Randomized Clinical Trial of Topical Sodium Hyaluronate After Excimer Laser Photorefractive Keratectomy

Role of Hyaluronic Acid Treatment in the Prevention of Keloid Scarring

BACKGROUND

Keloids are benign dermal scars characterized by enhanced growth factor signaling, hyperproliferation activity and reduced extracellular matrix (ECM) deposition of hyaluronic acid. Our hypothesis is that high molecular weight HA can be used to replenish HA deposition in keloids thereby normalizing the keloid fibroblast phenotype.

METHODS

One normal (NF1) fibroblast culture and five keloid (KF1, KF2, KF3, KF4, KF5) fibroblast cultures were analyzed for changes in hyperproliferation, growth factor production and extracellular matrix deposition following 72 hour treatment with or without 10 μg/ml HA.

RESULTS

Proliferation activity decreased significantly in KF3 following HA treatment. Pro-collagen I expression in KF2 was decreased following HA treatment in association with changes in fiber arrangement to more parallel collagen bundles. In addition, HA demonstrated a downregulation on TGF-b1 growth factor expression in KF3 and KF4 and a decrease in active TGF-b1 release in KF2 and KF5 using ELISA.

CONCLUSION

Our data demonstrates that HA has the potential to normalize keloid fibroblast characteristic features such as hyperproliferation, growth factor production and ECM deposition depending on the specific genotype of the keloid fibroblast cell line. This study suggests that high molecular weight HA can be used to replenish HA deposition in keloid fibroblasts thereby decreasing fibrosis and ultimately decreasing keloid manifestation.

Comparison of the analgesic efficacy and safety of nepafenac ophthalmic suspension compared with diclofenac ophthalmic solution for ocular pain and photophobia after excimer laser surgery: a phase II, randomized, double-masked trial

OBJECTIVE

The aim of this study was to evaluate the efficacy and safety of nepafenac ophthalmic suspension 0.03% and 0.1% for the treatment of postoperative pain and photophobia in patients undergoing excimer photoreactive keratectomy (PRK).

METHODS

In this 7-day, randomized, double-masked, parallel-group trial at 2 sites, patients undergoing PRK surgery were randomly assigned to receive nepafenac ophthalmic suspension 0.03% or 0.1%, or diclofenac sodium ophthalmic solution 0.1%. Patients were treated on day 0 (surgery) and day 1 (the day after surgery). The dose regimen for all 3 treatments was the same. On day 0, patients received 2 drops in the operative eye -1 hour before surgery; 2 drops within 1 hour after surgery; 1 drop -4 hours after the first postoperative dose; and 1 drop -8 hours after the first postoperative dose. On day 1, patients instilled 1 drop of study drug QID. Thereafter, the study medication was discontinued. In the perioperative period, study personnel instilled the drops. The patients instilled the drops when they went home. Patients recorded pain and photophobia from day 0 through day 2, rating pain from 0 to 9 on a visual analog scale (0=none, 9=extreme) and photophobia from 0 to 3 on an ordinal, categoric scale (0=none, 3=severe). Patients were permitted to take acetaminophen 500 mg as needed for pain. They returned for postoperative follow-up visits on days 1, 3, and 7. Adverse events were documented when reported by the patients themselves, and when study personnel asked about specific events.

RESULTS

Sixty patients (20 per group) were enrolled. On the day of surgery, there were no significant differences between groups, except at 3 hours after surgery, when the nepafenac 0.03% group had a significantly higher mean pain score than the nepafenac 0.1% group (4.0 vs 3.0; P<0.038). On day 2, the nepafenac 0.1% group had less pain at bedtime than the diclofenac group (mean score, 1.9 vs 3.1; P<0.024) and less photophobia in the morning (mean score, 1.2 vs 1.8; P<0.023). For the nepafenac 0.03% group, the mean pain and mean photophobia scores were 2.5 and 1.6, respectively. There were no significant differences between the 3 treatment groups in the proportion of patients who took acetaminophen for pain at any time point (P=NS). There was no statistically significant difference in corneal re-epithelialization rates among the 3 groups. Adverse events were infrequent, and no serious adverse events occurred. Two ocular adverse events related to therapy occurred: a corneal infiltrate in 1 patient in the nepafenac 0.03% group; and ocular discomfort in 1 patient in the nepafenac 0.1% group. Both patients continued the study.

CONCLUSIONS

Both nepafenac 0.03% and 0.1% were effective for treatment of pain and photophobia in these patients undergoing PRK surgery. There was no difference in the proportion of patients who took rescue acetaminophen for pain. All treatments were well tolerated in these patients.

Effect of Hyaluronic Acid on Corneal Haze in a Photorefractive Keratectomy Experimental Model

PURPOSE

To evaluate the ability of topical hyaluronic acid to decrease corneal opacity after excimer laser photorefractive keratectomy (PRK) in hens.

METHODS

Twenty-four white hens underwent bilateral 193-nm excimer laser PRK to correct -9.00 D of myopia. One eye received postoperative treatment with topical 1% hyaluronic acid six times daily for 3 days; the other eye received phosphate buffered saline. Slit-lamp evaluation by a masked observer was performed for 6 months after PRK, and electron microscopy was carried out at the end of the study.

RESULTS

There were no significant differences in postoperative haze between the eyes treated with hyaluronic acid and those treated with phosphate buffered saline.

CONCLUSION

Topical administration of hyaluronic acid had no effect on the development of corneal haze following PRK in hens.

Comparison of ketorolac tromethamine, diclofenac sodium, and moist drops for ocular pain after radial keratotomy

PURPOSE

To compare the 2 most popular commercially available topical nonsteroidal anti-inflammatory drugs (NSAIDs) in the treatment of ocular pain following radial keratotomy (RK).

SETTING

Multicenter clinical trial.

METHODS

Ninety-seven RK patients were randomly assigned to 1 of 3 treatment groups: ketorolac tromethamine, diclofenac sodium, and moist drops as a control. The patients used 1 drop of the masked medication and 1 drop of ofloxacin 3 times a day for 3 days prior to surgery. They received 1 drop of the masked medication 1 hour before surgery, immediately after surgery, and 4 times a day thereafter. Patients were given a written questionnaire preoperatively and were also instructed to call a central computerized telephone system to answer prerecorded questions about ocular comfort. The calls were placed 30 minutes and 1, 2, 3, 4, 5, 6, 24, and 48 hours after surgery.

RESULTS

Two hundred ten statistical values were calculated to compare symptoms in the unoperated eye at baseline with symptoms in the operated eyes at each of 9 postoperative time points. Only 7 of the 210 values (3.3%) were significantly different among patient groups (operated versus unoperated eyes) by psychometric testing.

CONCLUSIONS

Both ketorolac tromethamine and diclofenac sodium were more effective in reducing post-RK discomfort than the control (moist artificial tears). Given the large number of tests and the small number that tested as significant, the significant differences (7 of 210 measurements) observed among the 3 treatment groups probably occurred by chance, although the improved foreign-body sensation, functionality, and compliance scores in the ketorolac group during the first 4 hours might be clinically important.