Implanting two posterior chamber intraocular lenses in a case of microphthalmos

A 31-year-old male with bilateral microphthalmos and a history of severe refractive amblyopia presented with early nuclear sclerosis. Intraocular lens calculations determined the patient would need about a 46.0 diopter power intraocular lens in both eyes to achieve satisfactory vision postoperatively. When no manufacturer could or was willing to make such a high-power lens, we chose to implant two lenses in each eye. The patient is satisfied with his postoperative vision and overall outcome.

The four stages of surgical rehabilitation of the patient with dysthyroid ophthalmopathy

A logical and comprehensive program for the total ophthalmic rehabilitation of the dysthyroid patient is described. Surgical rehabilitation is always considered in four stages: orbital decompression, extraocular muscle surgery, eyelid margin repositioning, and blepharoplasty. Each stage must be considered in order. By observance of this protocol, repeat surgical procedures can be minimized.

Long-term Outcomes of Photorefractive Keratectomy for Anisometropic Amblyopia in Children

PURPOSE

To evaluate the long-term visual acuity (VA) and refractive error responses to excimer laser photorefractive keratectomy (PRK) for treatment of anisometropic amblyopia in children.

DESIGN

Prospective interventional case-control study.

PARTICIPANTS

Eleven children, 2 to 11 years old, with anisometropic amblyopia who were noncompliant with conventional therapy with glasses or contact lenses and occlusion therapy were treated with PRK. A cohort derived retrospectively of 13 compliant and 10 noncompliant children with refractive errors similar to those of the PRK group who were treated with traditional anisometropic amblyopia therapy served as control groups.

INTERVENTION

Photorefractive keratectomy for the eye with the higher refractive error.

MAIN OUTCOME MEASURES

(1) Refractive error reduction and stability in the treated eye, (2) cycloplegic refraction, (3) VA, (4) stereoacuity, and (5) corneal haze up to 3 years after PRK. Compliant and noncompliant children with anisometropia amblyopia were analyzed as controls for refractive error and VA.

RESULTS

Preoperative refractive errors were -13.70 diopters (D) (+/-3.77) for the myopic group and +4.75 D (+/-0.50) for the hyperopic group. Mean postoperative refractive errors at last follow-up (mean, 31 months) were -3.55 D (+/-2.2.5) and +1.41 D (+/-1.07) for the myopic and hyperopic groups, respectively. At last follow-up, cycloplegic refractions in 4 (50%) of 8 myopes and all hyperopes (100%) were within 3 D of that of the fellow eye. Five (63%) of 8 myopic children achieved a refraction within 2 D of the target refraction. Two (67%) of 3 hyperopic patients maintained their refractions within 2 D of the target. Refractive regressions (from 1 year after surgery to last follow-up) were 0.50+/-1.41 D (myopes) and 0.60+/-0.57 D (hyperopes). Seven children (77%) were able to perform psychophysical VA testing preoperatively and postoperatively. Five (71%) of the 7 children had uncorrected VA improvement of at least 2 lines, and 4 (57%) of 7 had best spectacle-corrected VA improvement of at least 2 lines, with 1 improving 7 lines. Five (55%) of 9 children had improvement of their stereoacuity at last follow-up. Subepithelial corneal haze remained negligible. The mean final VA of the PRK group was significantly better than that of the noncompliant control group (P = 0.003). The mean final refractive error for both myopic and hyperopic groups was also significantly better that that of the control groups (P = 0.007 and P<0.0001, respectively).

CONCLUSIONS

Photorefractive keratectomy for severe anisometropic amblyopia in children resulted in long-term stable reduction in refractive error and improvement in VA and stereopsis, with negligible persistent corneal haze.

Amblyopia and strabismus in congenital ptosis

Seventeen per cent of 216 cases of simple congenital ptosis developed amblyopia and 19% had a squint. Of those patients with amblyopia, 14% had amblyopia attributable to stimulus deprivation, 21% had anisometropic amblyopia and 51% had strabismic amblyopia. Early refraction, orthoptic assessment and treatment and, where the pupillary axis is occluded, surgery to prevent stimulus deprivation amblyopia are recommended.

Photorefractive keratectomy in children

PURPOSE

To evaluate photorefractive keratectomy (PRK) in pediatric patients who fail traditional methods of treatment for myopic anisometropic amblyopia and high myopia.

SETTING

Nonhospital surgical facility with follow-up in a hospital clinic setting.

METHODS

Photorefractive keratectomy was performed in 40 eyes of 27 patients. The patients were divided into 4 groups based on the type of myopia: myopic anisometropic amblyopia (15 eyes/13 patients), bilateral high myopia (20 eyes/10 patients), high myopia post-penetrating keratoplasty (3 eyes/2 patients), and combined corneal scarring and anisometropic amblyopia (2 eyes/2 patients). All procedures were performed under general anesthesia using the VISX 20/20 B laser and a multizone, multipass ablation technique. Appropriate corneal fixation was achieved with appropriate head positioning (turn and tilt) and an Arrowsmith fixation ring. Myopia was as high as -25.00 diopter (D) spherical equivalent (SE), but no treatment was for more than -17.50 D SE.

RESULTS

The mean SE decreased from -10.68 D to -1.37 D at 1 year, a mean change of -9.31 D. At 1 year, the mean best corrected visual acuity improved from 20/70 to 20/40 in the entire group. Forty percent of eyes were within +/-1.0 D of the targeted refraction. There was no haze in 59.5% of eyes. Three eyes initially had 3+ haze; 1 improved to 2+ and 2 required repeat PRK with significant haze reduction. Five eyes (3 patients) with greater than -17.00 D SE myopia before PRK (range -17.50 to -25.00 D) had 3.42 D more effect than predicted (range 0.50 to 5.50 D). A functional vision survey demonstrated a positive effect on the children's ability to function in their environments after the laser treatment.

CONCLUSION

Photorefractive keratectomy in children represents another method of providing long-term resolution of bilateral high myopia and myopic anisometropic amblyopia.

Generalized fibrosis of the extraocular muscles

We studied four patients with the general fibrosis syndrome. One patient had bilateral inguinal hernias and unilateral cryptorchism; the other patients had no other congenital abnormalities. The patients developed normally both neurologically and metally. We successfully treated amblyopia and achieved good functional and cosmetic results with strabismus and blepharoptosis surgery. Histopathologic study revealed fibrous infiltration of extrinsic eye muscle and Tenon's capsule without inflammatory changes.

Phakic posterior chamber intraocular lens for the correction of anisometropia and treatment of amblyopia

PURPOSE

To assess the potential visual benefits of posterior chamber phakic intraocular lens implants in eyes of children with anisometropic amblyopia.

METHODS

In a prospective study, three girls 9, 14, and 18 years old with high anisometropia and deep amblyopia were included in this study. The phakic posterior chamber intraocular lens (ICL; STAAR Surgical AG, Nidau, Switzerland) was used to correct the anisometropia. This intraocular lens was inserted in the anterior chamber through a 3.0-mm temporal clear cornea incision and manipulated into the posterior chamber using an iris manipulator. A peripheral iridectomy was performed using the Ocutome Probe (Storz; Premiere, St. Louis, Missouri). Local therapy with corticosteroids and antibiotics were prescribed for 2 weeks, and patients were followed regularly for a period of 6 to 9 months.

RESULTS

In the three amblyopic eyes of the three patients, the preoperative best-corrected visual acuity of 6/30, 6/60, and 6/30 improved, to 6/7.5 (20/25), 6/30 (20/100), and 6/15 (20/50), respectively, 6 months after the surgery. Binocular functions with development of fusional abilities and stereopsis were observed in two of these patients after the intraocular lens implantation. In the third patient, the fusional abilities developed only after surgical correction of the exotropia. The intraocular pressure remained within normal limits, and there was no significant change in the corneal endothelial cell count during the period of follow-up. No major intraoperative or postoperative complications were observed, except for a temporary pigment dispersion.

CONCLUSIONS

Implantation of phakic posterior chamber intraocular lenses may be beneficial for the treatment of amblyopia in children with anisometropia. Although additional cases and long-term follow-up observations are necessary, it appears that amblyopia may be overcome by the use of posterior chamber phakic intraocular lens implants, even in eyes of children beyond the age generally considered to be responsive to anti-amblyopic treatment.

Excimer laser photorefractive keratectomy in pediatric patients

PURPOSE

To evaluate the results of excimer laser photorefractive keratectomy (PRK) for myopia in pediatric eyes with amblyopia resulting from anisometropia.

SETTING

Clinica de Ojos Dr. Nano, Buenos Aires, Argentina.

METHODS

Five children with amblyopia resulting from anisometropia in whom conventional therapy was unsuccessful had PRK followed immediately by photoastigmatic refractive keratectomy. Mean patient age was 12.4 years, and follow-up was 12 months.

RESULTS

Postoperatively, all eyes had reduced anisometropia and a significant improvement in uncorrected and corrected visual acuities. Sixty percent of patients had no haze 12 months after PRK, 20% had trace haze, and 20%, mild. No patient had decreased best spectacle-corrected visual acuity.

CONCLUSION

The results of PRK for myopia were good in this small sample of children. Longer follow-up with more patients should be done.

Laser-assisted subepithelial keratectomy and photorefractive keratectomy versus conventional treatment of myopic anisometropic amblyopia in children

PURPOSE

To evaluate the visual and refractive results of photorefractive keratectomy (PRK) and laser-assisted subepithelial keratectomy (LASEK) for high myopic anisometropia with amblyopia and contact lens (CL) intolerance in children.

SETTING

Department of Ophthalmology, Masaryk University Hospital, Brno, Czech Republic.

METHODS

This prospective comparative study comprised 27 children with high myopic anisometropia and amblyopia. The mean age of the children was 5.4 years (range 4 to 7 years). Multizonal PRK (13 eyes) or LASEK (14 eyes) was performed in the more myopic eye under general anesthesia using the Nidek EC-5000 excimer laser. After surgery, the dominant eye was patched. The postoperative visual and refractive outcomes were analyzed; all children had a 2-year follow-up. The 27 children (Group A) were compared with a control group of 30 children (mean age 5.1 years) (Group B) in whom myopic anisometropia and amblyopia were treated conventionally by CLs and patching the dominant eye. The visual acuity and binocular vision outcomes in both groups were analyzed and compared.

RESULTS

In Group A, the mean spherical equivalent refraction was -8.25 diopters (D) +/- 2.37 (SD) (range -6.00 to -11.25 D) preoperatively and -1.61 +/- 0.73 D (range +0.50 to -2.25 D) postoperatively. The mean best corrected visual acuity (BCVA) was 0.23 +/- 0.21 preoperatively and 0.78 +/- 0.19 at 2 years. In Group B, the mean BCVA was 0.16 +/- 0.19 at the start of CL correction and amblyopia therapy and improved to 0.42 +/- 0.15 after 2 years. The mean BCVA at the final examination was significantly better in Group A (P<.05). Binocular vision improvement expressed by the proportion of patients who gained fusion and stereopsis was better overall in Group A (78%) than in Group B (33%) (P<.05). There were no complications postoperatively.

CONCLUSIONS

Photorefractive keratectomy and LASEK were effective and safe methods for correcting high myopic anisometropia and improving amblyopia in children aged 4 to 7 years who were CL intolerant. Visual acuity and binocular vision outcomes were better in children who received permanent surgical correction of anisometropia than in those who were treated conventionally by CLs.

Phakic posterior chamber lens implantation in children with high myopia

PURPOSE

To evaluate the anatomical and functional results after implantation of a phakic posterior chamber lens (implantable contact lens [ICL]) to correct high myopia with amblyopia in pediatric patients in whom conventional treatments had failed.

SETTING

Department of Ophthalmology, Purpan Hospital, University of Toulouse, France.

METHODS

An ICL was implanted in 5 eyes with amblyopic high myopia in 4 children aged 3 to 16 years. Mean preoperative spherical equivalent refraction was -12.8 diopters (D) (range -8.0 to -18.0 D) and best spectacle-corrected visual acuity (BSCVA) was counting fingers to 20/200. Mean follow-up was 11.8 months (range 4 to 21 months).

RESULTS

Postoperatively, the ICLs appeared to be well tolerated, with no inflammatory reactions, stable intraocular pressure, and good positioning in all eyes. Predictability was +0.5 D (range -0.5 to +2.0 D) and BSCVA improved, with a gain of 3 or more Snellen lines with recovery of binocular vision in 2 cases and orthotropia in 3 patients. All parents reported an improvement in their children's quality of life.

CONCLUSION

This preliminary study indicates that ICL implantation is a safe surgical procedure to correct amblyopia resulting from high myopia in children when conventional amblyopia treatments have failed. Longer follow-up of more patients is needed.

Anterior chamber iris-fixated phakic intraocular lens for anisometropic amblyopia

We report a child who had implantation of an iris-fixated Artisan phakic intraocular lens (IOL) to correct high unilateral myopia to support the therapy of anisometropic amblyopia. After IOL implantation, the patient continued occlusion therapy to further treat the amblyopic eye. One year postoperatively, the best corrected visual acuity in the amblyopic eye was 1.00 and binocular stereovision had developed. The visual acuity remained stable through 3 years of follow-up. There were no complications, although postoperative endothelial cell loss was significant.

Rates of Reoperation and Abnormal Binocularity Following Strabismus Surgery in Children

PURPOSE

To determine predictors of reoperation and abnormal binocularity outcomes (including amblyopia and diplopia) following pediatric strabismus surgery.

DESIGN

Retrospective cross-sectional study.

METHODS

setting: Review of a national insurance database.

STUDY POPULATION

Children under age 18 years having strabismus procedures between 2007 and 2013.

INTERVENTIONS

Adjustable- or fixed-suture strabismus surgery, or botulinum toxin injection.

OUTCOME MEASURES

Reoperation or diagnosis of abnormal binocularity in the first postoperative year.

RESULTS

Of 11 115 children having strabismus procedures, 851 (7.7%) underwent reoperation. The reoperation rate was 7.4% for fixed-suture surgeries, 9.6% for adjustable-suture surgeries (P = .18), and 44.9% for botulinum injections (P < .001). Age under 2 years was associated with higher reoperation and abnormal binocularity rates (P < .001). For horizontal strabismus, the postoperative abnormal binocularity rate was 12.8% for fixed-suture surgery and 26.5% for botulinum injection (P = .005). Reoperation rates tended to be higher with adjustable sutures (odds ratio [OR] 1.69, 95% confidence interval [CI] 0.94-3.03, P = .08) or botulinum toxin injection (OR 10.36, 95% CI 5.75-18.66, P < .001) and lower with 3- or 4-muscle surgery (P = .001). Esotropia, hyperopia, and botulinum injection were independently associated with higher rates of postoperative abnormal binocularity (P ≤ .005). For vertical surgeries, predictors of reoperation were adjustable-suture use (OR 2.51, P = .10) and superior oblique surgery (OR 2.36, P < .001).

CONCLUSIONS

Adjustable sutures were not associated with a lower reoperation rate in children. Younger age, esotropia, hyperopia, and botulinum injection were associated with postoperative abnormal binocularity. Superior oblique surgery and botulinum injection were associated with higher rates of reoperation.

Congenital ptosis and amblyopia: a retrospective study of 130 cases

PURPOSE

To provide supplementary data on the association between congenital ptosis and amblyopia.

METHODS

In a retrospective chart study of 130 patients whose congenital ptosis was surgically corrected between 1987 and 1999, 27 (20.8%) had strabismus and 30 (23%) had amblyopia. In 9 patients (6.3%), it was not attributable to any cause except ptosis.

RESULTS

There was a high incidence (6.9%) of amblyopia in patients with congenital ptosis.

CONCLUSION

We recommend early examination and follow-up of patients with congenital ptosis to diagnose and treat any subsequent amblyopia. Surgery may be indicated should stimulus deprivation amblyopia develop.

Phakic Intraocular Lens to Correct High Myopic Amblyopia in Children

PURPOSE

In a clinical investigation, we evaluated anatomical and functional outcomes of posterior phakic chamber lens (ICL) implantation for correction of high myopia with amblyopia in children.

METHODS

Twelve eyes of 11 children, age 3 to 16 years, with high myopic amblyopia were operated with implantation of a Staar Surgical ICL. In these patients, conventional therapy with spectacles or contact lenses was unsuccessful. Mean preoperative spherical equivalent refraction was -12.70 D (range -8.00 to -18.00 D) and best spectacle-corrected visual acuity ranged from count fingers to 20/63. Mean follow-up was 20.5 months (range 3 to 48 mo) Preoperative and postoperative anatomical and functional outcomes were compared.

RESULTS

We noted good tolerance of ICLs without inflammatory reactions or secondary capsular opacity, stable intraocular pressure, and good ICL position in all eyes. Predictability was +0.71 D (range -0.75 to +2.00 D). Mean postoperative best spectacle-corrected visual acuity was 20/63. Recovery of binocular vision was achieved in six patients and orthotropic position in seven patients. Quality of life was improved in all patients.

CONCLUSION

The Staar Surgical phakic ICL appeared to be an effective method to treat high myopia in children with amblyopia. Good results with high satisfaction were noted.

Reversal of Myopic Anisometropic Amblyopia With Phakic Intraocular Lens Implantation

PURPOSE

To report a case of reversal of myopic anisometropic amblyopia with phakic intraocular lens implantation.

METHODS

A 6-year-old boy with anisometropic amblyopia with spherical equivalent refraction of right eye: -14.00 -3.00 x 100 degrees, left eye: -0.50 -3.25 x 90 degrees, was treated for 2 years with occlusion to the left eye, with poor results. Refractive surgery was planned because of contact lens intolerance at age 8 years. A -15.00-D iris claw Artisan intraocular lens (IOL) was implanted.

RESULTS

Following surgery, treatment of the amblyopia and spectacle correction of -4.00 D cylinder at 85 degrees in the right eye and -3.50 D cylinder at 90 degrees in the left eye was necessary. Visual acuity 6 months after surgery was 20/25 in the right eye and 20/20 in the left eye, and has remained stable 18 months after surgery.

CONCLUSION

Myopic anisometropic amblyopia in an 8-year-old boy was treated successfully with implantation of an Artisan iris claw phakic anterior chamber IOL, combined with occlusion therapy, and resulted in reversal of amblyopia.

Very high frequency ultrasound analysis of a new phakic posterior chamber intraocular lens in situ

PURPOSE

To use very high frequency ultrasound scanning for in situ analysis of a new phakic posterior chamber intraocular lens (No-Touch; International Visions Inc, Cincinnati, Ohio).

METHODS

In this pilot study, very high frequency ultrasound (50 MHz) wide-angle (15 mm) full anterior segment scans were obtained in two patients who had undergone phakic posterior chamber intraocular lens implantation into legally blind eyes with normal anterior segment anatomy.

RESULTS

Very high frequency ultrasound B-scan images delineated the phakic posterior chamber intraocular lens within the posterior chamber. The relations to the sulci were clearly imaged. Anatomic relations of the phakic posterior chamber intraocular lens optic and haptics were visualized in both static (light/dark) and kinetic (distance/accommodative) states.

CONCLUSION

Very high frequency ultrasound wide-angle scanning provides a unique tool to noninvasively evaluate the eye preoperatively and the static and kinetic relations of this new refractive device within the posterior chamber.

Long-term stability of alignment in the monofixation syndrome

From a collection of 328 patients with congenital esotropia, 80 patients were identified who had a minimum 4-year follow-up after surgical alignment within 8 prism diopters (pd) of orthophoria. These patients were subdivided into two groups: the M.S. group (38 patients) demonstrated the monofixation syndrome; the NO M.S. group (42 patients) did not have monofixation. The alignment of patients in each group was followed over time. After 17.5 years, 74% of patients in the M.S. group maintained alignment within 8 pd of orthophoria. In the NO M.S. group, only 45% were well aligned after 14 years. The mean time to loss of stability was significantly shorter for the NO M.S. group (P less than 0.005). Our findings suggest achievement of the monofixation syndrome improves but does not guarantee stability of ocular alignment.

Laser-assisted subepithelial keratectomy in children

PURPOSE

To evaluate whether laser-assisted subepithelial keratectomy (LASEK) achieves effective targeted myopic correction with less post-treatment corneal haze than observed with photorefractive keratectomy (PRK) in children who fail traditional forms of treatment for myopic anisometropic amblyopia and high myopia.

SETTING

Nonhospital surgical facility with follow-up in a hospital clinic setting.

METHODS

This prospective study comprised 36 eyes of 25 patients. The mean patient age at treatment was 8.27 years (range 1.0 to 17.4 years). Patients were divided into 3 groups: those with myopic anisometropic amblyopia (13 patients/13 eyes), those with bilateral high myopia (11 patients/22 eyes), and those with high myopia post-penetrating keratoplasty (1 patient/1 eye). All patients were treated with LASEK under general anesthesia using the Visx 20/20 B excimer laser and a multizone, multipass ablation technique. Although the myopia was as high as -22.00 diopters (D) spherical equivalent (SE) in some eyes, no eye was treated for more than -19.00 D SE.

RESULTS

At 1 year, the mean SE decreased from -8.03 D to -1.19 D. Forty-four percent of eyes were within +/-1.0 D of the targeted correction; 78% of eyes had clear corneas with no haze. In the entire group, the mean best corrected visual acuity improved from 20/80 to 20/50. A functional-vision survey demonstrated a positive effect on the patients' ability to function in their environments after LASEK.

CONCLUSIONS

Laser-assisted subepithelial keratectomy in children represents another method of providing long-term resolution of bilateral high myopia and myopic anisometropic amblyopia with minimal post-laser haze. The reduction in post-laser haze with LASEK compared to that with the standard PRK technique may represent an advantage in treating these complex patients.

Facilitation of amblyopia management by laser in situ keratomileusis in high anisometropic hyperopic and myopic children

PURPOSE

To assess the efficacy of laser in situ keratomileusis (LASIK) in facilitating amblyopia management of children from 6 to 14 years old, with high hyperopic and myopic anisometropia.

PATIENTS AND METHODS

Between 2000 and 2005, 42 children with high hyperopic anisometropic amblyopia and 32 children with high myopic anisometropic amblyopia underwent LASIK to reduce their anisometropia. LASIK was performed under topical or general anesthesia. Pre- and postoperative best-corrected visual acuity, cycloplegic refraction, and binocular vision were recorded. Follow-up ranged from 6 months to 3 years, the averages of which were 17.45 months in the hyperopic group and 18.31 months in myopic group.

RESULTS

Hyperopic anisometropia correction ranged from +3.50 D to +7.75 D, and the mean postoperative anisometropia was +0.56 +/- 0.75 D at 3 years. Myopic anisometropia correction ranged from -15.75 to -5.00 D and the mean postoperative anisometropia at 3 years was -2.20 +/- 1.05 D. The best-corrected visual acuity for distance and reading in the myopic group improved from 0.4 +/- 0.25 and 0.58 +/- 0.27, respectively, before surgery to 0.59 +/- 0.28 and 0.96 +/- 0.35, respectively, 3 years after surgery. In the hyperopic group, best-corrected visual acuity for distance and reading improved from 0.23 +/- 0.21 and 0.34 +/- 0.32, respectively, before surgery to 0.53 +/- 0.31 and 0.80 +/- 0.33, respectively, 3 years after surgery. The proportion of patients who had stereopsis increased from 19.1% preoperatively to 46.7% postoperatively in the hyperopic group and from 19% to 89% in the myopic group.

CONCLUSIONS

LASIK reduced high hyperopic and myopic anisometropia in children, thus facilitating amblyopia management and improving their visual acuity and stereopsis.

Laser in situ keratomileusis for treated anisometropic amblyopia in awake, autofixating pediatric and adolescent patients

PURPOSE

To establish the safety and efficacy of laser in situ keratomileusis (LASIK) in pediatric and adolescent patients with anisometropic amblyopia who completed amblyopia therapy and had a visual acuity of 20/30 or better bilaterally.

SETTING

Department of Ophthalmology and Visual Science, University of Texas-Houston Medical School, Houston, Texas, USA.

METHODS

From August 2000 to March 2002, LASIK was performed in 21 eyes of 19 consecutive patients meeting eligibility requirements. The procedure was performed with the Summit Autonomous LADARVision 4000 excimer laser (Alcon Laboratories, Inc.) in the amblyopic eye for the correction of anisometropia or in both eyes. All patients were awake and autofixating during the procedure.

RESULTS

The mean patient age was 13.14 years (range 8 to 19 years). Seventeen patients were treated in the amblyopic eye only to correct anisometropia; treatment was performed in both eyes of 2 patients who were older than 18 years. Patients were followed for a mean of 18.0 months (range 8.6 to 26.5 months). Anisometropia was greater than 2.00 diopters (D) in all cases (mean 4.43 D, range 13.25 to 2.25 D). The percentage deviation from the attempted correction in the myopic group was 4.0% +/- 4.0% (SD) (range 2.0% to 10.0%) and 38.0% +/- 13.0% (range 5.0% to 58.0%) in the hyperopic group. Anisometropia decreased uniformly to less than 2.00 D in all patients (mean 1.52 D). The percentage of patients with stereo acuity increased from 63.0% preoperatively to 84.0% postoperatively.

CONCLUSIONS

Laser in situ keratomileusis safely and effectively reduced anisometropia in these patients. If stereo acuity is not possible preoperatively, it may be obtained postoperatively.

Ophthalmological problems of the premature infant

Preterm infants are more likely than term infants to have significant abnormalities of all parts of the visual system leading to reduced vision. The most common problem is retinopathy of prematurity (ROP). The frequency and severity of this disorder is inversely related to gestational age. Damage ranges from minor to catastrophic. Preterm infants also have higher rates of amblyopia, strabismus, refractive error, and cortical visual impairment. The later problem is largely associated with neonatal brain injury. Years later, these children may develop glaucoma and retinal detachments.

Optical Analysis of Visual Improvement after Correction of Anisometropic Amblyopia with a Phakic Intraocular Lens in Adult Patients

PURPOSE

To analyze possible reasons for an increase in visual acuity observed in myopic patients with anisometropic amblyopia after implantation of a phakic intraocular lens (PIOL) using a theoretical eye model.

DESIGN

Retrospective case series.

PARTICIPANTS

Fifty-nine eyes of 48 patients with anisometropic amblyopia implanted with an angle-supported PIOL.

METHODS

Inclusion criteria were anisometropia of at least 3 diopters (D) and a best spectacle-corrected visual acuity (BSCVA) of 0.7 or less in the best eye. Follow-up was performed at 1, 3, 6, and 12 months and then annually for up to 10 years. The theoretical analysis of mechanisms to explain the visual improvement was performed using a theoretical eye, based on the Kooijman model, in which the measured values of radii and thickness of the different surfaces were substituted. The magnification and spot size were calculated by a ray tracing process.

MAIN OUTCOME MEASURES

Uncorrected visual acuity, improvement in best spectacle-corrected visual acuity, and spherical equivalent.

RESULTS

Mean gain in visual acuity was 3 lines (range, 0-7 lines). Fifty-four eyes (91.5%) gained at least 1 line of visual acuity, whereas no eyes lost lines of vision. The change in BSCVA did not correlate with preoperative BSCVA (Pearson coefficient, r = 0.19) or with the degree of anisometropia (Pearson coefficient, r = 0.23). The calculations using a Kooijman eye model corrected with spectacles and with a PIOL accounted for the full increase in visual acuity in terms of the magnification (increased by a factor of 1.2) and the spot size (reduced by a factor of 2).

CONCLUSIONS

After implantation of a PIOL, the visual acuity of myopic patients with anisometropic amblyopia showed a significant increase. This increase was explained using a theoretical eye model not only in terms of magnification but also including changes in aberrations. An evident role of neuroprocessing in this visual improvement was not identified.

Successful implementation of a protocol for photorefractive keratectomy in children requiring anesthesia

PURPOSE

To describe a protocol for treating children with photorefractive keratectomy (PRK) under general anesthesia and to review intraoperative and postoperative complications.

SETTING

Institutional academic practice.

METHODS

Nine patients between 3 years and 9 years of age were treated with PRK under general anesthesia for anisometropia with unilateral high myopia or high hyperopia and amblyopia of the affected eye. Induction of anesthesia and the surgical procedure were carried out in separate rooms. The laser beam was centered on the entrance pupil, and eye position was monitored throughout the procedure. Specific precautions were taken before and during the procedure to prevent unwanted effects of inhalational anesthetic agents on laser performance.

RESULTS

All children did well, with no anesthesia-related or treatment-related complications.

CONCLUSIONS

Our protocol for PRK under general anesthesia was effective and efficient in children who were unable to cooperate for the procedure using local anesthesia. It can be adapted for laser in situ keratomileusis and other refractive surgical procedures in children and uncooperative adults.