Pulsed mode versus near-continuous mode delivery of diode laser photocoagulation for high-risk retinopathy of prematurity.

OBJECTIVE: To compare structural and functional outcomes and efficiency of diode laser photocoagulation for retinopathy of prematurity (ROP) when delivered in a pulsed mode versus a near-continuous mode. METHODS: A retrospective study was conducted of 138 patients who underwent diode laser photocoagulation for threshold ROP using either pulsed or near-continuous delivery. Laser-related complications and structural and functional outcomes were analyzed. Prospectively, time efficiency and total energy used were evaluated in nine infants with bilateral symmetric high-risk prethreshold ROP in which one eye of each infant was randomized to pulsed and the fellow eye to near-continuous delivery. RESULTS: There was no significant difference between groups with regards to prevalence of posterior disease (Zone 1 or posterior Zone 2) (p = 0.11), postoperative vitreous haze (p = 0.60), postoperative complications (p = 0.38), retinal detachment (p = 0.90), strabismus (p = 0.73), amblyopia (p = 0.69), or refractive error (p = 0.95). Mean time for treatment was 23 minutes using pulsed delivery versus 14 minutes per eye with near-continuous delivery (p < 0.001). The mean total power used per eye with pulsed mode delivery was 1.5 x 10(5) W versus 1.1 x 10(5) W with near-continuous delivery (p = 0.015). CONCLUSIONS: No differences in complications, functional outcome, or structural outcome were found between using pulsed mode and near-continuous mode diode laser delivery for high-risk ROP. Near-continuous laser delivery, in our hands, was more time-efficient and used less total power.

Rhombencephalosynapsis presenting antenatally with ventriculomegaly/hydrocephalus in a likely case of Gomez-López-Hernández syndrome.

Rhombencephalosynapsis is a rare cerebellar malformation that can be associated with anomalies of the cerebral hemispheres and variable degrees of neurodevelopmental delay. A syndromic association, comprising rhombencephalosynapsis, developmental delay, scalp alopecia and trigeminal anaesthesia (Gomez-López-Hernández syndrome) has been described in seven individuals. We report the case of a 2-year-old boy with rhombencephalosynapsis, and review the evidence for a possible diagnosis of Gomez-López-Hernández syndrome. We also discuss other malformations reported in combination with rhombencephalosynapsis, and consider the possibility that a genetic aetiology for syndromic and nonsyndromic forms of rhombencephalosynapsis may be established with more detailed clinical and genetic studies.

Involution of retinopathy of prematurity after laser treatment: factors associated with development of retinal detachment.

PURPOSE: To identify specific features during the process of involution of retinopathy of prematurity after treatment at threshold that are associated with development of a retinal detachment. DESIGN: Retrospective case series. METHODS: The evolution of retinal detachments over time was analyzed retrospectively in 262 treated eyes of 138 infants. Specific features hypothesized to be associated with development of a retinal detachment were analyzed, including vitreous organization defined as clinically important, active stage 3 disease and active plus disease more than 21 days after treatment, and vitreous hemorrhage defined as clinically important. RESULTS: A retinal detachment developed in 36 (13.7%) of 262 eyes. Vitreous organization meeting our clinically important definition was associated with a 31-fold (confidence interval [CI] 5.37-183.63; P < .0001) and 13-fold (CI 2.97-58.59; P < .0001) increase in the odds for retinal detachment for right and left eyes, respectively. Vitreous hemorrhage defined as clinically important was associated with a 38-fold (CI 2.69-551.19; P = .007) and 15-fold (CI 1.65-144.12; P = .02) increase in the odds for retinal detachment for right and left eyes, respectively. The timing of retinal detachment relative to vitreous hemorrhage was not determined. Prolonged activity of Stage 3 disease or plus disease more than 21 days after treatment was not associated with development of a retinal detachment. CONCLUSIONS: Clinically important vitreous organization and vitreous hemorrhage were predictive for development of a retinal detachment. Evaluation of preemptive reintervention strategies for eyes at highest risk for developing a retinal detachment may be reasonable.

Corneal thickness in children.

OBJECTIVE: To determine normal central and paracentral corneal thickness measurements in the pediatric population and to determine if these measurements are consistent across different pediatric age groups and different racial groups. DESIGN: Prospective observational case series. METHODS: Pachymetry measurements were performed on 198 eyes of 108 children. The measurements were taken centrally as well as at four paracentral sites 3 mm from the corneal center at the 3, 6, 9, and 12 o'clock positions. The two-tailed t test was used for comparison of the continuous means for values of corneal thickness. Analysis of variance (ANOVA) was performed to determine differences among age and ethnic groups RESULTS: The mean central corneal thickness (CCT) was 549 +/- 46 microm. Paracentral corneal thickness mean values, as measured 3 mm from the corneal center, were as follows: superior, 575 +/- 52 microm; nasal, 568 +/- 50 microm; inferior, 568 +/- 51 microm; and temporal, 574 +/- 47 microm. The mean CCT values were significantly thinner than at each of the mean paracentral points (P < .05 for each comparison, paired t test). Paracentral corneal thickness measurements demonstrated no significant differences between locations (P > .05, variance analysis). The mean CCT +/- SD for each age group was as follows: 6 to 23 months, 538 +/- 40 microm; 2 to 4 years, 546 +/- 41 microm; 5 to 9 years, 566 +/- 48 microm; and 10 to 18 years, 554 +/- 35 microm (ANOVA P = .012). ANOVA performed on central pachymetry values demonstrated no significant differences among racial subgroups. CONCLUSIONS: Pediatric central and paracentral corneal thicknesses increase slowly over time and reach adult thicknesses at 5 to 9 years of age.

Involution of threshold retinopathy of prematurity after diode laser photocoagulation.

OBJECTIVE: To characterize the process of involution of threshold retinopathy of prematurity after transpupillary diode laser photocoagulation. DESIGN: Retrospective case series. PARTICIPANTS: Neonates with threshold retinopathy who underwent diode laser photocoagulation of the peripheral avascular retina. METHODS: A retrospective chart review was done of the weekly examination records of infants treated for threshold disease. Features that were studied included the presence of residual stage 3 neovascularization, plus disease, and development of retinal detachment (RD). MAIN OUTCOME MEASURES: Timing of full involution and/or development of an RD. RESULTS: Of 262 eyes of 138 infants treated, full involution without RD was seen in 8%, 43%, 64%, 73%, and 86% of eyes at postoperative weeks 1, 2, 3, 4, and 9+/-3, respectively. Retinal detachments were diagnosed cumulatively in 0%, 1.5%, 4.2%, 6.5%, and 14% of eyes at weeks 1, 2, 3, 4, and 9+/-3, respectively. CONCLUSIONS: Full involution of laser-treated threshold retinopathy of prematurity required more than 2 weeks in more than half of treated eyes. Most RDs were not detected until > or =3 weeks after treatment.

Accuracy of clinical estimation of abnormal head postures.

PURPOSE: Correct diagnosis and analysis of an abnormal head posture (AHP) is critical in the clinical assessment of patients with strabismus and nystagmus. This study was performed to evaluate the accuracy and precision of clinicians estimating the degree of face turns and head tilts. DESIGN: Experimental simulation study. PARTICIPANTS: Two normal volunteers and 4 pediatric and 1 general ophthalmologists. METHODS: Using a cervical range of motion (CROM) device, single axis head position (chin up, chin down, right and left face turn, and head tilts) were modeled, and clinical estimates of the amount of deviation were estimated by the four ophthalmologists. Each of the 4 examiners estimated 108 single axis AHPs in a randomized and masked pattern. MAIN OUTCOME MEASURES: Accuracy of clinical estimation of AHP, intra- and inter- observer variability, and variability in terms of head position. RESULTS: The examiners tended to overestimate the AHPs by an average of 5 degrees (P less than 0.001). Two "right" positions (right head tilt and face turn) were the worst. The average error was 10 +/-8 degrees for the right tilt and turn positions, while the error for all other positions, excluding these two, averaged 0 +/-10 degrees (P = 0.0001). CONCLUSIONS: Clinical estimation of an AHP by ophthalmologists is in part remarkably accurate, even if imprecise, but some positions, notably right head tilt and right face turn in this study, were significantly overestimated. Objective methods of measuring AHPs such as the CROM may be preferable for these RHT and RFT AHPs and when maximum precision is needed for tracking changing AHPs or deviations.

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.

Nasolacrimal outflow drainage anomalies in Down's syndrome.

PURPOSE: To describe structural abnormalities of the lacrimal drainage system and outcomes after treatment for lacrimal outflow obstruction in children with Down's syndrome. DESIGN: Retrospective comparative interventional case series. PARTICIPANTS: Thirty-eight eyes of 22 consecutive Down's syndrome patients who underwent surgical treatment for nasolacrimal drainage obstruction (mean age, 32 months) and 59 eyes of 44 non-Down's syndrome patients who underwent surgical treatment after 2 years of age. MAIN OUTCOME MEASURES: Resolution of symptoms after surgery and presence of anatomic abnormalities of the lacrimal drainage system other than persistent Hasner's membrane. RESULTS: Among the Down's syndrome eyes, complete or partial resolution was noted in 34 (89%) of 38 eyes; 7 (18%) eyes underwent more than 1 procedure. Twenty-eight (74%) of 38 eyes had anatomic anomalies other than persistent Hasner's membrane; anomalies proximal to the nasolacrimal sac predominated. In comparison, 50 (85%) non-Down's syndrome eyes experienced complete or partial resolution, and 19 (32%) had anatomic abnormalities other than persistent Hasner's membrane; anomalies distal to the nasolacrimal sac predominated. CONCLUSIONS: Compared with older non-Down's syndrome patients, nasolacrimal outflow obstruction in Down's syndrome patients is more often complicated by anomalies of the lacrimal drainage system proximal to the lacrimal sac. Despite this, surgery can be similarly successful. Awareness of the possible peculiarities of lacrimal outflow obstruction in Down's syndrome patients may allow better selection and use of available treatment options.

SubTenon's infusion of steroids for treatment of orbital hemangiomas.

PURPOSE: To introduce an alternate technique for the treatment of infantile orbital hemangiomas. DESIGN: Non-comparative case series. PARTICIPANTS: Seven consecutive children with orbital hemangiomas. INTERVENTION: Posterior subTenon's steroid infusion using a blunt-tip cannula. MAIN OUTCOME MEASURES: Clinical stabilization, improvement, or resolution. RESULTS: Significant and sustained involution of the hemangiomas occurred in all cases. No local or systemic complications occurred. CONCLUSIONS: The results of subTenon's steroid infusion for the treatment of orbital hemangiomas in children are encouraging and may be associated with fewer intraoperative risks compared with direct intralesional injection.

Quantification of incidental needle and suture contamination during strabismus surgery.

PURPOSE: To quantify the level of bacterial contamination of needles and sutures immediately after use in strabismus surgery. METHODS: Strabismus surgery was performed on 56 eyes from 31 pediatric strabismus surgical cases. Preoperative site preparation included instillation of 5% povidone-iodine in the conjunctival fornices in all cases. A total of 124 needles and 127 sutures were cultured immediately after final scleral passage. RESULTS: Seventeen of the 31 cases (54.8%) produced at least one positive specimen. Nineteen per cent of the needles and 25.2% of the sutures were culture positive. The bulk of positive specimens (96.7% of needles, 91.3% of sutures) produced 3 or less colony forming units, corresponding to 7 or less total viable organisms per needle or sutures in accordance with the dilution scheme. Coagulase-negative staphylococci overwhelmingly predominated. CONCLUSIONS: Needles and sutures used in strabismus surgery can become contaminated during surgery despite preoperative povidone-iodine preparation. The number of viable bacterial contaminants is usually below the level known to consistently produce experimental endophthalmitis. However, a few needles and sutures carried a high contaminant load, suggesting the possibility that contaminated needles and sutures could potentially cause postoperative intraocular infection.

Epithelial healing and ocular discomfort after photorefractive keratectomy in children.

OBJECTIVE: To document the rate of healing of the corneal epithelial defect created by photorefractive keratectomy (PRK) and the degree of discomfort experienced by children treated with PRK. SETTING: Baylor College of Medicine, Texas Children's Hospital, Houston, Texas, USA. METHODS: Ten patients between 3 and 10 years of age were treated with PRK for severe anisometropia. All had anisometropic amblyopia refractory to conventional therapy with glasses or contact lenses and occlusion therapy. The size of the corneal epithelial defect was documented daily until the defect healed completely. Postoperative discomfort was documented daily using a pain-assessment scale until the epithelial defect healed completely. RESULTS: Two children were treated with PRK for hyperopic anisometropia; the rest were treated for myopic anisometropia. Cumulatively, the corneal epithelium had healed completely by day 3 in 6 patients (60%), by day 4 in 9 patients (90%), and by day 5 in all patients. The mean healing time was 3.5 days. Patients experienced mild discomfort on the day of surgery and on the first postoperative day. They had minimal pain on day 2. After day 2, no patient reported pain or other discomfort. CONCLUSIONS: The corneal epithelial defect created by PRK healed promptly and was associated with minimal postoperative discomfort in children treated with the protocol described.

Up-slanting palpebral fissures and oblique astigmatism associated with A-pattern strabismus and overdepression in adduction in spina bifida.

PURPOSE: To describe the spectrum of adnexal and ophthalmologic features in spina bifida. METHODS: A retrospective review of the medical records of 73 patients was conducted. Data concerning ocular motility, palpebral fissure orientation, presence and axis of astigmatism, visual acuity, amblyopia, and stereopsis were analyzed. RESULTS: Forty-three (59%) of the 73 patients had strabismus: 28 (65%) had esotropia, 12 (28%) had exotropia, and 3 (7%) had orthotropia in primary gaze and a significant A-pattern. Of the strabismic patients, 20 (47%) had an A-pattern, of which 13 (65%) demonstrated overdepression in adduction. Twenty-seven (84%) of the 32 patients with documented palpebral fissure orientation had exaggerated up-slanting palpebral fissures. Forty-nine (77%) of 64 patients exhibited astigmatism greater than 0.75 D in at least 1 eye, with a mean power of 1.6 D. The axis of cylinder was oblique in 76% of these patients. The astigmatic axis was consistently oriented perpendicular to the eyelid fissure orientation in the group of patients with up-slanting palpebral fissures, with the mean axis of cylinder being incyclorotated (OD axis, 77; OS axis, 108). Up-slanting palpebral fissures were associated with a 15-fold increased chance that the axis of cylinder would be incyclorotated (P =.07, chi-square test). An orbital computed tomographic (CT) scan of a spina bifida patient with A-pattern esotropia, overdepression in adduction, and up-slanting palpebral fissures demonstrated significant incyclorotated extraocular muscle pulley heterotopy. CONCLUSIONS: Exaggerated up-slanting palpebral fissures are a prominent feature in spina bifida. Up-slanting palpebral fissures in spina bifida patients are associated with incyclorotated oblique astigmatism, A-pattern strabismus, and overdepression in adduction. These associations might be related to an anomaly of orbital skeletal or extraocular muscle pulley development. Further prospective study is encouraged.

Acquired cataracts after diode laser photocoagulation for threshold retinopathy of prematurity.

PURPOSE: To report the incidence of acquired cataract after diode laser photocoagulation for threshold retinopathy of prematurity at our institution. DESIGN: Retrospective, noncomparative, interventional case series. PARTICIPANTS: One hundred fifty-three infants (293 eyes) with threshold retinopathy of prematurity. INTERVENTION: Transpupillary diode laser photocoagulation. MAIN OUTCOME MEASURE: Acquired cataract formation. RESULTS: One cataract (0.003%) in 293 eyes occurred after transpupillary diode laser photocoagulation. This cataract consisted of peripheral cortical punctate lenticular opacities that were not progressive or visually significant. CONCLUSIONS: The risk of acquired cataract after transpupillary diode laser photocoagulation for threshold retinopathy of prematurity is low. Transpupillary diode laser photocoagulation may be safer than argon laser photocoagulation for treatment of threshold retinopathy of prematurity.

Major review: the clinical spectrum of pediatric myasthenia gravis: blepharoptosis, ophthalmoplegia and strabismus. A report of 14 cases.

BACKGROUND: Myasthenia gravis is infrequently encountered in pediatric ophthalmology practice. The purpose of this study is to evaluate the clinical spectrum of this condition in children and to identify factors that may aid the clinician in its diagnosis and management. SUBJECTS AND METHODS: A retrospective chart review was performed on all pediatric patients presenting with myasthenia gravis to the Departments of Pediatric Ophthalmology and Neuro- ophthalmology at the Texas Children's Hospital from 1989-1999. Information regarding mode of presentation, myasthenic classification, ocular and systemic involvement, diagnostic investigations, therapy and outcome was collected and evaluated. RESULTS: Fourteen patients were included in the study whose ages ranged from 1-17 years at presentation. One patient had congenital myasthenia gravis and 13 had juvenile myasthenia gravis. Thirteen of 14 (93%) patients presented with ocular findings; two of whom had associated systemic disease at presentation. Six of 14 (43%) patients had systemic involvement during the course of their illness, of whom three (21%) had respiratory compromise requiring assisted ventilation. Thirteen of 14 (93%) patients received pyridostigmine as first line treatment. Ten of 14 (71%) patients had a favorable response. A favorable response was defined as improvement in the extraocular motility to within 10 prism diopters of orthotropia with resolution of the blepharoptosis. Three of 14 patients (21%) received a combination of pyridostigmine and steroids, all of whom had a favorable response. Seven of 14 patients (50%) underwent thymectomy; all had a favorable response. Two of 14 patients (14%) required both blepharoptosis and strabismus surgery. CONCLUSION: Pediatric myasthenia gravis may present initially to the ophthalmologist and should be considered in any pediatric patients with blepharoptosis and an ocular motility disturbance. Prompt diagnosis may be associated with significant reduction in morbidity. A favorable response to medical and surgery therapy was noted in most of our patients.

Use of augmented rectus muscle transposition surgery for complex strabismus.

PURPOSE: Full tendon rectus muscle transposition surgery augmented with posterior fixation sutures has been shown to be effective in the treatment of abducens palsy and Duane's syndrome. The purpose of this study is to summarize our experience with the use of this procedure and a three fourths partial tendon transposition modification of this procedure for a variety of complex vertical and horizontal paralytic eye movement disorders. DESIGN: Retrospective noncomparative interventional consecutive case series. PARTICIPANTS: Eighteen patients with paralytic strabismus. INTERVENTION: Full tendon rectus muscle transposition procedure augmented with posterior fixation sutures (13 patients) or a three fourths partial tendon transposition augmented with posterior fixation sutures (5 patients). MAIN OUTCOME MEASURES: Resolution of diplopia in the primary position and improved ocular alignment. RESULTS: Comparing preoperative to postoperative status, presence of primary position diplopia decreased from 64% to 14%, anomalous head posture decreased from 56% to 6%, and primary position alignment improved in all patients. CONCLUSIONS: Full tendon rectus muscle transposition surgery augmented with posterior fixation sutures and the vessel-sparing three fourths partial tendon transposition modification of this technique are effective for the treatment of a variety of complex vertical and horizontal paralytic ocular motility disorders.

Surgical management of the lens and retrolenticular fibrotic membranes associated with persistent fetal vasculature.

PURPOSE: To evaluate a surgical technique that allows safe, effective, near-total removal of retrolenticular fibrotic membranes in eyes with persistent fetal vasculature syndrome (PFVS). SETTING: Pediatric ophthalmologist's academic practice. METHODS: This retrospective review comprised 5 children (6 eyes) who had excision of a retrolenticular fibrovascular membrane during cataract surgery over a 6-month period. Long, spoke-like radial incisions of the membrane were made to the ciliary processes, resulting in wedge-shaped segmentation of the membrane. A vitrector was used to excise each wedge and perform an anterior vitrectomy. RESULTS: The mean age at time of surgery was 8 months (range 1 to 24 months) and the mean follow-up, 9 months (range 2 to 13 months). The membrane was successfully removed in all eyes. One eye of a patient who did not comply with the postoperative medical regimen or follow-up developed pupillary block glaucoma requiring pupilloplasty and trabeculectomy. CONCLUSION: This anterior surgical technique to remove tenacious retrolenticular membranes associated with PFVS was effective, allowing near-total removal of the offending fibrovascular membrane.

Spontaneous intracranial hypotension with unique strabismus due to third and fourth cranial neuropathies.

PURPOSE: To report an atypical case of Spontaneous Intracranial Hypotension (SIH) with bilateral trochlear nerve palsies and an oculomotor nerve palsy. DESIGN & METHOD: Case report and literature review. RESULTS (CASE REPORT): A 42 year old man was treated for SIH. His neurological symptoms resolved following neurosurgical treatment with the exception of diplopia due to bilateral trochlear nerve palsies and a pupil-sparing oculomotor nerve palsy. The cranial nerve palsies are believed to be secondary to brainstem ischemia and compression occurring during the acute phase of events. They did not spontaneously improve, but were treated successfully with eye muscle surgery. CONCLUSION: SIH is a rare disease that has been associated with a variety of symptoms and signs including cranial neuropathies. A diagnosis of SIH should be considered in a patient presenting with headache, diplopia secondary to cranial neuropathy and typical radiologic features. This is the first reported case in which bilateral trochlear nerve paresis has been reported in association with this condition.