Makoto Inatomi

Long-term study of children with implanted intraocular lenses

ABSTRACT We studied children between five and 15 years of age who were implanted with intraocular lenses (IOLs). The subjects comprised eight cases of traumatic cataract, 11 of congenital cataract, and six of steroid cataract. The follow‐up ranged from four months to nine and one half years. Twenty of the eyes studied achieved a postoperative visual acuity of equal to or better than 20/40. Binocular function was retained in most cases. Postoperative complications included seven cases of posterior iris synechia, three of iris capture, one of transitory elevated intraocular pressure, and one of cystoid macular edema. Corneal endothelial studies were normal in the eyes in which posterior chamber IOLs were implanted.

Intraocular lens power calculation for lens exchange.

Purpose: To examine patients who had intraocular lens (IOL) exchange for large postoperative refractive errors and determine the factors that contributed to the error in IOL power calculation. Setting: Thirteen affiliated hospitals in Japan. Methods: This study comprised 34 cases that required IOL exchange because of large refractive errors after primary lens implantation. Patients with intraoperative complications were excluded from the study. The potential contribution of axial length, corneal refractive power, IOL manufacturer, and IOL fixation to errors in the predicted power was examined retrospectively. Axial length was calculated by the SRK/T and Holladay formulas using refraction after primary IOL implantation. Results: There was no statistical difference between the corneal refractive power before and after cataract surgery. The axial lengths calculated using the SRK/T and Holladay formulas were longer than the ultrasonic axial lengths in 24 and 23 cases, respectively. Using IOLs from the same manufacturer for both primary implantation and exchange reduced the error in predicted refraction. Conclusion: Axial length and IOL manufacturer were important factors in predicting refraction power in eyes requiring IOL exchange.

Intraocular lens power calculation for microphthalmos

Purpose: To evaluate the refractive results and accuracy of intraocular lens (IOL) power calculation formulas in eyes with microphthalmos. Setting: Department of Ophthalmology, Showa University Hospital, Tokyo, Japan. Methods: The accuracy of IOL power calculated using the SRK, SRK II, S‐SRK, SRK/T, Holladay, and Hoffer Q formulas was evaluated in six eyes with axial lengths less than 19.0 mm. Results: Postoperative measurement of refraction showed a tendency toward hypermetropia compared with the refraction predicted by each formula. The best predicted refraction was calculated using the SRK/T formula. The tendency for hyperopic estimation was related to the axial length, particularly in eyes with a shorter axial length. However, there was no relationship between the refractive power of the cornea and the error in the predicted refraction by the SRK/T formula. Two eyes with an IOL power of 30.0 diopters (D) had severe hypermetropia. Conclusion: Theoretical formulas were more accurate than empirical ones in eyes with microphthalmos. The severe hypermetropia in the two eyes with a 30.0 D IOL indicates that such patients require a higher IOL power.

Errors in IOL Power Calculations for Axial High Myopia

We studied 115 eyes with axial lengths of 27 mm or more after implantation of a posterior chamber intraocular lens in order to determine discrepancies between the predicted refractions and the actual postoperative refractions. We then reviewed the three major variables used to predict refractions in these eyes--corneal curvature, anterior chamber depth, and axial length measurements--in an attempt to determine whether any of these variables were correlated with the discrepancies. We found that the main reason for postoperative refractive error was inaccurate measurements of preoperative axial length.

Surgical outcome of blowout fracture: early repair without implants and the usefulness of balloon treatment.

PURPOSE To determine the surgical intervention time, which is most likely to achieve a high success rate for blowout fracture repair without implants and the usefulness of treatment with an intramaxillary sinus balloon. METHODS Two hundred patients with isolated fractures of the orbit were evaluated by the Hess screen test, the Hertel exophthalmometer, and coronal computed tomography of the orbit. Operative criteria included diplopia within 30 degrees and enophthalmos >3 mm. An inferior lid incision approach was used to expose the orbital floor for realignment of bone fragments. Eighty of the patients received a gingival incision, followed by an osteotomy to create a 10-mm opening into the maxillary sinus for placement of a silicon-Teflon-silicon balloon. RESULTS The highest success rate, with diplopia completely improved in 66% of the patients, was observed when surgery was performed within 3 days after the injury. This success rate declined as surgical intervention was delayed. In 197 cases, enophthalmos was improved to <2 mm postoperatively for patients who had surgery within 14 days. The balloon treatment was well tolerated and caused no complications. CONCLUSIONS Surgery within 3 days is recommended in cases with diplopia and enophthalmos. An intramaxillary sinus balloon treatment was useful for the cases with large orbital floor fracture that could cause latent enophthalmos.

Preferred postoperative refraction after cataract surgery for high myopia

Abstract Eighty‐four patients (121 eyes) with high myopia who had cataract surgery and intraocular lens implantation completed a survey on preferred postoperative refraction. Forty‐two percent of the sample reported that they were accustomed to removing their glasses to read a newspaper or book. These respondents were fitted with soft contact lenses and their refraction changed to 0 D, −3.00 D, and −5.00 D. Of the patients whose best corrected postoperative visual acuity was 20/40 or better (n = 63), 48% preferred the −3.00 D correction; 38%, the 0 D correction; and 14%, −5.00 D. Of those with a best corrected postoperative visual acuity worse than 20/200 (n = 8), 80% preferred the −5.00 D refraction, which allowed them to read close up. Most patients with phakic eyes and good visual acuity (n = 13) preferred the 0 D and −3.00 D corrections. Our results indicate that in patients with high myopia, it is important to take patient preference into account when selecting postoperative refraction.

A Simple Modified SRK Formula for Severely Myopic Eyes

We describe our modification of the most accurate intraocular lens power calculation formula currently used, the SRK formula, to improve the accuracy with which it can be used to calculate the power of IOLs that are implanted in severely myopic eyes, especially in those with exceptional axial length. This modified formula, which we call the L-SRK, is I = A - 2.5 L - 0.9 K - 1.69R - 1.69 (where I = the actual implanted IOL power; A = the A-constant; L = the axial length; K = the average keratometer reading; and R = the predicted postoperative refraction). The results achieved using this modified formula demonstrate its superior accuracy in calculating lens powers for severely myopic eyes.

Accuracy of Intraocular Power Calculation Formulas

PURPOSE We examined the accuracy of intraocular lens power calculation formulas, with special emphasis on the prediction of refraction in different axial lengths. MATERIAL AND METHODS 786 cases were subdivided into four groups based on the axial length (short axial length < 22.0 mm, normal axial length = 22-24.4 mm, mid-range axial length = 24.5-26.9 mm and long axial length > 27 mm). Seven different formulas (Holladay, SRK, SRK II, SRK/T, S-SRK, M-SRK, L-SRK) were tested for their accuracy in predicting post-operative refraction. RESULT The best results were obtained using the S-SRK formula in the short axial length group (n = 114), The SRK and Holladay formulas in the normal axial length group (n = 278). The Holladay and SRK/T formulas in the mid-range axial length group (n = 135), and the SRK/T and L-SRK in the long axial length group (n = 259). CONCLUSION Our results emphasize the importance of using an intraocular lens formula specific for each range of axial length when calculating the predicted refraction.

Analysis of preoperative factors predictive of visual acuity in axial myopia

Purpose: To identify the factors predicting visual acuity after cataract surgery in patients with high myopia. Setting: Departments of Ophthalmology, Showa University School of Medicine and Showa University Fujigaoka Hospital, Kanagawa, Japan. Methods: Stepwise regression analysis was used to identify the factors determining the visuai acuity in 940 eyes with an axial length of 27.0 mm or longer having cataract surgery. Using a formula derived from the stepwise regression analysis, the predicted postoperative visual acuity was compared with the actual value measured in another group of 104 eyes. Results: Five factors were identified to significantly determine postoperative visual acuity axial length, age, corneal opacity, refractive power of the cornea, and history of retinal detachment surgery. There was a significant relationship between predicted and actual postoperative visual acuities (r= .51, P < .001). Postoperative visual acuity was similar in 63% of cases. Conclusion: The results showed that at least five factors determine visual acuity after cataract surgery in patients with high‐myopia.