Michael O'Keefe

Heterozygous mutations of the kinesin KIF21A in congenital fibrosis of the extraocular muscles type 1 (CFEOM1).

Congenital fibrosis of the extraocular muscles type 1 (CFEOM1; OMIM #135700) is an autosomal dominant strabismus disorder associated with defects of the oculomotor nerve. We show that individuals with CFEOM1 harbor heterozygous missense mutations in a kinesin motor protein encoded by KIF21A. We identified six different mutations in 44 of 45 probands. The primary mutational hotspots are in the stalk domain, highlighting an important new role for KIF21A and its stalk in the formation of the oculomotor axis.

Outcome and complications of intraocular lenses in children with cataract

Purpose: To assess prospectively the complications and changes in refraction, axial length, and keratometry after intraocular lens (IOL) implantation in children with congenital, developmental, and traumatic cataracts. Setting: The Children’s Hospital, Dublin, Ireland. Methods: The study comprised 24 eyes of 20 patients, aged 4 weeks to 12 years, who had extracapsular cataract extraction and posterior chamber IOL implantation. Mean follow‐up was 103 weeks (range 34 to 270 weeks). Results: Six eyes with congenital cataracts operated on between 4 and 28 weeks of age had central, steady, maintained fixation postoperatively. In the developmental cataract group, 64% achieved a visual acuity of 6/24 or better and 43%, 6/12 or better. In the three traumatic cases, visual acuities were 6/6, 6/9, and 6/24. Posterior capsule opacification occurred in 95.8% of eyes and was treated with a neodymium:YAG or Zeigler knife posterior capsulotomy as a secondary procedure. Other postoperative complications (membranous uveitis, iris capture, posterior synechias, iris prolapse) occurred in 29.2% of eyes. Conclusion: With careful management and patient selection, the use of IOLs in children can produce good visual results with a minimum of complications. Further follow‐up is needed to assess the long‐term visual outcome, complications, and changes in refraction.

Outcome in refractive accommodative esotropia

AIM To examine outcome among children with refractive accommodative esotropia. METHODS Children with accommodative esotropia associated with hyperopia were included in the study. The features studied were ocular alignment, amblyopia, and the response to treatment, binocular single vision, requirement for surgery, and the change in refraction with age. RESULTS 103 children with refractive accommodative esotropia were identified. Mean follow up was 4.5 years (range 2–9.5 years). 41 children (39.8%) were fully accommodative (no manifest deviation with full hyperopic correction). The remaining 62 children (60.2%) were partially accommodative. At presentation 61.2% of children were amblyopic in one eye decreasing to 15.5% at the most recent examination. Stereopsis was demonstrated in 89.3% of children at the most recent examination. Mean cycloplegic refraction (dioptres, spherical equivalent) remained stable throughout the follow up period. The mean change in refraction per year was 0.005 dioptres (D) in right eyes (95% CL −0.0098 to 0.02) and 0.001 D in left eyes (95% CL −0.018 to 0.021). No patients were able to discard their glasses and maintain alignment. CONCLUSIONS Most children with refractive accommodative esotropia have an excellent outcome in terms of visual acuity and binocular single vision. Current management strategies for this condition result in a marked reduction in the prevalence of amblyopia compared with the prevalence at presentation. The degree of hyperopia, however, remains unchanged with poor prospects for discontinuing glasses wear. The possibility that long term full time glasses wear impedes emmetropisation must be considered. It is also conceivable, however, that these children may behave differently with normal and be predestined to remain hyperopic.

Long-term results of laser in situ keratomileusis for high myopia : Risk for ectasia

PURPOSE: To ascertain the long‐term stability of laser in situ keratomileusis (LASIK) in highly myopic eyes. SETTING: Clinical practice office‐based surgery. METHOD: Charts of eyes with high myopia who had LASIK surgery by the same surgeon between 1994 and 2000 were reviewed in 2003, and patients were given an appointment for follow‐up examinations. In these highly myopic eyes, surgery was originally performed to create undercorrections with or without decreasing the ablation diameters to maximally conserve the residual stromal bed thickness. RESULTS: Of the 107 eyes with myopia between −10.00 diopters (D) and −35.00 D reviewed and operated on in a 3‐year period between 1994 and 1998, 35 eyes of 31 patients had a single enhancement procedure. One case of ectasia as a result of excessive tissue removal occurred in a patient with a preoperative refraction of −28.00 D. Of the 107 eyes reviewed, 78 (73%) were examined after 5 years, 68 (63%) after 7 years, and 15 (14%) between 9 years and 11 years. CONCLUSIONS: Operating on eyes with highly myopic refractive errors and removing substantial tissue thickness did not produce ectasia in this series. Although high myopia has been considered a risk factor for post‐LASIK ectasia, adherence to proper screening and intraoperative pachymetry appears to decrease the risk.

Endophthalmitis after astigmatic myopic laser in situ keratomileusis

Abstract A 36‐year‐old woman had uneventful astigmatic myopic laser in situ keratomileusis (LASIK) to correct −12.00 −1.50 × 70. Three days later, she developed a corneal abscess, hypopyon, and an intense vitreous cellular reaction—endophthalmitis. The patient was immediately given intravenous ciprofloxacin and topical vancomycin and ceftazidime. The infecting organism was Streptococcus pneumoniae. One day after therapy was instituted, the hypopyon resolved. Seven months later, best corrected visual acuity was 20/25 and refractive error, −4.00 diopters. A stromal scar (grade 2 haze) was causing a slight reduction in acuity. Endophthalmitis after LASIK, if treated promptly, need not lead to a permanent reduction in visual acuity.

Laser intrastromal keratomileusis for high myopia and myopic astigmatism

BACKGROUND Laser intrastromal keratomileusis (LASIK) is an evolving technique which enables high degrees of myopia (>8.0 dioptres) and myopic astigmatism to be corrected. This paper describes initial experience with this procedure. It also details the methodology, the results, the problems encountered, and discusses retreatment procedures. METHODS 51 eyes (48 primary cases and three retreatments) underwent LASIK for simple myopia or compound myopic astigmatism. After the keratotomy was fashioned with a Chiron corneal shaper, the ablation was performed with either a Summit or Meditec excimer laser. The actual preoperative astigmatism ranged from −0.5 D to −6.0 D (in the astigmatic myopic LASIK (AML) series), while the range of preoperative myopia in the combined myopic LASIK (ML) and AML series was −8.0 D to −37.0 D. Of the ML cases, group 1 (−8.0 to −15.0 D (dioptres)), group 2 (> −15.0 to −20.0 D), and group 3 (> −20.0 D) had mean preoperative myopia values (spherical equivalent) of −11.26 D, −16.84 D and −27.78 D. The same groupings (1, 2, and 3) for the AML cases had respective values of −9.702, −17.4, and −23.08. In the AML series the mean preoperative astigmatism was −2.109 D. Follow up ranged from 8 to 27 months (mean 15.8 months). Six of the cases required retreatment. RESULTS There was a reduction in best corrected visual acuity (BCVA) (of 1 Snellen line) in seven of the primary cases (14.5 %) (three in the ML group and four in the AML group), and in one of the retreatment cases. The BCVA improved in 28 cases (58%) in the primary treatment group. The mean correction attempted (spherical equivalent) for the ML groups 1, 2, and 3 was 10.51 D, −14.5 D, and −27.78 D, versus a mean correction achieved of −9.445 D, −15.625 D, and −21.571 D. Similarly, for the AML groups, attempted correction values were −9.702 D, −17.4 D, and −23.08 D, while the values achieved were −6.95 D, −51.425 D, and −15.708 D. Regression was minimal and stabilisation of the refractive result was achieved in all groups, except group 3 of the ML series, by the 3 month examination period. The mean postoperative astigmatism in the AML series was −0.531 D. Vector analysis of the AML series showed that the mean surgically induced astigmatism was +0.93 D. The most common complication encountered was undercorrection, which occurred in 35 cases—23 cases in the ML group and 12 cases in the AML series. Twenty eight per cent of the ML cases, and 25% of the AML cases were within plus or minus 1.5 D of the attempted refraction. CONCLUSION For the correction of high myopia and myopic astigmatism, LASIK results in less postoperative pain and relatively little subepithelial haze compared with high myopic photorefractive keratectomy. Furthermore, a stable refraction and reasonably predictable outcome occurs much earlier. High myopia up to −37.0 D can be corrected, albeit with some limitations at the extremes of myopia—in terms of the amount of myopia correctable; this represents a limitation of the technique. Retreatment is a technically straightforward and effective way to treat undercorrection. Undercorrection, the main complication seen in our series, should become less common when the ablation algorithms are further refined.

Intraocular lenses in children: changes in axial length, corneal curvature, and refraction

AIM To assess changes in axial length, corneal curvature, and refraction in paediatric pseudophakia. METHODS 35 eyes of 24 patients with congenital or developmental lens opacities underwent extracapsular cataract extraction and posterior chamber intraocular lens implantation. Serial measurements were made of axial length, corneal curvature, objective refraction, and visual acuity. RESULTS For patients with congenital cataracts (onset <1 year age) the mean age at surgery was 24 weeks. Over the mean follow up period of 2.7 years, the mean increase in axial length of 3.41 mm was not significantly different from the value of an expected mean growth of 3.44 mm (pairedt test, p=0.97) after correction for gestational age. In the developmental cataract group (onset >1 year of age) the mean age at surgery was 6.4 years with a mean follow up of 2.86 years. This group showed a mean growth in axial length of 0.36 mm that was not significantly different from an expected value of 0.47 mm (paired t test, p = 0.63). The mean preoperative keratometry was 47.78 D in the congenital group and 44.35 D in the developmental group. At final follow up the mean keratometry in the congenital group was 46.15 D and in the developmental group it was 43.63 D. In eyes followed for at least 2 years, there was an observed myopic shift by 24 months postoperatively of 3.26 D in the congenital cases (n=10) and 0.96 D in the developmental cases (n=18). CONCLUSION The pattern of axial elongation and corneal flattening was similar in the congenital and developmental groups to that observed in normal eyes. No significant retardation or acceleration of axial growth was found in the eyes implanted with IOLs compared with normal eyes. A myopic shift was seen particularly in eyes operated on at 4–8 weeks of age and it is recommended that these eyes are made 6 D hypermetropic initially with the residual refractive error being corrected with spectacles.

Refractive outcome following diode laser versus cryotherapy for eyes with retinopathy of prematurity.

The refractive error in 15 eyes with threshold retinopathy of prematurity treated with diode laser photocoagulation was compared with 25 eyes with the same disease severity treated by cryotherapy. Myopia was present in 40% (six eyes) of the first group ranging from -1.50 to -3.50 dioptres; while 92% (23 eyes) showed myopia which ranged from -0.50 to -8.00 dioptres in the cryotherapy group. Sixty per cent (nine eyes) were hypermetropic at less than +3.0 dioptres in the laser group, while only 8% (two eyes) of the cryotherapy group showed hypermetropia. There was no significant difference in astigmatism between the two groups. Eyes with threshold disease treated with diode laser photocoagulation developed significantly less myopia than those treated with cryotherapy (p = 0.0006, two tailed value).

Long term follow up of primary trabeculectomy for infantile glaucoma

BACKGROUND--The treatment for infantile glaucoma is surgical. Treatment options include goniotomy, trabeculotomy, combined trabeculotomy-trabeculectomy, and trabeculectomy. METHODS--Patients who had a follow up of 5 years or longer after primary trabeculectomy were examined to determine the long term stability in infantile glaucoma. RESULTS--In eyes with primary infantile glaucoma 92.3% achieved control of their glaucoma with a single trabeculectomy; 100% achieved control with two trabeculectomies; 85.7% of eyes with secondary infantile glaucoma achieved control with a single trabeculectomy. There were no serious complications experienced in either group. CONCLUSION--Primary trabeculectomy is a safe and successful operation for infantile glaucoma.

Topographical analysis of ablation centration after excimer laser photorefractive keratectomy and laser in situ keratomileusis for high myopia

Purpose: To evaluate the ablation centration after photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) for high myopia and to assess the association between decentration and best corrected visual acuity (BCVA), glare, monocular diplopia, and halo phenomenon. Setting: Mater Private Hospital, Dublin, Ireland. Methods: Corneal topography was used to analyze centration in two groups of patients with myopia of more than 6.0 diopters: 18 had PRK and 18, LASIK. A standardized questionnaire assessed the preoperative and postoperative prevalence of glare, monocular diplopia, and halo phenomenon. Results: “Significant” ablation decentration (0.5 mm) in the LASIK group (1.33 mm) was almost twice that in the PRK group (0.75 mm). Glare increased from 27% preoperatively to 42% in the PRK group; monocular diplopia increased in the LASIK group. Halo phenomenon decreased after both procedures. Conclusion: Laser in situ keratomileusis represents a step forward in the surgical correction of high myopia, but the accuracy of the corneal ablation location must be improved. Suction ring fixation of the globe or real time tracking systems may help improve centration.