Biomedical subjects

L Cardia

Publications and source records attributed to L Cardia.

53 records · Page 3Linked to original sources

PubMedDate not supplied

Retinal nerve fiber layer measurements using scanning laser polarimetry after photorefractive keratectomy.

PURPOSE: To assess the effects of corneal depth changes on retinal nerve fiber layer (RNFL) postoperative measurements in myopic patients who had undergone photorefractive keratectomy (PRK). METHODS: A total of 120 myopic patients underwent PRK for myopia (range -2 to -10 diopters) and were divided into three groups according to their myopic correction: lower than 3 diopters (low myopia group), between 3 and 6 diopters (medium myopia group), over 6 diopters (high myopia group). RNFL parameters were evaluated preoperatively and 5 days, 3 months and 6 months after surgery, using a GDx NFA II scanning laser ophthalmoscope. RESULTS: Significant changes were seen in the symmetry, superior maximum, and average thickness, comparing baseline with six-month measurements (p=0.008, 0.027, 0.015 respectively). Dividing the sample according to attempted myopic correction, it was found that mean postoperative RNFL thickness was significantly lower after PRK only in the high myopia group. Mean RNFL thickness did not change with time (p=0.884). Ablation depth was correlated with a change in RNFL thickness by the sixth postoperative month for each group. These variables were significantly related only in the high myopia group (p=0.003). CONCLUSIONS: As polarised light penetrates the ablation area, morphological and functional changes might affect Gdx NFA II measurements. It must always be borne in mind that RNFL thickness can decrease either in cases of glaucoma or after PRK for high myopia, so close attention must be paid to interpreting these measurements in patients who have undergone PRK.

Adult↗

PubMedDate not supplied

A randomized, comparative open-label study on the efficacy of latanoprost and timolol in steroid induced ocular hypertension after photorefractive keratectomy.

PURPOSE: To evaluate the effect of 0.005% latanoprost and 0.50% timolol for the treatment of steroid-induced ocular hypertension (SIOH) after excimer laser photorefractive keratectomy (PRK). METHODS: In this comparative, open-label study we enrolled 29 patients who received steroid therapy after PRK and developed intraocular pressure (IOP) elevation within 30 days of treatment. Fifteen were randomized to 0.005% latanoprost (group A) and 14 to 0.50% timolol (group B). IOP measurements were scheduled at 1, 3, 7, 15, 30, 60, 90 and 120 days of therapy. RESULTS; We did not find any real differences between latanoprost and timolol except at the 7-day and 15-day timepoints, when latanoprost reduced IOP significantly more than timolol (p=0.033, 0.035, respectively). After 7 days of therapy two of the 14 timolol-treated patients had high IOP (24 and 26 mmHg) but these promptly returned to normal when latanoprost was added. No significant differences were observed in the ocular side effects considered. CONCLUSIONS: 0.005% latanoprost is as safe and effective as 0.50% timolol in the treatment of SIOH after PRK. Both drugs provide a significant and stable IOP reduction in the majority of patients after short-term treatment. These findings are encouraging for the use of latanoprost in the management of SIOH after PRK, although further trials are necessary to consider it as a primary treatment.

Administration, Topical↗

PubMedDate not supplied

Corneal temperature changes during photorefractive keratectomy using the Laserscan 2000 flying spot laser.

PURPOSE: To evaluate the thermal variations during photorefractive keratectomy (PRK) induced by a Laserscan 2000 flying spot excimer laser. METHODS: Thermal changes during PRK were recorded using a non-contact infrared thermometer on 58 eyes with an attempted correction ranging from -1.25 to -9.00 D. The eyes were randomly divided into two groups to test the thermal effects of two different ablation scan techniques: sequential and randomized modes. Thermal measurements were also performed during myopic ablations on polymethylmethacrylate (PMMA) test plates. RESULTS: On PMMA plates, a significant relationship between the amount of attempted myopic correction and thermal changes was established (P=.017 in sequential mode and P=.007 in randomized mode); this was not established for human eyes. With the sequential mode, an unexpected cooling effect after PRK was reported for each myopia subgroup (P=.003 in the low and high myopia subgroups, P<.001 in the medium myopia subgroup). With the randomized mode, the cooling effect was detected only for low amounts of myopia. CONCLUSION: Despite a high repetition rate, the Laserscan 2000 flying spot laser minimized thermal shock. In comparison with randomized (nonsequential) pulse application, sequential pulsing showed no increase in the thermal loading of corneas. In fact, a cooling effect during PRK was produced.

Adult↗

PubMedDate not supplied

Prospective randomized comparison of simultaneous and sequential bilateral photorefractive keratectomy for the correction of myopia.

BACKGROUND AND OBJECTIVE: To evaluate the efficacy and safety of simultaneous bilateral photorefractive keratectomy (PRK). PATIENTS AND METHODS: There were 52 patients (104 eyes) with myopia less than -6 diopters entered in this prospective trial and randomized to simultaneous or sequential bilateral PRK. Main outcome measures were uncorrected visual acuity (UCVA), percentage of eyes within +/-0.5 D of attempted outcome, present pain intensity (PPI) and total pain rating index (PRI(R)T) scores resulting from McGill the Pain Questionnaire, subjective symptoms, haze, and patient satisfaction. Follow-up extended to 14 months. RESULTS: There was no significant difference in UCVA (P=0.996) and percentage of eyes within +/-0.5 D of attempted correction (P=0.932). Present pain intensity and PRI(R)T scores were significantly higher in the sequential group (P=0.037; P=0.034). The percentage of satisfied patients after bilateral PRK was significantly higher in the simultaneous group (P=0.036). CONCLUSIONS: Simultaneous bilateral PRK was safe and effective, without any significant difference from sequential treatment.

Adult↗

PubMedDate not supplied