Comparative evaluation of Comfilcon A and Senofilcon A bandage contact lenses after transepithelial photorefractive keratectomy

Drug-eluting contact lenses: Progress, challenges, and prospects

Topical ophthalmic solutions (eye drops) are becoming increasingly popular in treating and preventing ocular diseases for their safety, noninvasiveness, and ease of handling. However, the static and dynamic barriers of eyes cause the extremely low bioavailability (<5%) of eye drops, making ocular therapy challenging. Thus, drug-eluting corneal contact lenses (DECLs) have been intensively investigated as a drug delivery device for their attractive properties, such as sustained drug release and improved bioavailability. In order to promote the clinical application of DECLs, multiple aspects, i.e., drug release and penetration, safety, and biocompatibility, of these drug delivery systems were thoroughly examined. In this review, we systematically discussed advances in DECLs, including types of preparation materials, drug-loading strategies, drug release mechanisms, strategies for penetrating ocular barriers, in vitro and in vivo drug delivery and penetration detection, safety, and biocompatibility validation methods, as well as challenges and future perspectives.

Impact of soft and rigid gas-permeable contact lenses on visual performance in mesopic conditions

CONTEXT

Evaluation of visual quality in soft and rigid gas-permeable contact lens wearers, with an emphasis on twilight vision.

PURPOSE

To assess the visual acuity and visual performance at dusk before and after soft and rigid gas-permeable contact lens (CL) correction in healthy subjects.

SETTINGS AND DESIGN

This prospective study was conducted in a tertiary eye-care center.

METHODS

Sixty eyes corrected with soft contact lenses (SCLs) and 30 eyes with rigid gas-permeable contact lenses (RGPCLs) were enrolled in this study. Patients underwent corrected distance visual acuity with spectacles (CDVAs), corrected distance visual acuity with contact lenses (CDVAcl), and twilight vision (TV) testing (Vista Vision Far-Pola, DMD MedTech charts). Parameters were evaluated before and after the CL fitting and repeated 3 months after the baseline visit.

STATISTICAL ANALYSIS USED

MedCalc for Windows, version 11.4 (MedCalc Software, Ostend, Belgium).

RESULTS

Rigid gas-permeable CL wear showed significant improvement in CDVAcl compared to wearing spectacles on both visits ( P = 0.0039 and P = 0.0003, respectively). TV with CLs was significantly better in both groups compared to the TV with spectacles at the baseline visit ( P = 0.0011 in SCL group; P = 0.0001 in RGPCL group), and at the follow-up visit, this significance was proven for the RGPCL group ( P = 0.001). Also, spectacle TV showed a significant improvement on the follow-up visit ( P = 0.0022 in SCL group; P = 0.0269 in RGPCL group).

CONCLUSION

Contact lens wear improves visual performance compared to spectacles. TV results showed superiority of CLs compared to the spectacles, without a statistical difference regarding the CL type.

Performance of Bandage Contact Lens in Patients Post-ocular Surgeries: A Systematic Literature Review

ABSTRACT

This study systematically reviewed the performance of bandage contact lenses (BCL) such as lotrafilcon A, lotrafilcon B, senofilcon A, balafilcon A, and comfilcon A as postoperative treatment in different ocular surgeries. A systematic search of English and Chinese databases (from inception to December 2021) was conducted for studies reporting the efficacy of BCLs after ocular surgeries. Postoperative symptoms, corneal healing, and visual outcomes were studied. Overall, 38 studies were identified. Bandage contact lens was applied as a postoperative aid in corneal refractive, cataract, and vitrectomy surgeries. Most studies were on photorefractive keratectomy. Reduced postoperative symptoms were observed within 4 hr to 3 days, whereas re-epithelization of the cornea and healing was complete within 3 to 7 days after ocular surgeries except for vitrectomy. In a vitrectomy, greater comfort and improved corneal epithelium were observed on the seventh day after surgery. An improvement in dry eye symptoms was observed at 7 days with considerable benefits observed after 1 month of cataract surgery. These findings indicate that BCLs are effective for improving postoperative symptoms and facilitation of early visual rehabilitation with a wear time of 8 hr to 7 days depending on the type of ocular surgery.

Superhydrophilic Poly(2-hydroxyethyl methacrylate) Hydrogel with Nanosilica Covalent Coating: A Promising Contact Lens Material for Resisting Tear Protein Deposition and Bacterial Adhesion

Tear protein deposition and bacterial adhesion are the main drawbacks of the hydrogel contact lens. In this study, we developed a novel superhydrophilic poly(2-hydroxyethyl methacrylate) (NSCC-pHEMA) hydrogel with nanosilica covalent coating by the combination of colloidal silica immersion and dehydration treatment. The infrared spectroscopy and energy dispersive X-ray spectroscopy analyses confirmed the successful formation of Si-O covalent bonding between nanosilica and pHEMA hydrogel. This coating was highly stable against powerful sonication or long-term shaking immersion treatment. Among various NSCC-pHEMA hydrogels with different colloidal silica concentrations, the 7%NSCC-pHEMA hydrogel generated a superhydrophilic micro wrinkle surface with a root-mean-square roughness of 43.10 nm, which dramatically reduced the deposition of lysozyme and bovine serum albumin by 65% and 57%, respectively, and decreased the adhesion of S. aureus and E. coli by 59% and 66%, respectively, in comparison to the pHEMA hydrogel. However, the nanosilica coating had little effect on the mechanical properties, light transmittance, oxygen permeability, and equilibrium water content of the pHEMA hydrogel. NSCC-pHEMA hydrogels were nontoxic to both mouse fibroblasts (L929) and human immortalized keratinocytes (HaCaT). Thus, the superhydrophilic NSCC-pHEMA hydrogel is a potential contact lens material for resisting tear protein deposition and bacterial adhesion.

Lysozyme-immobilized bandage contact lens inhibits the growth and biofilm formation of common eye pathogens in vitro

Bandage contact lenses have an increased affinity to accumulate tear film proteins and bacteria during wear. Among the wide variety of tear film proteins, lysozyme has attracted the most attention for several reasons, including the fact that it is found at a high concentration in the tear film, has exceptional antibacterial and antibiofilm properties, and its significant deposits onto contact lenses. This study aims to evaluate the effect of lysozyme on bacterial biofilm formation on bandage contact lenses. For this purpose, several methods, including microtiter plate test and Colony Forming Unit (CFU) assay have been used to determine antibacterial and antibiofilm characteristics of lysozyme against the two most frequent contact lens-induced bacterial ocular infections, Staphylococcus aureus, and Pseudomonas aeruginosa. The results of these assays demonstrate lysozyme potential to inhibit 57.9% and 80.7% of the growth of S. aureus and P. aeruginosa, respectively. In addition, biofilm formations of P. aeruginosa and S. aureus reduced by 38.3% and 62.7%, respectively due to the antibiofilm effect of lysozyme. SEM and AFM imaging were utilized to visualize lysozyme antibacterial activity and topography changes of the contact lens surface, respectively, in the presence/absence of lysozyme. The results indicated that lysozyme can efficiently attack both gram-positive and gram-negative bacteria and consequently lysozyme-functionalized bandage contact lenses can reduce the risk of ocular infection after eye surgery.

Management of Pain after Photorefractive Keratectomy: A Report by the American Academy of Ophthalmology

OBJECTIVE

To evaluate current best practices for postoperative photorefractive keratectomy (PRK) pain control.

METHODS

Literature searches in the PubMed database were last conducted in October 2021 and were restricted to publications in English. This search identified 219 citations, of which 84 were reviewed in full text for their relevance to the scope of this assessment. Fifty-one articles met the criteria for inclusion; 16 studies were rated level I, 33 studies were rated level II, and 2 studies were rated level III.

RESULTS

Systemic opioid and nonsteroidal anti-inflammatory drugs (NSAIDs); topical NSAIDs; postoperative cold patches; bandage soft contact lenses (BCLs), notably senofilcon A contact lenses; and topical anesthetics were demonstrated to offer significantly better pain control than comparison treatments. Some other commonly reported pain mitigation interventions such as systemic gabapentinoids, chilled intraoperative balanced salt solution (BSS) irrigation, cycloplegia, and specific surface ablation technique strategies offered limited improvement in pain control over control treatments.

CONCLUSIONS

Systemic NSAIDs and opioid medications, topical NSAIDs, cold patches, BCLs, and topical anesthetics have been shown to provide improved pain control over alternative strategies and allow PRK-associated pain to be more tolerable for patients.

Clinical Outcomes of Aberration-Free All Surface Laser Ablation (ASLA) vs. Aberration-Free ASLA Assisted by Smart Pulse Technology in High Myopia: A One-Year Follow-Up Study

Purpose

To compare the clinical outcomes of aberration-free all surface laser ablation (ASLA) with and without the use of smart pulse technology (SPT) in high myopia.

Methods

This study retrospectively analyzed 138 eyes (138 patients, only the right eye was selected) treated for high myopia (spherical equivalent ≥−6.00 diopters) using aberration-free ASLA (non-SPT group; 85 eyes) and aberration-free ASLA assisted by SPT (SPT group; 53 eyes). Examinations such as visual acuity, refraction, and haze were performed before the 12-month follow-up. Corneal epithelial healing time was assessed in the first postoperative day. Visual acuity and refraction examination were performed at 7 days and 1, 3, 6, and 12 months postoperatively. Corneal haze was evaluated in 1, 3, 6, and 12 months. Safety, efficacy, and corneal wavefront aberrations were assessed 12 months after the treatment.

Results

At 12 months postoperatively, 60% versus 40% of eyes achieved 20/16 Snellen lines or better, and 92% versus 82% of eyes achieved 20/20 Snellen lines or better visual acuity in the SPT and the non-SPT groups, respectively. The average postoperative epithelial healing time was 3.75 ± 1.00 days in the SPT group and 3.73 ± 1.30 days in the non-SPT group (P ≥ 0.05). The safety and the efficacy index of the SPT group were better than those of the non-SPT group in the follow-ups. The attempted spherical equivalent before the surgery and the achieved spherical equivalent at 12 months were comparable between the two groups. Regarding the aberrations, the results of Coma 90° in the SPT group were better than those in the non-SPT group (P ≤ 0.05), but the increase of RMS HOAs (root mean square higher order aberrations), Coma 0°, and spherical aberration postoperatively had no statistical difference between the two groups (P ≥ 0.05). Conclusions: Both aberration-free ASLA with and without SPT showed favorable safety, effectiveness, and predictability within 12 months for high myopia. And, ASLA using SPT might have potential advantages in the long-term visual quality.

CLEAR - Medical use of contact lenses

The medical use of contact lenses is a solution for many complex ocular conditions, including high refractive error, irregular astigmatism, primary and secondary corneal ectasia, disfiguring disease, and ocular surface disease. The development of highly oxygen permeable soft and rigid materials has extended the suitability of contact lenses for such applications. There is consistent evidence that bandage soft contact lenses, particularly silicone hydrogel lenses, improve epithelial healing and reduce pain in persistent epithelial defects, after trauma or surgery, and in corneal dystrophies. Drug delivery applications of contact lens hold promise for improving topical therapy. Modern scleral lens practice has achieved great success for both visual rehabilitation and therapeutic applications, including those requiring retention of a tear reservoir or protection from an adverse environment. This report offers a practical and relevant summary of the current evidence for the medical use of contact lenses for all eye care professionals including optometrists, ophthalmologists, opticians, and orthoptists. Topics covered include indications for use in both acute and chronic conditions, lens selection, patient selection, wear and care regimens, and recommended aftercare schedules. Prevention, presentation, and management of complications of medical use are reviewed.

Efficacy of two silicone-hydrogel bandage contact lenses after corneal crosslinking

Silicone-hydrogel (SiH) contact lenses are frequently used as a bandage after anterior segment surgical procedures. Several types of lenses may exhibit clinical performances with different characteristics. This study aims to evaluate the efficacy of two SiH contact lenses following corneal crosslinking (CXL). Forty-nine keratoconus patients scheduled for consecutive CXL surgery in both eyes were included in this comparative, double-blind, prospective study. A Balafilcon A (Pure Vision 2 HD, Bausch+Lomb, Rochester, NY, USA) or Lotrafilcon B (Air Optix Aqua, Ciba Vision, Duluth, GA, USA) lens was fitted in a randomised fashion in the eyes at the end of the CXL. Remaining epithelial defect area measured by slitlamp biomicroscopy, subjective level of pain and discomfort with visual analogue scale (VAS) and total number of oral analgesics taken were evaluated and compared at post-operative days 0, 1, 2 and 3. The average epithelial defect size was significantly smaller in the eyes with Lotrafilcon B than the eyes with Balafilcon A at post-operative Day 1 (31.2 ± 4.3 mm² and 33.8 ± 5.2 mm², respectively, p < 0.001) and Day 2 (8.2 ± 3.6 mm² and 10.5 ± 5.4 mm², respectively, p = 0.039). There was no statistically significant in the average epithelial defect size between the groups at Day 3 (p = 0.859). Re-epithelialisation time was similar in both groups (p = 0.317) There was no statistically significant difference in VAS scores regarding the lens type in any post-operative follow-up. The mean oral analgesic numbers were similar in both groups (p = 0.217). SiH contact lenses can be used as an effective bandage for corneal re-epithelialisation after CXL. The material and features of bandage contact lens used after CXL may affect the corneal re-epithelialisation process. Lotrafilcon B lens showed faster re-epithelialisation at post-operative days 1 and 2 after CXL.

Therapeutic Contact Lenses in the Treatment of Corneal and Ocular Surface Diseases-A Review

Therapeutic contact lenses (TCLs) are often used in the management of a wide variety of corneal and ocular surface diseases (OSDs). Indications of TCL include pain relief, enhancing corneal healing, corneal sealing, corneal protection, and drug delivery. For painful corneal diseases such as bullous keratopathy, epidermolysis bullosa, and epithelial abrasions/erosions, bandage contact lenses (BCLs) provide symptomatic relief. Postoperatively in photorefractive keratectomy or laser epithelial keratomileusis, BCLs also alleviate pain. In severe OSDs such as severe dry eye, Stevens-Johnson syndrome/toxic epidermal necrolysis, gas-permeable scleral contact lenses are often used to enhance corneal healing. BCLs are used post-keratoplasty, post-trabeculectomy, and post-amniotic membrane transplantation to enhance healing. BCLs, with or without glue adhesives, are used to seal small corneal perforations and sometimes also used as bridging treatment before penetrating keratoplasty in larger corneal perforations. In patients with eyelid conditions such as trichiasis, ptosis, and tarsal scarring, BCLs are also effective in forming a mechanical barrier to protect the cornea. A relatively new use for TCLs is in ocular drug delivery where TCLs are used to maintain therapeutic concentrations of medication on the ocular surface. Contraindications of the use of TCLs include infective keratitis, corneal anesthesia, and significant exposure keratopathy with inadequate eyelid position or movement. Complications of TCL include infective keratitis, corneal hypoxia and associated complications, corneal allergies and inflammation, and poor lens fit. Overall, TCLs are effective in the treatment of corneal and OSDs but contraindications and complications must be considered.

Evaluation of commercial soft contact lenses for ocular drug delivery: A review

Soft contact lenses have generated growing interest in ocular drug delivery due to their potential to enhance drug bioavailability in ocular tissues. Commercially available soft contact lenses offer several advantages for ocular drug delivery as they are manufactured on a large scale, which guarantees the availability of a consistent and reproducible product, and their favorable safety profile is well-established through broad clinical use. Here we review the rationale for using commercially available soft contact lenses for ocular drug delivery; summarize the evolution of the materials used in contact lens fabrication; and explore various methods used to improve the drug release characteristics and its tissue penetration. While significant progress has been made, several issues still require further attention for the commercial launch of a viable drug-eluting contact lens product, including control of initial burst release, shelf-life stability, and drug loss during processing or storage.

Comparison of the balafilcon A and samfilcon A lenses on postoperative pain control and epithelial healing time after photorefractive keratectomy: a contralateral eye study

To compare the effects of balafilcon A and samfilcon A silicone hydrogel bandage contact lenses on postoperative pain control and epithelial healing time after photorefractive keratectomy (PRK). Seventy-four eyes of 37 patients who underwent bilateral PRK were included in this randomized clinical trial study. In the end of the surgery, a balafilcon A lens was used in one eye and a samfilcon A lens was used in the fellow eye randomly. Pain, blurred vision, epiphora, photophobia, and foreign body sensation were assessed on the first and third postoperative day using a visual analogue scale (0 = no ocular pain or discomfort, 10 = highest level of ocular pain and discomfort). For balafilcon A and samfilcon A lenses, mean scores for pain were 6.22 ± 2.81 and 3.11 ± 2.90 on first postoperative day (p < 0.001) and 1.57 ± 1.65 and 0.68 ± 0.85 on third postoperative day (p = 0.001), respectively; mean scores for foreign body sensation were 6.11 ± 2.53 and 3.19 ± 2.72 on first postoperative day (p < 0.001) and 3.16 ± 1.92 and 1.35 ± 1.43 on third postoperative day (p < 0.001), also respectively; and mean scores for epiphora were 6.46 ± 2.64 and 5.46 ± 3.40 on first postoperative day (p = 0.007) and 1.68 ± 1.60 and 1.32 ± 1.31 on third postoperative day (p = 0.065), again respectively. No significant difference in blurred vision or photophobia emerged between the lenses on first and third postoperative day after PRK. On the third postoperative day, reepithelialization was complete in 83.7% of eyes with the balafilcon A lens and 89.1% of eyes fitted with the samfilcon A lens. Wearing samfilcon A lenses after photorefractive keratectomy can significantly manage pain, decrease foreign body sensation on first and third postoperative day, and reduce epiphora on first postoperative day.

Masked comparison of two silicone hydrogel bandage contact lenses after photorefractive keratectomy

PURPOSE

To compare the efficiency and safety of two bandage contact lenses after photorefractive keratectomy (PRK).

METHODS

In this double-blind study, 45 patients (90 eyes) received PRK in both eyes and wore bandage contact lenses (BCLs), PureVision (Bausch & Lomb, Rochester, NY, USA) in one eye and PureVision2 (Bausch & Lomb, Rochester, NY, USA) in the other eye, randomly assigned. The medication regimen after surgery was the same for both eyes. The epithelial defect's size, conjunctival hyperemia and lens centration were graded objectively using slit-lamp biomicroscopy on days 1, 3 and 5 after surgery. Also ocular symptoms of discomfort including tearing, photophobia, foreign body sensation and visual fluctuations were assessed subjectively at each visit.

RESULTS

The mean epithelial defect size on the first day after operation was similar in eyes fitted with PureVision (30.08 ± 5.30 mm²) and PureVision2 (30.25 ± 5.72 mm²) lenses. (p = 0.79) Contact lens deposits and bulbar hyperaemia on days 1 and 3 after PRK were similar between the two eyes, but were significantly greater on day 5 for PureVision2 lenses. (p = 0.02; p = 0.04 respectively) There was no difference in contact lens decentration, and discomfort symptoms including pain, tearing, foreign body sensation, photophobia and visual fluctuations between the eyes fitted with PureVision and PureVision2. (p > 0.05) CONCLUSIONS: PureVision and PureVision2 contact lenses are equivalent as bandage lenses in important aspects such as corneal re-epithelialization and subjective comfort., although PureVision2 led to a higher incidence of contact lens deposits and conjunctival hyperemia early post-PRK.

Bandage Lenses in the Postoperative Care for Cataract Surgery Patients: A Substitute for Eye Patch?

Purpose

To explore whether bandage lenses could be a safe and effective substitute for eye patch in the postoperative care for cataract surgery patients in terms of infection prevention, ocular impacts, and patient satisfaction.

Methods

Patients who underwent cataract surgery were randomly divided into the eye patch group (Group A) and the bandage lens group (Group B). Bacterial culture samples were collected perioperatively from different sites. Evaluations of anterior segment condition and patient satisfaction were conducted on the first day of postoperative follow-up.

Results

The positive rate of bacterial cultures in Group A was higher than that in Group B, but the difference was not statistically significant. Group B had significantly longer tear breakup time, higher tear meniscus height, and slightly better patient satisfaction than Group A.

Conclusion

Bandage lenses can be used as a safe and effective substitute for eye patch in the postoperative care for cataract surgery patients. The Clinical Study registration number is ChiCTR-IOC-17012167.

Dysfunctional tear syndrome: dry eye disease and associated tear film disorders - new strategies for diagnosis and treatment

Dysfunctional tear syndrome (DTS) is a common and complex condition affecting the ocular surface. The health and normal functioning of the ocular surface is dependent on a stable and sufficient tear film. Clinician awareness of conditions affecting the ocular surface has increased in recent years because of expanded research and the publication of diagnosis and treatment guidelines pertaining to disorders resulting in DTS, including the Delphi panel treatment recommendations for DTS (2006), the International Dry Eye Workshop (DEWS) (2007), the Meibomian Gland Dysfunction (MGD) Workshop (2011), and the updated Preferred Practice Pattern guidelines from the American Academy of Ophthalmology pertaining to dry eye and blepharitis (2013). Since the publication of the existing guidelines, new diagnostic techniques and treatment options that provide an opportunity for better management of patients have become available. Clinicians are now able to access a wealth of information that can help them obtain a differential diagnosis and treatment approach for patients presenting with DTS. This review provides a practical and directed approach to the diagnosis and treatment of patients with DTS, emphasizing treatment that is tailored to the specific disease subtype as well as the severity of the condition.