Nick Mamalis

Toxic anterior segment syndrome and possible association with ointment in the anterior chamber following cataract surgery

PURPOSE: To report clinical and laboratory findings of 8 cases of toxic anterior segment syndrome (TASS) related to an oily substance in the anterior chamber of patients following cataract surgery with intraocular lens (IOL) implantation. SETTING: John Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: Eight patients had uneventful phacoemulsification by the same surgeon via clear corneal incisions with implantation of the same 3‐piece silicone IOL design. Postoperative medications included antibiotic/steroid ointment and pilocarpine gel; each eye was firmly patched at the end of the procedure. On the first postoperative day, some patients presented with diffuse corneal edema, increased intraocular pressure, and an oily film‐like material within the anterior chamber coating the corneal endothelium. The others presented with an oily bubble floating inside the anterior chamber, which was later seen coating the IOL. Additional surgical procedures required included penetrating keratoplasty, IOL explantation, and trabeculectomy. Two corneal buttons were analyzed histopathologically. Two explanted IOLs had gross and light microscopic analyses (as well as surface analyses of 1 of them), and 4 other explanted IOLs had gas chromatography‐mass spectrometry. RESULTS: Pathological examination of the corneas showed variable thinning of the epithelium with edema. The stroma was diffusely thickened and the endothelial cell layer was absent. Evaluation of the explanted IOLs confirmed the presence of an oily substance coating large areas of their anterior and posterior optic surfaces. Gas chromatography‐mass spectrometry of the lens extracts identified a mixed chain hydrocarbon compound that was also found in the gas chromatography‐mass spectrometry analyses of the ointment used postoperatively. CONCLUSIONS: The results indicate that the ointment gained access to the eye, causing the postoperative complications described. These cases highlight the importance of appropriate wound construction and integrity, as well as the risks of tight eye patching following placement of ointment.

Histology of AlphaCor skirts: Evaluation of biointegration

Purpose: To report histologic findings in 14 AlphaCor artificial corneas implanted during clinical trials and subsequently explanted from human subjects following complications, so as to evaluate biointegration within the device skirt. Methods: Explants were fixed and sectioned in paraffin. Histologic findings related to the device skirt were compared with earlier histologic results from animal studies and correlated with clinical histories. Results: Two devices had been removed due to complications related to the optic alone, 11 following stromal melting overlying the biointegratable sponge skirt and 1 due to a retroprosthetic membrane. All devices demonstrated normal skirt porosity. Biointegration was similar to that found in animal studies but qualitatively appeared reduced in the affected areas in patients with overlying stromal melting prior to explantation. Patients with a longer history of melting prior to explantation demonstrated presence of inflammatory cells around the device. Conclusions: Histologic findings of the AlphaCor skirt in humans are consistent with earlier animal studies. This study confirms that biointegration by host fibroblastic cells, with collagen deposition occurs after AlphaCor implantation in humans. In cases in which stromal melting had occurred, biointegration is seen to be reduced. On correlating preoperative clinical factors with biointegration observed histologically, preoperative vascularization appears not to be required for AlphaCor biointegration.

Cataract development associated with collagen copolymer posterior chamber phakic intraocular lenses: Clinicopathological correlation

PURPOSE: To assess the histopathology of anterior subcapsular cataract associated with a collagen copolymer posterior chamber phakic intraocular lens (pIOL) (Visian Implantable Collamer Lens) using light microscopy after pIOL explantation and cataract surgery. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN: Laboratory investigation. METHODS: Pathology specimens related to explanted pIOLs were reviewed and preoperative and postoperative patient data collected. The anterior lens capsules and explanted pIOLs were examined. RESULTS: Four eyes (3 patients) had pIOL explantation for low vault and anterior subcapsular cataract. The explanted pIOLs were the shorter length models (3, 12.1 mm; 1, 12.6 mm). Anterior segment optical coherence tomography (AS‐OCT) confirmed the low pIOL vault before explantation in 2 eyes. Histopathology of the anterior subcapsular cataract showed fibrous metaplasia with a variable number of lens epithelial cell (LEC) layers attached to the inner surface of the anterior capsulorhexis specimens. Light microscopy of the explanted pIOLs showed no pigment on 1 lens, mild pigment deposition on 1 haptic, and pigment deposition throughout the anterior surface of 2 pIOLs. CONCLUSIONS: Anterior subcapsular cataract associated with the pIOLs was caused by low vaulting (confirmed on AS‐OCT) and consequent fibrous metaplasia of the anterior LECs. Surgeons should consider the possibility of anterior subcapsular cataract associated with shorter platforms when selecting a pIOL length for appropriate vault. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Linear deposits on the surfaces of intraocular lenses implanted through a hexagonal cartridge which mimic scratches/cracks on the lenses.

Aim: To describe unique linear deposits on the surface of posterior chamber intraocular lenses (IOLs) occurring after implantation through a hexagonal cartridge. Methods: Five ACR6D SE IOLs (Corneal Laboratories, Pringy, France) were injected/implanted through hexagonal cartridges. Two of these were injected into a petri dish and the remaining three were inserted into the evacuated capsular bag of cadaver eyes. In addition, three other ACR6D SE IOLs were injected into a petri dish through round cartridges. The latter served as controls. Results: All lenses that were injected/implanted through the hexagonal cartridges demonstrated linear deposits on the posterior surface of the IOL optic component. The IOLs that were injected through the round cartridges had no deposits. All the hexagonal cartridges showed signs of internal cracking. None of the round cartridges were cracked. Conclusion: Implantation of at least one IOL model, the ACR6D SE IOL, through a hexagonal cartridge can result in linear deposits on the posterior optical surface of the IOL. The shape of the cartridge appears to be a significant factor in causing the depositions.

Comparison of capsulorhexis resistance to tearing with and without trypan blue dye using a mechanized tensile strength model

PURPOSE: To evaluate the influence of trypan blue staining on capsulorhexis tear resistance using a model for mechanical measurement of the entire capsular bag of fresh human cadaver eyes. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: After the cornea and iris were removed, a 5.0 to 5.5 mm anterior continuous curvilinear capsulorhexis (CCC) was created; the capsule in study eyes was stained with trypan blue. The nucleus was hydroexpressed and the capsular bag was evacuated by irrigation/aspiration. Two metal shoetree‐shaped fixtures were implanted separately in the capsular bag and assembled using a screw nut. After zonulectomy, the fixture–capsular bag assembly was removed from the eye and loaded onto a mechanized tester. The fixtures were separated at a velocity of 7.0 mm/min in 0.15 μm intervals to stretch the capsulorhexis to its rupture point. A graph was generated for each eye. RESULTS: Ten study eyes were compared with 23 control eyes. The groups were comparable in donor age, time from death, and CCC diameter. The mean rupture load was 0.40 Newton (N) ± 0.13 (SD) in the trypan blue group and 0.39 ± 0.16 N in the control group (P=.94). The mean extension was 5.70 ± 0.99 mm and 5.85 ± 1.17 mm, respectively (P=.74). CONCLUSIONS: There was no difference in CCC strength between trypan blue–stained capsules and control capsules. Staining with trypan blue did not reduce CCC tear resistance. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Mechanized model to assess capsulorhexis resistance to tearing

PURPOSE: To evaluate a model of mechanically measuring resistance to tearing of a continuous curvilinear capsulorhexis (CCC) using the entire capsular bag of fresh human cadaver eyes isolated from the eyes after complete evacuation. SETTING: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: After the cornea and iris were removed, a 5.0 to 5.5 mm anterior CCC was created. The nucleus was hydroexpressed and the capsular bag evacuated by irrigation/aspiration. A pair of metal shoetree‐shaped fixtures, designed based on human lens geometric dimensions, were implanted separately in the capsular bag and assembled together with a screw nut. After complete zonulectomy, the fixture–capsular bag assembly was removed from the eye and loaded onto a mechanical tester. The fixtures were separated at a velocity of 7.0 mm/min in 0.15 μm intervals to stretch the CCC to its rupture point. Rupture load (N) and extension were measured and graphed. RESULTS: Testing of 23 donor eyes a mean of 69.04 hours ± 22.72 (SD) after death showed the following mean values: CCC diameter, 5.3 ± 0.12 mm; load, 0.39 ± 0.16 N; extension at CCC tearing, 5.85 ± 1.17 mm. There was a moderately strong negative correlation between donor age and load (P = .0018). CONCLUSIONS: Previous mechanized methods of assessing CCC strength used excised anterior capsules or partially phacoemulsified crystalline lenses, yielding lower tension strength values. This force‐displacement method may facilitate assessment of small differences between anterior capsulotomy techniques. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. Additional disclosures are found in the footnotes.

Intraoperative explantation of two single-piece hydrophobic acrylic intraocular lenses due to surface deposits

PurposeTo report clinical, pathological, and laboratory analyses of two cases of single-piece hydrophobic acrylic intraocular lenses (IOLs), which presented with significant surface deposits during implantation.MethodsThe lenses were implanted with the manufacturers recommended injector (loaded with Viscoat® and Healon GV®, respectively). Immediately after injection into the anterior chamber, areas on the lenses surfaces were covered by deposits, which could not be entirely removed by irrigation/aspiration. The lenses were explanted and replaced with lenses of the same design. They underwent gross analyses, light microscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy for analysis of the elemental composition of the deposits. Liquid chromatography/mass spectroscopy was also performed to identify the presence of proteins.ResultsThe deposits on the first lens had a granular appearance, forming a homogeneous layer mostly on the posterior lens surface. Larger crystal-like deposits were present mostly on the anterior surface of the second lens. Elemental analyses of the deposits in both cases revealed the presence of peaks of sodium, chloride, phosphate, and potassium, in addition to the peaks of carbon and oxygen (normal constituents of the lens material). Only protein components normally found in the anterior chamber during surgery, such as haemoglobin and albumin, were identified.ConclusionsThe results obtained suggest that the deposits in both cases may have resulted from crystallization of the ophthalmic viscosurgical device normally used during the loading of the IOLs into the cartridges.

Toxicity comparison of intraocular azithromycin with and without a bioadhesive delivery system in rabbit eyes

PURPOSE: To determine whether the addition of a bioadhesive drug‐delivery system to topical azithromycin induces intraocular inflammation and damage when introduced intraocularly by different approaches and in varying doses. SETTING: John A. Moran Eye Center, Salt Lake City, Utah, USA. DESIGN: Experimental study. METHODS: Commercial topical azithromycin 1.0% was duplicated, including the benzalkonium chloride, but without inclusion of the Durasite bioadhesive drug‐delivery system. Injections of 50 μL, 25 μL, and 10 μL of the antibiotic solutions were administered in a masked fashion to 2 rabbits; 1 eye (study eye) in each rabbit was randomized to receive azithromycin with the delivery system and the fellow eye (control eye) to receive azithromycin without the delivery system. Two rabbits had topical drops of each solution placed after a 2.8 mm incision was created. Masked slitlamp examinations, pachymetry, and intraocular pressure (IOP) were determined 1 day and 2 days postoperatively. The animals were humanely killed, and the endothelial density and histopathology were examined. RESULTS: The IOP (P<.001), pachymetry (P<.001), and signs of inflammation (P=.38 to .003) were consistently higher in the study eye, especially at the 50 μL dose, than in the control eye. This was confirmed by histopathology. CONCLUSION: If the drug‐delivery system gains access to the anterior chamber, it may cause substantial corneal edema and inflammation, even at low doses and after topical administration. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned.

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.