Topical Review: Causes of Refractive Error After Silicone-oil Removal Combined with Cataract Surgery.

SIGNIFICANCE: This review summarizes the main factors of refractive error after silicone oil removal combined with cataract surgery.The post-operative refractive results of silicone oil removal combined with cataract surgery are closely related to the patient's future vision quality. This report summarizes the factors that influence the difference between the actual post-operative refractive power and the pre-operatively predicted refractive power after silicone oil removal combined with cataract surgery, including axial length, anterior chamber depth, silicone oil, commonly used tools for measuring intraocular lens power, and intraocular lens power calculation formulas, among others. The aim of the report is to assist clinical and scientific research on the elimination of refractive error after silicone oil removal combined with cataract surgery.

Refractive and topographic fluctuations due to intracorneal ring segments motility.

PURPOSE: To describe a patient with refractive and topographic fluctuations 5 years after intracorneal ring segments (ICRS) implantation for the management of corneal ectasia after LASIK. METHODS: Case report. RESULTS: A 48-year-old woman presented complaining of intermittent decreased vision over 1 year that improved with eye rubbing. Slit-lamp and optical coherence tomography (OCT) examinations revealed overriding ring segments that could be restored to normal position after minor corneal massage. Topographic and refractive findings were significantly influenced by the ICRS positioning and caused decreased visual function when overriding. To avoid ICRS override, surgical dissection of the corneal tunnel along with ring segment repositioning was performed. A suture was placed through the ring's positioning hole to stabilize the ICRS at its optimal position and to avoid recurrence of this phenomenon. CONCLUSIONS: Patients undergoing femtosecond laser-assisted ICRS implantation may experience ring segment migration and override of the segments that could lead to decreased visual function. Proper surgical repositioning and ring segment fixation may address this complication and offer satisfactory visual and refractive outcomes along with avoidance of ICRS migration and override.

Occupational health problems of dentists in the United Arab Emirates.

OBJECTIVE: The aim of this study was to investigate the prevalence of some occupationally related health problems among dentists in the United Arab Emirates (UAE). METHOD: A cross-sectional study using the one-stage complex sampling technique to evaluate the results of a self-reporting questionnaire distributed to 844 dentists working in three cities (Abu Dhabi, Dubai and Sharjah) in UAE. RESULTS: Seven hundred and thirty-three (87%) dentists, aged 22-70 years, responded. The most common occupational health problems were musculoskeletal pain [497 (68%)] and percutaneous injury [306 (42%)]. Around one-fifth [135 (18%)] of dentists had a history of contact dermatitis, mostly caused by latex gloves, 53% had eye problems and 5% had hearing problems. CONCLUSIONS: As exposure to potential infectious agents is of concern, continuing education in the avoidance of percutaneous injuries would be beneficial. Further studies are needed to identify the causes of musculoskeletal pain and the appropriate interventions to reduce its prevalence; similar measures are required to reduce exposure to agents which may produce contact dermatitis. The awareness of occupational health problems should be highlighted at all clinical and research symposia.

Refractive outcomes of a single-step and a two-step approach for silicone oil removal and cataract surgery.

Purpose: To compare the intermediate-term refractive outcomes of a single-step and a two-step approach for silicone oil removal (SOR) and cataract surgery. Methods: Case records of patients who had SOR and phacoemulsification (PE) from 2011 to 2013 at a tertiary center in South India were retrospectively analyzed. A total of 135 eyes that underwent ultrasound biometry (UB) were studied. Eighty-seven eyes had SOR and PE at a single surgery (Group A), where as UB was done in a silicone oil (SO) filled eye. Forty-eight eyes had SOR followed by PE later (Group B), where UB was done in a fluid-filled eye. The refractive error (RE) and best-corrected visual acuity (BCVA) at postoperative day 45 (D45) and postoperative month 3 (M3) were compared. Results: Baseline axial length, intraocular lens (IOL) power, and RE in both groups were comparable. A myopic shift (4.18 ± 5.47 diopters [D]) was noted in 92% eyes at M3. Forty-nine percent eyes had a RE of ≤±1.5D at M3. RE at D45 and at M3 was significantly lesser in Group B (-1.73 ± 2.04 vs. -0.64 ± 1.75; P, 0.002). BCVA was significantly lesser in Group A at baseline, at D45, and at M3 (P < 0.01 for all). There was no difference in other baseline characteristics of eyes that had RE ≤±1.5D and those that had RE >±1.5D at M3. Conclusion: SO-filled eyes had a myopic shift in refraction after SOR and PE. When UB is used for IOL power calculation, better refractive outcomes are obtained when SOR and PE are performed in a two-step approach.

Visual acuity tolerance to residual refractive errors in patients with an apodized diffractive intraocular lens.

PURPOSE: To assess visual acuity tolerance to defocus caused by residual refractive errors after clear lens extraction (CLE) with apodized diffractive intraocular lens (IOL) implantation. SETTING: Fernández-Vega Ophthalmological Institute, Oviedo, Spain. METHODS: In this prospective study, 150 eyes of 75 consecutive patients who had bilateral CLE with implantation of an AcrySof ReSTOR Natural IOL (Alcon) were evaluated. The eyes were divided into 2 groups: myopia and hyperopia. Residual refractive errors were analyzed using vector analysis. Monocular and binocular uncorrected distance visual acuity, best corrected distance visual acuity, uncorrected distance near visual acuity, and best distance-corrected near visual acuity 6 months after surgery were recorded. RESULTS: When the distance residual refractive error was corrected, there was a statistically significant improvement in uncorrected distance acuity in the myopia group and hyperopia group (P<.001). No differences were found between uncorrected-distance near acuity and best distance-corrected near acuity (P>.2). A significant trend toward worse visual acuity as a function of spherical equivalent (SE) value was significant only for uncorrected distance acuity (P<.001). No significant correlations were found for best corrected distance acuity, uncorrected-distance near acuity, and best distance-corrected near acuity as a function of SE (P>.2). CONCLUSIONS: Correction of distance residual refractive error improved distance visual acuity in patients with apodized diffractive IOLs. However, near visual acuity was maintained whether the residual refractive error was corrected or not.

Changes in spherical aberration after lens refilling with a silicone oil.

PURPOSE: It may be possible to restore accommodation to presbyopic human eyes by refilling the lens capsular bag with a soft polymer. In the present study, optical changes were measured that occurred in a pig eye model after the refilling of the capsular bag. METHODS: The optical power and spherical aberration in 10 isolated pig lenses were measured under different conditions. They were first determined by using a scanning laser ray-tracing technique over an effective pupil size of 6 mm. Second, the contours of the anterior and posterior lens surface were photographed, and a mathematical ray-tracing was performed by using a polynomial fit through the digitized surface contours, to determine optical power and spherical aberration. Third, the lenses were refilled with a silicone oil until their preoperative lens thickness was reached, and scanning laser ray-tracing, contour photography, and mathematical ray-tracing were repeated. Comparisons between the measurements were made to determine how the change from a gradient refractive index to a homogeneous refractive index influenced spherical aberration. The influence of the change in lens contour on spherical aberration after lens refilling was also studied. RESULTS: The natural lenses had a higher lens power than the refilled lenses (49.9 +/- 1.5 D vs. 36.8 +/- 1.5 D; P < 0.001). Moreover, there was a change in sign from negative spherical aberration before lens refilling (-3.6 D) to positive spherical aberration after lens refilling (7.9 D; P < 0.001). The comparison between scanning laser ray-tracing of the natural lens and mathematical ray-tracing of the photographed surface contours of the natural lens to determine the effect of refractive index substitution (i.e., replacement of a gradient refractive index by a homogeneous refractive index) showed a significant change in spherical aberration from -3.6 +/- 2.0 to 11.0 +/- 2.1 D (P < 0.001). The change in lens contour did not result in a significant change in spherical aberration (P = 0.08) before and after lens refilling with an equal refractive index. CONCLUSIONS: The lower lens power of refilled pig lenses compared to natural lenses was due to the lower refractive index of the refill material. Refilling pig lenses with the silicone oil used in this study resulted in an increase in spherical aberration. This increase was mainly caused by the change from a gradient refractive index to a homogeneous refractive index. The change in lens curvature after lens refilling did not result in an increase in spherical aberration. The influence of lens refilling on spherical aberration of human lenses must be determined in similar experiments in human eyes.

Effect of the hydrophilicity of acrylic intraocular lens material and haptic angulation on anterior capsule opacification.

AIM: To evaluate the influence of hydrophilic and hydrophobic acrylic material and haptic angulation on anterior capsule opacification (ACO). METHODS: Prospective study on 53 patients with bilateral age-related cataract. Patients underwent standard cataract surgery by the same surgeon and randomly received a hydrophilic acrylic intraocular lens (IOL) in one eye and a hydrophobic acrylic IOL in the other eye. Forty five of these patients completed the one-year follow-up. The following parameters were assessed: decentration, buttonholing, anterolenticular gap (ALG), ACO, outgrowth and refractive outcome. RESULTS: At the one-year follow-up, ACO was seen in 80% of the hydrophilic and 100% of the hydrophobic IOLs. ACO was more intense in the hydrophobic IOLs (p<0.001). Outgrowth was seen in 42% of the hydrophilic and 2% of the hydrophobic IOLs (p = 0.0003). No case of persisting ALG was seen in the hydrophobic IOLs, but in 42% of the hydrophilic IOLs. The refractive outcome was -0.29 (SD 0.56) dioptres for the hydrophilic and 0.003 (SD 0.44) dioptres for the hydrophobic IOLs (p<0.001). CONCLUSION: These results suggest that there is less ACO in hydrophilic acrylic than in hydrophobic acrylic IOLs. Although material properties might play a role, the angulated haptics of the hydrophilic IOLs exert an additional effect by the persisting ALG and a lack of contact between the IOL and the anterior capsule.

Wavefront aberrations in eyes with Acrysof monofocal intraocular lenses.

PURPOSE: To characterize and measure the ocular aberrations in eyes implanted with monofocal intraocular lenses (IOLs) and to study any correlation between postoperative aberrations and surgical factors. METHODS: A Tscherning aberroscope was used to measure the wavefront aberrations of 62 eyes that had undergone phacoemulsification with the implantation of foldable monofocal Acrysof MA60BM IOLs (Alcon Laboratories Inc, Ft Worth, Tex). The Zernike coefficients, measured with a pupil diameter of 6 mm, were compared with those of a normal dataset of 82 eyes of healthy young myopes. RESULTS: Spherical aberration (Z(0)4) was the most predominant higher order aberration, with a mean value of 0.37 +/- 0.16 microm. A statistically significant linear relationship was noted between the magnitude of postoperative spherical aberration and the dioptric power of the IOL. The mean spherical aberration was 33 times more in the pseudophakic group than in normal young myopic eyes. The other major higher order aberrations were trefoil (Z(-3)3) with a mean of -0.13 +/- 0.22 microm and vertical coma (Z(-1)3) with a mean value of -0.11 +/- 0.23 microm. On average, the root-mean-square of higher order aberrations in pseudophakic eyes was 2.1 times that in a normal population of young myopic eyes. CONCLUSIONS: Eyes that undergo cataract surgery with monofocal IOL implantation suffer from significant higher order aberrations. The optical design of the IOL is most likely responsible for the increase in spherical aberration, the magnitude of which is a function of the dioptric power of the IOL.

Ocular aberrations after cataract surgery with hydrophobic and hydrophilic acrylic intraocular lenses: comparative study.

PURPOSE: To compare tilt and some higher-order aberrations (HOAs) in patients who had cataract surgery and implantation of 2 types of acrylic intraocular lens (IOL), the hydrophobic MA60AC (Alcon) or the hydrophilic XLSTABI (Ioltech). SETTING: Fondation Ophtalmologique Adolphe de Rothschild, Department of Pr Hoang-Xuan, Paris, France. METHODS: Sixty eyes were included in this study. Eyes in group 1 (n = 30) received the acrylic hydrophobic MA60AC IOL, and eyes in group 2 (n = 30) received the acrylic hydrophilic XLSTABI IOL. Optical aberrations were measured with Nidek OPD-Scan at least 1 month after cataract surgery for a 6.0 mm pupil diameter using a 6th-order Zernike polynomials decomposition. RESULTS: In group 1, the mean root-mean-square (RMS) coefficient for the total higher aberration was 0.86 microm +/- 0.38 (SD). The mean RMS of the tilt, coma, trefoil, tetrafoil, spherical aberration, and secondary astigmatism was 0.81 +/- 0.45 microm, 0.38 +/- 0.30 microm, 0.55 +/- 0.18 microm, 0.13 +/- 0.23 microm, 0.30 +/- 0.13 microm, and 0.17 +/- 0.21 microm, respectively. In group 2, the mean RMS coefficient for the total higher aberration was 0.72 +/- 0.31 microm. The mean RMS of the tilt, coma, trefoil, tetrafoil, spherical aberration, and secondary astigmatism was 0.55 +/- 0.30 microm, 0.24 +/- 0.19 microm, 0.50 +/- 0.23 microm, 0.07 +/- 0.22 microm, 0.32 +/- 0.13 microm, and 0.14 +/- 0.14 microm, respectively. There was a statistical difference in aberrations between the 2 groups for the tilt and the coma aberrations (P<.05). There were more aberrations in the MA60AC IOL group. CONCLUSIONS: The design of the IOL influenced ocular aberrations after cataract surgery. There were more tilt and coma aberrations in the MA60AC IOL group.

Influence of intraocular lens optical design on high-order aberrations.

PURPOSE: To compare differences in high-order aberrations (HOAs) between 2 intraocular lens (IOL) optical designs. SETTING: Department of Ophthalmology, Nara Medical University, Nara, Japan. METHOD: Sixty eyes that had uncomplicated phacoemulsification and IOL implantation were assigned to 1 of 2 groups based on the type of IOL optical design: more posteriorly curved biconvex shape (AcrySof MA30BA, Alcon) (n=30 eyes) or more anteriorly curved biconvex shape (AcrySof MA30AC) (n=30 eyes). All patients had best corrected visual acuity better than 20/25. High-order aberrations were measured using a Hartmann-Shack aberrometer at 4.0 mm and 6.0 mm wavefront aperture diameters. RESULTS: At 4.0 mm aperture diameters, there were no differences between the 2 groups in HOAs (P>.05, Mann-Whitney U test) in the cornea and the whole eye. At 6.0 mm aperture diameters, MA30AC eyes had a smaller amount of spherical-like aberrations (P=.043) than MA30BA eyes; however, there were no significant differences between the 2 groups in coma-like aberrations and total aberrations in the whole eye (P>.05). At 6.0 mm aperture diameters, there were no differences between the 2 groups HOAs in the cornea. (P>.05). CONCLUSION: The optical design of the spherical IOL influenced the spherical-like aberrations in the whole eye. This may reduce retinal image quality.

Effect of cataract surgery incision location and intraocular lens type on ocular aberrations.

PURPOSE: To determine whether Hartmann-Shack wavefront sensing detects differences in optical performance in vivo between poly(methyl methacrylate) (PMMA) and foldable acrylic intraocular lenses (IOLs) and between clear corneal and scleral tunnel incisions and whether optical differences are manifested as differences in visual performance. SETTING: Department of Optometry, University of Bradford, West Yorkshire, United Kingdom. METHODS: This study comprised 74 subjects; 17 were phakic with no ocular pathology, 20 had implantation of a Pharmacia 722C PMMA IOL through a scleral tunnel, 21 had implantation of an Alcon AcrySof IOL through a scleral tunnel, and 16 had implantation of an AcrySof IOL through a corneal incision. Visual acuity and contrast sensitivity testing, ocular optical quality measurement using Hartmann-Shack wavefront sensing, and corneal surface measurement with a videokeratoscope were performed in all cases. RESULTS: There were significant differences between groups in the total root-mean-square (RMS) wavefront aberration over a 6.0 mm pupil (F=3.91; degrees of freedom=3,70; P<.05) mediated at the 4th-order RMS, specifically spherical and tetrafoil aberrations. The PMMA-scleral group had the least aberrations and the AcrySof-corneal group the most. For a 3.5 mm diameter pupil, the total higher-order RMS wavefront aberration was not significantly different between the groups (P>.05). There were no differences between groups in corneal shape, visual acuity, or contrast sensitivity. CONCLUSIONS: Implantation of the spherical PMMA IOL led to a slight reduction in total wavefront aberration compared to phakic eyes. AcrySof IOLs induced more aberrations, especially spherical aberration. Corneal-based incisions for IOL implantation compounded this increase. Studies of the optical performance of IOLs in vivo should use wavefront sensing as the main outcome measure rather than visual measures, which are readily confounded by multiple factors.

Comparison of the long-term clinical results of hydrophilic and hydrophobic acrylic intraocular lenses.

This study was performed to compare the incidence of posterior capsular opacity (PCO) and refractive errors between hydrophilic (ACR6D, Corneal) and hydrophobic (MA60BM, AcrySof) acrylic intraocular lenses (IOLs) over a 3-year follow-up after phacoemulsification surgery. The patients with AcrySof implanted in one eye and Corneal in the other eye were categorized as Group 1 (n=28), while those with one or both eyes implanted with IOLs of the same kind were categorized as Group 2 (AcrySof, n=90; Corneal, n=95). Refractive errors were evaluated at 3 months and 3 years postoperatively. The incidence of visually significant PCO was investigated 3 years postoperatively. Postoperative refractive values at 3 months were not significantly different between the two groups. However, refractive values at 3 years were significantly different between two IOLs in both groups [AcrySof -0.37+/-0.43D, Corneal -0.62+/-0.58D in Group 1 (p=0.04); AcrySof -0.38+/-0.52, Corneal -0.68+/-0.54 in Group 2 (p<0.01)]. The incidence of visually significant PCO was 14% and 32% in Group 1, and 13% and 28% in Group 2, for the AcrySof and Corneal implants, respectively. The incidence of visually significant PCO of hydrophilic acrylic IOLs was higher than that of hydrophobic acrylic IOLs in the 3-year follow-up. The postoperative 3-year refractive value of Corneal showed myopic shift.

Hydrogel intracorneal lenses in aphakic eyes.

BACKGROUND: The theoretical benefits of synthetic keratophakia over conventional corneal lamellar procedures are the elimination of donor concerns and superior refractive predictability. Additionally, synthetic material can be inspected for optical quality and power, and it can be sterilized. Furthermore, visual recovery should be more rapid since epithelium is not removed from the central part of the cornea and the need for keratocyte repopulation is eliminated. OBJECTIVE: To present results on patients who received an intracorneal implant (Kerato-Gel, Allergan Medical Optics, Irvine, Calif) that was made from lidofilcon A, a glucose-permeable hydrogel with an equilibrium water content of 68%. METHODS: The intracorneal implants were implanted in 35 adult patients for correction of aphakia. Inclusion criteria excluded patients with aphakia who were candidates for intraocular lenses. RESULTS: A total of 19 patients were followed up through 2 years postoperatively. For 16 patients with 2-year postoperative refractive data, the average spherical equivalent was -0.63 +/- 2.07 diopters (D). At 2 years, 88% of patients were within +/- 3.00 D of plano and 50% were within +/- 1.00 D. the mean change in Snellen's line for corrected visual acuity was -3.25 lines at 2 years for all patients and -2.0 lines for a subgroup of five patients who were free of vision-limiting preoperative disease. CONCLUSIONS: Results suggest that this intracorneal implant is well tolerated by the cornea and can provide predictable refractive results in patients with high-risk aphakia. Limitations of the procedure are uneven microkeratome resections, loss of best-corrected visual acuity, and irregular astigmatism in some patients. Although these data show good evidence of biocompatibility of the implant material, technical surgical progress is needed to advance this procedure into clinical therapeutic practice.

Glistenings with long-term follow-up of the Surgidev B20/20 polymethylmethacrylate intraocular lens.

PURPOSE: To evaluate the incidence and progression of small refractile vacuoles in a consecutive series of patients implanted with the Surgidev B20/20 (Surgidev Corporations, Goleta, California) polymethylmethacrylate intraocular lens. METHODS: Observational case series. A 4-year prospective study of the progression of glistenings in patients implanted with the Surgidev B20/20 intraocular lenses. In a consecutive series of 51 patients (73 eyes) that received the Surgidev B20/20 intraocular lens onset, number, and location of intraocular lens glistenings, best-corrected visual acuity, and associated ocular pathology were noted. RESULTS: With mean follow-up of 98 +/- 27 months (range, 48 to 176 months), 65 of 73 (89%) eyes had intraocular lens glistenings. Glistenings increased in frequency and size with increasing follow-up (P =.001). CONCLUSION: Glistenings may occur in polymethylmethacrylate intraocular lenses with long-term follow-up, and they are progressive.

High-order aberrations with Hydroview H60M and AcrySof MA30BA intraocular lenses: comparative study.

PURPOSE: To compare differences in high-order aberrations between 2 intraocular lenses (IOLs), the Hydroview H60M (Bausch & Lomb) and AcrySof MA30BA (Alcon). SETTING: Department of Ophthalmology, Nara Medical University, Nara, Japan. METHOD: Twenty-four eyes of 14 patients with a Hydroview IOL and 25 eyes of 20 patients with an AcrySof IOL who had uneventful phacoemulsification and a best corrected visual acuity better than 20/16 from 6 to 12 months after surgery were evaluated. High-order aberrations were measured using a Hartmann-Shack aberrometer at 4.0 mm and 6.0 mm wavefront aperture diameters, and IOL tilt and decentration were assessed by Scheimpflug videophotography. RESULTS: There were no differences between the 2 groups in IOL tilt and decentration (P>.05, Mann-Whitney U test). In the cornea, there were no differences between the 2 groups in high-order aberrations at 4.0 mm and 6.0 mm aperture diameters (P>.05, Mann-Whitney U test). In the whole eye, there was a significant difference between Hydroview (mean 0.441 microm +/- 0.147 [SD]) and AcrySof (0.696 +/- 0.287 microm) IOLs in spherical-like aberrations at the 6.0 mm aperture diameter (P =.00008, Mann-Whitney U test); there were no differences between the 2 groups in other aberrations. CONCLUSIONS: The type of IOLs influenced spherical-like aberrations. The IOL's shape was a particularly important factor in spherical-like aberrations. The aberrations may affect night driving in certain individuals.

Significant postoperative refractive errors in vivo with the Mentor Memorylens intraocular lens.

PURPOSE: To determine the difference between the predicted and postoperative refraction in eyes after implantation of the Mentor MemoryLens intraocular lens (IOL) and compare these results with those of 2 other types of foldable IOLs implanted by the same surgeons. SETTING: Community-based group practice ophthalmology clinic. METHODS: All operated eyes (341) of all patients who had routine phacoemulsification with implantation of a MemoryLens IOL performed by 1 of 2 surgeons were evaluated retrospectively. The predicted refractive error and actual postoperative refractive error were compared in each eye in the MemoryLens group and in 2 smaller control groups with an AcrySof acrylic (Alcon) or SI-40 silicone (Allergan Medical Optics) IOL implanted by the same surgeons using identical technique and IOL calculation parameters. Patients in whom the difference between the predicted and actual postoperative refraction fell significantly outside expected parameters were rechecked with repeat axial length and keratometric readings, and these measurements were used to back-calculate the effective in vivo IOL power. RESULTS: The MemoryLens group had significantly greater variability in postoperative refractive results from those predicted by the Hoffer program than the 2 control groups. The postoperative refractive error in the MemoryLens group differed from +1.50 to -5.50 diopters (D) from that predicted by the IOL calculation formulas. When the outlier groups (ie, greater than +0.50 D or less than -1.00 D from predicted refractive error) were evaluated and compared to the rest of the MemoryLens group and the 2 control groups, no significant difference in axial length, keratometric measurements, operative surgeon, surgical technique, or patient age was found. Repeat axial length and keratometric measurements in the outlier group were not significantly different from those in the same eyes preoperatively. Back-calculation using postoperative axial length and keratometric measurements in the highly myopic outlier group showed that the mean difference between the labeled IOL power and actual in vivo IOL power in the outlier group was -3.08 D (range -1.98 to -7.54 D). The best corrected visual acuity was not affected in patients in the outlier groups despite the refractive variability. CONCLUSION: The variation in postoperative refractive results in the MemoryLens group was significantly greater than in the 2 other foldable IOL groups.

High-order aberrations in pseudophakia with different intraocular lenses.

PURPOSE: To compare high-order aberrations in patients who had cataract surgery and implantation of different types of intraocular lenses (IOLs). SETTING: Sir Charles Gairdner Hospital and Lions Eye Institute, University of Western Australia, Perth, Australia. METHODS: Fifty eyes of 48 patients were included in this study. The optical aberrations were measured with the Hartmann-Shack wavefront sensor (Zyoptix, Bausch & Lomb) before and after surgery using a 5.0 mm wavefront aperture diameter for all comparisons. The eyes were divided into 4 groups according to the type of IOL (material and curvature). A fifth group of 10 eyes of 6 elderly patients with normal crystalline lenses had the same examination. RESULTS: There was no statistical difference in high-order aberrations between the 2 acrylic IOL groups with different curvatures (P>.05) or between the silicone and poly(methyl methacrylate) (PMMA) IOL groups (P>.05). However, the measured high-order aberrations were significantly higher (3rd through 5th order) in the 2 acrylic IOL groups than in the PMMA and silicone IOL groups (P<.05). CONCLUSIONS: An increase in IOL high-order aberrations contributed to the decline in retinal image quality. An IOL modifies the entire aberration pattern of the eye. There was a statistically significant increase in aberrations in patients with an acrylic IOL compared to those with a silicone or PMMA IOL. The exact mechanism is uncertain. Further study is required to optimize IOL design.

Intraocular lens implantation in infant monkeys: clinical and histopathological findings.

PURPOSE: To determine the long-term effects of intraocular lens (IOL) implantation in infant monkey eyes. SETTING: Yerkes Regional Primate Research Center, Emory University School of Medicine, Atlanta, Georgia, USA. METHODS: A 30.00 diopter (D), all-poly(methyl methacrylate) IOL with an overall diameter of 10.0 mm was implanted in the right eye of 11 infant monkeys. Seven monkeys developed postoperative complications and were not followed on a long-term basis. However, 4 monkeys were followed clinically for 4 1/2 years, after which their pseudophakic eyes were examined histopathologically. RESULTS: The final refractive error in the four pseudophakic eyes with long-term follow-up ranged from -4.75 to +0.75 D. Three of the four eyes had a Soemmering's ring. Only one haptic was in the capsular bag. whereas five had eroded into the iris root/ciliary body. The corneas and posterior segments of the eyes were normal. CONCLUSION: Two-thirds of the eyes having neonatal IOL implantation experienced significant postoperative complications. Haptic location was suboptimal in all four eyes followed for 4 1/2 years. The diameter of the IOLs implanted in these eyes was probably too large. Some of these complications might have been averted by implanting an IOL with a smaller diameter.

Batch-by-batch analysis of topographic changes induced by sutured and sutureless clear corneal incisions.

PURPOSE: To evaluate the effect of a suture on surgically induced corneal topographic changes in 5.0 mm clear corneal incisions. SETTING: University Eye Hospital, Vienna, Austria. METHODS: Thirty-seven eyes that had cataract surgery were included in the prospective study. A 5.0 mm long and 0.3 mm deep precut was followed by preparation of a corneal tunnel. After phacoemulsification and intraocular lens implantation, the self-sealing wound was left unsutured in 19 eyes; one radial 11-0 nylon suture was applied in 18 eyes. Using a TMS-1 videokeratoscope, corneal topography was measured preoperatively and at 1 week and 1 and 3 months postoperatively. The topographic data were evaluated by statistical batch-by-batch analysis. Each topographic image was cut into 178 fields in eight concentric rings. The refractive values of these fields were stored in a database. Differences between the four readings of each patient were calculated and the mean differences of the 178 fields in each group were transformed into color-coded maps. The significance of topographical changes and group comparisons of induced changes were computed by Wilcoxon tests. RESULTS: Both groups exhibited significant temporal flattening and vertical steepening. The unsutured eyes also displayed significant nasal flattening. Sutureless 5.0 mm clear corneal incisions induced significantly more vertical steepening and nasal flattening than sutured incisions. CONCLUSION: Application of one radial 11-0 nylon suture in 5.0 mm temporal clear corneal incisions significantly reduced shape changes in the nasal corneal region.

Intacs for early pellucid marginal degeneration.

A 42-year-old man had Intacs (Addition Technology Inc.) implantation for early pellucid marginal degeneration (PMD). Two Intacs segments (0.45 mm thickness) were inserted uneventfully in the fashion typically used for low myopia correction (nasal-temporal). Eleven months after the procedure, the uncorrected visual acuity was 20/200, compared with counting fingers preoperatively, while the best spectacle-corrected visual acuity improved to 20/25 from 20/50. Corneal topographic pattern also improved. Although the results are encouraging, concern still exists regarding the long-term effect of this approach for the management of patients with PMD.