Factors Affecting IOP Changes Following Neodymium: Yttrium Aluminum GARNET (Nd:YAG) Capsulotomy

Introduction: Transient intraocular pressure rise is acommonly observed phenomenon following Nd:YAGcapsulotomy. However, IOP change is considered to bedependent on multiple factors. Study aimed to assess factorsdetermining the IOP change following Nd:YAG capsulotomy.Material and Methods:A total of 150 adult patients, scheduledto undergo Nd:YAG laser capsulotomy for management ofposterior chamber opacification (PCO) were enrolled. Age,gender, time since cataract surgery, PCO grade, IOP, topicalhypotensive use was noted in all the cases. Amount of energyused in Nd:YAG procedure was recorded. Postoperative IOPchange was noted immediately, 1 hr and 3 hr postoperativeintervals. Rise >5 mm was considered clinically significant.Independent samples ‘t’-test, Chi-square test and binarylogistic regression were used. Data analysis was performedusing SPSS 15.0 software.Results: Mean age of patients was 60±11.3 years. Majoritywere females (59.3%). Majority of patients had Grade I andII of PCO (64%), 5-10 years duration since cataract surgery(79.3%) and topical hypotensive use was done(58%).Preoperative mean IOP was 15.99±2.72 mmHg. Energyused was 55.7±52.7 mJ. A total of 19 (12.7%) patients hadIOP rise >5 mm. On univariate analysis, Grade III or abovePCO, higher level of total energy use and low hypotensive usewere found to be significantly associated with IOP rise. Onmultivariate assessment, low hypotensive use and high energyuse were found to be significantly associated with clinicallysignificant IOP rise (p<0.05).Conclusions: Low energy and prophylactic topicalhypotensives were protective against IOP rise.

Tilt of IOLs and change of axial length in patients of posterior capsular opacification after Nd:YAG laser capsulotomy / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To study the tilt of the intraocular lens (IOL) after Nd:YAG capsulotomy (YAG) and variation of the axial length (AL) in patients with posterior capsular opacification (PCO).METHODS: The study involved 18 eyes of 14 patients with PCO after uncomplicated phacoemulsification surgery and IOL implantation.All patients had taken examinations,including testing best corrected visual acuity (BCVA) by using standard logarithmic visual acuity chart,images of ocular anterior segment and AL by OCT.After the examinations,YAG was operated upon all patients.Each eye received one drop of Diclofenac Sodium Eye Drops immediately after YAG,and patients had taken examinations listed above again.One week later,BCVA and OCT were tested as well.Data (BCVA,tilt of IOLs,and AL) were recorded and analyzed statistically by SPSS.RESULTS: Mean patient age was 73.93±6.94y,including 5 males and 9 females,8 left eyes and 10 right eyes,altogether 14 patients with 18 eyes.In this study,tilt of IOLs was defined as the angle of anterior surface of IOL and pupil plane (briefly called Tilt,unit:°).Before YAG,mean Tilt was 2.896±2.286°,mean AL was 23.56±0.55mm.1h after YAG,mean Tilt was 4.702±2.991°,mean AL was 23.40±0.59mm,and BCVA enhanced 3.72±1.74 lines.1wk after YAG,9 patients with 12 eyes were involved in the study.The mean Tilt of these 12 eyes was 3.175±1.791° 1h after YAG and 3.434±1.835° 1wk after YAG.There were significant differences between Tilt before YAG and Tilt 1h after YAG.There were no significant differences between AL before YAG and AL 1h after YAG.There were no significant differences between Tilt 1h after YAG and Tilt 1wk after YAG.The lines of enhancement of BCVA 1h after YAG was correlated to differences between Tilt before YAG and Tilt 1h after YAG,of which the correlation coefficient was-0.523.CONCLUSION: IOLs of patients with PCO tilted after YAG,while AL rarely changed.After YAG,the less IOLs tilted,the more BCVA enhanced.

Comparison of Nd:YAG Capsulotomy Rates between Hydrophobic and Hydrophilic Intraocular Lenses

PURPOSE: To compare neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy rates between hydrophobic and hydrophilic intraocular lenses. METHODS: The present retrospective study enrolled patients who received cataract surgery from a single surgeon between July 2006 to December 2009. Patients included in the study were implanted with SA60AT hydrophobic spherical intraocular lenses (Alcon, Fort Worth, TX, USA, 268 eyes) or I-FLEX hydrophilic spheric intraocular lenses (i-Medical®, Ophthalmic International Heidelberg GmbH, Mannheim, Germany, 331 eyes). The Nd:YAG capsulotomy rates and best-corrected visual acuity (BCVA) were compared between the two groups for 2 years after the operation. RESULTS: The mean follow-up period was 23.5 months and 22.6 months and the mean age was 68.6 years and 70.3 years in the SA60AT and I-FLEX groups, respectively. Follow-up periods were longer in the SA60AT group (p = 0.035), but ages were not significantly different between the two groups (p = 0.367). Nd:YAG laser capsulotomy rates were 6.3% in the SA60AT group and 11.2% in the I-FLEX group. Nd:YAG laser capsulotomy rates were significantly higher in the I-FLEX group (p = 0.020). BCVA before and after the Nd:YAG laser capsulotomy was not significantly different. CONCLUSIONS: Nd:YAG laser capsulotomy rates were higher in the I-FLEX hydrophilic spheric intraocular lens group than in the SA60AT hydrophilic spheric intraocular lens group. Adhesion between capsular bag and intraocular lens by bioadhesive character of hydrophobic acryl intraocular lens may contribute to the prevention of lens epithelial migration and posterior capsule opacification.

Comparison of Nd:YAG Capsulotomy Rates between Hydrophobic and Hydrophilic Intraocular Lenses

PURPOSE: To compare neodymium-doped yttrium aluminum garnet (Nd:YAG) laser capsulotomy rates between hydrophobic and hydrophilic intraocular lenses. METHODS: The present retrospective study enrolled patients who received cataract surgery from a single surgeon between July 2006 to December 2009. Patients included in the study were implanted with SA60AT hydrophobic spherical intraocular lenses (Alcon, Fort Worth, TX, USA, 268 eyes) or I-FLEX hydrophilic spheric intraocular lenses (i-Medical®, Ophthalmic International Heidelberg GmbH, Mannheim, Germany, 331 eyes). The Nd:YAG capsulotomy rates and best-corrected visual acuity (BCVA) were compared between the two groups for 2 years after the operation. RESULTS: The mean follow-up period was 23.5 months and 22.6 months and the mean age was 68.6 years and 70.3 years in the SA60AT and I-FLEX groups, respectively. Follow-up periods were longer in the SA60AT group (p = 0.035), but ages were not significantly different between the two groups (p = 0.367). Nd:YAG laser capsulotomy rates were 6.3% in the SA60AT group and 11.2% in the I-FLEX group. Nd:YAG laser capsulotomy rates were significantly higher in the I-FLEX group (p = 0.020). BCVA before and after the Nd:YAG laser capsulotomy was not significantly different. CONCLUSIONS: Nd:YAG laser capsulotomy rates were higher in the I-FLEX hydrophilic spheric intraocular lens group than in the SA60AT hydrophilic spheric intraocular lens group. Adhesion between capsular bag and intraocular lens by bioadhesive character of hydrophobic acryl intraocular lens may contribute to the prevention of lens epithelial migration and posterior capsule opacification.

A Case of Pupillary Block and Increased Intraocular Pressure after Nd:YAG Laser Posterior Capsulotomy

PURPOSE: To report a case of pupillary block and increased intraocular pressure caused by vitreous prolapse after Nd:YAG laser posterior capsulotomy. CASE SUMMARY: A 70-year-old male visited the hospital for decreasing visual acuity and ocular pain in the left eye. Two days earlier, he had undergone Nd:YAG laser posterior capsulotomy in the left eye. Best corrected visual acuity (BCVA) was 0.63 in the right eye and FC 60 cm in the left eye. Intraocular pressure (IOP) was 14 mm Hg in the right eye and 64 mm Hg in the left eye. Slit-lamp examination revealed diffuse corneal stromal edema and iris bombe with vitreous prolapse in the anterior chamber. Gonioscopy confirmed a closed angle. Pupillary block and increased intraocular pressure were diagnosed. A Nd:YAG laser iridotomy was performed. Three days after the iridotomy, BCVA was 0.2 and IOP was 11 mm Hg in the treated eye. Slit-lamp examination revealed reduced vitreous prolapse in the anterior chamber. CONCLUSIONS: This is the first report of pupillary block and increased IOP caused by vitreous prolapse after Nd:YAG laser posterior capsulotomy in Korea. Physicians should be aware that pupillary block could be caused by prolapsed vitreous after Nd:YAG laser posterior capsulotomy and Nd:YAG laser iridotomy could be performed effectively in such cases.

Incidence and Risk Factors of Nd:YAG Capsulotomy in Adult Cataract Patients Younger than 50 Years of Age

PURPOSE: To evaluate the cumulative incidence and estimate the risk factors of Nd:YAG capsulotomy due to posterior capsular opacification in adult cataract patients younger than 50 years of age. METHODS: In the present study we retrospectively reviewed 118 consecutive eyes that received phacoemulsification and intraocular lens implantation. We analyzed the cumulative incidence of Nd:YAG posterior capsulotomy and the associated risk factors. RESULTS: The cumulative incidence of posterior capsulotomy was 4.24%, 5.08%, 8.47%, 15.25%, and 20.34% in adults younger than 50 years of age at 3 months, 6 months, 12 months, 24 months, and more than 24 months after cataract surgery, respectively. The nuclear type (p = 0.021) and the mature type (p = 0.014) cataract groups were strongly associated with an increased risk of posterior capsulotomy compared with the posterior subcapsular type. The hydrophobic and single-piece intraocular lens caused the lowest incidence of posterior capsulotomy among intraocular lenses used for cataract surgery (p = 0.028). The subgroup analysis showed no statistical significance between gender, existence of diabetic mellitus or glaucoma, intraocular lens haptic material and the risk of posterior capsulotomy (p > 0.05). CONCLUSIONS: The cumulative incidence of Nd:YAG capsulotomy was 20.34% in adults younger than 50 years of age and at more than 24 months after cataract surgery. The risk factors associated with posterior capsulotomy included nuclear and mature cataract types. Additionally, there was a difference in the incidence of posterior capsulotomy according to the type of intraocular lenses.

Comparison of Nd:YAG Capsulotomy Rates between Spherical and Aspheric Intraocular Lenses

PURPOSE: The purpose of the present study is to compare Nd:YAG capsulotomy rates between spherical and aspheric intraocular lenses. METHODS: The present retrospective study enrolled patients who received cataract surgery by a single surgeon between March 1, 2006 and October 31, 2009. Patients included in the study were implanted with SA60AT spherical intraocular lenses (Alcon, Fort Worth, TX, USA, 66 eyes), SN60AT spherical intraocular lenses (Alcon, 48 eyes; a total of 114 eyes), or SN60WF aspheric intraocular lenses (Alcon, 187 eyes). The Nd:YAG capsulotomy rates were compared between the two groups 6 months after the operation. Ten patients who were implanted with a spherical intraocular lens in one eye and an aspheric intraocular lens in the contralateral eye were analyzed separately. RESULTS: Nd:YAG capsulotomy was performed in 2 of 114 eyes (1.8%) in the spherical intraocular lens group and 7 of 187 eyes (3.2%) in the aspheric intraocular lens group; no significant difference was found (p = 0.359). Among the 10 patients who were implanted with 2 different intraocular lenses, Nd:YAG capsulotomy was performed in only 1 eye in the aspheric intraocular lens group; no significant difference was found (p = 0.500). CONCLUSIONS: The design of the intraocular lens, especially the shape of the posterior optic, does not influence the rate of Nd:YAG capsulotomy.

Effect of Diabetes on the Developmental Duration of after-cataract in Pseudophakic Eyes with PMMA or Silicone IOL

PURPOSE: We studied the effect of the duration of diabetes or the severity of diabetic retinopathy on the development posterior capsular opacity in patients with PMMA or silicone intraocular lens (IOL) implan-tation following continuos capsulorhexis and phacoemulsification. METHODS: 41 eyes of diabetic patients (DM group) and 74 eyes of non-diabetic patients (control group) who had undergone Nd-YAG capsulotomy from January 1997 to May 2000 were included. RESULTS: The average interval from cataract surgery to Nd-YAG capsulotomy was 36.3+/-14.1 months with PMMA IOL and 25.3+/-11.8 months with silicone IOL in DM group (p<0.05). In control group, it was 38.0+/-15.1 months with PMMA IOL and 23.4+/-11.8 months with silicone IOL (p<0.05). There was no difference between DM and control groups. The severity of DM retinopathy did not influence the duration from cataract operation to posterior capsulotomy in DM group. Among the patients with diabeters for 10 years or longer, the mean interval from cataract operation to capsulotomy was longer in PMMA IOL group compared with silicone IOL group (P<0.05). CONCLUSION: Diabetics with PMMA IOL may maintain good vision for longer duration without posterior capsulotomy than those with silicone IOL. The silicone IOL group of more than 10-year DM duration needed posterior capsulotomy earlier than PMMA IOL group or the silicone IOL group of less than 10-year DM duration.