Laser in situ keratomileusis for hyperopia.

OBJECTIVE: To evaluate laser in situ keratomileusis (LASIK) ablation zone size and its relationship to refractive and visual outcomes in the treatment of hyperopia. METHODS: We evaluated retrospectively 40 eyes of 20 patients who had LASIK: 20 eyes had a refractive ablation zone ranging from 5.5 to 9.0 mm (Group 1); Group 2 consisted of 20 eyes with a refractive ablation zone from 5.5 to 8.25 mm. We used the Nidek EC-5000 excimer laser and the Hansatome microkeratome. Mean spherical equivalent refraction was +2.72 D in Group 1 and +2.75 D in Group 2. Objective refraction and visual acuity were evaluated over 6 months in both groups. RESULTS: Six months after LASIK, mean spherical equivalent refraction in Group 1 was +1.00 +/- 0.84 D and in Group 2 it was +0.75 +/- 0.42 D. One patient in Group 1 lost 1 line of spectacle-corrected visual acuity; none in Group 2 lost lines. Six patients gained 1 to 3 lines from their preoperative spectacle-corrected visual acuity. CONCLUSIONS: LASIK provides good results for mild and moderate hyperopia. LASIK with an ablation zone from 5.5 to 8.25 mm showed better predictability and more stable results. However, corneal diameter and the thickness and width of the flap appear to be important factors in the feasibility of LASIK in hyperopic eyes.

Transconjunctival corneoscleral tunnel "blue line" cataract incision.

PURPOSE: To report the technique and astigmatic results of the blue line cataract incision. SETTING: The Buzzard Eye Institute, Las Vegas, Nevada, USA. METHODS: This prospective study included 411 eyes of 271 patients who had cataract extraction by phacoemulsification with a self-sealing 3.0 mm blue line cataract incision. The blue line incision is performed with a diamond knife transconjunctively, 2.0 mm behind the surgical limbus. RESULTS: Mean patient age was 68 years (range 40 to 94 years) and mean preoperative astigmatism, 0.96 diopter (D) +/- 0.78 (SD). Uncorrected visual acuity at 1 day was 20/40 or better in 47% of patients. Mean spherical equivalent was -0.57 +/- 0.78 D at 6 months. Mean postoperative astigmatism measured with a subtraction method was 1.00 +/- 0.84 D at 6 months. Vector analysis showed an induced astigmatism of -0.47 +/- 1.00 D at 1 month, -0.58 +/- 0.81 D at 3 months, and -0.57 +/- 0.99 D at 6 months. No complications such as wound leakage or hyphema occurred. CONCLUSION: The blue line incision combines the efficiency of the clear corneal with the safety of the scleral tunnel cataract incision and appears to be relatively astigmatically neutral.

Treatment of mild to moderate keratoconus with laser in situ keratomileusis.

PURPOSE: To evaluate the effectiveness, stability, and complications of laser in situ keratomileusis (LASIK) to treat myopic astigmatism in patients with keratoconus. SETTING: Buzard Eye Institute, Las Vegas, Nevada, USA. METHODS: This study included 16 eyes of 9 patients who had keratometric and/or clinical evidence of keratoconus. Mean age was 45 years, and refraction was stable for at least 2 years. Two treatment approaches were evaluated. RESULTS: Mean preoperative spherical equivalent was -4.23 diopters (D) +/- 2.14 (SD) with a mean steep keratometry of 46.81 +/- 3.07 D. Mean preoperative keratometric cylinder was 3.08 +/- 2.22 D. Mean postoperative keratometric cylinder was 3.00 +/- 4.78 D and mean spherical equivalent, -0.44 +/- 0.86 D. Mean postoperative steep keratometry was 44.12 +/- 7.17 D. Two eyes lost 1 line of best corrected visual acuity (BCVA), 1 eye lost 3 lines, and 2 lost 4 lines. Penetrating keratoplasty (PKP) was scheduled in 3 eyes 1 to 2 years after the primary LASIK. CONCLUSION: The initial visual results appear promising; but longer term results revealed regression of the refractive outcome in some cases. Moreover, despite improvement in the postoperative spherical equivalent and uncorrected visual acuity in most cases, the risk of loss of BCVA and the necessity of performing PKP in 3 cases lead us not to consider LASIK as a primary solution for keratoconus.

Reoperations after myopic laser in situ keratomileusis.

PURPOSE: To evaluate the results after enhancement of myopic laser in situ keratomileusis (LASIK) using the VISX Star excimer laser. SETTING: The Buzard Eye Institute, Las Vegas, Nevada, USA. METHODS: In this prospective study, 52 eyes of 40 patients had LASIK enhancement. The existing flap was lifted and the excimer laser treatment reapplied for the residual refractive error. The VISX Star excimer laser was used for the primary LASIK and the enhancement procedure. Retreatments for undercorrection, regression, and overcorrection were performed after 6 weeks and up to 40 weeks after the primary LASIK. Follow-up was 96% at 1 month, 67% at 6 months, and 71% at 12 months. RESULTS: Mean pre-enhancement spherical equivalent was -0.77 diopters (D) +/- 0.94 (SD) and mean uncorrected visual acuity (UCVA), 20/60. One year after the enhancement, mean spherical equivalent was -0.13 +/- 0.33 D, and mean UCVA was 20/25. Refraction remained stable during the 1 year follow-up, with no treatment required. After the enhancement, all patients had a UCVA of 20/40 or better. At 1 year, 3% of patients had lost 1 line of best corrected visual acuity and 32% had gained 1 line. No epithelial ingrowth was noted. CONCLUSION: Retreatment for LASIK beginning 6 weeks after the initial procedure proved to be effective with minimal complications and good results. The technique to raise and reposition the flap appeared safe, and complications were few.

One year clinical results of photoastigmatic refractive keratectomy for compound myopic astigmatism.

PURPOSE: To evaluate the efficacy, predictability, and safety of excimer laser photoastigmatic refractive keratectomy (PARK) to correct compound myopic astigmatism. SETTING: Departments of Ophthalmology, Robert Debré Hospital and Rothschild Foundation, Paris, France. METHODS: This retrospective study included 27 eyes with compound myopic astigmatism treated with a Nidek EC 5000 excimer laser. The refractive results were measured at 1 year, and the cylindrical component was analyzed by the Alpins method. Mean preoperative myopia was -4.50 diopters (D) (range -0.75 to -4.00 D) and mean preoperative cylinder, -1.64 D (range -0.75 to -4.00 D). RESULTS: At 1 year, the spherical equivalent was -0.47 D (range +1.00 to -3.00 D) and residual subjective astigmatism, -0.40 (range -0.25 to -1.50 D). Uncorrected visual acuity of 20/40 or better was obtained in 22 of the 27 eyes; 21 eyes were within +/- 1.0 D of emmetropia. Vector analysis showed a mean coefficient adjustment of 1.50 D +/- 0.53 (SD), a mean axis shift of 2.64 +/- 12.10 degrees, and a mean magnitude of error of 0.45 +/- 0.56 D. Haze was absent in 22 eyes and grade 1+ in 5 eyes. Five eyes gained 1 line of best corrected visual acuity and 3 lost 1 line. No patient lost more than 1 line. CONCLUSION: Excimer laser PARK successfully corrected low and moderate myopia combined with up to 4.0 D of astigmatism with a low mean angle of error. To increase the accuracy of toric ablation, specific algorithms for the cylinder component are needed.

[Micro-endoscopy of the lacrimal apparatus combined with Erbium YAG laser: an anatomical study. New methods of imaging]. / Micro-endoscopie des voies lacrymales combinée au laser YAG Erbium: étude anatomique. Nouvelles méthodes d'imagerie.

PURPOSE: To study the anatomic structure and the endoscopic aspect of the lacrimal drainage system and to evaluate the efficacy of the Erbium laser with microendoscope in lacrimal obstruction. METHODS: Twenty lacrimal ducts from ten fresh cadaver heads were used to lead a special rigid probe of 1.1. mm diameter (Endognost Schwind). This probe combined a flexible endoscopic probe of 500 mu, an Erbium laser fiber of 375 mu and an irrigation. The probe was introduced through the inferior canaliculus. Progressing in the lacrimal system, all the images were analysed. Then, we used the laser fiber to open the lacrimal sac mucosa and the lacrimal bone. RESULTS: The anatomo-endoscopic analysis was performed using endoscopic data. We appreciated essentially the walls of valves and sinuses that appeared only functional when increasing the irrigation flow. The laser could easily open the mucosa and the lacrimal bone but not the maxilla. DISCUSSION: The small size of the cannula allows to use the system for the diagnosis of lacrimal obstructions. The combined laser allows to treat at same time canalicular obstructions and lower obstructions. CONCLUSION: The endocanalicular study of the lacrimal drainage system can diagnose the type of obstruction and can treat it. A clinical study is requested to confirm these results.