From the International Vision Correction Research Centre (IVCRC), Department of Ophthalmology, Ruprecht-Karls University, Heidelberg, Germany (Schmack, Auffarth, Holzer); and the Department of Ophthalmology, University of Zurich, Switzerland (Epstein).
The authors have no financial or proprietary interest in the materials presented herein.
Presented at the 7th International Congress on Surface Ablation & SBK, April 26, 2008, Ft Lauderdale, Fla; and the 21st Annual Meeting of the German Ophthalmic Surgeons (DOC), June 12–15, 2008, Nuremberg, Germany.
The authors thank Ms Katrin Guenthner, Ruprecht-Karls University, Heidelberg, Germany; and Martin Schumann, MD, Urology Practice at the Marienhospital, Osnabrueck, Germany, for assistance in preparing and distributing the study questionnaires.
Study concept and design (I.S., G.U.A., D.E., M.P.H.); data collection (I.S., M.P.H.); interpretation and analysis of data (I.S., G.U.A., M.P.H.); drafting of the manuscript (I.S.); critical revision of the manuscript (I.S., G.U.A., D.E., M.P.H.); statistical expertise (I.S., M.P.H.); obtained funding (G.U.A.); supervision (G.U.A., M.P.H.)
Correspondence: Gerd U. Auffarth, MD, Dept of Ophthalmology, University of Heidelberg, INF 400, 69120 Heidelberg, Germany. Tel: 49 6221 56 36631; Fax: 49 6221 56 5422; E-mail: firstname.lastname@example.org
Refractive surgery is a popular evolving field of ophthalmology. Therefore, an accurate understanding of the current practice styles and preferences in refractive surgery is important.1 Since the mid-1980s, various national and international surveys have been annually conducted to determine the differences in demographics, practice plans, surgical techniques, equipment, and complication rates in refractive surgery, with most surveys based or originating in the United States.2–7
The purpose of our survey was to provide information on the current status and latest trends in refractive surgery in Germany, which were obtained by members of the German Society of Intraocular Lens Implantation, Interventional, and Refractive Surgery (DGII) and the Commission of Refractive Surgery (KRC). Data were compared to our first German refractive surgery survey from 2005.8
Materials and Methods
In February 2008, a paper questionnaire with cover letter, explaining the purpose of the survey, and an enclosed reply envelope was distributed to 282 DGII and KRC members. To achieve a representative survey with an overall sufficient response, an Internet inquiry was performed prior to the mailing to distinguish active from nonpracticing DGII and KRC members as well as to identify active refractive surgeons who were not listed in the two German refractive societies. The survey was confidential, double-paged, and limited to seven simple, multiple-choice questions to encourage a high response rate. No financial incentive for returning the questionnaire was provided. Respondents were asked to mail the completed questionnaires anonymously to the International Vision Correction Research Centre (IVCRC), Department of Ophthalmology, Ruprecht-Karls University, Heidelberg, Germany. Surveys received by the deadline date were tabulated in a Microsoft Access database (Microsoft Corp, Redmond, Wash). Data analysis was performed in a masked fashion without knowledge of the respondent’s name or institution using the Microsoft Excel 2003 program. The results reported are based on the number of surgeons responding to each survey question, unless stated otherwise. All responses to any single question, including single and multiple responses, were taken into consideration.
The questionnaire was comprised of seven questions:
Where do you practice?
What types of refractive surgery procedures do you perform (i.e., laser in situ keratomileusis [LASIK], photorefractive keratectomy [PRK], laser-assisted subepithelial keratectomy [LASEK], epithelial laser in situ keratomileusis [EpiLASIK], intrastromal corneal rings [ICRs], refractive lens exchange [RLE], phakic intraocular lens implants [p-IOLs], and limbal relaxing incisions [LRIs])? How many surgeries do you perform per month of each type?
What excimer laser platform do you use?
What femtosecond laser flap cutting technology do you use, if any?
What mechanical microkeratome do you use, if any?
What preoperative diagnostic devices do you use?
Do you perform wavefront-guided, wavefront-optimized, or conventional ablations? How many ablations do you perform per month of each type?
The overall response rate was 42.2% (119 of 282 mailed questionnaires). The majority of respondents (86.6%, n=103/119) reported to actively perform refractive surgery. Sixteen (13.4%) respondents stated they currently are not doing any kind of surgical interventions; therefore, these questionnaires were excluded from further statistical analysis.
Fifty-three percent (n=55) of respondents practiced exclusively at a laser surgery center. Hospitals were used by 19.4% (n=20 general hospitals) and 12.6% (n=13 university hospitals) of respondents. In addition, 14.6% (n=15) of refractive surgeons reported performing refractive surgery at two different sites, such as a laser suite and a general hospital (11.7%, n=12) or a laser suite and a university hospital (2.9%, n=3).
Refractive Procedures (type and Monthly Volume)
Refractive surgical procedures performed by the questionnaire respondents included LASIK (80.6%, n=83), RLE (60.2%, n=62), PRK (47.6%, n=49), p-IOLs (45.6%, n=47), LASEK (36.9%, n=38), epiLASIK (15.5%, n=16), ICRs (5.8%, n=6), and LRIs (2.9%, n=3). Two respondents reported to also perform conductive keratoplasty (CK, 1.9%).
LASIK was the most frequently performed excimer laser refractive procedure, followed by PRK, LASEK, and epiLASIK (Fig 1). The monthly volume of LASIK procedures performed at different refractive institutions ranged from 1 to 131 cases (24.2±25.4 cases). The majority of respondents doing LASIK performed 1 to 20 cases per month (60%, n=50). No significant differences in the monthly volume of LASIK cases between the different refractive institutions were noted.
Figure 1. Reported Monthly Volume of Excimer Laser Refractive Surgical Procedures in Germany Performed by Respondents in 2008. PRK = Photorefractive Keratectomy, LASEK = Laser-Assisted Subepithelial Keratectomy, EpiLASIK = Epithelial Laser in Situ Keratomileusis, N/S = not Specified
Intraocular lens implantations were performed by 69.9% (n=72) of refractive surgeons. The majority of respondents reported a monthly volume of 1 to 10 cases (8.4±8.3 cases) (Fig 2). Refractive lens exchange with subsequent posterior chamber IOL implantation (86.1%, n=62) was more commonly performed compared to p-IOL implantation (65.3%, n=47).
Figure 2. Reported Monthly Volume of Intraocular Lens Implantation in Germany. p-IOL = Phakic IOL, RLE = Refractive Lens Exchange, N/S = not Specified
Excimer Laser Platforms
Excimer laser systems used by the respondents performing excimer laser-based refractive procedures (79.3%, n=92) included the ALLEGRETTO Wave (28.6%, n=26; WaveLight AG, Erlangen, Germany), the Technolas Keracor 217 Z100 (25.3%, n=23; Bausch & Lomb Inc, Rochester, NY), the ESIRIS (22.0%, n=20; SCHWIND eye-tech-solutions GmbH, Kleinostheim, Germany), the MEL 80 (9.9%, n=9; Carl Zeiss Meditec AG, Jena, Germany), the VISX S4 IR (9.9%, n=9; Abbott Medical Optics Inc, [AMO], Santa Ana, Calif), the MEL 70 (3.3%, n= 3; Carl Zeiss Meditec AG), the AMARIS (3.3%, n=3; SCHWIND eye-tech-solutions GmbH), and the NIDEK EC-5000 CX series (1.1%, n=1; NIDEK Co Ltd, Gamagori, Japan).
Refractive surgeons practicing in laser surgery centers (exclusively vs partially) demonstrated a preference for the ALLEGRETTO Wave (30.9%, n=17 vs 33.3%, n=5) compared with those practicing at university hospitals, which mainly used the ESIRIS excimer laser (30.8%, n=4). In contrast, respondents of general hospitals preferred the Technolas Keracor 217 or the ESIRIS excimer laser (20.0%, n=4 each). A detailed overview of the distribution of the various excimer laser systems among all respondents and separated for the different refractive institutions is shown in Figure 3.
Figure 3. Excimer Laser Systems Most Commonly Used by Refractive Surgeons in Germany. Numbers Above the Combined Settings Bars Indicate the Total Volume (%) of the Individual Product.
Femtosecond Laser Platforms
Twenty-eight percent (n=29) of refractive surgeons reported having a femtosecond laser at their institution. Femtosecond laser units included the Intra-Lase FS (AMO), Femtec (20/10 Perfect Vision AG, Heidelberg, Germany), Femto LDV (Ziemer Ophthalmic Systems AG, Port, Switzerland), and the VisuMax (Carl Zeiss Meditec AG). The IntraLase FS was the most frequently used femtosecond laser (72.4%, n=21) followed by the VisuMax (13.8%, n=4), Femtec (6.9%, n=2), and Femto LDV (6.9%, n=2). The distribution of the individual femtosecond laser systems among all respondents and separated for the different refractive institutions is illustrated in Figure 4.
Figure 4. Femtosecond Lasers Most Commonly Used by Refractive Surgeons in Germany. Numbers Above the Combined Settings Bars Indicate the Total Volume (%) of the Individual Product.
A variety of mechanical microkeratomes were used by the respondents. The individual reported microkeratomes included the Hansatome (27.2%, n=28; Bausch & Lomb), the Zyoptix XP (19.4%, n=20; Bausch & Lomb), the Carriazo Pendular (16.5%, n=17; SCHWIND eye-tech-solutions), the Amadeus II (12.6%, n=13; Ziemer Ophthalmic Systems AG), Amadeus (7.8%, n=8; Ziemer Ophthalmic Systems AG), the M2 Single Use (4.9%, n=5; Moria, Antony, France), the Lasitome (2.9%, n=3; Gebauer GmbH, Neuhausen, Germany), the LSK-1 (1.9%, n=2; Moria), MK-2000 (1.0%, n=1; NIDEK Co Ltd), the Supratome (1.0%, n=1; SCHWIND eye-tech-solutions), and the Excellus (1.0%, n = 1; Bausch & Lomb).
Slight differences in the use of the individual microkeratomes among different refractive surgery institutions were noted. More than half of the respondents (52.9%, n=37) who were practicing at laser surgery centers (exclusively vs partially) reported to prefer the Bausch & Lomb Hansatome (32.7%, n=18 vs 26.7%, n=4) or the Zyoptix XP (23.6%, n=13 vs 13.3%, n=2) microkeratomes. In contrast, the SCHWIND Carriazo Pendular was the microkeratome of choice (30.0%, n=6 vs 30.8%, n=4) by LASIK surgeons practicing in general and university hospitals, respectively (Fig 5).
Figure 5. Mechanical Microkeratomes Most Commonly Used by Refractive Surgeons in Germany. Numbers Above the Combined Settings Bars Indicate the Total Volume (%) of the Individual Product. N/S = not Specified
Preoperative Diagnostic Devices
Topography systems most commonly reported were the Pentacam (22.3%, n=23; Oculus Optikgeräte GmbH, Wetzlar, Germany) and the Pentacam HR (18.4%, n=19; Oculus Optikgeräte GmbH) followed by the Orbscan (7.8%, n=8; Bausch & Lomb), the ALLEGRO Topolyzer (2.9%, n=3; WaveLight AG), and ALLEGRO Oculzyer (2.9%, n=3; WaveLight AG).
Wavefront analyzers were used by 66% (n=68) of refractive surgeons. Among those, 19.4% (n=20) reported to prefer the Zywave (Bausch & Lomb), 17.5% (n=18) preferred the Corneal Wavefront Analyzer (SCHWIND eye-tech-solutions), and 14.6% (n=15) the Ocular Wavefront Analyzer (SCHWIND eye-tech-solutions). Additional aberrometers included the WASCA Wavefront Analyzer (11.7%, n=12; Carl Zeiss Meditec AG), the WaveScan WaveFront (8.7%, n=9; AMO), the ALLEGRO Analyzer (6.8%, n=7; WaveLight AG), and the OPD-Scan II (3.9%; n=4; NIDEK Co Ltd).
Figures 6 and 7 illustrate distribution of individual topography units and aberrometers among all respondents and separated for the different refractive institutions.
Figure 6. Topography Units Most Commonly Used by Refractive Surgeons in Germany. Numbers Above the Combined Settings Bars Indicate the Total Volume (%) of the Individual Product. All. = ALLEGRO; N/S = not Specified
Figure 7. Wavefront Analyzers Most Commonly Used by Refractive Surgeons in Germany. Numbers Above the Combined Settings Bars Indicate the Total Volume (%) of the Individual Product. All. = Allegro; N/S = not Specified
Wavefront-guided custom ablation and wavefront-optimized ablation profiles were performed by 51.5% (n=53) and 40.8% (n=42) of refractive surgeons, respectively. Thirty-four percent (n=35) used conventional ablation profiles and 5.8% (n=6) did not answer this question. Of those that perform wavefront-guided custom ablation, 30.1% (n=31) reported performing them with a low frequency (≤25%) compared with all refractive surgeries done, whereas 10.7% (n=11) reported performing them with a high frequency (≥75%). In contrast, wavefront-optimized ablations profiles were mainly (24.3%, n=25) performed with high frequency as only 12.6% (n=13) of respondents reported performing them with a low frequency.
Cataract and refractive surgery surveys, first started by David Leaming in the mid-1980s, have a long tradition in ophthalmology.2,3,6,9–17 They provide structured information on actual trends, preferences, and practice styles on various topics in cataract and refractive surgery, and contribute to an understanding of what is mainstream as well as what is going out of fashion or just coming down the line in the future. However, based on their nature and the complexity of a worldwide expanding ophthalmologic society, surveys have potential disadvantages such as varying response rates among different countries or an overall low and slowly decreasing response rate when performed too often (eg, annually, 11% to 27%).1–3,6,9–13 In addition, most surveys are often sent to members of a particular refractive society (eg, American Society of Cataract & Refractive Surgery [ASCRS]) only; therefore, do not guarantee to address all ophthalmologists performing cataract and refractive surgery worldwide.1,6,9,10,12
In our survey, we attempted to address these issues by contacting active practicing refractive surgeons of the two German refractive societies—the DGII and the KRC. In addition, we performed an Internet inquiry prior to mailing to also identify active refractive surgeons who were not listed in either the DGII or KRC. We further limited the amount of questions to major refractive surgical topics and asked the respondents to reply within a short time period of 2 weeks. Overall, we achieved a satisfactory response rate of 42% at deadline. The response rate was similar to our first German refractive survey (2005; response rate 43.1%) and comparable to other European refractive surgery surveys.2,8,15,16 Nevertheless, based on the anonymous nature of the survey, it was not possible to trace refractive surgeons who did not return their survey. Therefore, we were unable to determine if their responses might differ from those who returned questionnaires.
Overall, the 2008 survey provides an interesting view of refractive surgery being performed in Germany today. Compared with 2005, there was a slight shift in the site of surgery from laser surgery centers (77% in 2005 vs 68% in 2008) towards general hospitals (12% in 2005 vs 19% in 2008).8 In contrast, the number of refractive surgeons practicing at university hospitals remained fairly stable (11% in 2005 vs 13% in 2008).8
Among the different refractive procedures, LASIK was the predominant refractive surgical procedure performed in Germany (81%) followed by PRK, LASEK, and epiLASIK. However, the percentage of respondents performing excimer laser-based keratorefractive surgery slightly declined (Fig 8). As a consequence, the volume of lens refractive procedures, such as p-IOLs and RLE with insertion of multifocal or toric IOLs demonstrated an increase over the past 3 years (41% and 41% in 2005 vs 46% and 60% in 2008, respectively). The results are mainly similar to those of other European countries and the United States.13,15–18 However, differences exist with regard to the frequency of PRK and epiLASIK. The total volume of PRK in Germany was ~50% less compared with the United States (46% vs 94%); whereas the number of refractive surgeons performing epi-LASIK was almost double (37% vs 21%) in the United States.17
Figure 8. Changes in Refractive Surgical Practice Styles in Germany Between 2005 and 2008. LASEK = Laser-Assisted Subepithelial Keratectomy, EpiLASIK = Epithelial Laser in Situ Keratomileusis, PRK = Photorefractive Keratectomy, p-IOL = Phakic Intraocular Lens, RLE = Refractive Lens Exchange
In Germany, we were also able to indicate a trend shifting away from the Technolas 217 and MEL 70 excimer laser towards the ALLEGRETTO Wave and MEL 80 corneal laser systems. A similar trend was found among US refractive surgeons, which demonstrated an increased use of the ALLEGRETTO Wave (1% to 18%) over the past 5 years.11,13,17 In contrast, the ESIRIS excimer laser did not show a significant change between 2005 and 2008 (21% vs 19%).
Among all currently available femtosecond laser platforms, the IntraLase FS was the most widely used platform in Germany. Although we were not able to compare the femtosecond laser results with our previous survey, the current data are consistent with US trends, which show a significant increase in the distribution of the IntraLase FS over the past few years (eg, 12% to 40% increased use in the United States).11,13,17
For those who prefer mechanical microkeratomes to cut LASIK flaps, the Hansatome was the most commonly used; however, the percentage of respondents using the Hansatome microkeratome decreased (59% in 2005 vs 27% in 2008). These results are similar to those obtained in the United States, which also demonstrated a decline in the use of the Hansatome (46% in 2004 vs 20% in 2008), along with other mechanical microkeratomes over the past 5 years.11,13,17 In contrast, there was an increase in the use of the Amadeus and the Carriazo-Pendular microkeratomes among German refractive surgeons over this same time period.
Among the different diagnostic devices reported by respondents, there was a preference for wavefront analyzers compared to topography-based systems (58% vs 42%). Taking into consideration the increased worldwide popularity of wavefront-guided custom and wavefront-optimized ablations, the frequency of use of aberrometers in the preoperative assessment of refractive patients will potentially further increase in the future as indicated by the latest refractive surveys.11–13,19–21
The 2008 German refractive surgery survey demonstrates that refractive surgery remains a dynamic field of ophthalmology with trends and changes in practice style that are in line with other European countries. Differences for the use of surgical and diagnostic tools compared with the United States may in part be explained by delayed US Food and Drug Administration approval times (eg, ALLEGRETTO Wave vs VISX excimer laser), the individual manufacturers’ country of origin (eg, IntraLase FS laser [United States] vs VisuMax FS laser [Germany]), the time of market introduction, and the fact that some devices are only sold outside the United States. Overall, there is a clear shift towards newer, more advanced surgical techniques (eg, custom ablations) and instruments (eg, femtosecond lasers). This survey presents a summary of the current German refractive surgery situation and may help to improve the quality of refractive surgery performed in Germany or elsewhere.
- Kohnen T. The value of surveys for cataract and refractive surgery. J Cataract Refract Surg. 2003;29:1647–1648. doi:10.1016/j.jcrs.2003.08.001 [CrossRef]
- Leaming DV. Practice styles and preferences of ASCRS members–1985 survey. J Cataract Refract Surg. 1986;12:380–384.
- Oshika T, Masuda K, Hayashi F, Leaming DV. Current trends in cataract and refractive surgery in Japan–1992 survey. Jpn J Ophthalmol. 1993;37:432–444.
- Kraff MC, Sanders DR, Karcher D, Raanan M, DeLuca M, Neumann G. Changing practice patterns in refractive surgery: results of a survey of the American Society of Cataract and Refractive Surgery. J Cataract Refract Surg. 1994;20:172–178.
- Elder M, Tarr K, Leaming D. The New Zealand cataract and refractive surgery survey 1997/1998. Clin Experiment Ophthalmol. 2000;28:89–95. doi:10.1046/j.1442-9071.2000.00274.x [CrossRef]
- Solomon KD, Holzer MP, Sandoval HP, Vargas LG, Werner L, Vroman DT, Kasper TJ, Apple DJ. Refractive surgery survey 2001. J Cataract Refract Surg. 2002;28:346–355. doi:10.1016/S0886-3350(01)01318-9 [CrossRef]
- Ewbank A. Trends in laser refractive surgery in the UK 2003. Optician. 2003;226:12–16.
- Auffarth GU, Holzer MP, Schweipert J, Reuland MS, Epstein D. Refraktive Umfrage der DGII. In: Kohnen T, Auffarth GU, Pham DT, eds. 20. Kongreß der Deutschsprachigen Gesellschaft für Intraokulalinsen–Implantation und Refraktive Chirurgie. Köln, Germany: Biermann Verlag; 2006:273–277.
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- Kashani S, De Silva DJ, Aslam S, Maini R. A survey of excimer laser use among consultant ophthalmologists in the United Kingdom. Eye. 2007;21:279–281. doi:10.1038/sj.eye.6702526 [CrossRef]
- Gold R. Practice styles and preferences of French cataract and refractive surgeons: 2006–2007 survey. Presented at: European Society of Cataract and Refractive Surgeons Annual Meeting. ; September 8–12, 2007. ; Stockholm, Sweden. .
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- Waring GO IV, Durrie DS. Emerging trends for procedure selection in contemporary refractive surgery: consecutive review of 200 cases from a single center. J Refract Surg. 2008;24:S419–S423.
- Netto MV, Dupps W Jr, Wilson SE. Wavefront-guided ablation: evidence for efficacy compared to traditional ablation. Am J Ophthalmol. 2006;141:360–368. doi:10.1016/j.ajo.2005.08.034 [CrossRef]
- Randleman JB, Loft ES, Banning CS, Lynn MJ, Stulting RD. Outcomes of wavefront-optimized surface ablation. Ophthalmology. 2007;114:983–988. doi:10.1016/j.ophtha.2006.10.048 [CrossRef]
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