Stephen D. McLeod

Amniotic membrane transplantation for acute chemical or thermal burns

PURPOSE To determine whether preserved human amniotic membrane (AM) can be used to treat ocular burns in the acute stage. DESIGN Prospective, noncomparative, interventional case series. PARTICIPANTS Thirteen eyes from 11 patients with acute burns, 10 eyes with chemical burns and 3 with thermal burns of grades II-III (7 eyes) and grade IV (6 eyes), treated at 7 different facilities. METHODS Patients received amniotic membrane transplantation (AMT) within 2 weeks after the injury. MAIN OUTCOME MEASURES Integrity of ocular surface epithelium and visual acuity during 9 months of follow-up. RESULTS Ten patients were male and one patient was female; most were young (38.2 +/- 10.6 years). For a follow-up of 8.8 + 4.7 months, 11 of 13 eyes (84.63%) showed epithelialization within 2 to 5 weeks (23.7 +/- 9.8 days), and final visual acuity improved > or = 6 lines (6 eyes), 4 to 5 lines (2 eyes), and 1 to 3 lines (2 eyes); only one eye experienced a symblepharon. Eyes with burns of grade II to III showed more visual improvement (7.3 +/- 3 lines) than those with burns of grade IV (2.3 +/- 3.0 lines; P < 0.05, unpaired t test). In the group with grade II or III burns, none had limbal stem cell deficiency. All eyes in the group with grade IV burns did experience limbal stem cell deficiency. CONCLUSIONS Amniotic membrane transplantation is effective in promoting re-epithelialization and reducing inflammation, thus preventing scarring sequelae in the late stage. In mild to moderate burns, AMT alone rapidly restores both corneal and conjunctival surfaces. In severe burns, however, it restores the conjunctival ocular surface without debilitating symblepharon and reduces limbal stromal inflammation, but does not prevent limbal stem cell deficiency, which requires further limbal stem cell transplantation. These results underscore the importance of immediate intervention in the acute stage of eyes with severely damaged ocular surface. Further prospective randomized studies including a control group are required to determine the effectiveness of AMT in acute chemical and thermal burns of the eye.

The Role of Smears, Cultures, and Antibiotic Sensitivity Testing in the Management of Suspected Infectious Keratitis

PURPOSE To examine the role of routine smears, cultures, and antibiotic sensitivity testing in the treatment of suspected infectious keratitis. METHODS A retrospective chart and laboratory data review was performed for 81 consecutive patients seen in the Los Angeles County/University of Southern California Department of Ophthalmology between June 1991 and December 1993 with a primary diagnosis of community-acquired infectious keratitis. No patients were treated with antibiotics before evaluation in the authors department, and all underwent corneal scrapings for gram-stain and bacterial, fungal, and mycobacterium cultures. Ulcers were classified as moderate or severe. All initially were treated as inpatients with a regimen including fortified cefazolin and a fortified aminoglycoside. RESULTS Of 81 patients, 74 ulcers were either culture- negative (n=18) or grew bacteria (n=56). Fungal infection was suggested in seven patients. Of the nonfungal ulcers, 33 were classified as moderate, and 41 as severe; all moderate ulcers improved without requiring a modification in antibiotic treatment, whereas 3 severe ulcers required a change in treatment. CONCLUSION Most community-acquired bacterial ulcers resolve with broad spectrum empiric therapy. Alternatives to universal culture and sensitivity testing that might be considered include selectively performing cultures for more severe or suspected non-bacterial ulcers or routinely obtaining cultures in all cases, but pursuing identification and sensitivity studies only when those data are required for therapy modification.

A dual optic accommodating foldable intraocular lens

Aim: To design an accommodating intraocular lens with extended accommodative range that can be adapted to current standard phacoemulsification and endocapsular implantation technique. Method: Ray tracing analysis and lens design; cadaver eye implantation. Results: Ray tracing analysis indicated that axial movement of an exaggerated converging anterior optic linked by spring loaded haptics to a compensatory static diverging posterior optic produced greater change in conjugation power of the eye compared to axial movement of a single optic lens. A dual optic one piece foldable silicone lens was constructed and implanted via a 4 mm corneal incision into the capsular bag of two cadaver eyes. Conclusion: A dual optic intraocular lens design can increase the optical effect of a given displacement and suggests improvements for accommodating intraocular lenses.

Comparison of natamycin and voriconazole for the treatment of fungal keratitis.

OBJECTIVE To conduct a therapeutic exploratory clinical trial comparing clinical outcomes of treatment with topical natamycin vs topical voriconazole for fungal keratitis. METHODS The multicenter, double-masked, clinical trial included 120 patients with fungal keratitis at Aravind Eye Hospital in India who were randomized to receive either topical natamycin or topical voriconazole and either had repeated scraping of the epithelium or not. MAIN OUTCOME MEASURES The primary outcome was best spectacle-corrected visual acuity (BSCVA) at 3 months. Other outcomes included scar size, perforations, and a subanalysis of BSCVA at 3 months in patients with an enrollment visual acuity of 20/40 to 20/400. RESULTS Compared with those who received natamycin, voriconazole-treated patients had an approximately 1-line improvement in BSCVA at 3 months after adjusting for scraping in a multivariate regression model but the difference was not statistically significant (P = .29). Scar size at 3 months was slightly greater with voriconazole after adjusting for scraping (P = .48). Corneal perforations in the voriconazole group (10 of 60 patients) were not significantly different than in the natamycin-treated group (9 of 60 patients) (P >.99). Scraping was associated with worse BSCVA at 3 months after adjusting for drug (P = .06). Patients with baseline BSCVA of 20/40 to 20/400 showed a trend toward a 2-line improvement in visual acuity with voriconazole (P = .07). CONCLUSIONS Overall, there were no significant differences in visual acuity, scar size, and perforations between voriconazole- and natamycin-treated patients. There was a trend toward scraping being associated with worse outcomes. Application to Clinical Practice The benefit seen with voriconazole in the subgroup of patients with baseline visual acuity of 20/40 to 20/400 needs to be validated in a confirmatory clinical trial. Trial Registration clinicaltrials.gov Identifier: NCT00557362.

Synchrony dual-optic accommodating intraocular lens. Part 1: optical and biomechanical principles and design considerations.

PURPOSE: To describe a dual‐optic accommodating intraocular lens (IOL) based on theoretical considerations. SETTING: University and independent research group. METHODS: Ray‐tracing analysis using optical modeling software (ZEMAXTM, Focus Software Inc., Tucson, Ariz) in a theoretical model eye was used to analyze lens configurations to optimize the accommodative and magnification effects of axial lens displacement. Finite‐element modelling using a commercially available PC‐based software package (COSMOS DesignSTAR) was applied to design the biomechanical parameters of the inter‐optic articulations and optics. RESULTS: Ray‐tracing analysis indicated that a dual‐optic design with a high plus‐powered front optic coupled to a minus posterior optic produced greater change in conjugation power of the eye compared to a single‐optic intraocular lens and that magnification effects were unlikely to account for improved near vision. Finite‐element modelling indicated that the 2 optics can be linked by spring‐loaded haptics that allow anterior and posterior axial displacement of the front optic in response to changes in ciliary body tone and capsular tension. CONCLUSION: A dual‐optic design linked by spring haptics increases the accommodative effect of axial optic displacement with minimal magnification effect and has promise for improving the performance of accommodative intraocular lenses.

Corticosteroids for Bacterial Keratitis: The Steroids for Corneal Ulcers Trial (SCUT)

OBJECTIVE To determine whether there is a benefit in clinical outcomes with the use of topical corticosteroids as adjunctive therapy in the treatment of bacterial corneal ulcers. METHODS Randomized, placebo-controlled, double-masked, multicenter clinical trial comparing prednisolone sodium phosphate, 1.0%, to placebo as adjunctive therapy for the treatment of bacterial corneal ulcers. Eligible patients had a culture-positive bacterial corneal ulcer and received topical moxifloxacin for at least 48 hours before randomization. MAIN OUTCOME MEASURES The primary outcome was best spectacle-corrected visual acuity (BSCVA) at 3 months from enrollment. Secondary outcomes included infiltrate/scar size, reepithelialization, and corneal perforation. RESULTS Between September 1, 2006, and February 22, 2010, 1769 patients were screened for the trial and 500 patients were enrolled. No significant difference was observed in the 3-month BSCVA (-0.009 logarithm of the minimum angle of resolution [logMAR]; 95% CI, -0.085 to 0.068; P = .82), infiltrate/scar size (P = .40), time to reepithelialization (P = .44), or corneal perforation (P > .99). A significant effect of corticosteroids was observed in subgroups of baseline BSCVA (P = .03) and ulcer location (P = .04). At 3 months, patients with vision of counting fingers or worse at baseline had 0.17 logMAR better visual acuity with corticosteroids (95% CI, -0.31 to -0.02; P = .03) compared with placebo, and patients with ulcers that were completely central at baseline had 0.20 logMAR better visual acuity with corticosteroids (-0.37 to -0.04; P = .02). CONCLUSIONS We found no overall difference in 3-month BSCVA and no safety concerns with adjunctive corticosteroid therapy for bacterial corneal ulcers. APPLICATION TO CLINICAL PRACTICE Adjunctive topical corticosteroid use does not improve 3-month vision in patients with bacterial corneal ulcers. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00324168.

The importance of initial management in the treatment of severe infectious corneal ulcers

PURPOSE To identify factors that influence the outcome of patients with severe infectious corneal ulcers. METHOD A retrospective review was performed of the hospital records of all such patients admitted to the Doheny Eye Hospital during a 30 month period. Outcome variables examined were change in visual acuity, duration of hospitalization, hospital charges, and percentage of patients who required penetrating keratoplasty. RESULTS Sixty-two ulcers were included. An organism was identified and antibiotic sensitivities established in 52 patients (84%). Inpatient therapy involved a combination of fortified aminoglycoside and cephalosporin antibiotics in 39 patients (63%) and was found to be appropriate on the basis of sensitivity studies in 49 (94%) of 52 patients. Inappropriate initial treatment was related to increased hospital charge (P = 0.024) as well as increased risk of penetrating keratoplasty (P = 0.001). CONCLUSIONS Appropriate initial therapy is most critical in the course of serious corneal ulcers, and aggressive, broad-spectrum antibiotic coverage is advocated.

Synchrony dual-optic accommodating intraocular lens Part 2: Pilot clinical evaluation

PURPOSE: To evaluate the clinical outcomes of an accommodating dual‐optic intraocular lens (IOL). SETTING: Private practice and university centers. METHODS: A prospective noncomparative case series with retrospective control comprised 21 patients (26 eyes) scheduled for small‐incision extracapsular cataract extraction by phacoemulsification with implantation of the Synchrony dual‐optic accommodating IOL (Visiogen) (accommodating IOL group) and 10 patients who had small‐incision extracapsular phacoemulsification with implantation of a monofocal, single‐optic IOL at least 6 months previously (control group). Patients were examined 1, 3, 6, and 12 months after surgery. Defocus curves in the accommodating IOL group were compared with those in the control group. The main outcome measures were postoperative distance uncorrected and best corrected visual acuity; near uncorrected, distance corrected, and near corrected visual acuity; and accommodative range based on defocus curves. RESULTS: Twenty‐four eyes were available at the 6‐month follow‐up visit. All eyes had best corrected distance visual acuity of 20/40 or better, and 19 eyes (79%) had an uncorrected distance visual acuity of 20/40 or better. Uncorrected near visual acuity was 20/40 or better in all eyes. With distance correction, 23 eyes (96%) had an acuity of 20/40 or better at near. Defocus curve analysis suggested a mean accommodative range of 3.22 diopters (D) ± 0.88 (SD) (range 1.00 to 5.00 D) in the accommodating IOL group and 1.65 ± 0.58 D in the control group (range 1.00 to 2.50 D) (P<.05). CONCLUSION: The Synchrony dual‐optic IOL shows promise as an option to provide accommodative function in pseudophakic patients.

SPONTANEOUS CORNEAL HYDROPS AND PERFORATION IN KERATOCONUS AND PELLUCID MARGINAL DEGENERATION

Purpose. To report two cases of pellucid marginal degeneration and one case of keratoconus associated with spontaneous corneal hydrops leading either to perforation or imminent perforation, requiring urgent keratoplasty. Method. Retrospective interventional case series of three patients with noninflammatory peripheral corneal degenerations. A retrospective review was done of the clinical courses, surgical interventions, and pathologic specimens, development of spontaneous hydrops, perforation, need for surgical intervention, and final visual outcome. Results. Two patients with pellucid marginal degeneration and one with keratoconus developed spontaneous hydrops followed by aqueous leakage through markedly thinned anterior stroma. In one case, the leak site was successfully sealed after three separate applications of tissue adhesive, although the remaining two cases required penetrating keratoplasty. Conclusions. These cases document the very unusual occurrence of corneal hydrops leading to spontaneous corneal perforation in patients with keratoconus and pellucid marginal degeneration.

Effect of myopic LASIK on human corneal sensitivity

OBJECTIVE To evaluate the changes in corneal sensitivity after LASIK for the correction of different degrees of myopia. DESIGN Prospective, nonrandomized, comparative self-controlled trial. PARTICIPANTS One hundred two myopic eyes of 58 patients were included in this study. METHODS The eyes were divided into four groups: group 1, from -0.75 to -3.75 diopters (D); group 2, from -4.00 to -7.75 D; group 3, from -8.00 to -11.75 D; group 4, from -12.00 to -16.00 D. Corneal sensitivity was measured before and 1, 7, 30, 90, 180, 270, and 365 days after surgery or until full recovery. MAIN OUTCOME MEASURES The recovery of corneal sensation after LASIK. RESULTS Immediately after surgery, the lenticule was found to be completely anesthetic, and the full recovery varied according to the depth of the ablation. Normal levels of corneal sensitivity, but not full recovery, were found after 90 days in groups 1 and 2 and after 180 days in groups 3 and 4. Full recovery of corneal sensitivity was found after 180 days in groups 1 and 2 and after 270 days in groups 3 and 4. CONCLUSIONS After LASIK, corneal sensitivity is decreased at the central and paracentral areas for as long as 9 months. The depth of the ablation seems to be an important factor in the temporary decrease of corneal sensitivity and its recovery.