Jesse Chew

Interlenticular opacification: dual-optic versus piggyback intraocular lenses.

PURPOSE: To evaluate and compare the incidence of capsular bag opacification, particularly interlenticular opacification (ILO), in rabbit eyes implanted with a dual‐optic silicone intraocular lens (IOL) or piggyback lenses. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: Ten dual‐optic study IOLs (Synchrony), 10 control pairs of piggyback silicone‐plate lenses, and 10 control pairs of piggyback single‐piece hydrophobic acrylic lenses were implanted in the capsular bag of 30 rabbit eyes following phacoemulsification. After a 6‐week follow‐up, the rabbits were killed and their eyes enucleated. Anterior capsule opacification and posterior capsule opacification were graded on a 0 to 4 scale from a posterior or Miyake‐Apple view. Interlenticular opacification was noted in relation to the center of the interlenticular space (periphery, paracentral, and central area) and to the number of quadrants involved. The eyes were then evaluated histopathologically. RESULTS: Postoperative inflammatory reaction was similar in all groups. Interlenticular opacification formation was statistically different among the 3 groups of lenses (ILO extension, P = .0013, and ILO extension × ILO quadrants, P = .0023; Kruskal‐Wallis test). Pairwise post comparisons of ILO formation showed that the differences between the study IOL group and the silicone‐plate lens group were not significant. Interlenticular opacification post comparisons between the hydrophobic acrylic lenses and the study lens or the silicone‐plate lenses were significant (P = .002 and P = .001, respectively). Histopathologic examination showed extension of the proliferating cortical material from the peripheral Soemmerings ring into the interlenticular space, causing ILO, especially with the pairs of hydrophobic acrylic lenses. CONCLUSIONS: In this rabbit model, ILO was significantly associated with pairs of hydrophobic acrylic lenses implanted in the bag. This study appears to confirm clinical observations that implantation of 2 silicone‐plate lenses in the bag is not associated with ILO. There was also a relative lack of ILO with the dual‐optic silicone lens.

Hydrophilic acrylic intraocular lens as a drug-delivery system for fourth-generation fluoroquinolones

PURPOSE: To evaluate the ability and safety of a hydrophilic acrylic intraocular lens (IOL) as a drug‐delivery system for commercially available gatifloxacin and moxifloxacin. SETTING: David J. Apple, MD, Laboratories for Ophthalmic Research, John A. Moran Eye Center, Department of Ophthalmology and Visual Sciences, University of Utah, Salt Lake City, Utah, USA. METHODS: Thirty rabbits were divided into 2 similar groups. In Group A (15 rabbits, 30 eyes), hydrophilic acrylic IOLs (C‐flex, Rayner Intraocular Lenses, Ltd.) presoaked for 24 hours in commercially available solutions of gatifloxacin 3 mg/mL or moxifloxacin 5 mg/mL were implanted after evacuation of the crystalline lens. Group B (15 rabbits, 30 eyes) had topical preoperative and postoperative cataract prophylaxis with gatifloxacin 3 mg/mL or moxifloxacin 5 mg/mL; IOLs that were not presoaked were also implanted after evacuation of the crystalline lenses. In both groups, aqueous humor samples were taken 4, 8, or 12 hours after IOL implantation (5 eyes at each time point) to determine the antibiotic concentrations. Clinical examinations were performed 24 hours postoperatively. RESULTS: The antibiotic concentrations in Group A (presoaked IOLs) were statistically significantly higher than those in Group B (topical) for both antibiotics in all postoperative samples except moxifloxacin at 12 hours. In both groups, there was no statistically significant difference between the concentrations of the 2 antibiotics. No eye showed signs of clinical toxicity. CONCLUSION: Results show the C‐flex IOL is a safe and effective drug‐delivery system for fourth‐generation fluoroquinolones.

Late opacification of a silicone intraocular lens caused by ophthalmic ointment.

&NA; A 55‐year‐old man had uneventful phacoemulsification with implantation of a 3‐piece silicone intraocular lens (IOL). Postoperative medications included antibiotic–steroid drops and ointments. Eight months postoperatively, the patient started having recurrent episodes of anterior chamber inflammatory reaction. Suspicion that lens instability was causing the reactions led to a lens repositioning procedure 11 months after the initial surgical implantation and again at 13 months. Eighteen months postoperatively, the IOL had a “greasy” film. Despite antiinflammatory and antibiotic treatment, the clinical outcome did not improve. Twenty‐seven months after implantation, the lens was exchanged with a hydrophilic acrylic IOL. The course after the exchange was uneventful. The explanted lens was examined by gross and microscopic evaluations, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and gas chromatography–mass spectrometry (GC–MS) using electronic ionization. Gross and microscopic evaluations confirmed the presence of a thin, oily film covering the IOL optic surface. Surface analyses at the level of the oily substance showed unspecific peaks of sodium, chloride, and potassium. The GC–MS analysis showed the presence of compounds characteristic of hydrocarbons, including docosane, tricosane, and tetracosane, which are commonly found in the vehicle of ophthalmic ointments. The GC–MS analysis of 1 ointment used postoperatively found matching peaks, suggesting deposition of those compounds on the IOL.

Hydrophilic acrylic intraocular lens as a drug-delivery system: Pilot study

PURPOSE: To evaluate the ability of a hydrophilic acrylic intraocular lens (IOL) to serve as a drug‐delivery system for commercially available gatifloxacin and moxifloxacin. SETTING: David J. Apple, MD, Laboratories for Ophthalmic Devices Research, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: Hydrophilic acrylic IOLs (C‐flex, Rayner Ltd.), presoaked for 24 hours in commercially available solutions of gatifloxacin (Zymar) or moxifloxacin (Vigamox), were implanted in the capsular bag of 6 rabbits for a total of 12 eyes (6 in each group). Aqueous humor samples were taken 2, 4, and 6 hours after implantation. One rabbit served as a control and had nonpresoaked C‐flex IOLs implanted. At the end of the operation, 1 drop of Vigamox was applied to the right eye and 1 drop of Zymar was applied to the left eye of the control rabbit. RESULTS: High concentrations of both antibiotics were found in all the samples of the eyes implanted with the presoaked IOLs. The concentrations of the antibiotics decreased over time, but even the 6‐hour sample concentrations were markedly higher than the concentrations found in the control rabbit after 4 hours. CONCLUSION: The results suggest that the Rayner C‐flex IOL can be effective as a drug‐delivery system for fourth‐generation fluoroquinolones.

Meridional differences in internal dimensions of the anterior segment in human eyes evaluated with 2 imaging systems

PURPOSE: To evaluate meridional differences in angle‐to‐angle (A–A) and sulcus‐to‐sulcus (S–S) dimensions in human eyes using very high frequency ultrasound (VHF US) and anterior segment optical coherence tomography (AS‐OCT). SETTING: John A. Moran Eye Center, University of Utah, USA; Berlin Eye Research Institute, Germany; Quattroelle Centri Oftalmochirurgici, Italy. METHODS: Human autopsy eyes were fixated to special eye holders and had anterior segment scanning using 50 MHz ultrasound (Artemis, Ultralink) (20 eyes) and AS‐OCT (SL‐OCT, Heidelberg Engineering) (24 eyes). Seventy‐three eyes (58 patients) also had anterior segment scanning using the same systems (Artemis, 50 eyes; SL‐OCT, 23 eyes). Four meridians were evaluated in each eye. The A–A dimensions were measured by VHF US and AS‐OCT. The S–S dimensions were also measured by VHF US. Statistical analyses were done with the Huynh‐Feldt test. RESULTS: In the autopsy‐eye study, the differences in A–A and S–S dimensions between the 4 meridians in eyes analyzed with VHF US were statistically significant (P = .002 and P = .009, respectively). The differences in A–A dimensions in eyes analyzed with the AS‐OCT were also significant (P = .005). The same findings were observed in the clinical study (VHF US, P = .001 for A–A and P<.001 for S–S; AS‐OCT, P<.001 for A–A). CONCLUSIONS: This study suggests that the internal geometry of the anterior segment of human eyes does not constitute a circle. This may have significant relevance for the accurate sizing of phakic intraocular lenses.

Evaluation of the effects of hydrodissection with antimitotics using a rabbit model of Soemmering's ring formation

Background:  Regeneration/proliferation of lens material within the capsular bag still is the most frequent complication after cataract surgery. We aimed to evaluate the effects of hydrodissection with low doses of antimitotics on the overall regeneration/proliferation of lens material in rabbit eyes, using a model allowing the lens material to be confined to the equatorial region of the capsular bag, facilitating its quantification.

Health supplement associated with intraoperative floppy-iris syndrome

1. Bertino JS, Zhang J-Z. Besifloxacin, a novel ophthalmic fluoroquinolone for the treatment of bacterial conjunctivitis. Expert Opin Pharmacother 2009; 10:2545–2554 2. Haas W, Pillar CM, Zurenko GE, Lee JC, Brunner LS, Morris TW. Besifloxacin, a novel fluoroquinolone, has broad-spectrum in vitro activity against aerobic and anaerobic bacteria. Antimicrob Agents Chemother 2009; 53:3552–3560. Available at: http:// www.ncbi.nlm.nih.gov/pmc/articles/PMC2715578/pdf/041809.pdf. Accessed February 24, 2010 3. Proksch JW, Granvil CP, Siou-Mermet R, Comstock TL, Paterno MR, Ward KW. Ocular pharmacokinetics of besifloxacin following topical administration to rabbits, monkeys, and humans. J Ocul Pharmacol Ther 2009; 25:335–344 4. Ward KW, Lepage J-F, Driot J-Y. Nonclinical pharmacodynamics, pharmacokinetics, and safety of BOL-303224-A, a novel fluoroquinolone antimicrobial agent for topical ophthalmic use. J Ocul Pharmacol Ther 2007; 23:243–256 5. Tepedino ME, Heller WH, Usner DW, Brunner LS, Morris TW, Haas W, Paterno MR, Comstock TL. Phase III efficacy and safety study of besifloxacin ophthalmic suspension 0.6% in the treatment of bacterial conjunctivitis. Curr Med Res Opin 2009; 25:1159–1169 6. Karpecki P, DePaolis M, Hunter JA, White EM, Rigel L, Brunner LS, Usner DW, Paterno MR, Comstock TL. Besifloxacin ophthalmic suspension 0.6% in patients with bacterial conjunctivitis: a multicenter, prospective, randomized, double-masked, vehicle-controlled, 5-day efficacy and safety study. Clin Ther 2009; 31:514–526 7. Barequet IS, Habot-Wilner Z, Lavinsky F, Ziv H, Belkin M, Rosner M. Effect of fourth-generation fluoroquinolones on the healing rate of corneal erosions in an animal model. Cornea 2007; 26:606–609 8. Petroutsos G, Guimaraes R, Giraud JP, Pouliquen Y. Corticosteroids and corneal epithelial wound healing. Br J Ophthalmol 1982; 66:705–708. Available at: http://www.ncbi.nlm.nih.gov/pmc/ articles/PMC1039904/pdf/brjopthal00179-0035.pdf. Accessed February 24, 2010

Suturing a tear of the anterior capsulorhexis

Aim: To describe a new technique of suturing a tear in the anterior capsulorhexis. Methods: Continuous curvilinear capsulorhexis (CCC) with lens removal was done in five fresh cadaver eyes. The diameter of the CCC was measured with a calliper. Using the same calliper a tear of the CCC was created while opening the calliper’s arms. The distance between the calliper’s arms needed to tear the CCC was documented. Using 9-0 Ethilon 9011, CS 160-6 sutures in two eyes, 9-0 Prolene, D-8229, CTC-6L sutures in two eyes, and 10-0 Prolene, 9090, CTC-6 suture in one eye, the tears were sutured. A tear in the CCC was created again in the same way as the first tear. The distance between the calliper’s arms needed to tear the CCC was documented again. Results: Suturing of the tear restored some of the strength/elasticity of the CCC. Better results were found while using the 9-0 Prolene, D-8229, CTC-6L sutures than with the two others sutures. Conclusions: Suturing of a broken CCC can restore at least some of the strength/elasticity of the CCC. This can be important before intraocular lens (IOL) implantation for the safety of the implantation or after the implantation to ensure proper fixation of the IOL.