Fluorophotometry in myopic phakic eyes with anterior chamber intraocular lenses to correct severe myopia.

Implanting an anterior chamber intraocular lens in a phakic eye is an effective surgical procedure for the correction of severe myopia. However, the potential risks on the anterior segment structures are scarcely known. We conducted a prospective study to evaluate the permeability of the blood-aqueous barrier and the lens transmittance changes after Worst-Fechner lenses were implanted to correct myopia. Preoperative and serial postoperative fluorophotometry was done in 15 eyes that had a Worst-Fechner lens implanted to correct myopia. Lens transmittance was evaluated by lens autofluorescence, and permeability of the blood-aqueous barrier was estimated by anterior vitreous fluorophotometry, which was carried out before and after intravenous injection of fluorescein. Preoperative lens transmittance was 0.971 +/- 0.002 (mean +/- standard error), and, after the operation, lens transmittance decreased to 0.970 +/- 0.002 at one month, 0.966 +/- 0.001 at three months, 0.964 +/- 0.002 at six months, and 0.962 +/- 0.003 at 14 months. At three, six, and 14 months after the operation, lens transmittance values were significantly lower than preoperative values (P = .038 at three months, P < .001 at six months, and P = .005 at 14 months). Fluorescein concentration in the anterior vitreous was 18.522 +/- 1.797 ng/ml (mean +/- standard error) preoperatively and was 21.328 +/- 1.667 ng/ml at one month, 27.518 +/- 1.412 ng/ml at three months, 27.150 +/- 1.474 ng/ml at six months, and 27.012 +/- 1.980 ng/ml at 14 months postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical correction of high myopia in phakic eyes with Worst-Fechner myopia intraocular lenses.

BACKGROUND: Implanting an anterior chamber intraocular lens in a phakic eye is an effective surgical procedure for the correction of high myopia. However, the potential risks on the anterior segment structures are not well-known. We conducted a prospective study to evaluate the effectiveness, predictability, and safety after Worst-Fechner lenses were implanted to correct high myopia. METHODS: We studied 32 eyes with preoperative myopia from -9.50 to -27.00 diopters (D) (-16.60 +/- 6.29 D). All 32 eyes were studied by clinical specular microscopy, and the endothelium was analyzed for cell density. Twenty eyes were additionally examined by fluorophotometry for lens transmittance changes. Thirty eyes were additionally examined using the flare mode of a laser flare cell photometer for anterior chamber inflammation; the patients were divided into three subgroups of ten eyes each according to when the postoperative flare measurements were done: 12 months, 18 months, and 24 months. Thirteen phakic eyes with myopia greater than -6.00 D were used as a control group for the flare study. The mean follow-up was 18.3 +/- 8 months (range 6 to 24 mo). RESULTS: Fifty-seven per cent of eyes (16 of 28) had an uncorrected visual acuity of 20/40 or better 12 months after surgery, and 58% (10 of 17 eyes) at 24 months. Spectacle-corrected visual acuity improved: 0.15 at 12 months and 0.16 at 24 months (0.1 = one line) from preoperative values. Visual acuity was stable after 3 months. Eighty per cent of eyes (25 of 31) at 6 months, 75% (21 of 28) at 12 months, and 76.5% (13 of 17) at 24 months had been correctly planned to within +/-1.00 D of emmetropia. The refractive results were stable 3 months after surgery. The mean endothelial cell loss was 7.2% at 3 months, 10.6% at 6 months, 13% at 12 months, and 17.6% at 24 months after surgery. The mean lens transmittance loss was 0.62% at 3 months, 0.72% at 6 months, 0.82% at 12 months, and 1.03% at 18 months after surgery. Flare values were significantly higher for eyes implanted with Worst-Fechner lenses than were those of the control group in all periods under consideration (Mann-Whitney test, p < 0.05). A decentration greater than 0.5 mm was present in 43% of eyes (14 of 32), and halos in 56% (18 of 32). In three eyes (9.3%), fixation of the lens to the iris was not stable. CONCLUSIONS: Our results for the Worst-Fechner myopia lens confirm earlier findings on the effectiveness of the refractive results. However, our study showed a continual decrease in endothelial cell density, a decrease in lens transmittance, and a chronic subclinical inflammation after the implantation of these lenses. Moreover, decentration was common, and the fixation of the IOL to the iris was not stable in some eyes.

Photorefractive keratectomy after radial keratotomy.

We report the results of a prospective study that evaluated the efficacy, predictability, and safety of excimer laser photorefractive keratectomy (PRK) to correct residual myopia after radial keratotomy (RK). Using a 193 nm excimer laser, we performed PRK on ten undercorrected myopic eyes that had previous RK surgery. The mean interval between the RK and PRK was 1.5 years. Mean follow-up was seven months. Mean preoperative refraction was -4.08 +/- 1.35 diopters (D) and after PRK was +1.61 +/- 1.18 D at three months, +1.05 +/- 0.75 D at six months, and +0.79 +/- 0.83 D at 12 months. An uncorrected visual acuity of 20/40 or better was achieved in eight eyes at three months, seven eyes at six months, and three eyes at 12 months. One eye had a transient loss of two Snellen lines of best spectacle corrected visual acuity because of increased haze. No other significant complication was noted. Our study shows that PRK is a predictable, effective, stable, and safe technique to correct residual myopia after RK. The results were similar to those of PRK without prior surgery, although we noted a slightly greater hyperopic deviation. We believe that eyes undercorrected by RK may benefit from subsequent PRK.

Surgical correction of severe myopia with an angle-supported phakic intraocular lens.

PURPOSE: To evaluate the effectiveness, predictability, and safety of a fourth-generation angle-supported anterior chamber phakic intraocular lens (IOL) in patients with severe myopia. SETTING: Refractive Surgery and Cornea Unit, Alicante Institute of Ophthalmology, Miguel Hernández University School of Medicine, Alicante, Spain. METHODS: In this prospective study, 23 eyes (16 patients) with a mean preoperative myopia of -19.56 diopters (D) +/- 1.76 (SD) (range -16.75 to -23.25 D) were implanted with the ZSAL-4 phakic IOL. Basic examinations were performed before and after surgery in all patients. Eighteen eyes were also studied by clinical specular microscopy, and the endothelium was analyzed for cell density, coefficient of variation in cell size, and hexagonality. The location of the IOL in the anterior chamber was evaluated in 10 eyes by A-scan biometry. To evaluate haptic geometry, a theoretical mechanical model was used. The follow-up was 24 months in all patients. RESULTS: Uncorrected visual acuity was 20/40 or better in 13 eyes (56.0%) 12 months after surgery and in 14 eyes (60.8%) at 24 months. Best spectacle-corrected visual acuity improved 0.19 at 12 and 24 months (0.1 = 1 line) from preoperative values. The efficacy index was 1.12 at 24 months and the safety index, 1.45. The mean postoperative spherical equivalent was -0.65 +/- 0.65 D at 24 months. The postoperative spherical equivalent was within +/-1.00 D of emmetropia in 19 eyes (82.6%) at 12 and 24 months. The mean endothelial cell loss was 3.50% at 12 months and 4.18% at 24 months. The coefficient of variation in cell size decreased from 0.34 before surgery to 0.28 at 24 months after surgery. The IOL was located 0.79 +/- 0.24 mm in front of the crystalline lens. Postoperative complications included night halos in 6 eyes (26.1%) at 12 and 24 months and pupil ovalization in 4 eyes (17.4%). Intraocular lens rotation was observed in 10 eyes (43.5%) at 24 months. Two eyes (8. 7%) developed a slight inflammatory response during the first 6 months. Our mechanical model predicted that the compression forces against the angle structures were greater at the first footplate than at the second. CONCLUSIONS: Implantation of the ZSAL-4 IOL in the anterior chamber of phakic eyes was effective and predictable in correcting severe myopia. However, the ZSAL-4 did not prevent pupil ovalization, IOL rotation, or low-grade postoperative uveitis. Improvements in haptic design following our mechanical model could decrease these haptic-related complications.

Endothelial changes in phakic eyes with anterior chamber intraocular lenses to correct high myopia.

PURPOSE: To evaluate the long-term endothelial cell loss after implantation of Worst-Fechner and Baikoff ZB5M anterior chamber intraocular lenses. SETTING: Jiménez-Díaz Foundation and San Carlos University Hospital, Madrid, Spain. METHODS: Preoperative and serial postoperative specular microscopy was performed on 30 eyes that had a Worst-Fechner lens and on 28 eyes that had a Baikoff ZB5M lens to correct high myopia. A video specular microscope adapted to an image analysis system was used to analyze the endothelium for cell density. Follow-up was 24 months. RESULTS: In the Worst-Fechner lens group, postoperative endothelial cell density was significantly lower than preoperative density at all times (P < .001). Endothelial cell loss was 7.26% at 3 months, 10.64% at 6 months, 13.00% at 12 months, and 17.60% at 24 months. In the Baikoff ZB5M lens group, postoperative cell density was also significantly lower than preoperative density at all times (P < .001). It was 7.50% at 3 months, 10.94% at 6 months, 12.33% at 12 months, and 12.30% at 24 months. Cell loss did not stabilize between 1 and 2 years after surgery in the Worst-Fechner group (P = .047). However, no additional cell loss was noted during this period in the Baikoff ZB5M group (P = .968). Endothelial cell densities in the two groups did not differ during the first year. However, 2 years after surgery, cell density in the Worst-Fechner group was significantly lower than it was in the ZB5M group (P = .048). CONCLUSIONS: Endothelial cell loss during the first year was similar in eyes with Worst-Fechner and Baikoff ZB5M lenses; however, at 2 years after surgery, endothelial cell loss was higher in eyes with Worst-Fechner lenses than it was in eyes with Baikoff ZB5M lenses.

Ischemic optic neuropathy after intraocular lens implantation to correct high myopia in a phakic patient.

A 33-year-old patient had uncomplicated anterior chamber intraocular lens implantation (Worst-Fechner biconcave myopia lens) to correct high myopia. Immediately after surgery, she developed anterior ischemic optic neuropathy likely associated with increased intraocular pressure and systemic hypotension. To our knowledge, this is the first documented case of anterior ischemic optic neuropathy after anterior chamber intraocular lens implantation to correct high myopia in a phakic eye.

Chronic subclinical inflammation in phakic eyes with intraocular lenses to correct myopia.

PURPOSE: To evaluate whether either of two anterior chamber intraocular lenses (IOLs) implanted in myopic, phakic eyes induced an inflammatory response that was measurable with a laser flare-cell meter but that could not be measured by other methods. SETTING: Jiménez-Díaz Foundation and San Carlos University Hospital, Madrid, Spain. METHODS: Thirty eyes with a Worst-Fechner IOL and 30 eyes with a Baikoff ZB5M IOL were evaluated using the flare mode of a laser flare-cell meter. Patients in each group were divided into three subgroups of 10 eyes each according to when the postoperative flare measurements were done: 12 months, 18 months, and 24 months. Thirteen phakic eyes with myopia greater than -6.00 diopters were used as controls. RESULTS: Postoperative flare in the Worst-Fechner group was 27.05 +/- 19 photons per millisecond (photons/ms) (mean +/- SD) at 12 months, 18.09 +/- 17.38 photons/ms at 18 months, and 31.03 +/- 28.8 photons/ms at 24 months. Postoperative flare in the Baikoff group was 21.1 +/- 5.9 photons/ms at 12 months, 16.13 +/- 8.3 photons/ms at 18 months, and 21.05 +/- 23.5 photons/ms at 24 months. Flare in the control group was 4.24 +/- 2.8 photons/ms. Postoperative flare values were significantly higher in both IOL groups than in the control group at all follow-ups (Mann-Whitney test, P < .05). Postoperative flare values in the Worst-Fechner group were higher than in the Baikoff group at 12, 18, and 24 months, although the difference was not significant (Mann-Whitney test, P > .05). CONCLUSIONS: Our study shows chronic subclinical inflammation between 1 and 2 years after implantation of both IOL types.

Multizone versus monozone in the treatment of high and moderate myopia with an excimer laser.

BACKGROUND AND OBJECTIVE: Numerous modifications have been proposed to photorefractive keratectomy (PRK) in the treatment of myopia in excess of 6.00 diopters (D). One of the techniques employed in an attempt to achieve better refractive results and to avoid, above all, the appearance of an intense haze, is the technique known as multizone. PATIENTS AND METHODS: We have attempted, in a prospective study, to compare the refractive results and the complications of monozone and multizone techniques for the treatment of moderate and high myopia. We performed 139 monozone PRKs and 30 multizone PRKs with a one-year follow-up. RESULTS: We did not find statistically significant differences between the two groups either in the degree of correction obtained nor in the final visual acuity. A statistically significant difference was found only in the number of cases with severe haze (greater than 3) which proved more frequent in the monozone group. CONCLUSION: Our results suggest the techniques are comparable in predictability and effectiveness. However, the incidence of severe haze was lower in the multizone group, which may render its use preferable in the treatment of myopias in excess of 6.00 D.

[Binocular vision in congenital glaucoma]. / La vision binoculaire dans le glaucome congénital.

We have studied binocular vision in a group of 189 patients suffering from congenital glaucoma, before and after treatment, as well as the elements upon which vision depends. Therapeutic modalities, including occlusion are discussed. We insist on the possibility of recovering binocular vision in congenital glaucoma.

Surgically induced astigmatism after biaxial phacoemulsification compared to coaxial phacoemulsification.

PURPOSE: A comparison of the topographic astigmatism generated after coaxial phacoemulsification (CP) through temporal 2.8 mm incision and biaxial phacoemulsification (MICS) through superior-oblique trapezoidal 1.5-2 mm incisions. SETTING: Centre for Visual Sciences (Instituto de Ciencias Visuales, INCIVI), Madrid, SpainMethods This prospective randomized clinical study included 94 eyes of 64 patients; 43 eyes were operated on through CP and 51 through MICS. Corneal topography was measured before operation, and subsequently after 1, 3, and 6 months. Additionally, a control group (C) of 55 eyes was created (performing two topographies on them); the change in astigmatism was calculated without having performed any surgical procedure. The astigmatic change in the three groups was measured through arithmetic, polar and vector analysis (Alpins method). RESULTS: In the vector analysis, results after the first month following surgery were: mean module of the surgically induced astigmatism (SIA) 0.49+/-0.38 D in CP and 0.48+/-0.37 D in MICS, while 0.31+/-0.27 D in group C. Although no statistically significant differences were detected between the two surgical techniques, differences were noted when comparing group C with each of these techniques (P<0.05). The distribution of the SIA axes showed a slight tendency to be located more frequently at around 90 degrees in CP, and at around 50 degrees in MICS. CONCLUSIONS: The mean module of SIA was similar in CP and in MICS, although the distribution of the direction of such a vector revealed minor differences.

[Diagnostic value of anesthesia for the surgery of strabismus]. / Der diagnosticsche Wert der Anästhesie für die Chirurgie des Strabismus.

There is no clinical test to detect a blockade. Under Anesthesia it is possible to discover a suspected blockade, so this test is quite helpful. Even in small babies this test can be applied in order to dected a pseudoparalysis of the external recti. We decide to operate after evaluation of the clinical facts and the findings under anesthesia according to the Zato test. We especially observe the positions of the eyes during normal breathing and the position under deep anesthesia.

Short-term corneal endothelial changes after photorefractive keratectomy.

Clinical results show that photorefractive keratectomy (PRK) offers good predictability, efficacy, and safety. However, its potential risks on the human corneal endothelium are poorly known. We report the results of a prospective study conducted to evaluate the corneal endothelium changes after photorefractive keratectomy. Preoperative and serial postoperative specular microscopy was performed in 14 eyes undergoing excimer laser photorefractive keratectomy. The endothelium was analyzed for a variety of parameters, including cell density, coefficient of variation in cell size, and hexagonality. The follow-up was 6 months. The mean cell density was unchanged from 2463 cells/mm2 to 2498 cells/mm2 at 6 months after photorefractive keratectomy. The coefficient of variation of cell size (polymegathism) changed from 0.303 to 0.280 at 1 month, to 0.293 at 3 months, and to 0.290 at 6 months after surgery. The changes in this parameter were statistically significant when comparing pre- versus 1 month postoperative values. The hexagonality was unchanged from 72.08% at baseline to 73.35% at 6 months. No endothelial abnormalities were found after photorefractive keratectomy. Our results suggest a cell migration from the peripheral to central cornea after photorefractive keratectomy in contact lens wearing patients prior to photorefractive keratectomy.

Ocular pharmacokinetics of thiamphenicol in rabbits.

The ocular pharmacokinetics of thiamphenicol (TAP, CAS 15318-45-3) was studied in rabbits by means of the assessment of its ocular and systemic absorption, and urinary excretion after instillation of 0.5% TAP eye drops. TAP concentrations in aqueous humor, plasma and urine were evaluated by a coupled LC/GC method (detection limit = 0.1 ng/ml), because the necessity to have a technique much more sensitive than the traditional chromatographic ones available in order to quantify the very low drug concentrations in biological fluids produced by the ocular treatment, and generally by a topical administration. The intravenous route was chosen as reference and allowed the absolute bioavailability to be estimated. TAP proved to be well absorbed through the cornea with the peak aqueous humor concentration of 110 ng/ml at 45 min following the instillation. The good ocular absorption of TAP was confirmed by the plasma concentrations observed after instillation of 0.5% eye drops. In any case, these concentrations were more than 1000 times lower than those observed after the intravenous treatment at the dose normally used for infectious diseases, allowing to exclude any systemic toxicity of TAP eye drops. The absolute ocular bioavailability was 16.2% when estimated from the AUC values and 34.0% from the cumulative urinary excretion values.

[Sphenoidal hyperostosis. Problems of differential diagnosis: report of a case]. / Hiperostosis esfenoidal. Problemas del diagnóstico diferencial: a propósito de un caso.

A case of sphenoid hyperostosis is described in a patient whose clinical history and radiological work up suggested fibrous dysplasia. A year later, the biopsy and MRI showed evidence of a meningioma en plaque. Problems in the differential diagnosis are discussed among entities which present sphenoid hyperostosis: osteoma, Paget's disease, sphenoid meningioma and fibrous dysplasia.