Assessment of anterior chamber flare and cells after laser in situ keratomileusis.

PURPOSE: To determine the presence of anterior chamber flare and cells after laser in situ keratomileusis (LASIK) for the correction of myopia. SETTING: Hermann Eye Center and the University of Texas Medical School, Department of Ophthalmology and Visual Science, Houston, Texas, USA. METHODS: Forty-three eyes of 23 consecutive patients ranging in age from 24 to 62 years had LASIK for myopia. All surgeries were performed by a single surgeon using a VISX Star laser and the same technique. Patients received no preoperative antiinflammatory medications. Postoperatively, all patients were instructed to use 1 drop of ofloxacin (Ocuflox) and 1 drop of fluorometholone 0.1% (FML) in the operated eye 4 times daily while awake for 7 days. At baseline and postoperative days 1, 7, and 28, anterior chamber flare was measured and cells were counted using a Kowa laser flare meter (FM-500) and laser cell counter (LC-500), respectively. RESULTS: Flare and cells increased significantly on day 1 (P <.0001 for both flare and cells) and returned to preoperative levels by day 7. No statistically significant correlation was detected between the amount of inflammation and the number of laser pulses (P =.2922) or the ablation time (P =.8383). CONCLUSIONS: A significant increase in anterior chamber inflammation occurred during the first 24 hours after LASIK. Inflammation levels then subsided to preoperative levels by day 7 with steroid use. Anterior chamber inflammation did not appear to correlate with the duration of the ablation or the number of laser pulses.

Epithelial healing rates with topical ciprofloxacin, ofloxacin, and ofloxacin with artificial tears after photorefractive keratectomy.

PURPOSE: To determine whether corneal epithelial healing differs after the use of topical ciprofloxacin alone, topical ofloxacin alone, or topical ofloxacin with artificial tears in patients having photorefractive keratectomy (PRK). SETTING: Department of Ophthalmology and Visual Science, The University of Texas Health Science Center at Houston, Houston, Texas, USA. METHODS: Eighteen patients (6 women, 12 men) with moderate myopia (-1.50 to -6.00 diopters [D]) had standardized PRK. Patient age ranged from 25 to 62 years. The 28 eyes (16 right, 12 left) were randomized into 3 treatment groups: ofloxacin alone, n = 9 eyes; ciprofloxacin, n = 9 eyes; and ofloxacin with Refresh Plus, n = 10 eyes. The drugs were administered immediately after surgery and then every 6 hours. Video recordings of the corneal wounds stained with fluorescein were performed at 8:00 AM and 4:00 PM using a video slitlamp camera with a cobalt-blue light until the wound completely healed. The videotaped images were recorded and analyzed by a computer planimetry program. Wound areas were recorded and compared among the 3 drugs. The square-root transformation was applied to the wound area to obtain a constant healing rate. Statistical comparisons were analyzed using an analysis of variance test. RESULTS: Mean recovery time was 82.67 hours +/- 14.42 (SD) in the ofloxacin eyes, 120.89 +/- 34.05 hours in the ciprofloxacin eyes, and 76.80 +/- 19.30 hours in the ofloxacin with Refresh Plus eyes. Mean healing rate was 0.66 +/- 0.17 hours, 0.54 +/- 0.16 hours, and 0.67 +/- 0.15 hours, respectively. The healing rate was significantly higher in the ofloxacin with Refresh Plus eyes than in the ciprofloxacin eyes (P < .0001). There was no significant difference between the ofloxacin eyes and the ofloxacin with Refresh Plus eyes (P = .42). CONCLUSION: Ofloxacin with Refresh Plus and ofloxacin alone had a more positive effect on epithelial healing than ciprofloxacin. The ciprofloxacin eyes were significantly more prone to impaired or delayed wound healing and to the development of corneal haze.

Lyme disease associated with unilateral interstitial keratitis.

PURPOSE: To report a case of Lyme disease that presented with a single nummular unilateral interstitial keratitis. METHODS: Case report and review of the literature. RESULTS: A 57-year-old black man who had contact with freshly killed deer had a chief complaint of foreign-body sensation in his right eye (OD) that had been diagnosed and treated for herpes simplex stromal keratitis. The patient underwent a systemic workup for interstitial keratitis. All results including RPR and MHA-TP were negative except for Lyme antibody titer (enzyme-linked immunosorbent assay [ELISA]) 178 U/ml (normal, <159 U/ml). CONCLUSION: Interstitial keratitis from Lyme disease has been regarded as a bilateral disease in the literature. We present this infrequent ocular manifestation of Lyme disease as a rare single nummular unilateral presentation.

Lasso procedure to revise overcorrection with radial keratotomy.

PURPOSE: To report three patients who underwent the lasso procedure to revise overcorrection with radial keratotomy. METHODS: Case report and review of the literature. RESULTS: Four eyes of three patients who had undergone radial keratotomy with resultant hyperopic overcorrection underwent a lasso procedure. Before the procedure, average cycloplegic refraction spherical equivalent was +3.656 +/- 1.352 diopters, and average manifest refraction spherical equivalent was +2.250 +/- 0.621 diopters. A 10.0 monofilament nylon suture was placed in a circumferencial manner through the corneal stroma and overlapping the old radial keratotomy incisions. At 1 month postoperatively, best-corrected visual acuity was 20/20 in all four eyes, with average cycloplegic refraction spherical equivalent +0.438 +/- 1.423 diopters and average manifest refraction spherical equivalent -0.156 +/- 1.147 diopters. Mean delta cycloplegic refraction spherical equivalent was 3.219 +/- 1.724. CONCLUSIONS: The lasso procedure provides an immediate solution for symptomatic overcorrected hyperopic eyes after radial keratotomy. Predictability and long-term stability necessitate further follow-up.

Corneal aberrations and visual performance after radial keratotomy.

BACKGROUND: Refractive surgery and videokeratography have allowed us to study the effects on visual performance of relatively large changes in corneal aberration structure induced by surgical changes in corneal shape. METHODS: We quantified in one eye of nine normal and 23 radial keratotomy patients, the area under the log contrast sensitivity function (AULCSF) and corneal first surface wavefront variance for two artificial pupil sizes (3 and 7 mm). Contrast sensitivity was measured with sine-wave gratings at six spacial frequencies. Wavefront variance was derived from videokeratographs using Zernike polynomials. RESULTS: For normals eyes there were no significant changes over time. For eyes that had radial keratotomy, there were significant pupil size-dependent changes. For the 3 mm pupil, there were significant surgery-induced changes in the corneal wavefront variance which became large (approximately 30 times preoperative values) at 7 mm. Significant correlated changes in AULCSF for the 7 mm pupil but not for the 3 mm pupil occurred immediately following surgery and remained. CONCLUSIONS: Radial keratotomy, like photorefractive keratectomy, shifts the distribution of aberrations from third order dominance (coma-like aberrations) to fourth order dominance (spherical-like aberrations). Radial keratotomy-induced aberrations and loss in contrast sensitivity are reduced with increasing clear zone diameter. Radial keratotomy induces an increase in the optical aberrations of the eye and the increase for large pupils (7 mm) but not small (3 mm) is correlated to a decrease in contrast sensitivity.

Analgesic efficacy and safety of nonpreserved ketorolac tromethamine ophthalmic solution following radial keratotomy. Ketorolac Radial Keratotomy Study Group.

PURPOSE: To compare the analgesic efficacy and safety of nonpreserved ketorolac tromethamine 0.5% with those of its vehicle in the treatment of postsurgical ocular pain following radial keratotomy. METHODS: This study employed a multicenter, double-masked, randomized, parallel-group design. Radial keratotomy patients were treated with either nonpreserved ketorolac tromethamine 0.5% or its vehicle four times daily for up to 3 days following surgery. Patients were provided with an escape medication (acetaminophen) for use only as needed for intolerable pain. RESULTS: Patients treated with ketorolac reported significantly greater pain relief (P < or =.023), less pain intensity (P < or =.047), less use of escape medication (P < or =.001), fewer symptoms of ocular discomfort (P=.024), and fewer sleep disturbances (P < or =.013) than did patients treated with vehicle. No treatment-related adverse events were reported in the ketorolac group, and only one treatment-related adverse event was reported in the vehicle group. Most other safety findings were equivalent in the two treatment groups except that there were significantly less eyelid erythema (P=.026) and eyelid edema (P < or =.001) in the ketorolac group. CONCLUSIONS: Nonpreserved ketorolac tromethamine 0.5% ophthalmic solution was significantly more effective than, and as safe as, vehicle in the treatment of postoperative pain associated with radial keratotomy. Therefore, topical ketorolac may be a valuable treatment option for the maintenance of patient comfort following refractive surgery.

Linkage mapping of Thiel-Behnke corneal dystrophy (CDB2) to chromosome 10q23-q24.

Corneal dystrophy of the anterior basement membrane is a heterogeneous set of diseases characterized by painful, recurrent, bilateral erosions of the cornea, which often result in significant visual impairment. There are several similar but clinically distinct forms of anterior basement membrane/Bowman's membrane disease, including two autosomal dominant forms, Reis-Bücklers and Thiel-Behnke corneal dystrophy. Genes causing autosomal, nonsyndromic corneal dystrophy have been mapped to human chromosomes 1p, 5q, 12q, 16q, 17p, and 20p. Using microsatellite markers closely linked to the known corneal dystrophy loci, we excluded linkage between the known sites and the disease locus in a large, four-generation family with Thiel-Behnke corneal dystrophy. A genome-wide search using a panel of microsatellite markers demonstrated a maximum two-point lod score of 4.0 at 0% recombination between the disease locus in this family and the marker D10S1239, which maps to 10q23-q24. Testing with additional microsatellite markers from 10q places the disease locus between D10S677 and D10S1671, a distance of approximately 12.0 cM, with a maximum multipoint lod score of 5.5. Based on this evidence, we have identified another locus (CDB2) for corneal dystrophy of the anterior basement membrane/Bowman's membrane, Thiel-Behnke type, further demonstrating the exceptional genetic and phenotypic heterogeneity of these diseases.

Ocular integrity after refractive procedures.

PURPOSE: The purpose of the study was to determine the integrity of human eyes after refractive procedures. METHODS: Whole human globes underwent either radial keratotomy (RK) with eight incisions, automated lamellar keratoplasty (ALK), photorefractive keratectomy (PRK), or excimer laser assisted in situ keratomileusis (LASIK). Eyes then were subjected to quantitatively increasing levels of trauma until rupture occurred. RESULTS: All eyes operated on required less energy to rupture as compared with that of control eyes. The mean number of trials required for rupture is as follows (energy doubled with each successive trial): normal, 4.29; LASIK, 3.80; ALK, 3.67; PRK, 3.60; and RK, 2.83. The level of energy required to rupture normal, ALK, PRK, and LASIK eyes was not significantly different. All RK eyes ruptured at incisions. Most ALK, PRK, and LASIK eyes ruptured near the flap edge or limbus. Most normal eyes ruptured with both corneal and scleral involvement. Age of tissue donors at the time of death and time elapsed between death and procedure were not significantly different between groups (P = 0.88 and 0.79, respectively). CONCLUSIONS: The energy required to rupture ALK, PRK, and LASIK eyes is not significantly different from that for normal eyes. The RK eyes ruptured with significantly less energy than did normal eyes. All RK eyes ruptured at incision sites.

Intraoperative mitomycin in primary pterygium excision. A prospective, randomized trial.

PURPOSE: Conjunctival autograft transplantation and postoperative mitomycin therapy are two adjuvant treatment methods shown to lessen the high pterygium recurrence rate seen with simple excision alone. The authors conducted a prospective, randomized study comparing these two techniques with a relatively new treatment method using intraoperative mitomycin application. METHODS: Fifty patients with 56 primary pterygia were randomized to 1 of 3 treatment groups: conjunctival autograft (group 1), postoperative mitomycin 0.2 mg/ml four times a day x 7 days (group 2), and intraoperative mitomycin 0.4 mg/ml x 3 minutes (group 3). The mean follow-up time was 16 months (range, 6 to 28 months). RESULTS: Recurrences developed in 4 (22.2%) of 18 eyes in group 1, 4 (21.1%) of 19 eyes in group 2, and 2 (10.5%) of 19 eyes in group 3. Complications developed in two, patients from group 2, scleral thinning managed successfully with a scleral patch graft, and epithelial toxicity that resolved on discontinuation of mitomycin on postoperative day 6. There were no complications in the other two groups. CONCLUSIONS: Intraoperative mitomycin is a simple and effective alternative to postoperative mitomycin therapy, showing the lowest recurrence rate in their series with no toxicity during the study period. If the decision is made to use adjunctive mitomycin, the authors recommend intraoperative application over postoperative administration.

Ocular penetration and pharmacokinetics of topical fluconazole.

The high bioavailability and low toxicity of fluconazole, a stable, water-soluble, low-molecular-weight bis-triazole antifungal, makes it a good candidate for consideration as a topical ocular agent. The penetration of fluconazole (0.2%) into the corneas and aqueous humors of New Zealand white rabbits was assayed by gas liquid chromatography (GLC). Peak corneal levels occurred essentially immediately at 5 min in the corneas [debrided, 8.2 +/- 1.2 micrograms/g; nondebrided, 1.6 +/- 0.6 microgram/g; (mean +/- SEM)] and at 15 min after application in the aqueous [debrided, 9.4 +/- 2.3 micrograms/ml; nondebrided, 1.6 +/- 0.6 microgram/ml; (mean +/- SEM)]. Estimating from semilogarithmic plots of the data, the halflife (t1/2) in the debrided eyes was 15 min; in the nondebrided eyes, t1/2 was 30 min. A loading dose of a 20-microliter drop per min for 5 min yielded levels of 59.9 +/- 11.3 micrograms/g (mean +/- SEM) in the debrided corneas and 32.4 +/- 1.9 micrograms/ ml (mean +/- SEM) in the corresponding aqueous humor. A regimen consisting of this loading dose followed by one 20 microliters drop/h for 6 h showed 45.9 +/- 3.5 micrograms/g (mean +/- SEM) in the debrided corneas and 8.8 +/- 1.7 micrograms/ml (mean +/- SEM) in the corresponding aqueous. The same regimen yielded values of 3.1 +/- 0.2 micrograms/g in the nondebrided corneas and 1.3 +/- 0.2 micrograms/ml (mean +/- SEM) in the aqueous. Minimal inhibitory concentrations (MIC) at 24 h for yeasts ranged from < 1.25 to 20 micrograms/ml, for hyaline molds from 2.5 to > 20 micrograms/ml, and dematiaceous molds from < 1.25 to > 20 micrograms/ml. Topical fluconazole exhibits pharmacokinetics and selective MICs that merit further evaluation for its ophthalmic use as a topical antifungal agent.

Effects of acetylcholine and carbachol on bovine corneal endothelial cells in vitro.

PURPOSE: To assess the relative cytotoxicity of Miochol (1% acetylcholine and mannitol), Miostat (0.01% carbachol, sodium, potassium, magnesium, and calcium salts), and their individual components using in vitro models of bovine corneal endothelial cells (BCECs). SETTING: Laboratories of the Departments of Ophthalmology and Physiology, The University of Texas Health Science Center, Houston. METHODS: The study was divided into four experiments. Experiment 1 used a confluent model to compare the relative cytotoxicity of Miochol and Miostat on BCECs following short-term exposure. In Experiments 2, 3, and 4, the proliferation model (preconfluent BCECs) was used to detect the possible cytotoxicity of individual components in the commercial preparations of the miotics; i.e., the preconfluent BCECs were exposed to buffered salt solutions containing mannitol (1%, 3%, and 4%), acetylcholine (0.5%, 1%, and 2%), or carbachol (0.1%, 0.5%, and 1%) for 3 hours. RESULTS: Confluent BCECs exposed to Miochol for 30 minutes underwent necrosis and degeneration, while those treated with Miostat did not show any morphological changes. None of the tested solutions except 2% acetylcholine and 1% carbachol caused observable changes in the nuclear densities of BCECs at 24, 72, 120, and 168 hours. CONCLUSION: The major components of Miochol (acetylcholine and mannitol) were found to be nontoxic; the cytotoxicity of the preparation was possibly due to the lack of an appropriate balanced salt solution. These findings may influence the selection of a miotic for use during intraocular surgery.

Microscopic polyangiitis with ocular involvement.

Microscopic polyangiitis is an exclusively small-vessel (arterioles, capillaries, or venules) vasculitis that primarily involves the kidney and often involves the lungs, skin, or nervous system. Characteristic features include focal segmental glomerulonephritis, nongranulomatous necrotizing vasculitis, and serum positive for perinuclear-staining antineutrophil cytoplasmic antibodies (P-ANCA). We report a case of microscopic polyangiitis with previously unreported eyelid and conjunctival manifestations that responded well to immunosuppressive therapy.

Standardization of conjunctival impression cytology.

Lack of standardization limits the potential of conjunctival impression cytology as a clinical and research tool. This may be attributed to the variety of filter paper currently used. MF Millipore membrane filters of pore sizes 8.0, 3.0, 0.45, 0.22, and 0.025 micron were tested. Samples obtained from 30 eyes of rabbits were randomized and scored by four masked observers for cellularity and morphologic preservation. Cellularity was significantly greater with pore sizes 8.0, 3.0, and 0.45 micron versus 0.22 and 0.025 micron (p < or = 0.001), with an 83% correlation among four scorers. In contrast, morphology was better preserved in the smaller pore size papers (0.22 and 0.025 micron) when compared with larger pore sizes (p = 0.048). Using the best two filter papers (0.22 and 0.025 micron) and an ophthalmodynamometer, either 40, 60, or 80 g of pressure was applied for 3 s to each pore size paper to see whether cellularity could be increased. Cellularity was greater with pore size 0.22 than 0.025 micron (42.3 +/- 19.8 versus 8.7 +/- 6.4). Regardless of the pore size of the filter paper, cellularity was significantly improved at 60 g when compared with either 80 or 40 g. The results show that to maximize cell acquisition, a paper with medium pore size (0.22 micron) and a pressure of 60 g may be the best choice.

Low-dose intraocular tissue plasminogen activator treatment for traumatic total hyphema, postcataract, and penetrating keratoplasty fibrinous membranes.

Tissue plasminogen activator (tPA) has been used to treat severe postcataract and vitrectomy fibrinous membranes, but intraocular bleeding has occurred with doses of 25 micrograms or higher. We report three patients, one with nonclearing total hyphema and uncontrollable intraocular pressure and two with severe fibrinous membrane formation, who had treatment with low-dose (4 micrograms to 6 micrograms) intraocular tPA. Although the fibrinous membranes or hyphema resolved in all three patients, they recurred and bleeding that required additional treatment occurred in one patient. Intraocular low-dose tPA may minimize the risk of corneal and retinal toxicity and may be considered an alternative treatment in intractable cases. However, secondary intraocular hemorrhage can occur, and the timing between the initial vascular injury, treatment with tPA, and subsequent bleeding may reduce the risk of further hemorrhaging.

Healon GV in extracapsular cataract extraction with intraocular lens implantation.

A randomized masked study was performed to compare Healon GV, a new higher molecular weight sodium hyaluronate viscoelastic, with Healon in extracapsular cataract surgery with posterior chamber intraocular lens insertion. Seventy patients were randomly divided into two groups. Postoperative intraocular pressures, pachymetry, endothelial cell counts and morphology, amount of viscoelastic and irrigating solution used, difficulty of surgery, and postoperative flare and cells were measured. Postoperative pressures were not significantly different between the Healon and Healon GV treatment groups, except at the eight-hour observation period, when the pressure was higher in the Healon GV group (P = .02). There was a significant (P = .002) reduction in the amount of viscoelastic required in the Healon GV group. Cell counts and morphology were not significantly different between the groups. Other parameters showed no significant difference. Clinically, Healon GV handled like Healon during instillation into the anterior chamber and aspiration at the end of the case. It did, however, appear to be much more effective at maintaining the anterior chamber, as demonstrated in the smaller amount of viscoelastic required.

Intrastromal photorefractive keratectomy with a new optically coupled laser probe.

BACKGROUND: Intrastromal photorefractive keratectomy is a new procedure in which compact linear or area regions of the corneal stroma can be vacuolized, yielding changes in corneal curvature. METHODS: Diffraction-limited 1064-nanometer light pulses from a high rep rate Q-switched Nd-YAG laser were coupled through novel means into a probe with index-matched optical contact with the cornea. The resulting extremely reduced focal region initiated a plasma point that was free of shock front effects where tissue was reduced to liquid. This probe process was applied to the corneas of eye-bank eyes, and to living rabbit and primate eyes. The refractive effects were evaluated with slit-lamp microscopy, keratoscopy light and electron microscopy. RESULTS: Refractive effects similar to refractive keratotomy were observed immediately after treatment. Intrastromal highly localized vacuolized regions were observed at the depth of focus with variability of only 20 microns. The plasma point vacuoles were about 100 microns in diameter. Stromal material that occupied the vacuole space appeared completely reduced to liquid. The transition region between vacuole and normal tissue was less than 0.5 microns. The treatment vacuoles disappeared to the unaided eye 24 to 48 hours after treatment. CONCLUSIONS: Corneal refractive power can be achieved with intrastromal keratectomy.

Effects of flurbiprofen and suprofen on the miotic activity of 1% acetylcholine and 0.01% carbachol.

The nonsteroidal antiinflammatory agents (NSAIAs) flurbiprofen and suprofen applied topically to reduce miosis may counteract the desired effects of miotics used during ocular surgery. In a pigmented rabbit model, 1% acetylcholine was shown to cause a greater, significant initial (for the first 30 minutes) constriction (P less than .05) than 0.01% carbachol in eyes pretreated with flurbiprofen and suprofen. From 2 to 8 hours, NSAIA pretreatment had a greater miotic effect with carbachol than with acetylcholine. There were no significant differences between flurbiprofen and suprofen on the miotic effect of carbachol or acetylcholine.