Sloughing of corneal epithelium and wound healing complications associated with laser in situ keratomileusis in patients with epithelial basement membrane dystrophy.

PURPOSE: To report sloughing of corneal epithelium during laser in situ keratomileusis and subsequent wound healing complications in patients with epithelial basement membrane dystrophy. METHODS: In a retrospective study, the surgical procedures, postoperative course, and visual acuities of 16 eyes of nine patients with epithelial basement membrane dystrophy who underwent laser in situ keratomileusis complicated with epithelial sloughing at three centers were reviewed. The mean follow-up period was 23 weeks (range, 4 to 52 weeks). RESULTS: In 13 (81%) of 16 eyes with epithelial basement membrane dystrophy, epithelial sloughing occurred during laser in situ keratomileusis. In eight of the 13 eyes, epithelial growth beneath the flap was observed. The flap was lifted and the interface epithelium scraped in six eyes. Flap melt or keratolysis occurred in four eyes. At the last follow-up visit, 13 of 16 eyes had an uncorrected visual acuity of 20/30 or better, and all eyes had a best-corrected visual acuity of 20/30 or better. CONCLUSIONS: Patients with epithelial basement membrane dystrophy have poorly adherent corneal epithelium and are predisposed to epithelial sloughing during the microkeratome pass of laser in situ keratomileusis. This may lead to flap distortion, interface epithelial growth, flap keratolysis, and corneal scarring. It is not recommended that laser in situ keratomileusis be performed in patients with classic, symptomatic epithelial basement membrane dystrophy. In patients who present with mild and asymptomatic epithelial basement membrane dystrophy, laser in situ keratomileusis should be performed with caution, or photorefractive keratectomy may be the preferred refractive procedure.

Comparison of visual results in initial and re-treatment laser in situ keratomileusis procedures for myopia and astigmatism.

PURPOSE: To report the results of initial and re-treatment laser in situ keratomileusis procedures for myopia and astigmatism. METHODS: A total of 1161 consecutive inital and retreatment laser in situ keratomileusis procedures in 697 patients performed between September 19, 1996, and June 20, 1998, were retrospectively analyzed. Baseline and postoperative best spectacle-corrected visual acuity, uncorrected visual acuity, spherical and cylindrical refractions, computerized video keratography, and biomicroscopy were measured or performed on each eye. RESULTS: Of 1,071 eyes, 900 (84%) underwent a single-laser in situ keratomileusis procedure, and 171 of 1,071 eyes (16%) underwent one or two re-treatment procedures. The preoperative mean +/- SD spherical equivalent was -5.09 +/- 3.15 diopters (range, -0.75 to -14.38 diopters) and the cylinder was 0.97 +/- 1.09 diopters (range, 0.00 to 3.25 diopters) in the group that underwent a single laser in situ keratomileusis treatment. The preoperative mean +/- SD spherical equivalent was -6.26 +/- 3.04 diopters (range, -1.75 to -12.88 diopters) and the cylinder was 1.53 +/- 1.11 diopters (range, 0.00 to 3.50 diopters) in the group that underwent re-treatment. Before re-treatment, 110 eyes (64.3%) in the group that underwent re-treatment achieved 20/40 or better uncorrected visual acuity and 23 eyes (13.5%) achieved 20/25 or better. Three months after re-treatment, 155 eyes (90.6%) achieved 20/40 or better, and 80 eyes (46.8%) achieved 20/25 or better. In the single-procedure group, uncorrected visual acuity at 3 months revealed 20/40 vision or better in 856 eyes (95.1%) and 20/25 vision or better in 572 eyes (63.6%). In this study group, 23.6% of eyes with a preoperative spherical equivalent greater than -6.0 diopters underwent re-treatment compared with 11.8% of eyes with a preoperative spherical equivalent of -6.0 diopters or less. CONCLUSIONS: Laser in situ keratomileusis appears to be an effective procedure for mild, moderate, and severe myopia. In eyes with residual refractive error, re-treatment laser in situ keratomileusis procedures can result in good visual outcomes.

Penetrating keratoplasty for keratoconus: a long-term review of results and complications.

PURPOSE: To study the long-term complications of penetrating keratoplasty (PKP) to evaluate current recommendations to patients with keratoconus. SETTING: John Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: Retrospective study of all PKP procedures for keratoconus performed by 4 surgeons during a 312 year period. Follow-up was 1 day and 1, 3, 6, 12, and 24 months post-PKP. Data from 93 eyes were reviewed for allograft reaction, astigmatism, visual acuity, reasons for decreased visual acuity, and other complications. RESULTS: Allograft reaction was seen in 31% of cases but no graft failure due to allograft reaction. Mean astigmatism was 2.76 diopters (D) +/- 1.99 (SD) at 24 months, with only 15% > 5.00 D. Last best corrected visual acuity was 20/25 or better in 77% of cases (87% had 20/25 or better at some time during follow-up). Complications that did not cause decreased visual acuity were noted. Punctate keratitis was noted in 20% of patients 180 days or more after surgery. CONCLUSIONS: Penetrating keratoplasty is a good treatment option for patients with keratoconus but should be reserved for those who do not tolerate contact lenses or do not get needed visual acuity with contact lenses because of complications. This procedure has become a second-line treatment for keratoconus patients and has generally good results.

Tarsal fibroma.

PURPOSE: To report a case of an isolated tarsal fibroma. METHODS: Case report. Excisional biopsy and histopathological evaluation were performed on a solid lesion originating from the tarsal conjunctival surface of an upper eyelid. RESULTS: Histopathological evaluation, including positive trichrome stains, was consistent with fibroma of the left upper tarsus. No recurrence has developed after a follow-up interval of a year. CONCLUSION: Tarsal fibroma is a rare condition that should be considered in the differential diagnosis of tarsal lesions.

Initial results of photorefractive keratectomy and laser in situ keratomileusis performed by a single surgeon.

PURPOSE: To determine the safety and efficacy of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) early in a surgeon's experience. SETTING: Ophthalmology Department, John A. Moran Eye Center, Salt Lake City, Utah, USA. METHODS: Between October 1995 and April 1997, a retrospective analysis was performed of 200 eyes in 128 patients who had PRK or LASIK with a follow-up of at least 3 months. The mean age was 38.1 years +/- 10.4 (SD) in the PRK group and 42.3 +/- 10.1 years in the LASIK group. There were 36 women and 30 men in the former and 32 women and 30 men in the latter. Photorefractive keratectomy, PRK/astigmatic keratotomy (AK), LASIK, or LASIK/AK was performed with the Summit Omnimed excimer laser. Preoperative evaluation included uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), cycloplegic refraction, tonometry, and computerized videokeratography. At 1, 3, and 6 months, UCVA, BSCVA, mean spherical equivalent (SE), astigmatism, corneal haze, subjective vision (day, night, glare, and halo), and complications were measured. RESULTS: Mean SE was 0.16 +/- 0.82 diopter (D) in the PRK group and -0.09 +/- 0.63 D in the LASIK group at 1 month (P < .05), -0.18 +/- 0.66 D and -0.16 +/- 0.58 D, respectively, at 3 months, and -0.33 +/- 0.73 D and -0.09 +/- 0.62 D, respectively, at 6 months. Achieved correction was similar in the 2 groups. Mean BSCVA was 22.8 +/- 6.0 in the PRK group and 22.2 +/- 5.3 in the LASIK group at 1 month, 21.1 +/- 6.0 and 21.1 +/- 3.1, respectively, at 3 months, and 19.8 +/- 3.5 and 22.9 +/- 5.2, respectively, at 6 months (P < .005). Mean surface regularity index was 0.68 +/- 0.40 in the PRK group and 0.86 +/- 0.41 in the LASIK group at 1 month, 0.54 +/- 0.26 and 0.72 +/- 0.37, respectively, at 3 months (P < .05), and 0.49 +/- 0.27 and 0.84 +/- 0.42, respectively, at 6 months. Mean surface asymmetry index was 0.71 +/- 0.43 in the PRK group and 0.55 +/- 0.21 in the LASIK group at 1 month (P < .05), 0.53 +/- 0.24 and 0.51 +/- 0.23, respectively, at 3 months, and 0.46 +/- 0.19 and 0.64 +/- 0.54, respectively, at 6 months. The subjective parameters between the groups were significantly different only at 6 months; patients in the PRK group reported better day and night vision. CONCLUSION: With careful preparation and proper training, PRK and LASIK appear to be safe and efficacious even during the surgeon's early learning phases.

Comparison of mechanical and transepithelial debridement during photorefractive keratectomy.

OBJECTIVE: Comparison of clinical results from mechanical and transepithelial debridement during photorefractive keratectomy. DESIGN: Randomized, prospective study. PARTICIPANTS: Two hundred seventy-eight eyes in 173 patients between November 1995 and June 1997. INTERVENTION: Photorefractive keratectomy treatments with a Summit Omnimed excimer laser (6-mm). Clinical results were measured at 1, 3, and 6 months. MAIN OUTCOMES MEASURES: Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BCVA), mean spherical equivalent (MSE), astigmatism, corneal haze, and subjective vision (day, night, glare, and halo). RESULTS: At all postoperative intervals, no significant difference was present between mean values of MSE, haze, or any subjective parameters. For mean UCVA, BCVA, and astigmatism values, a significant difference (P < 0.05) was present only at 6 months. At all postoperative intervals, mechanical values tended to be superior to transepithelial valves. CONCLUSION: Clinical results were not statistically different between the two techniques; however, the mechanical technique tended to have superior values for almost all tested parameters.

Decentration of 3-piece versus plate-haptic silicone intraocular lenses.

PURPOSE: To compare the incidence of decentration with 2 types of silicone intraocular lenses (IOLs). SETTING: John A. Moran Eye Center, University of Utah Medical Center, Salt Lake City, Utah, USA. METHODS: Selection criteria for this retrospective study included patients who had uncomplicated cataract surgery with a clear cornea or scleral tunnel incision with a curvilinear capsulorhexis and capsular bag implantation of a silicone IOL. After a mean follow-up of 14 months (range 12 to 18 months), 54 eyes implanted with a 3-piece lens (AMO SI-30) and 58 eyes implanted with a plate-haptic lens (Staar AA403) were examined for posterior chamber IOL decentration. The decentration criterion was 0.5 mm or more from the center of the pupil. Detailed chart review of preoperative and postoperative measurements was performed for each patient. RESULTS: Eighteen of the 3-piece IOLs (33%) and 11 of the plate-haptic IOLs (20%) were decentered 0.5 mm or more (P = .129). Using photographic analysis, the mean IOL decentration with the 3-piece IOL (1.12 mm +/- 0.198 [SD]) was significantly greater than with the plate-haptic IOL (0.632 +/- 0.278 mm)(P < .001). No statistically significant correlation was found between the centered or decentered IOL groups' preoperative refraction, axial length, capsulorhexis size, type of incision, or rate of neodymium:YAG laser capsulotomy. CONCLUSIONS: No statistically significant difference was seen between the decentration rates of 3-piece and plate-hepatic IOLs; however, the amount of decentration with the 3-piece IOL was significantly greater than with the plate-hepatic IOL. Other factors did not contribute to IOL decentration.

Prospective evaluation of topical versus retrobulbar anesthesia: a converting surgeon's experience.

PURPOSE: To evaluate and compare the efficacy of topical versus retrobulbar anesthesia for cataract surgery performed by a surgeon newly converting to the topical technique. SETTING: Department of Ophthalmology, Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. METHODS: Ninety patients were prospectively assigned by permuted block restricted randomization to receive topical (Group 1; n = 45) or retrobulbar (Group 2; n = 45) anesthesia. Group 1 received topical bupivacaine 0.75% and intravenous midazolam and fentanyl for anesthesia. Group 2 received intravenous methohexital followed by retrobulbar block with an equal mixture of lidocaine 2% and bupivacaine 0.75% plus hyaluronidase 150 units. A visual pain analog scale was used to assess the degree of pain during anesthesia administration and surgery and postoperatively. The degree to which eye movement, touch, and light caused patient discomfort was assessed. Intraoperative conditions and complications were recorded. RESULTS: Intraoperative operating conditions were significantly better in Group 2 (P < .05). There was a small but statistically significant difference in the degree of discomfort during anesthesia administration and surgery (P < .05). There was no difference in postoperative discomfort. Chemosis, subconjunctival hemorrhage, and eyelid hemorrhage occurred only in Group 2, in which there was one retrobulbar hemorrhage. Although eyelid squeezing and ocular motility were present more frequently in Group 1, neither was a problem to the surgeon. CONCLUSION: Cataract surgery was safely performed by a surgeon converting to topical anesthesia. After a distinct learning curve, the procedure was performed with minimal patient discomfort. Surgical training and patient preparation are the key to safe use of topical anesthesia.

Anti-interleukin-6 antibodies inhibit herpes simplex virus reactivation.

Herpes simplex viruses (HSVs) infect epithelial cells, become localized in neurons, and can reactivate in response to a variety of stimuli, including ultraviolet light and hyperthermia. The sequence of gene activation during viral replication is known, but the molecular linkage between exogenous stimuli and HSV reactivation has not been determined. It was hypothesized that interleukin (IL)-6 acts as a signal between exogenous stimuli and neurons, stimulating HSV reactivation from latency. Mouse corneas were infected with HSV-1, and ocular reactivation was induced 5-7 weeks later by thermal stress or corneal exposure to ultraviolet light. Anti-IL-6 monoclonal antibodies were administered to the latently infected mice 8-12 h before the reactivation stimulus. Treatment with anti-IL-6 antibodies resulted in significantly lower frequencies of ocular reactivation compared with those in mice treated with a control immunoglobulin. These results support the hypothesis that IL-6 plays a role in HSV reactivation from latency.

Clear corneal cataract surgery in ocular cicatricial pemphigoid.

We present the results of clear corneal cataract surgery in a patient with stable ocular cicatricial pemphigoid. By eliminating trauma to the conjunctiva, cataract surgery was successfully performed without exacerbating the disease.

Testing for hepatitis B surface antigen in processing donor tissue for penetrating keratoplasty.

PURPOSE: The Food and Drug Administration recently proposed a change in the screening of eye bank cornea donors for hepatitis B virus. Currently, most eye banks run confirmatory tests to reduce the frequency of false-positive hepatitis B virus surface antigen (HBsAg) tests. The Food and Drug Administration is considering a policy that would not allow confirmatory testing. METHODS: A retrospective study of records of a regional eye bank was done to evaluate the results of screening and confirmatory tests for hepatitis B virus. RESULTS: The positive predictive value of the HBsAg screening test (using hepatitis B virus antibody neutralization for comparison) was low, 12.5%. False-positive donors accounted for 11.4% of the tissue used for penetrating keratoplasty during 1994. CONCLUSIONS: If confirmation tests were not allowed, considerable loss of suitable tissue would have occurred. We believe that the current standards allow safe and effective processing of donor ocular tissue.

A comparison of topical and retrobulbar anesthesia for cataract surgery.

PURPOSE: To evaluate and compare the efficacy of topical and retrobulbar anesthesia for cataract extraction with intraocular lens implantation. METHODS: One hundred thirty-eight patients prospectively were assigned to the topical (group 1; n = 69) or retrobulbar (group 2; n = 69) anesthesia groups by permuted block restricted randomization. Group 1 received topical 0.75% bupivacaine and intravenous midazolam and fentanyl for anesthesia. Group 2 received intravenous methohexital followed by retrobulbar block with an equal mixture of 2% lidocaine and 0.75% bupivacaine plus hyaluronidase (150 U). A visual pain analogue scale was used to assess the degree of pain during the administration of anesthesia, during surgery, and post-operatively. The degree to which eye movement, touch, and light caused patient discomfort was assessed. Complications and surgical conditions were recorded. RESULTS: There was no difference in the surgical conditions (P = 0.5) or pain during surgery (P = 0.35) between the two groups. There was more discomfort during administration of topical anesthesia (P < 0.0001) and postoperatively (P < 0.05) in the topical group. Chemosis, subconjunctival hemorrhage, and eyelid hemorrhage were seen almost exclusively in the retrobulbar group. One patient in group 2 had a retrobulbar hemorrhage. Although eyeball movement and squeezing of the eyelids were present more frequently in the topical group, neither was a problem to the surgeon. CONCLUSION: Topical anesthesia can be used safely for cataract extraction. The degree of patient discomfort is only marginally higher during administration of the anesthesia and postoperatively. However, surgical training and patient preparation are the keys to the safe use of topical anesthesia.

Phototherapeutic keratectomy for corneal scars.

BACKGROUND AND OBJECTIVE: Phototherapeutic keratectomy (PTK) is an effective method of treating a variety of corneal disorders. We report our experience in using PRK to treat corneal scars. PATIENTS AND METHODS: We retrospectively analyzed the data from a cohort of 22 eyes with corneal scars. The etiology of the scar was recorded for each patient. The change in best corrected visual acuity, spherical equivalent, and astigmatism were evaluated at one and three months after surgery. RESULTS: At three months, seven of 18 eyes (39%) had improved 2 or more lines of best corrected visual acuity and 3 eyes (16%) had lost 2 or more lines. Eleven of 18 eyes (61%) had a hyperopic shift of more than 1.00 diopter (D) and eight of 18 eyes (44%) had a hyperopic shift of more than 2.00 D. There was a mean reduction in astigmatism of 0.67 +/- 4.00 D. Four of eight eyes with traumatic scars had significant improvement as compared to none of five eyes with infectious scars. CONCLUSION: PTK is a relatively safe and effective means of treating corneal scars and thereby may offer an alternative to corneal transplantation.

Efficacy of tobramycin drops applied to collagen shields for experimental staphylococcal keratitis.

Treatment of staphylococcal keratitis includes tobramycin drops at repeated intervals, a prolonged therapy that is disruptive to the patient. To identify a regimen involving less frequent drug application, we compared the efficacy of fortified tobramycin (1.36%) administered by collagen shields or in topical drop form to rabbit corneas intrastromally infected with staphylococci. Eyes were treated with shields hydrated in and supplemented with fortified tobramycin drops (1.36%) applied every 1, 2, 5, or 10 h, from 10 to 20 h postinfection. For topical drop treatment alone, tobramycin was applied following the identical regimen. Untreated corneas contained 10(6) colony forming units. Shields supplemented with tobramycin drops applied every 1, 2, or 5 h sterilized 100% of the corneas. Shields supplemented with tobramycin drops applied at 10 h sterilized 58% of the corneas. Topical delivery of tobramycin every h sterilized all corneas; drops alone applied at longer intervals, such as 2, 5, or 10 h, sterilized 83%, 17%, and 0% of the corneas, respectively. Collagen shield delivery of tobramycin with supplemental topical drops can eradicate staphylococci in this model with less frequent dosing intervals than are required with topical therapy alone.

Microbial keratitis in children.

In a five-year review, we identified 29 cases of microbial infection in 28 patients who were 16 years old or younger. Herpes simplex infections were excluded. Predisposing factors included trauma (ten cases, 34%), severe systemic illness (eight cases, 27%), contact lens use (seven cases, 24%), exposure keratopathy (seven cases, 24%), and previous ocular surgery (six cases, 21%). A total of 24 microorganisms were identified in cultures of corneal scrapings from 22 of the 29 cases; two cases involved polymicrobial infections. Of the 24 identified pathogens, gram-positive cocci were the most common (12). Other microorganisms included gram-negative bacteria (five) and fungi (four). Isolated cases of Acanthamoeba species, Borrelia burgdorferi, and Bacillus species were also present. Therapy with intensive topical antibiotics was successful in this series. The rate of surgical intervention (6/29, 21%) was similar to that of previous reports.

An adjustable double running suture technique for keratoplasty.

In a retrospective analysis, we examined 30 consecutive cases of penetrating keratoplasty in which a double running 10-0/11-0 nylon suture technique was used and the 10-0 suture was adjusted early in the postoperative period to reduce astigmatism. When the response to suture adjustment was inadequate, the presence of the 11-0 suture allowed for early (ten to 18 weeks) removal of the 10-0 suture. Rapid visual recovery (12.3 +/- 0.95 weeks; mean +/- standard error) and low levels of final astigmatism (2.66 +/- 0.24 diopters) were achieved. Visual acuity was 20/20 to 20/40 in 25 of the 28 patients (89%) who were visually rehabilitated. In these 28 patients, visual acuity remained stable for the remainder of the study. All patients had a minimum of six months' follow-up from the time of surgery; mean follow-up was 10.6 +/- 1.70 months.

Repair of inadvertent conjunctival filtering blebs with a scleral flap.

We describe a new technique to correct inadvertent conjunctival filtering blebs. This method creates a partial-thickness scleral flap to seal the region of the excised fistula. Closure of this flap with sutures permanently covers the fistula and eliminates any route for recurrence of the bleb or downgrowth of epithelium. No complications have been associated with this procedure, which has been used in more than 10 cases during the last 3 years.

Collagen shields containing tobramycin for sustained therapy (24 hours) of experimental Pseudomonas keratitis.

We compared collagen shields hydrated in 1.36% tobramycin with topical 1.36% tobramycin for sustained treatment of experimental Pseudomonas keratitis in rabbits. Antibiotic therapy for a total of 24 hours was initiated 14 hours after an intrastromal injection of 10(3) logarithmic phase Pseudomonas aeruginosa. Seven groups were treated as follows: groups 1-3, collagen shields hydrated in tobramycin supplemented with topical 1.36% tobramycin drops at 4, 6, or 8 hour intervals; group 4, collagen shields hydrated in tobramycin without any further topical supplementation; group 5, topical tobramycin therapy, initially every half-hour for 4 hours, then hourly; group 6, collagen shields hydrated in balanced saline solution; and group 7, no treatment. Each group contained four eyes. The groups treated with collagen shields supplemented every 4 or 6 hours with topical tobramycin had significantly fewer colony forming units (CFU) than those receiving topical or collagen shield therapy alone (P < 0.001). The group treated with collagen shields hydrated in sterile saline had 10(7) CFU per cornea, which was not significantly different from the untreated group (P > 0.2). Collagen shields hydrated in tobramycin and supplemented with topical tobramycin were effective in sustained treatment of experimental Pseudomonas keratitis.

Fungal keratitis from nylon line lawn trimmers.

Ocular trauma from nylon line lawn trimmers is becoming more prevalent. Previous case reports have described penetrating trauma caused by these tools. We managed three cases of fungal keratitis caused by injuries from nylon line trimmers. Fungal keratitis should be strongly considered as the cause of any corneal ulcer related to trauma from a nylon line lawn trimmer.