Keratometry Changes Between Year One to Seven After Corneal Cross-Linking in Patients With Keratoconus.

PURPOSE: We evaluated the timing at and extent to which midterm to long-term keratometric changes can occur in year 1 to 7 after corneal collagen cross-linking (CXL) in patients with keratoconus. METHODS: We conducted a subgroup analysis of a retrospective cohort study of all consecutive patients who underwent CXL at our cornea center between 2007 and 2011. The inclusion criteria comprised CXL according to the Dresden protocol and a full set of keratometry parameters collected by Scheimpflug tomography preoperatively and at year 1, 3, 5, and 7 after CXL. In addition, best-corrected visual acuity was evaluated. RESULTS: Sixty-three eyes of 47 patients were enrolled. Mean age was 25.46 years ±7.39 years (80.9% male patients). All relevant keratometric parameters showed significant improvement at year 1 after CXL (except for posterior astigmatism). According to mixed-effects model analysis, they all showed further significant change at different points in time between year 1, 3, 5, and 7 (except for K1). In addition, best-corrected visual acuity improved statistically significant between year 1, 3, 5, and 7. Suspected disease progression was noted in 22.2% of patients, mostly between year 1 and 3 after CXL. CONCLUSIONS: After initial improvement 1 year after CXL, keratometric and functional parameters were stable until year 5 after CXL in most cases; further improvement can take place even after up to 7 years post-CXL. By contrast, in case of disease progression, changes seem to occur already between year 1 and 3 after CXL.

Evaluation of Automated Measurement of Macular Ischemic Changes in Retinal Vein Occlusion With Optical Coherence Tomography Angiography.

OBJECTIVE: The foveal avascular zone (FAZ) is altered in patients with retinal vein occlusion (RVO) and correlates inversely with visual acuity. Optical coherence tomography angiography (OCTA) is an imaging tool to visualize FAZ safely and easily. Automated measurements can facilitate interpretation of OCTA images. In this comparative cross-sectional study, we compare the results of manual measurement of the FAZ with automated measurement by built-in application (Metrix). METHODS: The study included patients with RVO who underwent OCTA. Manual measurement was compared with automated evaluation by Metrix in 3 mm x 3 mm and 6 mm x 6 mm scan sizes and correlations of the circularity, circumference, and size of the FAZ were calculated. RESULTS: Forty-seven eyes were included in the study. A reliable measurement result in both Metrix 3 mm x 3 mm and 6 mm x 6 mm was found in only 25 of 47 eyes. The mean FAZ in these eyes by manual measurement was 0.50 mm2 compared with 0.20 mm2 and 0.24 mm2, respectively, by automated measurement. A statistically significant inverse correlation was found in both the automated 3 mm x 3 mm and 6 mm x 6 mm measurements for FAZ circumference with FAZ circularity but not FAZ area. CONCLUSION: The two automated measurements showed no significant bias regarding the size of the FAZ, but the plausibility of the data should be checked on a case-by-case basis. The manual measurements were higher, indicating limited agreement of manual and automated measurements. The information on circularity can point to ischemic maculopathy early in the course of the disease. [Ophthalmic Surg Lasers Imaging Retina 2023;54:462-469.].

[Thyroid Eye Disease-Compressive Optic Neuropathy]. / Optikuskompression bei endokriner Orbitopathie.

BACKGROUND: The aim of this study was to evaluate the functional outcomes in terms of best-corrected visual acuity (BCVA) and visual field (VF) defects in optic nerve compression (thyroid eye disease-compressive optic neuropathy, TED-CON) patients after treatment. PATIENTS AND METHODS: In this observational, retrospective study, the medical charts of 51 patients (96 eyes) with a diagnosis of definitive TED-CON between 2010-2020 were included. RESULTS: After the diagnosis of TED-CON, 16 patients (27 eyes) received steroid-pulse (medical) treatment alone, 67 eyes received an additional surgical orbital decompression, whereas 1 patient (2 eyes) refused both treatment methods. In 74 eyes (77.1%) we detected an improvement of the BCVA ≥ 2 lines after the treatment over a mean time interval of 31.7 weeks (with no significant difference between treatment methods). In 22 eyes (27.2%) out of the 81 that underwent a posttreatment VF examination, we observed a complete resolution of the defects over a mean time interval of 39.9 weeks. When we limited analysis to patients with a minimum follow-up of 6 months at last visit, we found 33 eyes (61.1%) out of 54 eyes still had a VF defect. CONCLUSION: In our data, more than half of the TED-CON cases (61.5%) had a good prognosis with a final BCVA ≥ 0.8  at the last visit; however, only 22 eyes (27.2%) showed a complete resolution of VF defects, while 33 eyes (61.1%) had residual defects measured after a minimum follow-up of 6 months. These results suggest that while the BCVA recovers relatively well, the VF of patients is likely to remain marked by optic nerve compression.

Reutilization of disposable rebound tonometer probes: Risk or return?

Purpose: An advantage of rebound tonometry (RT) is its ease of use so that it can also be operated by health care technicians. However, the cost of the disposable measuring probes is high and their reuse carries the risk of infection. Therefore, this study aims to objectify the potential risk of bacterial transmission by RT. Methods: Our experimental setting consisted of two experiments. The first aimed to quantify the number of bacteria on a tonometer probe after immersion in a bacterial suspension in vitro. The experiment was carried out with two different bacteria and compared with results from a Goldmann tonometer probe. The second experiment tested whether bacteria could be transmitted by simulating reuse of a nondisinfected rebound tonometer probe. Results: First experiment: After immersion of the rebound tonometer probe, we measured a bacterial count of 2.43 × 106 Escherichia coli (EC) and 1.12 × 106 Pseudomonas fluorescens. In total, 1.09 × 107 bacteria for EC and 2.61 × 106 for Pseudomonas fluorescens (PF) were measured on the Goldmann tonometer probe. Second experiment: A bacterial transmission could be detected in 36% of cases in which reuse of nondisinfected tonometer probes was simulated. Conclusion: These results show that despite the small surface of the rebound tonometer probe, there is a clear risk of bacterial transmission. Thorough disinfection according to general standards should be mandatory if the tonometer probes are to be reused.

See clearer: survey on the subjective and objective information levels as well as perception and information transfer using virtual reality headsets in patients with diabetic macular edema receiving anti-VEGF treatment.

PURPOSE: The purpose of this study is to investigate the use of a VR Headset in routine clinical practice as an additional source of information for patients with diabetic macular edema (DME) and their companions. METHODS: Survey including 121 patients with DME, 22 companions, and 14 healthcare professionals from 8 ophthalmology centers in Germany. Patients' and their companions' health literacy was assessed by questionnaires including knowledge statements before and after watching a VR-based 3-D educational video. HCPs' perspectives on the usability of a VR Headset were also assessed. RESULTS: Patients' mean age was 63.4 ± 12.2 years, 64.5% were men, and 76% (92/121) had previous anti-VEGF (VEGF, vascular endothelial growth factor) injections. After using the VR Headset, over 85% of patients and companions felt better informed about DME and its treatment. Patients' mean (± SD) number of correct answers to knowledge statements increased from 13.2 ± 3.7 before to 15.5 ± 2.3 after using the VR Headset. Over 95% of patients and companions rated content and ease of understanding of the video as "very good" or "good." Most patients and all companions considered the use of a VR Headset as a positive experience, most wishing to obtain information via VR Headset in the future. Most physicians and all medical assistants rated the effect of the VR Headset on patient satisfaction as positive and suggested further VR modules. CONCLUSION: After using the VR Headset, patients with DME and their companions demonstrated knowledge gains that may be meaningful individually and contribute to better adherence. This may offer an additional opportunity for knowledge transfer.

Corneal cross-linking in patients with keratoconus: up to 13 years of follow-up.

INTRODUCTION: To evaluate long-term safety and efficacy of corneal collagen cross-linking (CXL) in patients with keratoconus up to 13 years. MATERIALS AND METHODS: In this mono-centre exploratory study, we included all consecutive patients who underwent CXL in our cornea centre from 01/01/2007 to 12/30/2011 and met the inclusion criteria. CXL was performed in all patients according to the Dresden protocol. Evaluation included best-corrected visual acuity (BCVA), topographic keratometry by Scheimpflug corneal tomography and endothelial cell count (ECC). Follow-up measurements were taken up to 13 years after treatment were compared with baseline values. RESULTS: The study enrolled 168 eyes. The mean age of our patients was 26.3 years ± 7.8 years. A complete topographic dataset was available 1 year postoperatively for 142 eyes, 5 years postoperatively for 105 eyes, 10 years postoperatively for 61 eyes and 13 years postoperatively for 9 eyes. BCVA increased statistically significant after 1 year, 5 years and 10 years and non-significantly after 13 years. All keratometric parameters with exception of posterior astigmatism showed a statistically significant decrease after 1 year, 5 years and 10 years. After 13 years, the decrease was statistically significant only in Kmax, K2 and thinnest cornea. No significant changes in ECC were detected. Three eyes received Re-CXL, none of the eyes received penetrating keratoplasty and no infections occurred in this cohort. CONCLUSIONS: CXL can slow down or even stop the progression of keratoconus in the majority of cases. The effect is long-lasting with excellent safety.

Central Serous Chorioretinopathy: Morphological and Functional Outcome after Subthreshold Thermal Laser Coagulation with a Frequency-Doubled Nd:YAG Continuous-Wave Laser.

PURPOSE: Central serous chorioretinopathy (CSCR) presents itself as a serous detachment of the central neurosensory retina (NR), which may be accompanied by focal detachment of the retinal pigment epithelium (RPE) and changes in the RPE itself. It is often self-limiting; however, if the macular region is affected, visual impairment can be serious. If spontaneous remission does not occur, data on the effectiveness of further treatment options are sparse. We therefore decided to examine the effectiveness of subthreshold laser photocoagulation (ST-LP) on best-corrected visual acuity (BCVA) and subretinal fluid (SRF) resorption. We conducted a retrospective analysis of all patients who underwent ST-LP based on the diagnosis of CSCR in a German university eye hospital from 2009 to 2014. METHODS: The diagnosis of CSCR was based on the following criteria: detachment of the NR and possibly the RPE visible on ophthalmoscopy, evidence of SRF on optical coherence tomography (OCT), visualization of one or more source points typical for CSCR in fluorescein angiography, and exclusion of differential diagnoses. The time between the anamnestic onset of symptomatic complaints and ST-LP was determined as well as BCVA and OCT before ST-LP. ST-LP was performed as a subthreshold thermal laser coagulation with a frequency-doubled Nd:YAG continuous-wave laser. Follow-up examinations were scheduled at 4, 8, and 12 weeks after ST-LP. RESULTS: Fifty-four eyes of 49 patients were included in the study. The median age of patients was 47 years. Eighty-nine percent of the included patients were male. Twenty percent of patients had a first manifestation of CSCR, 69% had a recurrence, and 11% had persistent SRF for >6 months. The median visual acuity rose from 0.30 at baseline (BL) to 0.10 at 4 weeks and 0.00 at 8 weeks, before dropping slightly to 0.05 at 12 weeks. Changes of visual acuity in comparison to BL were statistically significant (p < 0.05). The initial median retinal thickness of 397 µm at BL decreased to 264 µm at 4 weeks, to 236 µm at 8 weeks, and to 239 µm at 12 weeks (decreases to BL all statistically significant p < 0.05). CONCLUSION: In our cohort, we were able to achieve substantial and significant clinical benefit through ST-LP measured by improvement in BCVA. Furthermore, we were also able to demonstrate measurable, significant morphological improvements as decreased retinal thickness and increased resorption of SRF as probable mechanisms explaining clinical improvement of CSCR with ST-LP. The advantage of ST-LP over other methods is the low risk of adverse events and its high availability. Controlled, randomized studies are necessary to confirm the data and demonstrate the effect over a longer period of time.

[Patient's Knowledge after Informed Consent for Intravitreal Injections]. / Intravitreale Injektionen ­ welche Informationen aus dem Aufklärungsgespräch bleiben Patienten im Gedächtnis?

BACKGROUND: Intravitreal treatment (IVT) is one of the most common ophthalmological procedures. Therapeutic effectiveness is however dependent on patient compliance. Unwanted treatment cessation rates are high though. The authors therefore decided to analyse the patient's knowledge and treatment expectations, as discrepancies are known to negatively affect compliance and thus treatment outcomes. PATIENTS AND METHODS: The study was designed as an exploratory survey. In total, 100 patients presenting to an outpatient clinic of a tertiary care centre from October to December 2016 were included. A structured, anonymised questionnaire was handed out, consisting mainly of question items with closed code lists as response domains. Solely descriptive analysis of results was performed. RESULTS: The median age of patients was 73 years. 70% had received more than 3 IVTs in at least one eye. Age-related macula degeneration was the most common underlying cause (52%). 64% expected improvement of visual acuity after IVT. 42% could not name one medication used in their IVT. 55% felt that the information provided during informed consent had been adequate. 69% did not know the post-surgical occurrence of endophthalmitis. Three patients were confident of being able to drive a car directly after IVT. CONCLUSION: Patient's knowledge of their underlying disease, treatment goals and complications rates exhibited some deficiencies. Standardised patient information sheets could be of significant use and were actively suggested by patients to improve the informed consent process.

[The Importance of the Preoperative Information from a Patient's Perspective - a Structured Interview of 100 Ophthalmological University-Based Outpatients]. / Die Erwartungen an das Aufklärungsgespräch aus Patientensicht ­ strukturierte Befragung von 100 Patienten einer ophthalmologischen Universitätsambulanz.

BACKGROUND: The patient's knowledge about their illness, as well as their expectations regarding pre-intervention, consultation and treatment, may differ from the physician's assumptions. Therefore, it is of great importance that the physician can identify misconceptions and missing knowledge and to focus on those points in the preoperative consultation, as well as meeting patient expectations as to the consultation itself. The aim of this study was to identify such expectations and the knowledge gaps of patients scheduled for ophthalmologic treatment. METHOD: An anonymous questionnaire containing predominantly closed questions was handed out to 100 patients in an ophthalmological outpatient clinic of a tertiary care center. Answers were mostly single choice items on a rating scale. RESULTS: 55% of patients had received ophthalmological interventions prior to receiving the questionnaire; 36% received more than two. More than half had not informed themselves about the planned procedure prior to their appointment. They were worried the most about complications (59%) and least about the anaesthesia (29%). When asked, patients attributed the highest priority to provision of information regarding complications and most often requested information on implications of the planned surgery on daily activities. CONCLUSION: Roughly half of the patients came without having informed themselves prior to the consultation. A comprehensive explanation with regard to success rates and possible post-surgical impairments appears to be essential. Possibilities of new media, such as the internet, surprisingly do not seem to be of importance to patients in this context.

Comparison between Findings in Optical Coherence Tomography Angiography and in Fluorescein Angiography in Patients with Diabetic Retinopathy.

OBJECTIVE: To compare typical findings of diabetic retinopathy in optical coherence tomography angiography (OCTA) and fluorescein angiography (FA). SUBJECTS/METHODS: 42 patients were enrolled in this study. We performed FA and obtained en face 3 × 3 mm OCTA images of the macular region. The count of microaneurysms (MAs) and the size of the foveal avascular zone (FAZ) were compared. The assessability of the imaging modalities was graded in each eye. RESULTS: 53 eyes of 42 patients with a mean age of 61 years were included. 36/53 eyes revealed nonproliferative diabetic retinopathy, 17/53 eyes had proliferative diabetic retinopathy. The mean size of the FAZ was 0.39 mm2 in FA and 0.42 mm2 in OCTA. The mean MA count was 14 in FA and 13 in OCTA. The assessability was favorable to OCTA in 38-41/53 eyes regarding the FAZ and favorable to FA in 45-49/53 eyes regarding MAs. CONCLUSION: We found a good agreement for the size of the FAZ and a weak agreement regarding the count of MAs in both imaging modalities. The readers favored OCTA for the assessment of the FAZ and FA for the assessment of MAs. Complementary use of FA and OCTA ensures the best diagnostic approach in patients with diabetic retinopathy.

[Visualization of Retinal Neovascularization with Optical Coherence Tomography Angiography in Comparison with Fluorescein Angiography]. / Darstellung von retinalen Neovaskularisationen mit der optischen Kohärenztomografie-Angiografie im Vergleich mit der Fluoreszeinangiografie.

OBJECTIVE: Comparison of retinal neovascularizations of the disc (NVD) and elsewhere (NVE) in optical coherence tomography angiography (OCTA) and fluorescein angiography (FA) in patients with proliferative diabetic retinopathy. MATERIALS AND METHODS: 15 consecutive patients were included in this study. All patients received an OCTA with a 3 × 3 mm scan of the region of interest with the ZEISS OCT Cirrus 5000 with the AngioPlex module. The size of the neovascularization (NV) was determined manually in OCTA and FA and compared between the two methods. RESULTS: 20 eyes of 15 patients with proliferative diabetic retinopathy with an average age of 57 years were included. The mean size of NVDs was 3.44 mm2 in OCTA and 3.75 mm2 in FA, the mean size of NVDs was 1.06 mm2 in OCTA and 1.54 mm2 in FA. Taking into account a generally larger area measured in the FA, the two methods showed good overall agreement. CONCLUSION: There was a good agreement for the size of the NVs in both methods. OCTA can be used as a simple and non-invasive method to visualize retinal neovascularizations.

[Comparison Between Automated and Manual Measurement of Foveal Avascular Zone Retinopathy in Optical Coherence Tomography]. / Evaluation der automatisierten Messung von ischämischen Veränderungen der Makula bei diabetischer Makulopathie.

OBJECTIVE: A comparison between automated and manual measurements of a foveal avascular zone in optical coherence tomography angiography (OCTA) in patients with diabetic retinopathy (DR). MATERIAL AND METHODS: Consecutive patients with non-proliferative DR were included in this study. All patients received an OCTA, with a 3 × 3 mm scan of the macular region taken with the Zeiss OCT CIRRUS 5000 with the AngioPlex module. The size of the foveal avascular zone (FAZ) was determined both manually and with the help of the automated measurement metrics. Next, the measurements obtained using manual and automated methods were compared. In addition, the circularity index determined in metrics was examined for correlations with the size and area of the FAZ. RESULTS: Thirty-four eyes from 28 patients with non-proliferative diabetic retinopathy with a mean age of 63 years were included. The mean size of the foveal avascular zone was 0.34 ± 0.12 mm2 (0.08 - 0.65 mm2) for manual evaluation and 0.23 ± 0.11 mm2 (range 0.03 - 0.49 mm2) in metrics. The circularity index in metrics averaged 0.58 and showed a statistically significant correlation with the size of the manually measured FAZ. CONCLUSION: There was a comparable result for the size of the FAZ in both measurement methods. Automated measurements with metrics can reliably represent changes in the FAZ for most patients, based on the calculated area, as well as on the circumference and the circularity index.

Comparison of foveal avascular zone between optical coherence tomography angiography and fluorescein angiography in patients with retinal vein occlusion.

OBJECTIVE: To compare area of foveal avascular zone (FAZ) in different retinal vascular layers in optical coherence tomography angiography (OCTA) and fluorescein angiography (FA) in patients with retinal vein occlusion (RVO). DESIGN AND METHODS: Prospective cross-sectional comparative study in 47 eyes of 47 patients. FA was recorded with the Zeiss FF450plusIR camera and OCTA was obtained with the Zeiss Cirrus 5000 equipped with the AngioPlex module. Area of FAZ was graded by two independent investigators and calculated with Adobe Photoshop. Analysis for the total study population as well as subgroup analysis for branch retinal vein occlusion (BRVO), central retinal vein occlusion (CRVO) and patients with and without macular edema (ME) was performed. RESULTS: For all patients, FAZ was 0.449 mm2 in FA, 0.496 mm2 in OCTA superficial capillary layer (SCL) and 3.168 in OCTA deep capillary layer (DCL). In patients without ME FAZ was 0.288 mm2 in FA, 0.342 mm2 in OCTA SCL and 1.384 mm2 in OCTA DCL. FAZ area measurement in patients with ME revealed 0.482 mm2 in FA, 0.527 mm2 in OCTA SCL and 3.554 mm2 in OCTA DCL. CONCLUSIONS: Especially the SCL of OCTA shows a good agreement to FA in measurement of FAZ in all patients with low limits of variation in patients without ME. There were no considerable differences in BRVO and CRVO. OCTA could replace FA in FAZ area measurement in patients with RVO, especially in those without ME, achieving similar measurements whilst being non-invasive.

Quantity and quality of image artifacts in optical coherence tomography angiography.

OBJECTIVE: To analyze quality and frequency of OCTA artifacts and to evaluate their impact on the interpretability of OCTA images. DESIGN: 75 patients with diabetic retinopathy (DR), retinal artery occlusion (RAO), retinal vein occlusion (RVO), or neovascular age-related macular degeneration (nAMD) and healthy controls were enrolled in this cross-sectional study in the outpatient department of a tertiary eye care center. METHODS: All participants underwent an OCTA examination (spectral domain OCT Cirrus 5000 equipped with the AngioPlex module). OCTA scans were analyzed independently by two experienced ophthalmologists. Frequency of various artifacts for the entire OCTA scan and for different segmentation layers and the grading of OCTA interpretability were investigated. RESULTS: The analysis of 75 eyes of 38 women and 37 men between 24 and 94 years were included. Six eyes had no retinal disease, 19 eyes had nAMD, 16 had DR, 19 eyes had RVO, and 15 eyes showed RAO. A macular edema (ME) was present in 40 of the diseased eyes. Projection artifacts occurred in all eyes in any structure below the superficial retinal vessel layer, segmentation and motion artifacts were found in 55% (41/75) and 49% (37/75) of eyes, respectively. Other artifacts occurred less frequently. Segmentation artifacts were significantly more frequent in diseased than in healthy eyes (p<0.01). Qualitative assessment of OCTA images was graded as excellent in 65% and sufficient in 25% of cases, adding up to 91% images deemed acceptable for examination. Presence of ME was associated with a significantly poorer interpretability (p<0.01). CONCLUSION AND RELEVANCE: Various artifacts appear at different frequencies in OCTA images. Nevertheless, a qualitative assessment of the OCTA images is almost always possible. Good knowledge of possible artifacts and critical analysis of the complete OCTA dataset are essential for correct clinical interpretation and determining a precise clinical diagnosis.

Short-Term Intraocular Pressure Rise during Locally Induced Force by Ophthalmologic Surgery Applications.

PURPOSE: Surgical or diagnostic procedures are often accompanied by a short-term increase in intraocular pressure (IOP). A short-term increase in IOP can occur during refractive procedures, vitreoretinal surgery, transillumination, photocoagulation, or cryocoagulation. A porcine eye model was chosen (n = 89) to compile comparable study data and to de termine correlations between the force induced and the resulting intraocular pressure while excluding the effect of surgeons. METHODS: The IOP was measured in the anterior chamber. IOP changes were induced by applying an external force and measured when using a cannula, trocar, and cryocoagulation (n = 32), and correlations between force and resulting IOP were assessed (n = 57). RESULTS: A correlation was noted between the force induced and the IOP increase, which showed a linear dependency. The insertion of a 29-G cannula caused a mean ΔIOP value of 49.1 ± 2.9 mm Hg and an external force of 0.76 N, and that of a 23-G trocar 344.4 ± 5.9 mm Hg and 6.09 N, respectively. The rise in IOP during a simulated cryocoagulation reached values between 57.3 ± 14.8 mm Hg (cryoprobe tip diameter: 0.9 mm) and 130.3 ± 2.9 mm Hg (cryoprobe tip diameter: 7.0 mm). CONCLUSION: The values of the forces applied can be converted into the resulting IOP based on the specific action. Surgical or diagnostic procedures should, therefore, be evaluated with regard to preexisting pathologies, such as glaucoma.

[Innovative Teaching Methods: Wet Lab-based Ophthalmosurgical Education for Medical Students]. / Innovative Lehrmethoden: Einsatz eines ophthalmochirurgischen Wetlabs im Studentenunterricht.

BACKGROUND: An increased demand for young physicians in Germany is causing increased competition to attract the best minds, even during their undergraduate studies. Therefore, it is the task of the university hospitals to offer their students the best possible courses in order to arouse interest in the relevant subject area. We therefore examined the impact of an ophthalmosurgical wet lab on teaching undergraduate medical students. MATERIAL/METHODS: Undergraduate medical students were offered voluntary participation in the ophthalmosurgical wet lab during an ophthalmology block week. At the beginning and at the end of the week, as well as at the end of the wet lab, the students answered questionnaires with questions about the interest in the field of ophthalmology and the specific assessment of the wet lab. RESULTS: The interest of the students in ophthalmology was increased by the block week and additionally by the wet lab. The wet lab enriched the block week and was rated as very good by the participants. The overall rating of the block week was significantly better among participants in the wet lab than in the group without wet lab participation. The wet lab gave the students great pleasure, enabled them to apply the acquired knowledge, gain valuable insights into ophthalmology, and was easily implemented. CONCLUSION: The integration of a wet lab into the block week was evaluated very positively by the students and gives them a valuable insight into the field of ophthalmology.

[Free-Floating Intraocular Cysts]. / Frei fluktuierende intraokulare Zysten.

BACKGROUND: Free-floating intraocular cysts may be found in the anterior chamber (FZV) and the vitreous (FZG). The first description of a cyst was 150 years ago, and they are considered to be ocular rarities. MATERIALS AND METHODS: The actual knowledge about FZV and FZG is shown on the basis of two exemplary patients. RESULTS AND DISCUSSION: Patient 1 had a FZV as an incidental finding which had a smooth surface, a slight pigmentation and was translucent. The ultrasound biomicroscopy revealed an echo-free interior space. Without the patient's discomfort and missing treatment indication, a watch-and-wait strategy was chosen. Cysts of the iris can be classified as primary and secondary cysts. Primary cysts of the iris can arise from the stroma as the pigment epithelium wherein it is believed that FZV descend from the pigment epithelium. Secondary cysts and FZV can be generated by tumors, inflammation, epithelial ingrowth, the use of eye-drops or intraocular foreign bodies. Patient 2 showed marked myopic fundus changes and an FZG with a yellowish-greenish surface; the transparency was reduced and the surface was not pigmented. The ultrasound examination also revealed an echo-free interior space. Clinical controls were advised. Congenital and acquired causes are discussed for the formation of FZG. FZG could originate from the pigment epithelium of the iris, but there are conflicting study results. Trauma, inflammation and chorioretinal diseases are considered as a reason for acquired causes of FZG. The genesis, especially of FZG, is still unclear. For the treatment of patients with FZV and FZG, it is important to know the potential causes to be able to make a therapeutic decision. High quality photographic and sonographic documentation is needed in the watch-and-wait strategy.