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Biomedical subjects

S R Lambert

Publications and source records attributed to S R Lambert.

At least 19 recordsLinked to original sources
PubMed2003

Weaning children with accommodative esotropia out of spectacles: a pilot study.

BACKGROUND/AIM: Many children with accommodative esotropia must continue spectacle use throughout life. This study was undertaken to determine which factors are predictive of successfully weaning children with accommodative esotropia out of spectacles. METHODS: A retrospective review of 10 children with accommodative esotropia, who were gradually weaned from their hyperopic correction, and three age matched controls was performed. The main outcome measure was resolution or non-resolution of esotropia following weaning and eventual discontinuation of spectacles. Secondary outcome measures were final refractive error and the final esotropic or esophoric angle without correction. RESULTS: Six patients were successfully weaned from spectacles. At the completion of the weaning period one child was orthophoric and the other five children had well controlled esophorias. The other four patients remained spectacle dependent because of persistent esotropia or decreased vision without spectacles. The baseline and final refractive errors were significantly lower in the children successfully weaned from spectacles (p = 0.014). While the children who were successfully weaned from spectacles were older when initially diagnosed with accommodative esotropia (4.6 v 2.5 years), this difference was not statistically significant (p = 0.09). CONCLUSION: Some children with accommodative esotropia may be weaned out of spectacles during the grade school years with resolution of their esotropia. It is likely that gradual reduction of the hyperopic correction increases divergence amplitudes, but it is unclear whether this facilitates emmetropisation.

Accommodation, Ocular↗
PubMed2001

Accommodative esotropia.

Accommodative esotropia is the most common type of strabismus with a very favorable prognosis if the appropriate treatment is initiated promptly. Spectacles remain the preferred treatment, but both contact lenses and refractive surgery may be helpful in some situations to correct the associated hyperopia. Strabismus surgery should only be used if optical correction or refractive surgery are ineffective in restoring normal ocular alignment.

Accommodation, Ocular↗
PubMed2001

Slipped and lost extraocular muscles.

A slipped or lost muscle should be considered in the differential diagnosis of a patient presenting with a marked limitation of duction and inability to rotate the eye beyond the midline. Loss of a rectus muscle can occur after strabismus surgery, trauma, paranasal sinus surgery, orbital surgery, or retinal detachment surgery. The extraocular rectus muscle most frequently slipped or lost is the medial rectus muscle. Forced ductions, active force generation, saccadic velocity studies, differential intraocular pressure measurements, and orbital imaging studies may aid in identifying a slipped or lost muscle. However, no single diagnostic test provides absolute reliability for determining a lost muscle. Slipped muscles develop when the muscular capsule is imbricated without including the muscle or muscle tendon during strabismus surgery. When the capsule is reattached to the sclera, the tendon and muscle are then free to slip posteriorally from the site of attachment. Slipped muscles are retrieved by following the thin avascular muscle capsule posteriorally until the muscle is identified. A lost muscle can be found using a traditional conjunctival approach, by an external orbitotomy, or by an endoscopic transnasal approach. Although many diagnostic maneuvers are useful in identifying a lost rectus muscle, the oculocardiac reflex is the most important. Once the lost muscle is identified, the muscle should be imbricated with a nonabsorbable synthetic suture and securely reattached to the globe.

Diagnosis, Differential↗
PubMed2001

Peters' anomaly. A synopsis of surgical management and visual outcome.

Peters' anomaly is not an isolated anterior segment abnormality, but occurs as a diverse, phenotypically heterogeneous condition associated with multiple underlying ocular and systemic defects. Surgical treatment of Peters' anomaly is a complex and challenging undertaking. The broad spectrum of disease severity, the lack of uniformity in clinical features, the differences and overlap of preoperative risk factors, and the variability in the numbers and types of intraocular procedures that are performed on individual eyes, as well as postoperative complications all contribute to the difficulties involved in surgical management. This article discloses useful information pertaining to keratoplasty for Peters' anomaly. The study by Yang et al showed that long-term graft clarity could be achieved in 36% of eyes. However, 93% of all clear grafts were first grafts, whereas only 7% were second grafts. All third or subsequent grafts failed. Other important findings were: (1) the significantly greater chance of maintaining a clear graft with initial grafts, compared with subsequent grafts; (2) the disclosure of periods of differential risk for graft failure; and (3) the identification of risk factors for graft failure. Surgical intervention involving one or more procedures is effective in controlling IOP in 32% of eyes with associated congenital glaucoma. Still, multiple procedures and adjunctive medical therapy are often required to achieve and maintain adequate IOP control. The visual outcome is guarded in children with Peters' anomaly. Achieving a satisfactory visual outcome and preventing further visual loss is impeded by the presence of congenital anterior and posterior segment anomalies, structural defects of the CNS, cognitive dysfunction and amblyopia, as well as postoperative complications such as graft failure, cataract, inoperable retinal detachment, and phthisis.

Anterior Eye Segment↗
PubMed2001

Pediatric cataracts.

The management of infantile cataracts continues to be a challenging task, however with new surgical techniques, IOL implantation, and new patching regimens, the visual outcomes are improving.

Cataract↗
PubMed2001

A comparison of grating visual acuity, strabismus, and reoperation outcomes among children with aphakia and pseudophakia after unilateral cataract surgery during the first six months of life.

PURPOSE: The method of correcting aphakia after unilateral cataract extraction during infancy is controversial. Some authorities advocate correction with an intraocular lens (IOL) whereas others advocate correction with a contact lens (CL). We compared grating visual acuity, alignment, and reoperative outcomes in age-matched children treated with these 2 modalities at 5 clinical centers. METHODS: Twenty-five infants born in 1997 or 1998 with a dense unilateral congenital cataract who had cataract surgery coupled with (IOL group, n = 12) or without (CL group, n = 13) primary IOL implantation were enrolled in this study. All patients were prescribed half-time occlusion therapy. In July 1999, their grating visual acuities, ocular alignments, and reoperation rates were assessed. RESULTS: The mean grating visual acuity (LogMAR) for the affected eye was 0.70 +/- 0.32 for the IOL group and 0.87 +/- 0.31 for the CL group (P =.19). The mean interocular difference in grating visual acuity was 0.26 +/- 0.30 for the IOL group and 0.50 +/- 0.28 for the CL group (P =.048). The incidence of strabismus (>10 PD) was 75% in the IOL group compared with 92% in the CL group (P =.24). The incidence of reoperations was 83% in the IOL group compared with 23% in the CL group (P =.003). CONCLUSIONS: Our preliminary data suggest that correcting aphakia after unilateral congenital cataract surgery with primary IOL implantation results in an improved visual outcome but a higher rate of complications requiring reoperation. A randomized clinical trial, the Infant Aphakia Treatment Study, is planned to further study the optimal treatment for aphakia following unilateral cataract extraction during infancy.

Aphakia, Postcataract↗
PubMed2000

Isolated comitant esotropia and Chiari I malformation.

PURPOSE: To report four patients with isolated comitant esotropia and Chiari I malformation and discuss the most appropriate management. METHODS: Case reports and literature review. RESULTS: All four patients (5, 14, 16, and 37 years of age) presented with an isolated comitant esotropia that led to the diagnosis of Chiari I malformation. The first two patients underwent uncomplicated neurosurgical decompression of their malformation, followed by complete resolution of their esotropia. The third patient underwent strabismus surgery and experienced initial resolution of the esotropia, but eventual recurrence resulted in the strabismus surgery being repeated 5 years later. The fourth patient had strabismus surgery with resolution of the esotropia but only 2 months of follow-up. CONCLUSION: Although management of patients with Chiari I malformation and severe neurologic findings typically includes surgical decompression, management is less straightforward in cases with subtle findings or in which ocular findings are isolated. The decision to perform neurosurgical decompression or strabismus surgery should still be made on a case-by-case basis, with the understanding that strabismus surgery may provide only temporary ocular alignment.

Adolescent↗
PubMed2000

Tonic pupil associated with congenital neuroblastoma, Hirschsprung disease, and central hypoventilation syndrome.

PURPOSE: To report the association of tonic pupil, congenital neuroblastoma, Hirschsprung disease, and central hypoventilation syndrome. METHODS: Case reports. RESULTS: Two infants with central hypoventilation syndrome and Hirschsprung disease were evaluated for dilated, nonreactive pupils present since birth. In both cases, pharmacologic testing with dilute pilocarpine confirmed denervation supersensitivity consistent with tonic pupil. The diagnosis of congenital neuroblastoma was subsequently established in both infants. CONCLUSIONS: The close association of these conditions in these two young children supports the concept of a common neural crest abnormality being present. A careful systemic evaluation to rule out congenital neuroblastoma should be performed in any young child who presents with tonic pupil in the setting of central hypoventilation syndrome and Hirschsprung disease.

Adrenal Gland Neoplasms↗
PubMed2000

Retrieval of lost medial rectus muscles with a combined ophthalmologic and otolaryngologic surgical approach.

PURPOSE: To report retrieval of a medial rectus muscle completely detached from the globe and lost in the orbital tissue in four eyes. METHOD: A lost medial rectus muscle was retrieved in four eyes of four patients with either a transcutaneous medial orbitotomy approach or a transnasal endoscopic ethmoid sinus approach. RESULTS: The lost medial rectus muscle was successfully retrieved in all four patients. One patient lost the medial rectus muscle secondary to trauma, and the other three cases resulted from complications of strabismus surgery. The mean preoperative angle of exotropia was 44 prism diopters. The endoscopic approach was attempted in three patients, and the medial rectus muscle was successfully found in two of these patients. In one case in which the endoscopic approach was used, an image guidance system was used to aid in finding the lost medial rectus muscle. The endoscopic approach was abandoned in one case in which the medial rectus muscle could not be identified after extensive searching, but the muscle was subsequently found by means of the transcutaneous medial orbitotomy approach. A transcutaneous medial orbitotomy alone was used to find the lost medial rectus muscle in one of the cases. The postoperative ocular deviation for primary position at distance fixation was a mean of 24 prism diopters of exotropia. With one additional operation in two patients, the mean ocular deviation was less than 12 prism diopters. CONCLUSION: We successfully retrieved a lost medial rectus muscle in four patients with the use of nontraditional strabismus surgical techniques. We effectively combined techniques taken from both ophthalmology and otorhinolaryngology to help solve this difficult problem.

Adult↗
PubMed2000

Cataract and phthisis bulbi after laser photoablation for threshold retinopathy of prematurity.

PURPOSE: To describe the visual and structural outcome of eyes that developed a dense cataract after laser photoablation for threshold retinopathy of prematurity. METHODS: A retrospective review of eight consecutive infants who developed dense cataract(s) after bilateral laser photoablation for threshold retinopathy of prematurity. Of the 10 eyes with cataract, five eyes were treated with a diode laser and five with an argon laser. The stage and zone of the retinopathy of prematurity, number of burns applied, time of onset of the cataract, clinical findings at the time of cataract surgery, and the course after cataract surgery were reviewed. RESULTS: Six eyes had zone 1 disease and four had zone 2 disease. The mean number of burns applied per eye was 2532 +/- 856 (range, 1400 to 4500). A cataract was diagnosed a median of 3 [corrected] weeks (range, 1 to 28 weeks) after laser photoablation. Nine of the 10 cataracts were sufficiently dense to preclude a view of the fundus. All 10 eyes had clinical signs suggestive of an inflammatory or ischemic process that included one or more of the following findings: corneal edema, pupillary membrane, iris atrophy, depigmentation of ciliary processes, pigment on the anterior lens surface, posterior synechiae, hyphema, and shallow anterior chamber. Nine eyes underwent cataract surgery. Five of the 10 eyes had retinal detachment ranging in severity from stage 4A to stage 5 at the time of cataract surgery. Nine of the 10 eyes progressed to phthisis bulbi and no light perception. CONCLUSIONS: A dense cataract developing in the eye of an infant after laser photoablation for threshold retinopathy of prematurity is associated with a poor visual prognosis. The constellation of associated clinical findings appears to be most consistent with anterior segment ischemia.

Birth Weight↗
PubMed2000

A comparison of the rate of refractive growth in pediatric aphakic and pseudophakic eyes.

OBJECTIVE: To compare the rate of refractive growth in pseudophakic children's eyes to that of aphakic eyes. DESIGN: Multicenter, retrospective observational case series. PARTICIPANTS: 83 patients with pseudophakic eyes (100 eyes) and 74 patients with aphakic eyes (106 eyes), with an age of surgery between 3 months and 10 years and a minimum follow-up time of 3 years or more, depending on the age at surgery. METHODS: A logarithmic model was used to analyze the rate of refractive growth for each eye. MAIN OUTCOME MEASURES: Age at surgery, intraocular lens power, intraocular lens A-constant, initial postoperative refraction, final refraction, and final age. RESULTS: Overall, pseudophakic eyes showed a lesser rate of refractive growth than aphakic eyes (-4.6 diopter vs. -5.7 diopter, P = 0.03). This trend was also present but less significant when the eyes were grouped into those less than 6 months of age at surgery (-3.3 diopter vs. -4.6 diopter, P = 0.09) and older patients (-5.0 diopter vs. -6.1 diopter, P = 0.07). However, the mean quantity of myopic shift was greater in pseudophakic eyes than in aphakic eyes (-5.26 diopter vs. -4.54 diopter), despite shorter follow-up times in the pseudophakic eyes. This is due to the optical effects of a constant intraocular lens power in a growing eye. CONCLUSIONS: Pediatric pseudophakic eyes have a slightly lesser rate of refractive growth than aphakic eyes. The new rate values should be used for predicting future refractions in these eyes.

Aphakia, Postcataract↗
PubMed2000

Heterochromia after pediatric cataract surgery.

PURPOSE: Changes in iris color have been noted anecdotally after cataract surgery in infants, but they have not been studied systematically. The mechanism for these iris color changes has not previously been reported in the biomedical literature. METHODS: Photographs were taken of both eyes of 15 children and 11 rhesus monkeys who had undergone unilateral cataract surgery. Masked examiners reviewed the photographs and compared the iris color of the eyes that were operated on with the eyes that were not operated on. Between 4 and 6 weeks postoperatively, the level of prostaglandin F(2alpha) in the aqueous humor (n = 4) and vitreous humor (n = 2) was measured in both the operated and nonoperated eyes of 4 monkeys that had undergone a neonatal lensectomy during the first 5 days of life. RESULTS: Thirteen of 15 children had a darker iris color in the operated eye in relation to the nonoperated (control) eye. Four of 11 monkeys had a uniformly darker iris in the operated eye; the other 7 monkeys had regional darkening or patches of darker iris in the eye that was operated on. The prostaglandin F(2alpha) levels in neonatal monkeys were higher in the aqueous humor and in the vitreous humor of the operated eye in relation to the nonoperated eye. CONCLUSION: In some children, cataract surgery is associated with a darkening of the iris color in the operated eye. We speculate that this darkening results from an exuberant prostaglandin release stimulated by the cataract surgery and may occur through the same or a similar mechanism by which latanoprost causes the darkening of iris color.

Animals↗
PubMed2000

Visual outcome after contact lens and intraocular lens correction of neonatal monocular aphakia in monkeys.

PURPOSE: A monkey model was used to evaluate intraocular lenses (IOLs) and extended-wear contact lenses (EWCLs) for the optical treatment of infantile aphakia in humans. Specifically, the relative effectiveness of EWCLs used alone and IOLs used in combination with EWCLs in preventing amblyopia was assessed. METHODS: A total of 33 rhesus monkeys was studied in this project, 24 assigned to experimental treatment groups and 9 to normal controls. Contact lenses made from a diffusing material or dyed opaque were placed on one eye at birth to simulate an infantile cataract. A unilateral lensectomy was then performed on the same eye within 2.5 weeks after birth. In 15 monkeys this was combined with implantation of an IOL. The eyes were left aphakic in the remaining 9 animals. EWCLs were used to adjust the optical correction of both aphakic and pseudophakic eyes to a near point (3-5 D). Opaque lenses were used to maintain daily part-time (approximately 70%) occlusion of the fellow eye. The primary outcome measure was grating acuity assessed with behavioral methods. Some animals were also assessed for acuity with sweep visually evoked potentials (VEPs) and for optotype acuity (Landolt C) with behavioral methods. RESULTS: Two of the animals with IOLs developed complications in the eye that precluded completion of the behavioral assessment protocol. Only behavioral outcomes obtained before or in the absence of surgical complications are presented. There was a developmental delay in the maturation of grating acuity in both eyes of both treatment groups. Normal adult levels of grating acuity were eventually achieved in the group treated with IOLs combined with EWCLs. Grating acuity was significantly poorer than normal in aphakic eyes treated only with EWCLs. Comparison of the two treatment groups revealed that pseudophakic eyes treated with multifocal IOLs had significantly better gating acuity than aphakic eyes. Assessments of optotype acuity and sweep VEP acuity revealed amblyopic deficits in both pseudophakic and aphakic eyes. CONCLUSIONS: Given an absence of serious postoperative complications, neonatal correction of aphakia with IOLs combined with EWCLs can lead to normal grating acuity in a primate model. Correction with EWCLs alone was not sufficient to produce normal grating acuity. Multifocal IOL treatments combined with EWCL provided a significantly better outcome than EWCL methods alone. However, neither IOL nor EWCL methods were able to prevent amblyopia as evaluated using behavioral testing with optotypes or with sweep VEPs.

Animals↗
PubMed1999

Long-term results of corneal graft survival in infants and children with peters anomaly.

OBJECTIVE: To determine the long-term results of corneal graft survival after penetrating keratoplasty for Peters anomaly and to identify risk factors for graft failure. DESIGN: Noncontrolled interventional case series: a single-center retrospective review of a consecutive surgical series. PARTICIPANTS: The records of all children 12 years of age or younger who underwent penetrating keratoplasty for Peters anomaly between January 1971 and December 1992 were reviewed. All study eyes had completed a minimum of 3 years of follow-up from the date of first keratoplasty and had undergone most of their corneal surgery at Emory University. INTERVENTION: Characteristics of the recipient, the eye, the donor, and the surgical procedure were analyzed for their influence on survival of the first graft. Survival probabilities were estimated using the Kaplan-Meier method. Multivariate regression analysis was performed to estimate relative risks and adjusted survival probabilities. MAIN OUTCOME MEASURE: Graft clarity. RESULTS: One hundred forty-four penetrating keratoplasties were performed in 72 eyes of 47 patients. The median age at first keratoplasty was 4.4 months. The median follow-up was 11.1 years. Fifty-four percent of eyes received one graft, 18% received two grafts, and 28% received three or more grafts. The overall probability of maintaining a clear first graft was 56% at 6 months, 49% at 12 months, 44% at 3 years, and 35% at 10 years. The probability of second or subsequent grafts surviving for 3 years was less than 10%. Thirty-nine percent of eyes had a clear graft at the time of review; 36% of eyes had a clear first graft. Multivariate analysis identified disease severity, donor cornea size, coexisting central nervous system abnormalities, and quadrants of anterior synechiae as the strongest risk factors for graft failure. Supplemental multivariate analysis, restricted to observable preoperative variables, identified stromal vessels, total limbal opacification, and preoperative glaucoma as independent preoperative predictors of graft failure. Allograft rejection was the most frequently identified cause of graft failure. Major complications after keratoplasty were phthisis, retinal detachment, cataract, and glaucoma. CONCLUSIONS: The overall long-term probability of maintaining a clear graft after initial penetrating keratoplasty for Peters anomaly is 35% +/- 0.06%, with subsequent grafts rarely surviving. Eyes with severe disease, larger donor corneas, coexisting central nervous system abnormalities, and anterior synechiae have significantly poorer outcomes than eyes without these factors. These data should be carefully considered before recommending corneal transplantation for Peters anomaly, particularly after previous graft failure.

Anterior Eye Segment↗
PubMed1999

Effect of age at time of cataract surgery on subsequent axial length growth in infant eyes.

PURPOSE: To determine whether removal of the crystalline lens and placement of an intraocular lens (IOL) in human infant eyes retard the growth of the pseudophakic eye. METHODS: A unilateral lensectomy with placement of a posterior chamber IOL in the sulcus was performed in 11 infants between 2 and 4 months of age. Axial length measurements of both eyes were obtained preoperatively and postoperatively. RESULTS: Patients were followed for a mean of 5.6 years. In 7 patients, the mean axial growth was 0.46 mm less in the pseudophakic eye than in the fellow eye (range 0.15 to 0.70 mm). In 1 patient, there was no interocular axial length difference and in 3, the pseudophakic eye was longer. When measurements from the only patient with microphthalmia were excluded, the interocular difference in axial growth was highly significant (signed rank test, P = .006). Median visual acuity of the pseudophakic eyes at the last follow-up was 20/60 (range 20/30 to 20/200). The final visual acuity in the pseudophakic eyes did not correlate with the degree of interocular axial length difference (P > .05). CONCLUSIONS: Our study suggests there may be a reduction in axial growth in infantile eyes following cataract extraction and IOL implantation. This effect probably reduces the magnitude of the myopic shift in these eyes.

Aging↗
PubMed1999

Successful treatment of tractional corectopia using 2 mJ of energy with an Nd:YAG laser.

Although the Nd:YAG laser is most commonly used to perform posterior capsulotomies after cataract surgery, it has also been used to treat a variety of other anterior segment abnormalities including tractional corectopia, iridocorneal adhesions, persistent pupillary membranes, and posterior synechiae. Numerous reports on the use of the Nd:YAG laser to treat structures in the anterior segment have emphasized the need to use higher pulse energy for pupillary membranes, compared with the lower settings required for posterior capsulotomy. Steinert and Puliafito noted that single pulses of 4 to 12 mJ may be required to treat pupillary membranes "in a manner similar to that of a stonemason chipping at marble" in their description treating a membrane considerably thicker than what we describe. We report the successful treatment of tractional corectopia due to an anterior membrane strand in a child with only 2 mJ of total energy.

Eye Abnormalities↗
PubMed1999

Anterior hyaloid face opacification after pediatric Nd:YAG laser capsulotomy.

PURPOSE: The purpose of this study was to examine the clarity of the visual axis after Nd:YAG laser capsulotomy following cataract extraction and primary intraocular lens implantation in a pediatric population. METHODS: A retrospective review was performed of all cases of cataract extraction and primary intraocular lens implantation over a period of 5 years. A group of children who had been treated by primary surgical posterior capsulotomy and anterior vitrectomy (Group 1) was used as the "gold standard," with whom the children treated with Nd:YAG laser capsulotomy (Group 2) were compared. The groups were studied for the incidence of opacification of the visual axis after the primary procedure. RESULTS: Data on 78 eyes were reviewed, and 56 eyes met inclusion criteria. Of these, 33 eyes were treated with primary posterior capsulotomy and anterior vitrectomy (Group 1) and 23 eyes were treated with Nd:YAG laser capsulotomy (Group 2). One eye (3%) of Group 1 experienced postoperative visual axis reopacification. Thirteen (57%) of 23 eyes in Group 2 experienced reopacification, requiring retreatment. Four eyes (17%) treated with Nd:YAG laser required a third treatment. CONCLUSIONS: In our series, 57% of patients treated with Nd:YAG laser capsulotomy experienced reopacification across the anterior hyaloid face. With the removal of the anterior vitreous at the time of cataract extraction, the scaffolding for cell migration is removed and reopacification of the visual axis is rarely seen. For patients in whom slit-lamp capsulotomy is not possible, especially if there is no Nd:YAG laser available for use in the operating room or when loss to follow-up may be an issue, primary posterior capsulotomy and anterior vitrectomy should be strongly considered.

Cataract↗