Retinal safety of the irradiation delivered to light-adjustable intraocular lenses evaluated in a rabbit model.

PURPOSE: To evaluate the safety to the retina of a light-delivery device used to irradiate a light-adjustable intraocular lens (IOL) after implantation in a rabbit model. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: In this study, rabbits had phacoemulsification with implantation of an ultraviolet (UV)-filtering light-adjustable IOL (study IOL) in 1 eye and a custom-made silicone IOL without a UV filter (control IOL) in the opposite eye. The study IOLs were irradiated at 1.0, 2.0, 3.0, and 5.0 times the expected maximum UV irradiation doses and the control IOLs, at 0.3, 0.6, 1.0, and 2.0 times. One week after irradiation, slitlamp and fundus (indirect ophthalmoscopy) examinations were performed. The rabbits were then humanely killed and their eyes enucleated and processed for histopathology. RESULTS: The 16 eyes with the study IOL (with UV filter) showed no signs of corneal, anterior segment, or retinal toxicity on histopathologic evaluation. The 16 eyes with the control IOL (no UV filter) also showed no signs of corneal or anterior segment toxicity; however, 3 eyes receiving the higher radiation doses had focal areas of retinal damage consistent with laser burn. CONCLUSION: Pigmented rabbit eyes with a light-adjustable IOL with a UV filter showed no signs of retina toxicity after near-UV light exposure up to 5 times the expected maximum treatment dosage. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

Intraocular pressure changes during injection of microincision and conventional intraocular lenses through incisions smaller than 3.0 mm.

PURPOSE: To compare intraocular pressure (IOP) during insertion of a new microincision intraocular lens (IOL) (Akreos AO MI60) and a conventional IOL (AcrySof Natural SN60AT) and to determine the minimum incision sizes for insertion in a cadaver eye model. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: After phacoemulsification in phakic cadaver eyes, multiple IOL insertions were attempted through 1.8 mm to 2.5 mm wounds. The final incision size and insertion success were evaluated in each case. A pressure transducer placed in the vitreous cavity measured real-time IOP changes (100 readings per second), including the mean and peak IOP during IOL implantation. RESULTS: The minimum incision size for the microincision IOL insertion was 1.9 mm using a wound-assisted technique and 2.2 mm using a cartridge-insertion technique. The minimum incision size for wound-assisted implantation of the conventional IOL was 2.4 mm. During successful implantation, the mean and peak IOPs were similar between the 2 IOL types. The peak IOPs exceeded 60 mm Hg (retinal perfusion pressure). In unsuccessful attempts, the mean and peak IOPs were higher for the conventional IOL, reaching 306.05 mm Hg in 1 eye. CONCLUSIONS: Monitoring during implantation of both IOL types confirmed that IOP increases during insertion, including during microincision surgery using a wound-assisted technique. Further studies are necessary to evaluate the effect of pressure spikes on the optic nerve during IOL insertion.

A novel method for screening the multifocal electroretonogram in patients using hydroxychloroquine.

PURPOSE: To evaluate retinal function in patients on hydroxychloroquine using multifocal electroretinography. METHODS: A retrospective chart review was performed for 23 patients (46 eyes) on hydroxychloroquine therapy and referred for multifocal electroretinogram (mfERG) testing. Duration of treatment, daily hydroxychloroquine dose, visual acuity, fundus examination, color vision testing, Amsler grid testing, visual field examination, and fluorescein angiography results were obtained when available. Multifocal electroretinogram response amplitudes were calculated for the central and paracentral regions and compared with previously published normal values. The central and paracentral regions of the mfERG color difference plot, which assigns colors to localized areas of the mfERG based on deviation from normal, were assessed using a novel Color Difference Plot Scoring System which relies on the color pattern observed within each region. RESULTS: Ninety-two regions were assessed for response amplitudes, 31 of which showed a depressed response amplitude. Of the 17 eyes which had at least one region with a depressed response amplitude, clinical examination findings were relatively benign. Color difference plot scoring showed strong agreement with response amplitude, with a Color Difference Plot Scoring System score of 2 or 3 showing 93.55% sensitivity and 60% specificity for a depressed response amplitude. Interrater reliability of the scoring system as measured by Kendall's W coefficient of concordance was 0.6484 (P < 0.00001). CONCLUSION: The mfERG appears to be able to detect decreased retinal function in hydroxychloroquine patients with normal clinical examinations, and may be useful in identifying patients that require close monitoring for the development of clinically relevant toxicity. The Color Difference Plot Scoring System may be used as a tool to aid in the interpretation of results of the mfERG in the clinic setting.

Pigmentary dispersion syndrome with a secondary piggyback 3-piece hydrophobic acrylic lens. Case report with clinicopathological correlation.

We describe a case of pigmentary dispersion syndrome resulting from secondary piggyback implantation of a 3-piece hydrophobic acrylic squared-edged intraocular lens (IOL) in the ciliary sulcus. The intraocular pressure remained elevated despite pharmacological treatment, with a heavily pigmented trabecular meshwork. The piggyback IOL was subsequently explanted and replaced by a silicone IOL with smooth round edges. Examination of the explanted IOL under light and scanning electron microscopy showed clusters of pigment epithelial cells located around the periphery of the anterior optic surface.