Clear lens extraction and intraocular lens implantation in Marfan's syndrome.

Intracapsular clear crystalline lens extraction and intraocular lens (IOL) implantation were performed in 4 highly myopic eyes of 2 patients with Marfan's syndrome. One eye of each patient received an anterior chamber IOL and the other, a scleral-fixated posterior chamber IOL. The preoperative spherical equivalent ranged between -14.50 and -28.00 diopters (D) and axial length range, between 25.32 and 36.02 mm. The SRK II formula was used. Mean uncorrected visual acuity improved from counting fingers to 20/80. Postoperative spherical equivalent correction ranged from -0.75 to +2.75 D. One eye had vitreous loss that was managed by anterior vitrectomy. Modern surgery for cataract and management of its complications suggest that clear crystalline lens extraction and IOL implantation can be attempted in selected cases with Marfan's syndrome.

Seven years experience with LASIK for myopia.

PURPOSE: This paper presents the results of the last seven years with LASIK for the treatment of myopia. METHODS: 4170 eyes of 3163 patients with a mean preoperative spherical equivalent--9.66 diopters were submitted to LASIK. The eyes were divided in three groups according to the preoperative refraction: Group A (-5 to 10D), group B (-10 to 16D) and group C (over -16 D). RESULTS: At one year the percentage of eyes within +/- 1D of emmetropia was the following: group A: 84.4%, group B: 70.8%, and group C: 42.8%. CONCLUSIONS: The method is safe, effective, and predictable especially in the range of myopia between -5 and -15 D of myopia. Predictability could be further improved by secondary procedures.

Photorefractive keratectomy with a transition zone for myopia from -7 to -14 diopters.

PURPOSE: To study transition zone excimer laser photorefractive keratectomy (PRK) in moderate and high myopia defined as a spherical equivalent of -7.00 diopters (D) or more. The follow-up period was 18 months. METHODS: Forty eyes of 40 patients with myopia of 7.00 to -13.50 D (mean +/- SD, -921 +/- 1.98) underwent transition zone (5.0 to 7.0 mm transition zone) PRK using the Aesculap Meditec Mel 60 excimer laser. The mean attempted correction was 8.3 +/- 1.64 D (range: -6.50 to -12.00 D). RESULTS: At 18 months, 83% achieved an unaided visual acuity of 20/50 or better and HOW 12% 20/25 or better. Eighty-eight percent were within +/-2 D of emmetropia. the mean spherical equivalent was -1.1 D (+3.00 to -9.00 D). CONCLUSIONS: Transition zone PRK is useful in moderate to high myopia. Regression, as well as overcorrection are issues for further investigation.

Histological evaluation of phthalocyanine mediated photodynamic occlusion of corneal neovascularization enhanced by hyperbaric oxygenation.

PURPOSE: We evaluated the effective irradiation parameters for photodynamic thrombosis of experimental corneal neovascularization enhanced by simultaneous hyperbaric oxygenation. METHODS: Neovascularization was provoked in both eyes of each of 35 albino rabbit corneas using the intracorneal suture technique. The lasered animals were divided in 3 groups. Group 1 (10 rabbits) was treated under hyperbaric conditions (28 atm for 25 min.); group 2 (5 rabbits) was treated breathing pure oxygen delivered by a face mask; group 3 (10 rabbits) was treated breathing room air. The fourth group (10 rabbits) was used for control. Animals were anaesthetized, and irradiation of new corneal vessels was carried out 30 minutes after the injection of 5 mg/kg chloroaluminum sulfonated phthalocyanine. A 670 nm diode laser with a power 4 mW and a spot diameter 350 mm was used. Exposure times necessary for vascular occlusion were registered. Histological examination was carried out at the end of the follow-up time. RESULTS: Exposure times were significantly lower in groups 1 and 2 as compared to group 3 (1.75 +/- 0.15 min., 3.1 +/- 0.4 min., and 4.75 +/- 0.15 min. respectively). Total light dose averaged 490 J/cm,2 870 J/cm,2 and 1330 J/cm,2 respectively. Histological examination revealed thrombus formation in the targeted vessels of all three investigated groups. CONCLUSION: Combination of PDT with hyperbaric oxygenation results in an acceleration of the photodynamic process and provides for a possibility of significant reduction of photodynamic dose.