Potential of the 1 CU accommodative intraocular lens

AIM: To assess the accommodative power of a new foldable monofocal intraocular lens. METHOD: A prospective randomised non-masked clinical interventional study. The study included 40 patients attending the hospital for cataract surgery and who were randomly distributed into a study group receiving a new foldable monofocal intraocular lens with flexible haptics, and a control group receiving a standard foldable intraocular lens. Mean follow up period was 8.51 (SD 1.34) months (range 4-11 months) Standard cataract surgery consisted of clear cornea incision, capsulorrhexis, phacoemulsification, and intraocular lens implantation, with topical anaesthesia. The main outcome measures were preoperative and postoperative visual acuity for near and distance; range of accommodation; change in anterior chamber depth. RESULTS: In the study group compared with the control group, range of accommodation was significantly (p = 0.01) higher (1.01 (SD 0.4) dioptres versus 0.50 (0.11) dioptres) and change in anterior chamber depth was significantly more pronounced (0.82 (0.30) versus 0.40 (0.32), p = 0.01). Both groups did not vary significantly in best corrected vision (0.94 (0.12) versus 0.93 (0.18); p = 0.74). CONCLUSION: During a mean follow up period of 8 months after implantation, the new foldable monofocal intraocular lens with flexible haptics showed an accommodative power of about 1 dioptre, which was significantly higher than the accommodative power of a conventional monofocal flexible intraocular lens. The difference in the accommodative power between the two intraocular lenses was paralleled by a difference in the change of the anterior chamber depth.     

Biometrie des vorderen Augensegmentes zur Implantation phaker Vorderkammerlinsen

Background

Implantation of phakic intraocular lenses (pIOL) is gaining in importance. Exact measurement of the anterior chamber is important to assure safe and effective pIOL implantation. In this study six currently available diagnostic devices were tested in order to compare accuracy of measurements (anterior chamber depth and diameter) and ease of handling.

Patients and methods

In this study 100 eyes from 50 healthy patients were enrolled. All measurements were done by the same operator (L.?K.) on the same day and under the same lighting conditions. The following devices were used to measure anterior chamber depth and diameter: IOLMaster 500, Visante?OCT, UBM Vumax?II, Galilei, Pentacam Classic und Orbscan?IIz. Correlations between each method were assessed using Pearson??s correlation. Bland Altman plots were composed to evaluate the range of agreement between two methods.

Results

The mean epithelial anterior chamber depth was 3.45±0.38?mm with IOLMaster 500, 3.69±0.33?mm with Visante OCT, 3.59±0.35?mm with Pentacam, 3.67±0,36?mm with Galilei, 3.48±0.38?mm with Orbscan IIz and 3.52±0.34?mm with UBM VumaxII. The mean white-to-white measurements were 11.98±0.37?mm with IOLMaster 500 and 11.71±0.36?mm with Orbscan IIz. The mean angle-to-angle distances were 11.83±0. 43?mm with Visante OCT, 10.73±0.38?mm with Pentacam, 12.30±0.45?mm with Galilei, and 11.15±0.52?mm with UBM Vumax?II. In the Bland Altman plots the range of agreement was 0.5?mm between Visante OCT and IOLMaster?500, regarding anterior chamber depth as well as anterior chamber diameter.

Conclusion

The IOLMaster 500 provides exact measurement of the anterior chamber depth and diameter and is easy to handle in the daily clinical routine.     

Position-dependent accommodative shift of retropupillary fixated iris-claw lenses

Purpose

After implantation of retropupillary fixated iris-claw lenses, changes of the objective refraction can occur depending on the patients’ position. The purpose of this study was to evaluate and quantify these changes as well as the influencing factors.

Methods

Within a retrospective study, postoperative refraction visual, acuity and anterior chamber depth after implantation of a retropupillary fixated iris-claw lens (Artisan? / Verisyse?) were measured in 51 eyes (49 patients) depending on their head position. These parameters were determined with the assistance of a mobile auto-refractometer, acoustic biometry, IOL-Master, chart projector and accommodometer in primary position, as well as in forward- and backward-tilted head position.

Results

The data analysis indicated a position-dependent change of the anterior chamber depth, which was largest in the backward-tilted head position (median: 4.25?mm/min.: 3.39?mm/max.: 5.37?mm). In comparison to the primary position (4.15?mm), it decreased in a forward-tilted position of the head (4.08?mm). A significant difference in anterior chamber depth was verified for backward- and forward-tilted heads (median: 0.155?mm). Refraction showed a significant difference (0.37 D) between forward- and backward-tilted head position. In comparison to the back-tilted head position (mean: ?0.065 D), a smaller spherical equivalent could be demonstrated by bending the head forward (mean: ?0.438 D). In addition, no correlation was found between lens movement and other continuous attributes.

Conclusions

Significant changes in anterior chamber depth and refraction due to the iris-claw lens shift were found, depending on head position. The phenomenon of pseudophakic accommodation is explained by pseudo-myopia and pseudo-hyperopia. A considerable influence on visual acuity depending on patients′ head position could not be verified.     

Validity of anterior chamber depth measurements for the evaluation of accommodation after implantation of an accommodative Humanoptics 1CU intraocular lens

BACKGROUND: Changes in the anterior chamber depth (ACD) after pilocarpin application are generally regarded as reflecting an accommodative effect of accommodative intraocular lenses (IOLs) METHODS: We implanted Humanoptics 1CU accommodative IOLs into 25 eyes of 20 patients aged 53.2+/-14.7 years (range: 30-83 years). In seven of these patients, we were able to measure anterior chamber depth changes after the application of pilocarpine (2%) eye drops 3 months postoperatively using a Zeiss IOLMaster, an Orbscan II topography system, as well as by ultrasound biomicroscopy (20 MHz-US-head). RESULTS: Uncorrected near acuity was on average 0.4+/-0.23 (0.1-0.8) and uncorrected distance acuity was 0.76+/-0.23 (0.3-1). Before pilocarpine, ACD was 3.19+/-2.11 mm (IOL-Master), 3.35+/-2.22 mm (Orbscan II) and 3.35+/-2.21 mm (US-biomicroscopy) ( P=0.96). After pilocarpine, ACD was 2.61+/-1.71 mm (IOL-Master), 2.63+/-1.78 mm (Orbscan II) and 3.15+/-2.08 mm (US-biomicroscopy) ( P=0.002). The average individual ACD change before/after pilocarpine was 0.83+/-0.25 mm with the IOL-Master, 1.04+/-0.39 mm with the Orbscan II System and 0.28+/-0.14 with US-biomicroscopy ( P=0.0004). DISCUSSION: The 1CU Humanoptics accommodative IOL presented with potential accommodative capabilities in clinical evaluation. Drug induced accommodation by pilocarpine does not reflect real accommodative effects. The differences in ACD measurements between three different methods were statistically significant. Evaluation methods for accommodative IOLs should be carefully analysed and further development of objective means for evaluation is needed.     

Accommodative changes in human eye observed by Kitasato anterior segment optical coherence tomography

Purpose

To study accommodative changes in the human lens using swept-source optical coherence tomography (Kitasato anterior segment OCT/KAs-OCT), which can image the whole anterior segment of the eye.

Methods

Thirty-five healthy subjects (mean age 41 years, range 13–79 years) were recruited. Using KAs-OCT, we measured the curvature of the anterior (ASC) and posterior surfaces (PSC), the thickness (LT) of the lens and the anterior chamber depth (ACD) in response to far (0.4 D) and near (10 D) accommodative stimuli.

Results

In response to accommodative stimuli (0.4/10 D), the mean values ± standard deviations were: radius of ASC, 9.72 ± 2.53/7.84 ± 1.85 mm (Wilcoxon ranked-sign test, p < 0.0001); radius of PSC, 5.06 ± 0.71/4.70 ± 0.76 mm (p = 0.0012); LT, 3.86 ± 0.77/4.00 ± 0.76 mm (p < 0.0001); ACD, 2.72 ± 0.61/2.61 ± 0.54 mm (p = 0.0002). The rate of accommodation-associated changes in ASC, LT, and ACD showed significant correlation with aging (Pearson correlation coefficient: r = ?0.725, p < 0.0001; r = ?0.626, p = 0.0001; r = ?0.720, p < 0.0001, respectively), but there was no such correlation in PSC (r = ?0.064, p = 0.401).

Conclusion

The radius of ASC and PSC decreased with accommodation, and the rates of changes in ASC were larger than those in PSC.     

Comparison of 6-month results of implantation of the 1CU accommodative intraocular lens with conventional intraocular lenses

OBJECTIVE: To evaluate the clinical results of implantation of the new 1CU accommodative intraocular lens (IOL) in cataract patients and to compare results with those of conventional IOLs. DESIGN: Nonrandomized comparative trial. PARTICIPANTS: Twenty eyes of 20 patients (mean age = 65.8+/-13.3 years) in the 1CU group and 20 eyes of 20 patients (mean age = 67.4+/-11.6 years) in the control group. METHODS: All patients underwent phacoemulsification and IOL implantation. The 1CU accommodative lens was used in 20 eyes, and conventional IOLs (polymethyl methacrylate, hydrophilic or hydrophobic acrylate) were used in the control group. Patients were observed prospectively, and 6-month data were analyzed. MAIN OUTCOME MEASURES: Accommodative ranges determined by 3 different methods (near point, defocusing, and retinoscopy). Secondary outcome measures were (1) increase of anterior chamber depth after topical application of 1% cyclopentolate eyedrops and (2) distance-corrected near visual acuity with Birkh?user reading charts at 35 cm. RESULTS: We observed a higher accommodative range with all 3 methods (mean = 1.83+/-0.49 vs. 1.16+/-0.27 diopters [D] [near point], 1.85+/-0.43 vs. 0.64+/-0.21 D [defocusing], and 0.98+/-0.55 vs. 0.17+/-0.22 D [retinoscopy]), a larger increase of anterior chamber depth after cyclopentolate eyedrops (mean = 0.42+/-0.18 vs. 0.11+/-0.06 mm), and better distance-corrected near visual acuity (median = 0.4 vs. 0.2) in the 1CU group relative to the control group. All differences between the 2 groups were statistically highly significant (P<0.001). CONCLUSIONS: In the present study, the 1CU accommodative IOL showed increased accommodative range and better near visual acuity than a control group with conventional IOLs. Further research is necessary to confirm these results in masked, randomized, prospective studies and to confirm further the accommodative power of this group of new IOLs.     

Two years experience with the new accommodative 1 CU intraocular lens

After marked improvement of optical rehabilitation of cataract patients during the last decades due to small incision surgery and foldable intraocular lenses (IOL), presbyopia is now one of the great unsolved questions in ophthalmology. During recent years a new accommodative IOL, the 1CU lens, has been developed based on the concepts of K.D. Hanna and on finite element computer simulation models. The 1CU IOL is designed to transform contracting forces of the ciliary muscle into anterior movement of the IOL optic (optic-shift concept). After the first implantation of a 1CU IOL in Erlangen in June 2000, we have now successfully implanted the 1CU IOL in over 90 patients. Our experiences and the results of several clinical studies indicate good and safe implantability, good centration, no IOL-specific complications, and good distance visual acuity. In comparison to control groups with conventional IOL, patients with the 1CU enjoyed significantly better distance-corrected near visual acuity, a larger accommodative range, and increased anterior and posterior axial movement of the lens optic after medical stimulation or inhibition of the ciliary muscle. We interpret our results as confirmation of the optic-shift concept of the 1CU IOL. Overall, the concept of accommodative IOL appears attractive and may have a great potential in the future. Additional studies including randomized blind multicenter evaluation of the 1CU IOL are necessary to further evaluate long-term and accommodative results.     

角膜塑形术后眼前节形态及调节功能

目的研究近视儿童在配戴角膜塑形镜前及3个月后,调节反应及调节过程中眼前节形态的变化。方法前瞻性实验研究。本实验共纳入18名进展性近视青少年[（14.4±2.6）岁]作为研究对象。在配戴角膜塑形镜前及持续夜戴3个月后（摘镜后2 h内）,在采用Badal光学系统矫正受检者屈光不正的基础上,使用开放视野型红外验光仪分别在0 D、3 D和5 D的调节刺激下测量眼球屈光力,并计算调节反应量。同时使用实验室自行搭建的超长深度光学相干断层扫描仪（OCT）获取不同调节刺激下眼前节形态,每种刺激均重复拍摄2次。眼前节形态参数包括瞳孔直径（PD）、前房深度（ACD）、晶状体厚度（LT）以及晶状体前表面曲率半径（LAC）。分析戴镜前及戴镜3个月后调节反应及眼前节形态变化量的差异,数据采用配对t检验进行比较。结果在配戴角膜塑形镜3个月后,调节反应在3 D[（1.72±0.59）D vs. （2.42±0.84）D]和5 D[（3.09±0.63）D vs. （3.61±0.86）D]刺激下均显著增加,差异有统计学意义（t=2.84、2.12,P＜0.05）。戴镜3个月后,2种调节刺激下调节刺激前后的ΔACD、ΔLAC、ΔPD、ΔLT均较戴镜前变化更为显著。ΔACD[3 D：（-0.11±0.04）mm vs. （-0.16±0.06）mm,t=3.88,P＜0.01;5 D：（-0.15±0.05）mm vs. （-0.20±0.07）mm,t=2.37,P＜0.05]、ΔLAC[3 D：（-2.60±0.79）mm vs. （-3.81±1.08）mm,t=3.96,P＜0.01;5 D：（-3.57±1.14）mm vs. （-4.32±1.36）mm,t=2.08,P＜0.05]、ΔLT[3 D：（0.22±0.13）mm vs. （0.27±0.06）mm,t=-1.94,P＜0.05;5 D：（0.26±0.09）mm vs. （0.30±0.10）mm,t=-1.99,P＜0.05]在戴镜前后的差异均有统计学意义,而ΔPD仅在3 D[（-1.55±0.42）mm vs. （-1.71±0.37）mm]调节刺激下变化量具有统计学意义（t=1.76,P＜0.05）。结论配戴角膜塑形镜后,调节过程中调节反应及眼前节形态的变化幅度增大,调节滞后减少,调节功能得到改善。     

Implantation of a new accommodative posterior chamber intraocular lens

PURPOSE: A new, potentially accommodative posterior chamber lens (PCIOL) was designed based on principles elaborated by Hanna using finite element computer simulation methods. We report 3-month postoperative results in patients. METHODS: In a prospective study, 12 eyes of 12 patients (age 45 to 87 yr) underwent phacoemulsification for cataracts and PCIOL implantation. The PCIOL, 1 CU, has haptics designed for anterior optic movement following ciliary muscle contraction. Patients were examined postoperatively after 1 and 2 days, 1, 2 and 6 weeks, and 3 months, and results were compared with a control group of 12 eyes that received standard PMMA or acrylic PCIOLs. RESULTS: Surgery was uncomplicated and all PCIOLs were well-tolerated and stable with good centration in the capsular bag. The results were (mean +/- SD [range] and median; 1 CU versus control PCIOL): near visual acuity (Birkh?user reading chart at 35 cm) with best distance correction 0.34 +/- 0.17 (0.2 to 0.6), 0.3 (J10-J1, median J7) versus 0.15 +/- 0.07 (0.1 to 0.3), 0.15 (J16-J7, median J13), P=.001; subjective near point 59 +/- 10 cm (40 to 100 cm), 53.5 cm versus 93 +/- 20 cm (64 to 128 cm), 86 cm, P=.004; retinoscopic accommodative range 1.2 +/- 0.4 D (0.63 to 1.5 D), 1.2 D versus 0.2 +/- 0.19 D (-0.25 to 0.5 D), 0.25 D, P < .001; decrease of anterior chamber depth after 2% pilocarpine 0.63 +/- 0.16 mm (0.40 to 0.91 mm), 0.63 mm versus 0.15 +/- 0.05 mm (0.08 to 0.20 mm), 0.17 mm, P < .001. CONCLUSIONS: The new PCIOL appears to be safe at short to medium term. Our results indicate pseudophakic accommodation secondary to focus shift with this PCIOL. Additional larger and long-term studies are necessary for exact evaluation of safety and accommodative power of this new PCIOL.     

Improvement of fluctuations of intraocular pressure after cataract surgery in primary angle closure glaucoma patients

Background

Cataract surgery has been shown to reduce intraocular pressure (IOP) in eyes with primary angle closure glaucoma (PACG). In this study, we examined IOP fluctuations and circadian IOP patterns before and after cataract surgery in PACG patients using the contact lens sensor (CLS) Triggerfish®.

Methods

This was a prospective open-label study. Ten consecutive patients with PACG were included. The patients underwent phacoemulsification and intraocular lens implantation (PEA+IOL) surgery. In each eye, IOP fluctuations over 24 h were measured with the CLS before and at three months after the surgery. Changes in corneal curvatures and anatomic parameters of the anterior chamber were measured by anterior segment optical coherence tomography (AS-OCT).

Results

The mean IOP was significantly reduced from 14.7?±?1.5 mmHg to 11.2?±?2.2 mmHg at three months after the surgery in PACG patients (P?=?0.002). Although the mean range of 24-h IOP fluctuations was not significantly changed after the surgery (P?=?0.49), the mean range of IOP fluctuations during the nocturnal period was significantly decreased from 246?±?61 mVeq to 179?±?64 mVeq after the surgery (P?=?0.02). After the surgery, seven eyes of the ten (70 %) showed the same circadian IOP patterns. AS-OCT showed significant improvements in the anatomic parameters of the anterior chamber after the surgery.

Conclusions

Cataract surgery decreased IOP fluctuations during the nocturnal period in PACG patients. These effects might partly prevent the progression of PACG.     

超声乳化联合人工晶状体植入术对前房深度及房角宽度的影响

目的:探讨超声乳化联合人工晶状体植入术对患者前房深度、房角宽度的影响.方法:选取2015-06/2016-05在我院行白内障超声乳化吸除联合人工晶状体植入术的患者74例89眼,于术前及术后3 mo测量患者眼压、中央前房深度(ACD)、房角开放距离(AOD500)和房角角度(ACA500).结果:术后3mo,眼压为11.34±2.38mmHg,较术前(12.60±2.5 1mmHg)有所降低,差异有统计学意义(P＜0.05);ACD为4.01 ±0.30rmm,较术前(2.30±0.42mm)明显增厚,差异有统计学意义(P＜0.05);AOD500和ACA500分别为0.915±0.223mm和41.71 °±6.55°,明显高于术前0.514±0.201mm和24.01°±8.43°,差异有统计学意义(P＜0.05);眼压值与ACD、AOD500和ACA500呈负相关(r=-0.239、-0.211、-0.252,P＜0.05).结论:超声乳化联合人工晶状体植人术可降低患者眼压,增加患者前房深度和房角宽度,从而对眼内房水循环起到积极作用.     

Changes of axial length measured by IOL master during 2 years in eyes of adults with pathologic myopia

Objective

To examine the change of the axial length measured by IOL Master in adults with high myopia during a 2-year period.

Design

Open-label, consecutive, prospective longitudinal case series.

Methods

One hundred and eighty-five eyes of 185 consecutive patients with bilateral high myopia (myopia ≤ ?6 diopters (D) or axial length ≥26.5 mm) were studied. The mean age of the patients was 48.4 ± 12.2 years, with a range of 22 to 84 years. The axial length, the anterior chamber depth, and the radius of curvature of the cornea were measured by IOL Master at the initial examination and at 2 years after the first visit. The significance of the changes in the axial length after the 2-year periods was determined. Multiple regression analyses were performed to identify the factors which were significantly associated with the increase of the axial length.

Results

The mean axial length increased significantly from 29.35 ± 1.80 mm to 29.48 ± 1.85 mm in 2 years, a mean increase of 0.13 mm with a range of ?0.12 to 1.10 mm. The difference in the increase of the axial length between the patients with and without a posterior staphyloma was not significant. Among the possible explanatory factors, age, axial length, anterior chamber depth, the radius of curvature of the cornea, and intraocular pressure at the initial examination, the increase in the axial length was significantly and positively correlated with the axial length at the initial examination.

Conclusions

The measurement by IOL Master in a large population of highly myopic patients clearly showed that the axial length continued to increase in a span of 2 years even in the 4th decade of life. The eyes with longer axial length showed a greater increase of axial length, suggesting the possibility that the more myopic eyes become more myopic with increasing age.     

Evaluierung der Wertigkeit objektiver und subjektiver Verfahren zur Messung von pseudophaker Akkommodation

Purpose

The aim of this study was to compare the validity and plausibility of various subjective and objective measurement methods for evaluation of pseudophakic accommodation.

Setting

Eye Clinic Bellevue, Kiel, Germany.

Methods

A total of 21 patients were examined over an average period of 34 months (range 12–51 months) after implantation of a potentially accommodative, model 1CU intraocular lens (IOL, HumanOptics, Germany). The following subjective measurements were taken: near point measurement with the accommodometer (Clement Clarke, Harlow, UK), defocus curve and near visual acuity with far and near reading charts. The IOLMaster (Carl Zeiss Meditec, Germany), ACMaster (Carl Zeiss Meditec, Germany) and Shin-Nippon K 5001 AR (Shin-Nippon, Japan) were employed as objective measurement devices. With this devices information is obtained about the anterior chamber depth (ACD, preoperative and postoperative), the movement of the IOL and the refractive change of eyes during the accommodative process.

Results

Depending on the method utilized there were large variations of the examined IOL in relation to the extent of the measured accommodative effects in their entirety with the objective as well as the subjective measurement method.

Conclusions

A differentiation of pseudophakic accommodation and pseudophakic pseudoaccommodation is not possible with the conventional measurement methods applied and examined in this study. Only the ACMaster is an objective method for measurement of the axial shift of an IOL. However, subjective measurement methods can only record the total of both accommodation portions but do not allow any scientifically-founded statement about the functional principle of a potentially accommodative IOL.     

Short-term blood-aqueous barrier breakdown after implantation of the 1CU accommodative posterior chamber intraocular lens

PURPOSE: To quantify intraocular inflammation after phacoemulsification with implantation of an accommodative posterior chamber intraocular lens (IOL). SETTING: Department of Ophthalmology, University of Erlangen-Nürnberg, Erlangen, Germany. METHODS: Twenty cataractous eyes of 20 patients without preexisting blood-aqueous barrier (BAB) deficiencies or previous intraocular surgery were included in this study. The mean age of the patients was 64.6 years +/- 16.0 (SD). A single surgeon performed phacoemulsification through a superior sclerocorneal tunnel incision and implantation of a 1CU IOL (HumanOptics AG) though a 3.2 mm incision. The haptics of the single-piece acrylic 1CU lens are designed for anterior optic movement following ciliary muscle contraction. The postoperative treatment was standardized. Postoperative BAB breakdown was quantified by laser flare photometry (FC-1000, Kowa) at 1 day, 1 and 4 weeks, and 3 and 6 months. RESULTS: The mean aqueous flare was 6.3 photons/ms +/- 3.0 (SD) (range 4.0 to 12.2 photons/ms) 1 day postoperatively, with 64% of patients having normal aqueous flare values (<8.0 photons/ms). One week after surgery, the mean aqueous flare was 5.3 +/- 2.8 photons/ms (range 2.0 to 10.5 photons/ms). Four weeks postoperatively, aqueous flare was normal in all patients and remained stable below the normal limit for up to 6 months (mean 3.3 +/- 1.2 months; range 2.0 to 5.4 months). The number of aqueous cells did not increase at any follow-up and was normal in all eyes. No postoperative complications such as fibrin formation, synechias, macrophages on the IOL optic, or endophthalmitis were observed. CONCLUSIONS: Phacoemulsification with implantation of the 1CU accommodative IOL led to minimal and short-lasting BAB alteration. No signs of persistent inflammation or pigment dispersion were detected.     

Comparing accommodative function between the dominant and non-dominant eye

Background

To compare the accommodative amplitude (AA), facility (AF), and lag between dominant and non-dominant eyes.

Methods

Seventy students [mean (SD) age: 21.2 (1.7) years, range 18–25] from Zahedan University of Medical Sciences were selected. Retinoscopy and subjective refraction was used to determine the refractive error. The hole-in-the card method was used to determine eye dominance. The accommodative amplitude (AA) was measured in the dominant and non-dominant eye using the push-up method, and accommodative facility (AF) using ±2.00 dioptre flipper lenses at 40 cm. Accommodative lag was determined using monocular estimate method (MEM) retinoscopy at 40 cm.

Results

The right eye was dominant in 53 subjects (75.7 %). There was no significant difference in refractive error (sphere, cylinder, and spherical equivalent) between dominant and non-dominant eyes. The mean (SD) for the AA, AF, and lag in dominant eyes was 12.48 (2.56) dioptres, 12.45 (4.83) cycles per minute, and 0.80 (0.27) dioptres respectively. The mean (SD) for the AA, AF, and lag in non-dominant eyes was 12.16 (2.37) dioptres, 12.20 (4.88) cycles per minute, and 0.83 (0.28) dioptres respectively. The mean (SD) difference in AA, AF, and lag between dominant and non dominant eyes was 0.32 (0.75) dioptres (P?=?0.001), 0.25 (1.05) cycles per minute (P?=?0.04), and ?0.02 (0.11) dioptres (P?=?0.10) respectively. The AA and AF was statistically better (P?<?0.05) in the dominant eye group than in the non-dominant eye group. These data provided little evidence of any difference in the accommodative lag between dominant and non-dominant eyes (P?>?0.05).

Conclusion

The right eye was dominant in 76 % of subjects. Superior AA and AF was found in the dominant eye as determined by hole-in-the card method in young healthy adults, although these differences are perhaps not of clinical significance (<0.50 dioptres and <2 cycles per minute).     

Scheimpflug-Fotografie bei akutem Winkelblock

Purpose

In acute angle-closure glaucoma a laser iridotomy (IO) is performed to balance the intraocular pressure between the anterior and posterior chambers. The changes induced in the anterior chamber architecture were analyzed using Scheimpflug photography.

Material and methods

Scheimpflug photography was performed in eyes with acute angle closure and in the contralateral eyes before and after IO.

Results

In a group of 10 patients (8♀, 2♂, average age71.2?±?5.3 years) 10 eyes with acute angle closure and 10 contralateral eyes were analyzed. The anterior chamber depth, central corneal thickness and anterior chamber angle did not change significantly after IO. The mean anterior chamber volume showed a statistically significant increase in the 10 eyes with acute angle closure and in the 10 contralateral eyes.

Conclusion

Anterior chamber volume increases due to IO but not anterior chamber depth, central corneal thickness and anterior chamber angle in eyes with acute angle closure.     

Bag and chamber flushing: a new method of using intracameral moxifloxacin to irrigate the anterior chamber and the area behind the intraocular lens

Background

Intracameral moxifloxacin is currently administered by injecting small doses (0.05–0.2 mL) of either undiluted or diluted solutions. It is difficult to ensure delivery of small amounts of antibiotic into the area behind the intraocular lens (IOL). Moreover, the anterior chamber pressure decreases as the tip of irrigation is removed, often leading to contaminated fluid flowing into the chamber. Conventional intracameral injection administers the diluted antibiotic without irrigating the recontaminated anterior chamber. Therefore, we developed a method of intracameral moxifloxacin delivery which flushes both the anterior chamber and the area behind the IOL immediately after surgery.

Methods

Surgical technique (bag and chamber flushing = BC flushing): After removing the viscosurgical device, 1.5–1.8 mL diluted moxifloxacin was injected. Both the anterior chamber and the area behind the IOL were irrigated by lifting the IOL edge so that a stream of solution could circulate behind the IOL. Experiment 1 (pig): The anterior chamber was filled with condensed milk, and irrigated with 150-fold diluted moxifloxacin (33.3 μg/mL) in six eyes (BC flushing) to observe the irrigating effect. The anterior aqueous humor was sampled. Experiment 2 (human): A conventional intracameral injection (500 μg/mL) or BC flushing (33.3 μg/mL) was followed by sampling 0.1 mL of the anterior aqueous humor in six eyes each. High-performance liquid chromatography was performed to determine antibiotic levels.

Results

Experiment 1: The antibiotic concentration in the anterior chamber was 33.0 μg/mL (99.0 % was displaced). The area behind the IOL was not effectively irrigated without inserting the cannula tip. Experiment 2: The final antibiotic concentration was 152.3 μg/mL using the conventional method and 29.4 μg/mL using the BC flushing (88.3 % was displaced).

Conclusion

BC flushing technique enables surgeons to completely displace the anterior chamber including the posterior IOL surface, resulting in effective irrigation and a stable antibiotic concentration in virtually all cases.     

Miyake-Apple video analysis of movement patterns of an accommodative intraocular lens implant

BACKGROUND: The potentially accommodative intraocular lens (IOL) is a new development in IOL design METHODS: We evaluated the new Humanoptics 1CU accommodative IOL in a laboratory study with human post mortem autopsy eyes. Using the Miyake-Apple posterior view video technique, the movement pattern of the IOL was tested and observed from the posterior perspective. RESULTS. A circular bend at the level of the ciliary body applied slight circular force onto the sclera allowing the relaxation of the zonules. The shift of focus was demonstrated by using a reading target. In addition, viscoelastic was injected into the vitreous resulting in the same anterior movement of the IOL optic. CONCLUSIONS: The 1CU Humanoptics accommodative IOL showed potential accommodative behaviour in the laboratory. The accommodative (respectively pseudoaccommodative) effect was based on the anterior shift principle with anterior movement of the IOL-optic in the state of relaxing zonules. Whether this reflects the clinical situation, especially to this extent, must be further evaluated.     

Comparison of slit lamp-adapted optical coherence tomography features of fellow eyes of acute primary angle closure and eyes with open angle glaucoma

Purpose

The aim of this study was to assess the possibility of discriminating a narrow and occludable chamber angle by means of digital gonioscopy.

Methods

In a prospective controlled clinical study 40 eyes of 40 patients were enrolled. 20 patients that had suffered acute angle closure glaucoma (ACG) on the fellow eye were compared to 20 patients with open angle glaucoma (OAG). Anterior segment imaging with SL-OCT (Heidelberg Engineering, Heidelberg, Germany) enabled the delineation, by means of automatic signal analysis, of several important parameters of the anterior chamber angle region, which were compared to those revealed from direct contact glass gonioscopy and ultrasound biometry.

Results

The anterior segment structures were automatically recognized by the SL-OCT software in 70 % of the ACG patients and in all of the OAG cases (100 %) (p = 0.025). Anterior chamber angle (ACA) was 15.55° ± 6.92° in the ACG group and 34.6° ± 8.9° in the OAG group, whereas angle opening distance (AOD) was 199.55 ± 62.29 μm in ACG and 452.67 ± 123.91 μm in OAG. A good correlation was found in the direct gonioscopic findings (r = 0.85, p < 0.001), but there were significant differences between both groups (p < 0.001). Mean real central anterior chamber depth (rACD) was evaluated to be 1.75 and 2.79 mm in ACG and OAG, respectively, showing a significant difference (p < 0.0001) and the highest (although not statistically significant) sensitivity and specificity above all other parameters tested in discriminating between OAG and ACG eyes. Discrimination criteria revealed a relevant narrowing of the anterior chamber angle region for values below 22° (ACA), 276 μm (AOD) and 2.08 mm (rACD).

Conclusions

Digital gonioscopy by means of SL-OCT allowed a non-invasive and objective imaging of the anterior chamber configuration that could be used as a screening method for narrow and occludable angles. The method could contribute to a timely identification of angle closure and alert clinicians to further determine whether a peripheral iridotomy should be performed.     

Evaluation of rigid gas permeable lens fitting in keratoconic patients with optical coherence tomography

Purpose

To assess fitting of rigid gas permeable (RGP) lenses in patients with keratoconus, using spectral domain optical coherence tomography (SD-OCT).

Methods

The study was conducted on 30 eyes of 30 keratoconic patients fitted with RGP lenses, namely Rose K2 lens. Biomicroscopic examination with and without RGP lens was done. Fluorescein pattern was examined to determine the fitting, if ideal (three-point light touch), steep (central fluorescein pooling) or flat (central heavy bearing touch). Post-lens tear film thickness was measured centrally and at the lens edges using SD-OCT. Patient’s comfort was assessed and graded.

Results

Mean central post-lens tear film thickness was 35.1?±?7.3 μ in patients with ideal fitting. Mean post-lens tear film thickness of 50.4?±?8.2 μ and 25.3?±?6.1 μ was noted in patients with steep and flat fitting, respectively. Mean post-lens tear film thickness of 102.5?±?12.1 μ, 85.4?±?11.4 μ, 135.6?±?13.3 μ was demonstrated in eyes with ideal, steep and flat edge lift, respectively. Tear film thickness under the edges was significantly (p?=?0.04) lower in patients unsatisfied with their contact lenses.

Conclusion

SD-OCT can image and measure the tear film thickness in keratoconic patients with different fitting patterns of RGP lenses. OCT- guided fitting can be used to evaluate and modify the lens parameters to increase patient satisfaction. Lens intolerance may be related to edge lift rather than central fitting.