Biomedical subjects

Massimo Camellin

Publications and source records attributed to Massimo Camellin.

4 recordsLinked to original sources

PubMed2006

A new formula for intraocular lens power calculation after refractive corneal surgery.

PURPOSE: When calculating the power of an intraocular lens (IOL) with conventional methods in eyes that have previously undergone refractive surgery, in most cases the power is inaccurate. To minimize these errors, a new IOL power calculation formula was developed. METHODS: A theoretical formula empirically adjusted two variables: 1) the corneal power and 2) the anterior chamber depth (ACD). From the average curvature of the entrance pupil area, weighted according to the Stiles-Crawford effect, the corneal power is calculated by using a relative keratometric index that is a function of the actual corneal curvature, type of keratorefractive surgery, and induced refractive change. Anterior chamber depth is a function of the preoperative ACD, lens thickness, axial length, and the ACD constant. We used our formula in 20 eyes that previously underwent refractive surgery (photorefractive keratectomy [n = 6], laser subepithelial keratomileusis [n = 3], laser in situ keratomileusis [n = 6], and radial keratotomy [n = 5]) and compared our results to other formulas. RESULTS: Mean postoperative spherical equivalent refraction was +0.26 diopters (D) (standard deviation [SD] 0.73, range: -1.25 to +/- 1.58 D) using our formula, +2.76 D (SD 1.03, range: +0.94 to +4.47 D) using the SRK II, +1.44 D (SD 0.97, range: +0.05 to +4.01 D) with Binkhorst, 1.83 D (SD 1.00, range: -0.26 to +4.21 D) with Holladay I, and -2.04 D (SD 2.19, range: -7.29 to +1.62 D) with Rosa's method. With our formula, 60% of absolute refractive prediction errors were within 0.50 D, 80% within 1.00 D, and 93% within 1.50 D. CONCLUSIONS: In this first series of patients, we obtained encouraging results. With a greater number of cases, all statistical adjustments related to the different types of surgery should be improved.

Adult↗

PubMed2005

Measurement of the spatial shift of the pupil center.

PURPOSE: To evaluate the effectiveness of the pupil center as an anatomic landmark for excimer laser treatments. SETTING: Sekal-Microchirurgia-Rovigo Centre, Rovigo, Italy. METHODS: Pupillometry with the Costruzione Strumenti Oftalmici S.R.L. (CSO) pupil-measuring module (incorporated in Eye Top videokeratoscope) was performed in 52 patients with a diagnosis of myopia and in 25 patients with a diagnosis of hyperopia. Measurements both in mesopic and photopic conditions consisted of pupil diameters, spatial shift of the pupil center, and the distance between the pupil center and keratoscopic axis. RESULTS: The mean pupil diameter in photopic conditions of illumination in myopic eyes was 3.52 mm +/- 0.56 (SD), while in mesopic conditions it was 5.37 +/- 0.78 mm; in hyperopic eyes the mean photopic pupil diameter was 3.01 +/- 0.46 mm, while the mean mesopic diameter was 5.12 +/- 0.48 mm. The mean spatial shift of the pupil center in myopic eyes was 0.086 mm (maximum 0.269 mm), while in the hyperopic eyes it was 0.095 mm (maximum 0.283 mm). The mean distance between the pupil center and keratoscopic axis in myopic eyes was 0.226 +/- 0.13 mm (maximum 0.75 mm), while in hyperopic eyes it was 0.45 +/- 0.19 mm (maximum 0.8 mm). CONCLUSIONS: The mean of the measured pupil sizes was greater in myopic eyes than in hyperopic eyes. The spatial shift of the pupil center, as the pupil dilates, was relatively small in all groups; therefore, the pupil center is a good anatomic landmark for both traditional refractive surgery and wavefront-guided treatments. The mean distance between the keratoscopic axis and pupil center was greater in the hyperopic group than in the myopic group. Therefore, centration of any laser treatment on the basis of the keratoscopic analysis should be done carefully, especially in hyperopic eyes and in cases in which the pupil center is meaningfully shifted from keratoscopic axis, even in photopic conditions of illumination.

Adolescent↗

PubMedDate not supplied

Laser epithelial keratomileusis for myopia.

PURPOSE: To describe a new technique for excimer laser corneal surgery: laser epithelial keratomileusis (LASEK). METHODS: We report 76 eyes with spherical equivalent refractive myopia ranging from -8.00 to -22.00 D (mean -11.00 +/- 3.00 D). Using ethanol applied over an 8.5-mm-diameter area for 20 seconds, the epithelium was detached and photorefractive keratectomy (PRK) was performed. The epithelium was reapplied to the ocular surface and covered with a therapeutic soft contact lens. Treatments were carried out with the Nidek EC-5000 excimer laser. RESULTS: At a mean of 803 days after LASEK, mean spherical equivalent refraction was -1.80 +/- 2.40 D (range -9.27 to +2.00 D). Stability was reached in approximately 60 days. Fifty-nine percent of the epithelial flaps were easy to detach intact during surgery and 62.7% of patients reported no postoperative pain. Eighty-four percent of eyes had the therapeutic bandage lens removed by the fourth postoperative day. Twelve percent of eyes had incomplete epithelial flap removal. Epithelium can fall off the cornea during the healing phase. No significant subepithelial haze was seen in 95% of eyes. CONCLUSION: With LASEK, it may be possible to treat a larger diameter ablation zone in thinner corneas without the problems of a LASIK stromal flap and with less postoperative pain than PRK, with minimal subepithelial haze.

Adult↗

PubMedDate not supplied

Laser epithelial keratomileusis with mitomycin C: indications and limits.

PURPOSE: To assess the advantages and safety of using mitomycin C (MMC) with laser epithelial keratomileusis (LASEK) by measuring high order aberrations of the cornea. METHODS: We analyzed the results of 86 eyes that had LASEK plus a brushstroke of MMC 0.01%. Another group of 100 eyes had LASEK only (control group). Mean follow-up was 312 days for the MMC group and 774 days for the control group. A Nidek EC-5000 laser was used in all eyes. We measured mean refractive error, best spectacle-corrected visual acuity (BSCVA), haze, and high order aberrations before and at 1 month and nearly 1 year after LASEK. RESULTS: Mean baseline spherical equivalent refraction was -6.80 +/- 3.00 D for the MMC group and -6.00 +/- 3.10 D for the control group (P=.34). In eyes with low myopia (-1.20 to -10.80 D), a single ablation zone of 6 mm with a transition zone of 8 mm was used, and in the higher myopia group (-5.60 to -15.50 D), smoothing and a cross sphere procedure (+0.75 D) were used. Mean spherical equivalent refraction after LASEK for low myopia in the MMC group at last examination (mean follow-up 312 days) was +0.50 +/- 0.93, and 0 +/- 0.34 D for the control group. Mean spherical equivalent refraction after LASEK for high myopia in the MMC group at last examination (mean follow-up 312 days) was +0.50 +/- 1.03 D, and +0.40 +/- 0.78 D for the control group. Mean haze in the low myopia MMC group was 0.06 and in the control group, 0.11; in the high myopia MMC group it was 0.1, and in the control group, 0.27 (all differences P<.05). No differences between baseline and postoperative BSCVA were noted. Early and late overcorrection were noted in the MMC group. Increased high order aberrations were evident at 1 month and 1 year in the MMC groups. CONCLUSIONS: The use of mitomycin C 0.01% with LASEK significantly decreased subepithelial haze. However, refractive outcome was less predictable. High order aberrations increased after LASEK with MMC. Additional studies with longer follow-up are necessary to evaluate long-term effects, and ideal MMC concentration and exposure time.

Antibiotics, Antineoplastic↗