Bharti R. Nihalani

Comparison of intraocular lens power calculation formulae in pediatric eyes.

PURPOSE To evaluate accuracy of intraocular lens (IOL) power calculation formulae (SRK II, SRK/T, Holladay 1, Hoffer Q) in pediatric eyes. DESIGN Retrospective case series. PARTICIPANTS One hundred thirty-five eyes of 96 children with congenital, developmental, or acquired cataracts who underwent uncomplicated cataract surgery and IOL implantation by a single surgeon over a 10-year period. METHODS Axial length (AL), keratometry (K), and manufacturers A constant were employed in 4 common IOL power calculation formulae to predict the refractive outcome. Retinoscopy was measured at 4 to 8 weeks postoperatively and converted to spherical equivalent. For analysis, eyes were grouped by age at surgery, AL, and mean K. MAIN OUTCOME MEASURES We determined the prediction error (PE) = predicted refraction - actual refraction and the absolute PE = |predicted refraction - actual refraction|. The formula that gave the best prediction (minimum PE) was determined. RESULTS The mean age at surgery was 6.4 years. Mean absolute PE was 1.11 for the SRK II, 0.84 for SRK/T, 0.76 for Holladay, and 0.76 for Hoffer Q formulae. There was a trend toward greater PE in eyes of younger children (< or =2 years), shorter AL (AL < or = 22 mm) and steeper corneas (mean K > 43.5 diopters [D]). On comparing absolute PE obtained with 4 formulae in each patient, Hoffer Q gave the minimum PE in 46% of eyes compared with 23% with SRK II, 18.5% with SRK/T, and 12.5% with Holladay 1. The SRK/T, Holladay 1, and Hoffer Q were similar in accurately predicting refractive error within +/-0.5 D in about 43% eyes. When clinically significant deviation in PE occurred (>0.5 D), there was usually an undercorrection (72%), except for Hoffer Q, which was almost as likely to overcorrect as undercorrect (44% vs 56%). The PE was lower with office measurements when compared with anesthesia measurements, owing probably to better fixation in older children with higher ALs. CONCLUSION The PE was insignificant (PE < or = 0.5 D) in 43% eyes, and similar for all formulae. However, the Hoffer Q was predictable for the highest number of eyes. When the PE was >0.5 D, most formulae gave an undercorrection, except for the Hoffer Q, which the surgeon may want to consider when targeting postoperative refractions.

Adjustable suture strabismus surgery

Surgical management of strabismus remains a challenge because surgical success rates, short-term and long-term, are not ideal. Adjustable suture strabismus surgery has been available for decades as a tool to potentially enhance the surgical outcomes. Intellectually, it seems logical that having a second chance to improve the outcome of a strabismus procedure should increase the overall success rate and reduce the reoperation rate. Yet, adjustable suture surgery has not gained universal acceptance, partly because Level 1 evidence of its advantages is lacking, and partly because the learning curve for accurate decision making during suture adjustment may span a decade or more. In this review we describe the indications, techniques, and published results of adjustable suture surgery. We will discuss the option of ‘no adjustment’ in cases with satisfactory alignment with emphasis on recent advances allowing for delayed adjustment. The use of adjustable sutures in special circumstances will also be reviewed. Consistently improved outcomes in the adjustable arm of nearly all retrospective studies support the advantage of the adjustable option, and strabismus surgeons are advised to become facile in the application of this approach.

Single-piece AcrySof intraocular lens implantation in children with congenital and developmental cataract

PURPOSE: To evaluate surgical outcomes of 1‐piece AcrySof SA30AL intraocular lens (IOL) (Alcon Laboratories) implantation in children having surgery for congenital and developmental cataracts. SETTING: Iladevi Cataract & IOL Research Centre, Raghudeep Eye Clinic, Ahmedabad, India. METHODS: This prospective observational study comprised 134 consecutive eyes of 84 children from 2 to 15 years old who had surgery for congenital and developmental cataract. Two groups were formed depending on the age of the child at surgery. Primary posterior continuous curvilinear capsulorhexis (PCCC) was performed in children younger than 6 years (Group 1, 66 eyes), and no PCCC was performed in children older than 6 years (Group 2, 68 eyes). Vitrectomy was not performed. An AcrySof IOL was implanted in the bag in all eyes except 1 in Group 1, which received a sulcus‐fixated IOL. The studys primary outcome measures were the incidence of visual axis obscuration and the need for a secondary procedure to clear the axis. Secondary observations included the incidence of posterior synechias, cell deposits, and haptic compression. A test of proportion was applied to determine whether age was a risk factor for the development of visual axis obscuration. RESULTS: The mean age at surgery was 6.0 years ± 3.2 (SD). The mean follow‐up was 2.6 ± 0.6 years. In Group 1, 20 eyes (30.3%) developed visual axis obscuration but only 6 (9.1%) required a secondary procedure. In Group 2, 20 eyes (29.4%) developed visual axis obscuration and 10 (14.7%) required secondary procedures. Posterior synechias were observed in 2 eyes (3.0%) in Group 1 and none in Group 2. Cell deposits were seen in 8 eyes (12.1%) in Group 1 and 8 eyes (11.8%) in Group 2. Haptic compression was noted in 1 eye in Group 2. Mild IOL decentration was observed in the 1 eye with a sulcus‐fixated IOL. CONCLUSION: The 1‐piece AcrySof IOL provided satisfactory visual axis clarity, produced an acceptable inflammatory response, and maintained centration in pediatric eyes.

Secondary intraocular lens implantation after pediatric aphakia

PURPOSE To describe our technique for secondary intraocular lens (IOL) implantation in aphakic children and report patient outcomes. PATIENTS AND METHODS In our technique for in-the-bag IOL implantion, we used a microvitreoretinal (MVR) blade to separate the capsular leaflets for aspiration of reproliferated lens material within Soemmerings ring. When sufficient capsular opening was not possible or capsular support deemed inadequate, an IOL was implanted in the sulcus. Records of patients with secondary IOL implantation between 1999 and 2009 were retrospectively reviewed with regard to intra- and postoperative complications and visual and refractive outcomes. RESULTS A total of 50 consecutive eyes of 32 patients were evaluated. Mean age at secondary IOL implantation was 9.1 years. Of these, 26 eyes had in-the-bag IOLs and 24 had sulcus IOLs. Forty-four eyes (88%) had an AcrySof IOL (Alcon Inc, Ft. Worth, TX). The prevalence of any corneal edema (54% vs 19%, P = 0.04) and uveal inflammation >2+ (92% vs 31%, P < 0.05) in immediate postoperative period was greater with sulcus IOL than in-the-bag placement. Late inflammation at 6 months developed in 1 eye, and glaucoma developed in 2 eyes with sulcus IOLs. All eyes maintained or gained lines of best-corrected visual acuity. Mean absolute prediction error was 0.9 ± 0.9 with no significant difference between in-the-bag and sulcus placement. CONCLUSIONS Eyes achieving secondary in-the-bag IOL showed less inflammation and corneal edema in the early postoperative period partly as the result of greater surgical and anatomic challenges in some eyes receiving sulcus IOL. Visual and refractive outcomes were satisfactory in eyes with secondary IOL implantation. Mean prediction error was similar for in-the-bag and sulcus IOLs.

Technological Advances in Pediatric Cataract Surgery

Purpose: Managing pediatric cataracts is often challenging. It is technically difficult to perform surgery in these small complaint eyes and there is higher prevalence of postoperative complications. The outcomes of surgery depend on technique and technology. The purpose of this study is to review the current literature on technological advances in pediatric cataract surgery. Methods: Review of literature on management of pediatric cataract surgery. Results: The advent of vitrectomy machines and intraocular lenses (IOLs) has revolutionized pediatric cataract surgery. “Vitrectorhexis” has become a good alternative to manual capsulorhexis. Primary management of posterior capsule and limited anterior vitrectomy has reduced the incidence of visual axis opacification. Primary IOL implantation is becoming a standard of care in the youngest children. Single piece Acrysof® is preferred for in-the-bag implantation and 3-piece Acrysof® for sulcus implantation. Newer IOLs are being evaluated in pediatric eyes. Precise measurement of intraocular lens power and predicting refractive change are major challenges in long term care of children after surgery. Conclusion: New technology and surgical techniques have refined pediatric cataract surgery. It is critical to focus our efforts on precise biometry measurements, IOL power calculation, and designing IOLs that may address refractive changes in the growing pediatric eye.

Benchmarks for outcome indicators in pediatric cataract surgery

PurposeThe purpose of this study was to establish benchmarks for outcome indicators that may help ascertain the quality of pediatric cataract surgery with primary intraocular lens (IOL) implantation.Patients and methodsA retrospective chart review of patients older than 2 years undergoing cataract surgery with primary IOL implantation, by multiple surgeons in a tertiary-care center, from November 2005 to February 2016 was conducted. Patients with ocular comorbidities that would affect the outcomes were excluded. The outcome measures chosen were as follows: (1) final best corrected Snellen visual acuity (BCVA) in patients who had bilateral cataract surgery analyzed at the last clinic visit; (2) prediction error (PE)=expected refraction−actual refraction. Mean PE and mean absolute PE were assessed 1 month postoperatively, irrespective of age or laterality.ResultsMean age at surgery was 8.3±4.6 years and mean follow-up duration was 3.7±2.7 years. The results of outcome measures were as follows: (1) BCVA was 20/40 or better in 96% (n=124 eyes, mean patient age: 8.3±4.6 years). Remaining five eyes had amblyopia with two eyes having BCVA worse than 20/100 that did not respond to amblyopia treatment. (2) Mean PE was 0.3±1.1 D and mean absolute PE was 0.9±0.7 D. PE was within ±0.5 D in 43.0%, ±1.0 D in 66%, and ±2.0 D in 95% (n=235 eyes).ConclusionGood visual acuity after cataract surgery should be expected for children with bilateral cataracts, setting a high benchmark similar to that recommended in adult cataract surgery. Prediction error is greater in pediatric eyes than in adult eyes, setting a lower benchmark. This study establishes benchmark for outcome indicators in pediatric patients older than 2 years undergoing cataract surgery with primary IOL implantation.

Optic nerve sheath fenestration for an isolated optic nerve glioma

The treatment modalities for neurofibromatosis type 1-associated optic gliomas include chemotherapy, radiation therapy, and surgical excision. The current recommendation is to consider treatment for an optic nerve glioma only if there is clear evidence of either ophthalmologic or radiographic progression with significant visual dysfunction. We report a case of a child with neurofibromatosis type 1 and an isolated optic nerve glioma with documented progression and visual loss in which clinical signs improved and visual deterioration stabilized after optic nerve sheath fenestration.

Uncorrected visual acuity in children with monofocal pseudophakia

Purpose To report uncorrected distance and near visual acuity in pediatric eyes treated with primary monofocal intraocular lens (IOL) implantation. Setting Boston Childrens Hospital, Boston, Massachusetts, USA. Design Retrospective chart review. Methods Records of children older than 5 years who had uneventful monofocal IOL implantation targeted for emmetropia within ±1.00 diopter (D) spherical equivalent were reviewed. Eyes with secondary IOL placement and sulcus‐fixated IOLs were excluded. Vision was tested using the Mentor BVAT or M&S system for distance and the standard Jaeger near card for near visual acuity. Keratometry, axial length, type of IOL, and preoperative and postoperative refractions were recorded. The main outcome measure was uncorrected visual acuity at distance and near. Good visual acuity was defined as 20/40 or better. Results Forty‐one eyes of 25 children had uncorrected distance and near visual acuity recorded in the early postoperative period. The mean age was 11.2 years ± 3.6 (SD). Twenty eyes (49%) had good visual acuity at distance and near, 11 had good visual acuity at distance only, 6 had good visual acuity at near only, and 4 had worse than 20/40 at distance and near. Thirty eyes (70%) had with‐the‐rule astigmatism. All but 2 eyes (95%) had 20/70 or better uncorrected acuity at distance and near. In children with bilateral pseudophakia, 12 (75%) of 16 had 20/40 or better uncorrected acuity at distance and near. Conclusion Monofocal IOL placement resulted in good uncorrected distance and near visual acuity in almost 50% of pediatric eyes and in 75% of patients when targeted within ±1.00 D of emmetropia. Financial Disclosure Neither author has a financial or proprietary interest in any material or method mentioned.

Response to: ’Unmet needs of cataract blind children in special schools in Southeast Nigeria’

Response to: ’Unmet needs of cataract blind children in special schools in Southeast Nigeria’

Pediatric genetic disorders of lens

Pediatric genetic disorders of lens include various cataractous and non-cataractous anomalies. The purpose of this review is to help determine the genetic cause based on the lens appearance, ocular and systemic associations. Children with bilateral cataracts require a comprehensive history, ophthalmic and systemic examination to guide further genetic evaluation. With advancements in genetics, it is possible to determine the genetic mutations and assess phenotype genotype correlation in different lens disorders. The genetic diagnosis helps the families to better understand the disorder and develop realistic expectations as to the course of their childs disorder.