Long-term follow up of autologous serum treatment for recurrent corneal erosions.

PURPOSE: The aim of the study was to evaluate long-term results of autologous serum treatment for recurrent corneal erosions. METHODS: In this prospective single-centre study, 33 eyes of 33 patients (21 male and 12 female) were treated with autologous serum eye drops for recurrent corneal erosions. Mean age of the patients was 49.3 ± 9.8 standard deviation (range 24-73) years. All subjects had failed to respond to other treatments. Autologous serum drops were administered for a 6-month period: six times daily for the first 3 months and four times daily for the remaining 3 months. Detailed informed consent was obtained from the entire patient group before the study. RESULTS: The mean follow-up period was 30 ± 6.3 standard deviation (range 12-48) months. None of the patients experienced a recurrence while under treatment. Twenty-eight patients (85%) had complete healing of erosions with no relapses of the disease over the whole follow-up period. Five patients (15%) presented a single recurrence 3-12 months after the end of the treatment. No sight-threatening complications were reported over the follow up. There was no statistically significant difference in the best spectacle-corrected visual acuity values (t(stat) = 2.1, F = 0.096, degree of freedom = 40,166, P < 0.41) or in the intraocular pressure measurements (P < 0.38) between the pre- and post-treatment patient groups. CONCLUSIONS: Autologous serum drops proved to be a safe and efficient treatment modality for patients with recurrent corneal erosion syndrome as observed through a long-term follow up.

Conductive keratoplasty followed by collagen cross-linking with riboflavin-UV-A in patients with keratoconus.

PURPOSE: To evaluate the combined effect of conductive keratoplasty (CK) followed by corneal collagen cross-linking (CXL) in 2 patients with keratoconus. METHODS: CK spots were applied on the flatter side of the cornea followed by CXL using riboflavin and UV-A light. RESULTS: Immediately after CK, a significant corneal topographic improvement was observed. The CK effect regressed 3 months postoperatively and remained unchanged until the sixth postoperative month in both patients. CONCLUSION: Corneal remodeling with CK in patients with keratoconus seems to have a temporary effect despite the subsequent application of CXL.

Contact transscleral ciliary body photodynamic therapy in pigmented rabbits using verteporfin and diode laser: evaluation of treatment parameters.

PURPOSE: To evaluate the treatment parameters necessary for achieving ciliary body photodynamic damage, enough to significantly reduce IOP, using verteporfin and a diode laser. DESIGN: Animal study. METHODS: The right eye ciliary body of 30 pigmented rabbits was irradiated using verteporfin (Visudyne) and a diode laser. Photosensitizer dose ranged from 0.375 to 2 mg/kg. Three adjacent laser spots were applied 0.5 mm behind limbus at 12 o'clock position using a contact transscleral technique. The laser power was ranging from 10 to 70 mW and the duration of irradiation from 1 to 5 min per spot. The left eyes of the rabbits were used as controls. Animals were sacrificed 24 hours after the procedure and their eyes were evaluated by means of light and electron microscopy. A step-by-step approach was adopted with adjustment of experimental parameters according to histological findings. The end point was to identify the irradiation parameters necessary for induction of photodynamic damage while minimizing thermal damage. Subsequently, 10 more animals were used in order to verify the effectiveness of these irradiation parameters in reducing the intraocular pressure. RESULTS: The therapy parameters that led to photodynamic effect avoiding thermal damage were laser power of 25 mW, irradiation time of 3 min per spot, and verteporfin dose of 1 mg/kg. Transscleral ciliary body irradiation using these parameters resulted in vascular thrombosis of ciliary vessels and in substantial edema, resulting in separation of the two ciliary epithelium layers. These parameters were applied to 4 rabbits, resulting in a mean IOP reduction of 1.8 mmHg +/- 1.2 that lasted for 4 days. An increase of the laser power to 35 mW tested in 6 additional animals, resulted in mean IOP reduction of 2.2 mmHg +/- 1.2, lasting 6 days; some minimal thermal damage was seen with the later settings. CONCLUSION: The combination of verteporfin and 690 nm diode laser is effective for the induction of ciliary body photodynamic damage, which results in significant but temporary IOP reduction, after transscleral PDT in pigmented rabbits. With appropriate parameter selection, intraocular pressure reduction can be achieved while thermal damage is kept to a minimum.

Two-year follow-up of conductive keratoplasty for the treatment of hyperopic astigmatism.

PURPOSE: To evaluate the safety, efficacy, predictability, and stability of conductive keratoplasty (CK) for the treatment of hyperopic astigmatism. SETTING: University of Crete Medical School, Vardinoyannion Eye Institute of Crete, Heraklion, Greece. METHODS: In this prospective nonrandomized noncontrolled single-center study, 47 eyes of 34 patients (15 women and 19 men) were treated for hyperopic astigmatism (up to + 3.50 diopters [D]) with a Refractec ViewPoint CK system and followed for 24 months +/- 0.6 (SD). The treatment consisted of 4 to 36 spots applied to the periphery of the cornea. Mean age was 48.5 years +/- 9.7 years, range 25 to 68 years. All the treated eyes were analyzed for safety, efficacy, predictability, and stability. RESULTS: The mean patient age was 48.5 +/- 9.7 years (range 25 to 68 years). Preoperatively, the mean manifest refraction spherical equivalent (MRSE) was +2.11 +/- 0.88 D (range -0.50 to + 4.13 D); at 12 months, it was -0.52 +/- 0.73 D and at 24 months, -0.50 +/- 0.77 D. At 24 months, the mean MRSE was within +/-0.50 D in 61% of eyes, within +/-1.00 D in 83%, and within +/-2.00 D in all eyes. At 24 months, the uncorrected visual acuity was 20/20 or better in 37% of eyes and 20/40 or better in 97%. By the end of the follow-up period, no eye had lost > or =2 Snellen lines or had an induced cylinder > or =1.50 D. CONCLUSIONS: Conductive keratoplasty for low hyperopic astigmatism was a safe, effective, and stable procedure. Nomogram adjustments and careful patient selection should contribute to higher levels of predictability when treating hyperopic astigmatism.

Conductive keratoplasty: histological study of human corneas.

PURPOSE: To determine the morphologic changes in human corneas over time following radiofrequency-based conductive keratoplasty (CK) treatment. DESIGN: Prospective, observational case series. METHODS: In a single-center study six human corneas of six patients with localized peripheral keratoconus underwent CK treatment followed by penetrating keratoplasty. Three spots were applied in the periphery of each cornea (6 mm optical zone). Corneal buttons were examined with light and electron microscopy at different postoperative intervals up to 6 months post-CK. RESULTS: In samples assessed on day one post-CK, small areas of detachment between the basal layer of epithelial cells and Bowman's layer were observed. At 1 week after the CK procedure, the epithelium appeared almost normal. Endothelium and Descemet's membrane had no alterations. In all samples, thermally induced misconfiguration of collagen fibers, described as "crumpled" changes of collagen layers, was observed reaching 75% to 80% of the stromal depth. The area of alterations had a cylindrical shape with a diameter of 120 mum. CONCLUSIONS: The conductive keratoplasty procedure produced collagen "crumpling and splitting" changes in human corneas, which were observed during the follow-up of 6 months. Areas adjacent to treatment site were minimally damaged.

Long-term results of conductive keratoplasty for low to moderate hyperopia.

PURPOSE: To assess the long-term safety, efficacy, predictability, and stability of conductive keratoplasty (CK) for the treatment of low to moderate hyperopia and to evaluate the impact of the procedure on the quality of vision. SETTING: University of Crete, Medical School, Vardinoyannion Eye Institute of Crete, Crete, Greece. METHODS: In this prospective nonrandomized noncontrolled single-center study, 38 eyes of 26 patients (13 women and 13 men) were treated for hyperopia with a Refractec ViewPoint CK system and followed for 30 months. Preoperatively, the mean manifest refraction spherical equivalent (MRSE) was +1.89 diopters (D) +/- 0.6 (SD) (range +1.00 to +3.25 D), and the mean follow-up was 30.9 +/- 1.1 months. All eyes were treated with the regular CK nomogram for the treatment of spherical hyperopia. The treatment consisted of 8 to 32 spots applied to the periphery of the cornea. Mean age was 50.3 +/- 8.8 years (range 31 to 71 years). All treated eyes were analyzed for safety, efficacy, predictability, and stability. RESULTS: At 12 months, the MRSE was -0.06 +/- 0.8 D and at 30 months was -0.02 +/- 0.7 D. At 30 months, the mean MRSE was within +/-0.50 D in 68%, within +/-1.00 D in 92%, and within +/-2.00 D in all eyes. At 30 months, uncorrected visual acuity was 20/20 or better in 52.5% and 20/40 or better in 89% of eyes. No eye lost 2 or more Snellen lines or had an induced cylinder of 2.00 D or greater. The procedure did not cause statistically significant changes in contrast sensitivity. CONCLUSION: Results show that CK for low to moderate hyperopia is a safe, effective, predictable, and stable procedure.

Intraocular pressure measurements after conductive keratoplasty.

PURPOSE: To determine the possible impact of conductive keratoplasty (CK) on intraocular pressure (IOP) measurements. METHODS: A prospective, single-center, noncomparative interventional case series was performed. Baseline and postoperative IOPs were measured by Goldmann applanation tonometry in 32 eyes of 18 patients who underwent CK for hyperopia correction. Mean follow-up was 11.9 months (range: 8 to 18 months). RESULTS: After CK, a statistically significant decrease in the measured IOP was observed (before CK: 14.22+/-1.64 vs after CK: 12.66+/-2.21, P<.001). The change in IOP readings postoperatively was not correlated with age, sex, keratometric readings, or attempted correction. CONCLUSIONS: Despite the limitations due to the small number of patients enrolled in this study, the applanation tonometer appears to underestimate the true IOP after CK.

Laser in situ keratomileusis for residual hyperopic astigmatism after conductive keratoplasty.

PURPOSE: To report a case of laser in situ keratomileusis (LASIK) in a patient with previous conductive keratoplasty. METHODS: A 48-year-old man underwent conductive keratoplasty for low hyperopic astigmatism (manifest refraction OD: +2.25 -0.50 x 77 degrees; OS: +2.50 -0.50 x 105 degrees). Three months postoperatively, UCVA was 20/25 and BSCVA was 20/20 in both eyes; manifest refraction OD: -0.25 -0.75 x 110 degrees; OS: +0.75 -0.75 x 50 degrees. Sixteen months after the operation, regression of refractive outcome was (manifest) OD: +1.75 -1.25 x 90 degrees; OS: +2.50 -0.50 x 85 degrees; UCVA was 20/40 in the right eye and 20/63 in the left eye and BSCVA was 20/20 in both eyes. LASIK was performed for hyperopic regression in the left eye using an automated microkeratome (Alcon SKBM, 130-microm plate; Aesculap-Meditec MEL 70 excimer laser). RESULTS: LASIK was uneventful and no intraoperative or postoperative complications related to the previous conductive keratoplasty procedure or LASIK were observed. Three months after LASIK and 19 months after the initial conductive keratoplasty, the patient's left eye was emmetropic; UCVA was 20/20(-2), BSCVA was 20/20 and manifest refraction was +0.25 -0.25 x 35 degrees. There was a uniform increase in topographical steepening. Visual acuity, refraction and topographic findings remained unchanged at 6 months. CONCLUSIONS: Even though our experience is limited, treatment of hyperopia with LASIK in an eye with refractive regression following previous conductive keratoplasty resulted in a predicted refractive outcome, with no complications, and improvement in visual acuity at 6 months follow-up.

Conductive keratoplasty for low to moderate hyperopia: 1-year results.

PURPOSE: To assess the safety, efficacy, and stability of conductive keratoplasty in the treatment of low to moderate hyperopia and evaluate the impact of the procedure on the quality of vision. METHODS: Thirty-six eyes (25 patients; 13 female and 12 male) were treated for hyperopia up to +3.25 D with a Refractec ViewPoint CK system and followed for 1 year. Mean age was 50.2 +/- 8.7 years (range 31 to 71). RESULTS: Before surgery, mean spherical equivalent refraction was +1.90 +/- 0.60 D (range +1.00 to +3.25 D), decreasing at 1 year after conductive keratoplasty to -0.06 +/- 0.80 D, and was within +/- 0.50 D of emmetropia in 68% (24 eyes) and within +/- 2.00 D in all eyes. Twelve months after conductive keratoplasty, uncorrected visual acuity was 20/20 or better in 19 eyes (50%) and 20/40 or better in 32 eyes (89%). No eye lost > or = 2 Snellen lines or had induced cylinder > or = 2.00 D. The mean root mean square values for higher order optical aberrations were 0.060 +/- 0.039 before and 0.174 +/- 0.170 at 3 months after surgery. No statistically significant changes in contrast sensitivity were noted. CONCLUSIONS: Conductive keratoplasty for low to moderate hyperopia provided safe, effective, and stable results both in refraction and quality of vision.

Conductive keratoplasty to correct hyperopic astigmatism.

PURPOSE: To evaluate the efficacy of conductive keratoplasty in the treatment of pre-existing and surgically induced hyperopic astigmatism. METHODS: In this prospective, noncomparative case series, four eyes of four subjects, two female and two male (age 25 to 47 yr) were treated for hyperopia (up to +5.50 D) and hyperopic astigmatism (up to +5.75 D) with the Refractec ViewPoint conductive keratoplasty system. The follow-up period was 6 months. Uncorrected and spectacle-corrected visual acuity, manifest and cycloplegic refraction, and videokeratographs were obtained before and after surgery. We treated two patients who had already had LASIK, one of them with a decentered ablation and the other with flap striae, one patient after PRK, and one patient with keratoconus. RESULTS: No complications were observed. No eye lost lines of spectacle-corrected visual acuity. All eyes showed improvement of uncorrected visual acuity of 3 or more lines. Videokeratographs demonstrated improved centration and reduction in keratometric power readings. Each eye was analyzed separately, including a comparative analysis of the proposed nomograms and quality of vision after surgery. CONCLUSIONS: Conductive keratoplasty may be a minimally invasive solution for patients with irregular hyperopic astigmatism, offering improved quality of vision in instances of flap striae by tightening the central cornea.

Corneal iron ring after conductive keratoplasty.

PURPOSE: To report formation of corneal iron ring deposits after conductive keratoplasty. DESIGN: Observational case report. METHODS: Case report. RESULTS: A 54-year-old woman underwent conductive keratoplasty for hyperopia. One year after conductive keratoplasty, iron ring pattern pigmentation was detected at the corneal epithelium of both eyes. CONCLUSIONS: This is the first report of the appearance of corneal iron ring deposits following conductive keratoplasty treatment in a patient. It is suggested that alterations in tear film stability, resulting from conductive keratoplasty-induced changes in corneal curvature, constitute the contributory factor for these deposits.