Removal of Silicone Oil From Intraocular Lens Using Novel Surgical Materials

Quantification of Straylight Induced by Silicone Oil Adherent to Intraocular Lenses of Different Materials

PURPOSE

A complication of using silicone oil as an intraocular endotamponade is its adhesion to intraocular lenses (IOLs). Forward light scattering is a measure to quantify the optical disturbance caused by adherent oil droplets. We tested the straylight caused by silicone oil adhesion to different IOLs and examined whether an approved cleaning solution, F4H5, reverses the induced straylight.

DESIGN

An experimental study.

METHODS

Two hydrophobic acrylic IOL models and 1 hydrophilic model with a hydrophobic surface (n = 8 per model: 24 lenses) had straylight measured before contact with silicone oils, providing a baseline for subsequent testing: 12 lenses with lighter-than-water silicone oil (Siluron 2000) and 12 with heavier-than-water oil (Densiron 68). The final measurement was performed after cleansing with F4H5 when we used scanning electron and light microscopy to detect surface changes.

RESULTS

Straylight was majorly increased in IOLs with adherent silicone oil (baseline vs adherent oil median 3.1 [2.1, 3.9] and 39.7 [22.7, 87.8] deg2/sr, respectively; P < .001). No difference was seen between heavier- and lighter-than-water silicone oils. Between IOL types, induced straylight varied significantly, with 1 hydrophobic model reaching the highest average straylight. F4H5 significantly reduced straylight values in all IOL types (median 9.4 [5.4, 13.8] deg2/sr). The microscopy revealed surface changes on the IOLs even after cleaning.

CONCLUSIONS

Silicone oil adhesion to IOLs can induce amounts of straylight known to cause severe optical disturbance. F4H5 cleansing solution reversed straylight values to only slightly increased values. We found no difference in straylight formation between the lighter- and heavier-than-water silicone oils.

Alternative Techniques To Remove Retained Silicone Oil Droplets On IOLs

BACKGROUND/PURPOSE

To describe several modified approaches to remove retained silicone oil droplets on intraocular lens (IOLs).

METHODS

Four novel techniques for removing retained silicone oil droplets on IOLs were described.

RESULTS

All four techniques led to an improved IOL with a good view to the posterior segment. No intraoperative or long-term postoperative complications have been seen in any of these eyes. These modified approaches are safe, efficient, low cost, and use existing vitreoretinal operating room supplies to add to the vitreoretinal surgeon's armamentarium to clear retained IOL silicone droplets.

CONCLUSION

It is advocated for having multiple techniques at the disposal of the vitreoretinal surgeon to address retained silicone oil on IOLs. Being able to use multiple techniques may not be superior than a single approach but is often necessary to accomplish the surgical goal of removing these adherent droplets.

Persistent Air Bubble Sequestered at the Silicone Oil–Silicone Intraocular Lens Interface as a Cause of Reversible Visual Distortion

Purpose:

To report a novel cause of post-operative reversible visual distortion due to a persistent air bubble sequestered at the intraocular lens (IOL)–silicone oil interface.

Methods:

Two cases of persistent, sequestered air at the IOL-silicone oil interface were identified and reviewed. Relevant clinical information, images and surgical videos were analyzed and described.

Results:

Resolution of the visual distortion was achieved in both cases after silicone oil removal.

Conclusions:

Silicone oil adhesion to the posterior surface of silicone IOLs is a known cause of visual degradation. The IOL-silicone oil interface can sequester air that persists and causes visual distortion until the oil is removed. We report the first cases, to our knowledge, of reversible visual distortion due to sequestered air at the IOL-silicone oil interface.

Microporous Drug Delivery System for Sustained Anti-VEGF Delivery to the Eye

Purpose

To describe a novel microporous drug delivery system (DDS) for sustained anti- vascular endothelial growth factor (VEGF) delivery to the eye and to evaluate its efficacy in a corneal injury model.

Methods

A macro-porous DDS (1.5 × 1.5 × 4 mm) loaded with 2 mg of bevacizumab was implanted subconjunctivally in three Dutch-belted pigmented rabbits after corneal alkali injury (2N NaOH). Three rabbits received sham DDS. Animals were followed for three months and assessed in vivo and ex vivo for corneal neovascularization (NV), epithelial defect, stromal scarring, endothelial cell loss, and expression of angiogenic and inflammatory markers in the cornea and retina.

Results

Anti-VEGF DDS treatment led to complete inhibition of superior cornea NV and complete corneal re-epithelialization by day 58 whereas sham DDS resulted in severe cornea NV and persistent epithelial defect (9%∼12% of total cornea area) through the end of the study. Histologically, anti-VEGF DDS significantly reduced CD45⁺ and F4/80 CD11b⁺ cell accumulation (79%, P < 0.05) in the cornea, ameliorated tumor necrosis factor–α expression (90%, P < 0.05), reduced corneal stromal scarring and prevented corneal endothelial cell loss, as compared to sham DDS. Moreover, anti-VEGF DDS achieved retinal penetration and reduction in retinal VEGF levels at 3 months.

Conclusions

Use of subconjunctival anti-VEGF DDS suppresses cornea NV, inflammation, stromal scarring, prevents endothelial cell loss, and abrogates retinal VEGF upregulation in a rabbit corneal alkali burn model. Moreover, it delivers anti-VEGF antibodies to the retina for three months. This delivery platform could enable antibody therapy of other corneal and retinal vascular pathologies.

Translational Relevance

We describe a method for sustained anti-VEGF delivery to the eye for the treatment of ocular injuries.

A Drug Delivery System for Administration of Anti-TNF-α Antibody

PURPOSE

To describe the fabrication, evaluation, and preliminary in vivo safety of a new drug delivery system (DDS) for topical anti-TNF-α antibody administration.

METHODS

A DDS was fabricated using inverse template fabrication of a hydrophobic three-dimensional porous scaffold (100-300 μm in diameter porosity) loaded with 10% polyvinyl alcohol hydrogel carrying 5 mg/ml (weight/volume) of anti-TNF-α antibody. Drug-loaded DDS was sterilized with 25 kGy of gamma irradiation. Long-term in vitro antibody affinity and release was evaluated at room temperature or 37°C using enzyme-linked immunosorbent assay (ELISA) and protein fluorescence. In vivo clinical and histolopathological assessment was performed by subcutaneous implantation in BALB/c mice for 3 months.

RESULTS

Gamma irradiation, repeated dry/wet cycles, and storage at room temperature for 1 year or 37°C for 1 month had no deleterious effects on antibody affinity. Anti-TNF-α release was high during the first minutes of aqueous exposure, followed by stabilization and gradual, low-dose, antibody release over the next 30 days. Histopathologic evaluation of explanted DDS showed a fibrous pseudocapsule and a myxoid acute/chronic inflammation without granuloma formation surrounding the implants.

CONCLUSIONS

Sustained local delivery of anti-TNF-α antibody is feasible using the described DDS, which provides stability of the enclosed antibody for up to 1 year of storage. Preliminary results show good in vivo tolerance following subcutaneous placement for 3 months. The proposed fabrication and sterilization process opens new possibilities for the delivery of biologic agents to the anterior surface of the eye.

TRANSLATIONAL RELEVANCE

The described DDS will facilitate the treatment of ocular surface diseases amenable to biologic therapy.