocompatibility was assessed in vitro by determining the cell viability, seeding efficiency and growth behavior of corneal epithelial cells. The amount of incorporated DEX influenced the transparency and biomechanical properties of the films, but even highly loaded films showed properties similar to those of AM. The suspension technique was identified as the best incorporation approach regarding chemical stability and prolonged DEX release. Moreover, suspended DEX in the films did not negatively impact cell seeding efficiencies, and the cell-growth behaviors on the specimens with moderate DEX loads were satisfactory. This suggest that these films could comprise a suitable alternative material with additional anti-inflammatory activity for ocular surface reconstruction. Graphical abstract.

Associated risk factors of postoperative pain after glaucoma surgery: a prospective study

PURPOSE

This study aimed to determine degree of postoperative pain and the incidence of serious postoperative pain after glaucoma surgery and further to identify the associated risk factors.

METHODS

A total of 194 consecutive patients who were diagnosed with glaucoma and underwent glaucoma surgery were enrolled in this study. The intensity of postoperative pain was evaluated using numerical rating scale (NRS) within 24 h after surgery; NRS ≥ 5 was considered as clinically significant postoperative pain. Risk factors associated with the development of postoperative pain were analyzed by multivariate logistic regression analysis.

RESULTS

Clinically significant postoperative pain was experienced at any time after glaucoma surgery in 41.75% of the patients, which peak at 2 h. 27.8% of the patients requested analgesic medication within 24 h after surgery. According to multivariate logistic regression analysis, preoperative anxiety (OR = 4.13 [1.29-13.2], p = 0.017), cyclophotocoagulation (OR = 30.9 [3.47-375.1], p = 0.002), and phacotrabeculectomy combined with or without intraocular lens implantation (OR = 30.0 [2.69-335.6], p = 0.006) were associated with increased clinically significant postoperative pain. Interestingly, patients with diabetes and/or hypertension were associated with less postoperative pain after glaucoma surgery (OR = 0.23 [0.08-0.64], p = 0.005).

CONCLUSION

Patients undergoing glaucoma surgery tend to experience postoperative pain in the early postoperative period. Anxiety level and surgery types of cyclophotocoagulation and phacotrabeculectomy are risk factors for postoperative pain. Patients with diabetes and/or hypertension are less likely to develop postoperative pain.

Plasma Pharmacokinetic Parameters of Dexamethasone Following Administration of a Dexamethasone Intracanalicular Insert in Healthy Adults

Purpose

Intracanalicular dexamethasone insert is a resorbable sustained-release polyethylene glycol-based hydrogel insert delivering a 0.4 mg tapered dose of dexamethasone for up to 30 days to the ocular surface. It is FDA-approved for treating inflammation and pain after ocular surgery. It has also been studied for ocular surface diseases such as allergic conjunctivitis. This study assessed the plasma pharmacokinetic (PK) parameters of dexamethasone following intracanalicular insertion.

Patients and Methods

Study subjects (N=16) were healthy adults. A dexamethasone insert was unilaterally placed into the canaliculus, and blood samples were obtained for analysis 1 hour prior to insertion and 1, 2, 4, 8, 16, 24 hours and 4, 8, 15, 22 and 29 days after insertion. Safety analyses included slit lamp and dilated fundus examinations, best corrected visual acuity, intraocular pressure (IOP) and adverse events (AEs).

Results

Plasma results were below the lower limit of quantitation (LLOQ) at all time points in five subjects (31.3%). Among subjects with quantifiable plasma concentrations, C_max was <1 ng/mL (range, 0.05 to 0.81 ng/mL), AUC_0-last ranged from 0.13 to 7.18 h∙ng/mL, and T_max ranged from 4.0 to 163.0 hours. Mean (SD) IOP increased from 16.3 (1.4) mmHg at baseline to 19.3 (3.2) at Day 22 but returned to baseline after treatment. No changes occurred in dilated fundus, punctum, or visual acuity examinations.

Conclusion

The dexamethasone 0.4 mg insert results in minimal systemic exposure following intracanalicular administration.

Safety and Comfort of an Innovative Drug Delivery Device in Healthy Subjects

Purpose

The aim of this study was to investigate safety and comfort of two versions of a placebo-microsphere filled ocular coil (straight and curved) in healthy subjects.

Methods

The study was a single-center intervention study. One ocular coil was placed in the inferior conjunctival fornix for the intended duration of 28 days. Forty-two healthy adult subjects were included. At baseline, 30 minutes, 8 hours, 24 hours, 48 hours, 7 days, 14 days, 21 days, and 28 days after insertion, examinations were performed, including slit lamp evaluation to score ocular redness, intraocular pressure measurement, visual acuity, tear secretion test, and questionnaires.

Results

The straight and curved ocular coils had a median retention time of 5 days and 12 days, respectively. After 48 hours, 57% and 81% subjects retained the straight and curved ocular coil, respectively. Four (19%) subjects with the straight coil and six (29%) with the curved coil completed the entire study period. Minor changes in ocular hyperemia were observed in both groups. On day 7, the straight coil was more comfortable than the curved coil with a visual analogue scale (VAS) score of 77 ± 21 compared to 94 ± 11 (P = 0.028), respectively. No other ocular adverse events were observed.

Conclusions

Comfort and safety of the straight and curved ocular coil are high. Because the retention time is too short for long-term sustained drug release, the use in the perioperative or immediate postoperative period could prove to be more valuable.

Translational Relevance

The ocular coil is a noninvasive, comfortable and safe short-term drug delivery device.

A Randomized Fellow-Eye Clinical Trial to Evaluate Patient Preference for Dexamethasone Intracanalicular Insert or Topical Prednisolone Acetate for Control of Postoperative Symptoms Following Bilateral Femtosecond Laser in Site Keratomileusis (LASIK)

Purpose

To determine the preference of patients undergoing bilateral LASIK for either the dexamethasone intracanalicular insert or topical prednisolone acetate for control of postoperative symptoms and ocular surface signs.

Methods

In this randomized clinical trial, one eye was randomized to receive the dexamethasone insert or topical prednisolone acetate 1% four times daily for one week and 2 times daily for a second week; the fellow eye received the alternate therapy. One month postoperatively, patient preference for these two therapies was assessed using an adapted COMTOL questionnaire. Ocular comfort was assessed using the SPEED questionnaire. Corneal staining and uncorrected distance visual acuity (UDVA) were also assessed.

Results

Twenty patients participated. At Month 1, 80% of patients preferred the dexamethasone insert, 10% preferred prednisolone acetate, and 10% expressed no preference (p<0.001). SPEED scores measuring ocular comfort/discomfort related to dry eye symptoms were similar between groups (p=0.72), and both the incidence of patient-reported ocular dryness and the corneal staining scores were similar between groups. Both groups attained the same final UDVA.

Conclusion

Patients undergoing elective bilateral femtosecond LASIK surgery overwhelmingly (by an 8-to-1 margin) preferred the dexamethasone insert to topical prednisolone acetate for postoperative treatment. The insert produced comparable ocular comfort, corneal staining, and visual acuity outcomes to topical prednisolone. The insert is an appropriate means of postoperative symptom control in this quality of life-conscious population.

Chitosan Derivatives with Mucoadhesive and Antimicrobial Properties for Simultaneous Nanoencapsulation and Extended Ocular Release Formulations of Dexamethasone and Chloramphenicol Drugs

The aim of this work was to evaluate the effectiveness of neat chitosan (CS) and its derivatives with 2-acrylamido-2-methyl-1-propanesulfonic acid (AAMPS) and [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (MEDSP) as appropriate nanocarriers for the simultaneous ocular administration of dexamethasone sodium phosphate (DxP) and chloramphenicol (CHL). The derivatives CS-AAMPS and CS-MEDSP have been synthesized by free-radical polymerization and their structure has been proved by Fourier-Transformed Infrared Spectroscopy (FT-IR) spectroscopy. Both derivatives exhibited low cytotoxicity, enhanced mucoadhesive properties and antimicrobial activity against Staphylococcus aureus (S.aureus) and Escherichia coli (E. coli). Encapsulation was performed via ionic crosslinking gelation using sodium tripolyphosphate (TPP) as the crosslinking agent. Dynamic light scattering measurements (DLS) showed that the prepared nanoparticles had bimodal distribution and sizes ranging from 50–200 nm and 300–800 nm. Drugs were encapsulated in their crystalline (CHL) or amorphous (DexSP) form inside nanoparticles and their release rate was dependent on the used polymer. The CHL dissolution rate was substantially enhanced compared to the neat drug and the release time was extended up to 7 days. The release rate of DexSP was much faster than that of CHL and was prolonged up to 3 days. Drug release modeling unveiled that diffusion is the main release mechanism for both drugs. Both prepared derivatives and their drug-loaded nanoparticles could be used for extended and simultaneous ocular release formulations of DexSP and CHL drugs.