Comparison of IOL power calculation formulae for pediatric eyes.

PurposeTo evaluate and compare the accuracy of modern intraocular lens (IOL) power calculation formulae in pediatric eyes and compare prediction error (PE) obtained with manufacturer's vs personalized lens constant.Patients and methodsAn observational case study was conducted in 117 eyes (117 patients) undergoing pediatric cataract surgery with IOL implantation. PE was calculated as predicted refraction minus actual postoperative refraction, and absolute PE as absolute difference independent of the sign, (APE)=predicted refraction minus actual postoperative refraction. This was done for each formula using manufacturer's and personalized lens constant. Further, PE and APE were evaluated according to axial length (AL).ResultsMean age of children was 2.97 years. About 66/117 eyes (56.4%) were below 2 years of age. Using Holladay 2, Holladay 1, Hoffer Q, and SRK/T formulae with manufacturer's lens constant, mean PE was 0.36, 0.41, 0.69, and 0.28 diopter (D), respectively. With personalized lens constant, it was 0.16, 0.15, 0.50, and -0.12 D, respectively. Difference in mean PE between the formulae was statistically significant (P<0.0001). SRK/T and Holladay 2 formulae had the least PE, both with manufacturer's and personalized constant. For eyes with AL<20 mm, SRK/T and Holladay 2 formulae gave the least PE. Personalizing the lens constant led to a decrease in mean PE in all formulae, except the Hoffer Q formula. However, personalizing the lens constant did not significantly improve the APE. At least 21% eyes had an APE of >2 D with all formulae, even with personalized lens constants.ConclusionIn pediatric eyes, SRK/T and the Holladay 2 formulae had the least PE. Personalizing the lens formula constant did reduce the PE significantly for all formulae except Hoffer Q. In extremely short eyes (AL<20 mm), SRK/T and Holladay 2 formulae gave the best PE.

Secondary intraocular lens implantation following infantile cataract surgery: intraoperative indications, postoperative outcomes.

PurposeThe purpose of this study was to determine the long-term complications and outcomes of secondary intraocular lens (IOL) implantation in patients with congenital cataracts.Patients and MethodsThe medical records of children operated for secondary IOL implantation surgery between 2000 and 2014 were retrospectively reviewed. Those who had undergone their initial congenital cataract surgery before 7 months of age were included and were analyzed for intra- and postoperative factors and postoperative refractive outcomes. We focused on three complications: visual axis opacification (VAO), glaucoma, and IOL exchange after at least 1 year of follow-up.ResultsA total of 49 eyes of 49 patients were analyzed for intraoperative indications. Of those, 37 eyes of 37 patients had at least 1 year of follow-up and were analyzed for postoperative outcomes. The mean age at secondary implantation was 55.2±21.6 months. At secondary implantation, 69.4% of eyes were implanted in the capsular bag, 28.6% in the sulcus, and 2.0% that were angle-supported. There was no significant correlation between the site of secondary IOL implantation and age at implantation (P=0.216). The mean follow-up after implantation was 57.6±33.6 months. The rate of VAO was 5.4%, the rate of glaucoma occurring after secondary implantation was 16.2%, and the rate of IOL exchange was 2.7%. The median visual acuity at final follow-up was 20/40. For patients with unilateral cataracts it was 20/60 and for bilateral patients it was 20/30.ConclusionsThe secondary IOL implantation in children is a relatively safe procedure associated with low rates of postoperative complications. Visual outcomes are acceptable and are better for bilateral patients than for unilateral patients.

Intraocular lens exchange for high myopia in pseudophakic children.

PurposeThe purpose of this study was to examine the preoperative factors and postoperative outcomes following intraocular lens (IOL) exchange for high myopia in pseudophakic children.MethodsThe medical records of all patients undergoing IOL exchange for high myopia were retrospectively reviewed.ResultsA total of 15 eyes were identified that had undergone an IOL exchange for myopic shift. Average age of cataract extraction (CE) was 5.4 months. In all, 10/15 had a unilateral cataract. IOL exchange usually occurred at an average of 6 years following cataract surgery. The average spherical equivalent (SE) of the refractive error at that time was -9.6 D. Following IOL exchange, SE was -1.3 D. A two-line reduction in best-corrected visual acuity was observed in 1/13 of our patients for whom pre- and post-exchange data were available. The average axial length (AL) of the eye undergoing the IOL exchange was 24.0 mm, average AL in the non-operative eye was 22.1 mm. On average, the operative eyes grew 4.4 mm and the non-operative eyes 3.02 mm. No adverse events were seen in the operative eyes.ConclusionYounger age at the time of CE creates a greater likelihood of AL elongation and predisposes a child to myopic shift. IOL exchange should be considered an option to reduce anisometropia and associated aniseikonia to improve visual outcomes. Successful visual rehabilitation and predictable post-exchange refractions were seen with our patients.

Visual acuity and its predictors after surgery for bilateral cataracts in children.

PurposeThe objective of this study was to investigate preoperative factors associated with postoperative visual acuity outcomes and to develop a model to predict visual acuity prognosis.MethodsA retrospective study was conducted by reviewing clinical charts of pediatric patients who underwent bilateral cataract surgery by a single surgeon (MEW) at the Storm Eye Institute. A multiple logistic regression model was constructed to predict the odds of poor postoperative visual acuity, that is, worse than 20/40, based on age at surgery, gender, primary intraocular lens (IOL) placement, ethnicity, and preoperative nystagmus.ResultsA sample size of 157 children (314 eyes) was investigated with median duration of follow-up of 6.4 years. A total of 78% of children with bilateral cataract had postoperative visual acuity of 20/40 or better. The presence of preoperative nystagmus was highly correlated with poor postoperative visual acuity (OR=6.0; 95% CLs, 2.5-14.1; P-value<0.0001). Children of age <1 year at time of cataract extraction (OR=3.2; 95% CLs, 1.4-7.6; P-value=0.0073), male gender (OR=2.3; 95% CLs, 1.1-4.5; P-value=0.02), the absence of primary IOL placement (OR=3.0; 95% CLs, 1.05-8.4; P-value=0.04), and non-Caucasian ethnicity (OR=2.0; 95% CLs, 1.02-4.03; P-value 0.0447) were associated with poor visual acuity postoperatively.ConclusionsSatisfactory visual outcomes occurred in 78% of children operated on for bilateral cataracts. Preoperative nystagmus, age <1 year at time of cataract extraction, absence of primary IOL placement, male gender, and non-Caucasian ethnicity, were all factors associated with poor postoperative visual acuity.

Post cataract-intraocular lens (IOL) surgery opacification.

Intraocular lens (IOL) implantation has no doubt been one of the most satisfying advances of medicine. Millions of individuals with visual disability or frank blindness from cataracts had and continue to have benefit from this procedure. It has been reported by ophthalmologists that the modern cataract-intraocular lens (IOL) surgery is safe and complication-free most of the time. This makes the watchword for any cataract surgeon to be 'implantation,' 'implantation,' 'implantation.' In the mid-1980s, as IOLs were evolving rapidly, the watchword of the implant surgeon was 'fixation,' 'fixation,' 'fixation.' Most techniques, lenses and surgical adjuncts now allow us to achieve the basic requirement for successful IOL implantation, namely long-term stable IOL fixation in the capsular bag. However despite this advancement some items 'slipped through cracks.' In this article, we would like to alert the reader to a new watchword, namely 'opacification,' 'opacification,' 'opacification.' Here we will be talking about the good, the bad, and the ugly. Examples of the 'good' include the recent successes now being achieved in reducing the incidence of posterior capsule opacification. Examples of the 'bad' include various proliferations of anterior capsule cells, problems caused by silicone oil adherence to IOLs and problems with piggyback IOLs. The 'ugly' include the sometimes striking and often visually disabling opacifications occurring on and within IOL optics, both on some modern foldable IOLs as well as a poly(methyl methacrylate) (PMMA) optic degradation occurring with some models a decade or more after implantation.

[Postoperative opacification of posterior chamber intraocular lenses - a review]. / Postoperative Trübung von Hinterkammerlinsen - eine Ubersicht.

Postoperative opacification of intraocular lenses (IOLs) is a very unpleasant complication for the ophthalmic surgeon and the patient. We report on our experiences with opacification of different foldable IOL designs and rigid poly (methyl methacrylate) (PMMA) posterior chamber lenses.1. Snowflake degeneration of PMMA IOLs: This condition is an unanticipated and surprising late postoperative finding 8 to 15 years after implantation. In our opinion, this complication is probably not related to the PMMA biomaterial itself, but rather it appears to represent a manufacturing problem that has affected a selected, albeit large number of lenses manufactured in the 1980s-mid 1990s.2. Degeneration of UV absorber material and calcium deposits within the optic of hydrophilic IOLs: Two years postoperatively degenerations of UV absorber material and calcium deposits within the optic of single piece hydrophilic acrylic lenses SC60B-OUV manufactured by MDR (Medical developmental research Inc. Clearwater FL, USA) can occur. Although the precise mechanism is not fully known, it was assumed that these opacifications are due to premature aging of the UV blocking agent incorporated in the lens biomaterial and calcification.3. Calcification on the surface of the Bausch & Lomb Hydroviewtrade mark IOLs: Twelve to 15 months postoperatively granular surface calcifications in Hydroviewtrade mark IOLs occured. The mechanism is not fully understood. According to Bausch and Lomb studies, part of the components of the packaging contained silicone, which may have come off the packaging onto the lens optic, where it then appears to be a catalyst for calcium precipitation. The manufacturer has correlated a change in packaging with the appearance of the opacification. The manufacturer now believes that this problem has been solved. However, final verification will require a careful 1 - 2 years clinical study.4. Glistenings in the hydrophobic acrylic AcrySoftrade mark IOLs: The time frame of glistenings in the AcrySoftrade mark IOLs is highly variable. It has been suggested that the occurrence of glistenings may be related to variations in the temperature of the lens just prior to and or during insertion into the eye. Formation of vacuoles may occur within the submersed acrylic polymer when there is a transient increase and then decrease in temperature during the surgical procedure. "Glistenings" may then subsequently form by ingress of anterior chamber fluid. Contrast sensitivity can been decreased in some patients, but clinically significant decrease of visual acuity has been rare.

Necessity of vitrectomy when optic capture is performed in children older than 5 years.

PURPOSE: To determine whether anterior vitrectomy is necessary when optic capture is performed in children between 5 and 12 years old with congenital cataract. SETTING: Iladevi Cataract and IOL Research Center, Ahmedabad, India. METHODS: This prospective randomized controlled study comprised 41 eyes of 25 children whose mean age was 83.57 months (range 60 to 144 months). Intraocular lens (IOL) implantation with optic capture through a primary posterior continuous curvilinear capsulorhexis was performed in all the eyes. The IOL haptics were bag fixated. Patients were randomly assigned to 1 of 2 groups. Vitrectomy was performed in 1 group (n = 21 eyes) and not performed in the other group (n = 20 eyes). The mean follow-up was 21.04 months. A Student t test and chi-square test were used for statistical analysis. RESULTS: All eyes in the vitrectomy group and 30% in the no-vitrectomy group had a clear visual axis at the last follow-up (P <.001) The visual axis was obscured as a result of anterior vitreous fibrosis in 70% of eyes in the no-vitrectomy group. High-contrast visual acuity was not significantly different between groups (P =.28). Low-contrast sensitivity was significantly better in the vitrectomy group (P =.02). Eighteen eyes (85.7%) in the vitrectomy group and 16 eyes (80%) in the no-vitrectomy group developed deposits on the IOL (P =.62). The deposits were present at the last follow-up in 4 eyes (19.0%) in the vitrectomy group and in 6 eyes (30.0%) in the no-vitrectomy group (P =.85). Three eyes (14.3%) in the vitrectomy group and 8 eyes (40.0%) in the no-vitrectomy group developed synechias (P =.06). CONCLUSION: The results suggest that anterior vitrectomy is necessary with optic capture in children with congenital cataract who are between 5 and 12 years old.

The effect of ship scrapping industry and its associated wastes on the biomass production and biodiversity of biota in in situ condition at Alang.

The main pollutants for the ship scrapping industry and its associated wastes at Alang are heavy metals, petroleum hydrocarbon and bacterial contaminations. The concentration of iron, manganese, cobalt, copper, zinc, lead, cadmium, nickel and mercury were 25 to 15,500% more at nearshore station of Alang as compared to control site at Piram. The concentration of heavy metals in the nearshore station of Alang was always higher than its concentration at 10 km away. The concentration of petroleum hydrocarbon was 16,973 and 53,900% more at the nearshore and 10 km away respectively at Alang as compared to controls. The concentration of chlorophyll-a and phaeophytin were in non-detectable range (< 0.2 and < 0.1 mg m3) or much lower concentration at both the stations of Alang as compared to controls. The total viable count, total coliform, Escherichia coli, Vibrio cholerae, Vibrio parahaemolyticus and other Vibrio, Streptococcus faecalis, Shigella, Salmonella, Proteus, and Klebsiella were always higher (17%-605%) at the nearshore station of Alang as compared to control. Similar trend was observed at 10 km away from Alang. Bacteria in sediment also showed the same pattern of variation. Phytoplankton counts at the nearshore station and 10 km away from Alang were only slightly raised. In contrast to phytoplankton, the zooplankton showed considerable reduction of growth (-10 to -66%) at Alang.

Role of optic capture in congenital cataract and intraocular lens surgery in children.

PURPOSE: To evaluate the role of optic capture in eyes having cataract extraction, anterior vitrectomy, and intraocular lens (IOL) implantation for congenital cataract. SETTING: Iladevi Cataract & IOL Research Centre, Ahmedabad, India. METHODS: This prospective study comprised 40 eyes of 28 children, whose mean age was 26.08 months (range 4 to 55 months). Primary posterior continuous curvilinear capsulorhexis, anterior vitrectomy, and IOL implantation were performed in all eyes. Eyes were randomly assigned to 1 of 2 groups of 20 each: in 1 group, optic capture would be used and in the other, the noncapture technique. Permanent optic capture was achieved in 14 eyes, and 26 eyes had no optic capture. Mean follow-up was 16.53 months (range 5 to 24 months). A Student t test and chi-square test were used for statistical analyses. RESULTS: All eyes in both groups maintained a clear visual axis. One eye in the optic-capture group developed a membrane in front of the IOL that required a secondary procedure. Posterior synechia formation was significantly greater in the optic-capture group (P =.04), as were deposits on the IOL optic (P =.0086). Although all eyes in both groups maintained a clinically centered IOL, geometric decentration was more common in the no-capture group (P =.0000). CONCLUSION: Optic capture resulted in better IOL centration but predisposed the eye to an increased uveal inflammatory response.

Is pseudophakic astigmatism a desirable goal?

PURPOSE: To determine whether pseudophakic astigmatism is a desirable goal, and if so, which one is better: against-the-rule (ATR) or with-the-rule (WTR). METHOD: Eyes were included only if they had an uncorrected vision > or = 6/18 and N/18. Three groups, of 40 patients each were evaluated: group 1, pseudophakes with neutral astigmatism; group 2, with ATR and group 3, with WTR astigmatism Unaided distance and near visual acuity was recorded. Statistical analysis was performed using the chi-square test for independence. RESULTS: Unaided distance vision of > or = 6/7.5 was achieved in 19 eyes (47.5%) of group 1 (neutral), 12 eyes (30%) in group 2 (ATR), and 5 eyes (12.5%) in group 3 (WTR) (p = 0.0133, significant). Unaided near vision of > or = N/9 was achieved in 17 eyes (42.5%) in group 1 (neutral), 34 eyes (85%) in group 2 (ATR), and 10 eyes (25%) in group 3 (WTR) (P < 0.001, significant). Group 1 (neutral) fared the best for unaided distance visual acuity. Group 2 (ATR) was better than in group 3 (WTR) for distant vision. Group 2 (ATR) fared the best for unaided near vision. CONCLUSION: ATR astigmatism could be a desirable goal after cataract extraction in selected populations because the largest proportion of these cases achieved good unaided near vision with acceptable distant vision.