Augenverätzungen.

Chemical burns of the ocular surface (CBOS) are emergencies of highest urgency. Therefore, an adequate emergency care is mandatory. Following a precise analysis of the initial damage, a staged therapeutic approach is used to prevent persistent impairment of the ocular surface. In the acute stage, the prevention of complications is targeted (symblepharon, conjunctival scarring, lacrimal stenosis, corneal ulceration, intraocular inflammation, elevated intraocular pressure, etc.). In later stages, if complications have developed, a secondary restoration of the ocular surface is focussed. Sometimes this requires several surgical interventions. Based on a review of international literature, this review highlights the pathophysiology according to different chemical agents, CBOS stages as well as main therapy strategies in early and advanced stages of CBOS. Acute treatment aims to lower inflammation, oxidative stress and tries to promote reepithelialisation. Besides conjunctival scarring, loss of goblet cells and corneal opacification a limbal stem cell insufficiency is the most harming complication. Several new techniques have been developed to recover the ocular surface with a sufficient and clear epithelial layer in order to avoid neovascularization of the cornea. The knowledge concerning the high risk potential for persistent visual impairment in CBOS patients and the ability for appropriate emergency care should be kept in every physician's mind dealing with CBOS.

Transcutaneous (External) Dacryocystorhinostomy with Reconstruction of the Ductus nasolacrimalis. / Transkutane (externe) Dakryozystorhinostomie mit Rekonstruktion des Ductus nasolacrimalis.

BACKGROUND: Dacryocystorhinostomy (DCR) is regarded as the gold standard for the treatment of chronic dacryocystitis (CDC). Different modifications of the surgical procedure have been developed over the years. METHODS: Patients with CDC due to postsaccal lacrimal stenosis and under treatment with DCR have been included in this retrospective study. Two groups of different surgical procedures were analysed: firstly DCR without reconstruction of the ductus nasolacrimalis (DNL, group 1) and secondly patients with reopening the DNL (group 2). Criteria for success were absence of permanent epiphora, absence of inflammation of the lacrimal sac (functional success), and no recurrent surgery with free patency of the lacrimal duct (anatomical success). This was obtained by questionnaire after a follow-up of at least 12 months. The impact of gender, ectasia of the lacrimal sac, dacryoliths, and prior lacrimal surgeries was analysed. RESULTS: Overall, 248 surgeries were enrolled in this trial. Mean age in group 1 was 68 years (range: 22 to 92 years) and gender ratio was 3.2 to 1 (female : male). In that group, 68 operations could be followed up. In group 2, 62 operations on patients of a mean age of 63 years (range: 24 to 89 years) and a gender ratio of 2.9 to 1 (female : male) were observed. Complete success occurred in 75.0% in group 1 and 75.8% in group 2. Recurrent operations were necessary in one case of group 2 (1.6%) and 4 cases of group 1 (5.9%). Gender (group 1 p = 1; group 2 p = 0.115; between groups p = 0.511), ectasia of the lacrimal sac (group 1 p = 0.877; group 2 p = 0.674; between groups p = 0.878), dacryolith (group 1 p = 1; group 2 p = 0.465; between groups p = 1), and prior lacrimal surgery (group 1 p = 0.092; group 2 p = 0.051; between groups p = 0.520) did not influence the success rates in each group or between groups. Significantly more dacryoliths were found during operations of group 2 (p = 0.010). CONCLUSION: Reconstruction of the DNL during DCR is a possible and easy modification, with a slightly better success rate in curing CDC. Intraoperatively, dacryoliths might not be apparent remain in the deeper parts of the lacrimal ducts. Therefore, these segments should be inspected during surgery.

[Concrements of the lacrimal apparatus]. / Konkremente des Tränenapparates.

Concrements of the lacrimal apparatus, known as dacryoliths, can occur at different localizations and can cause a variety of symptoms. A common clinical sign is chronic inflammation, possibly exhibiting acute exacerbation. Based on a literature review and descriptive clinical cases with histopathological correlations, this contribution summarises the most important information concerning epidemiology, aetiopathogenesis, composition, histology, and therapy of lacrimal concrements. Furthermore, factors known to affect lacrimal lithogenesis are addressed. Concrements of the lacrimal gland cause a swelling at the lateral canthus. With only mild pain, this manifests as circumscribed conjunctival hyperaemia. Histologically, the gland tissue is characterised by acute-erosive to chronic inflammation. The concrements consist of amorphic material. Inflammatory infiltration is dominated by neutrophil granulocytes. Canalicular concrements are highly correlated with chronic canaliculitis. Besides epiphora, patients present with purulent discharge at the affected canaliculus. Actinomyces are frequently found inside these deposits and form drusen-like formations. The surrounding tissue reacts with plasma-cellular and granulocytic inflammation. Dacryoliths (concrements of the lacrimal sac) are associated with dacryocystitis, whereby acute and chronic types are common. Stones can be found in up to 18% of patients undergoing dacryocystorhinostomy or dacryoendoscopy. Preoperative diagnostic testing is challenging, as many lacrimal sac stones cannot be reliably visualised by diagnostic procedures. Recurring episodes of epiphora, mucopurulent discharge, and dacryocystitis are common indicators of dacryoliths. Lacrimal syringing is often possible and shows that total blockage is not present. Histology of the lacrimal mucosa reveals lymphocytic infiltration and submucosal fibrosis. The immediate vicinity of the dacryoliths shows acute inflammation. Therapy consists of stone extraction and improving lacrimal drainage, as the latter is recognised as the main risk factor for dacryolith formation.

[Congenital anomalies in lacrimal drainage]. / Angeborene Fehlbildungen der ableitenden Tränenwege.

Congenital dacryostenosis is the most common reason for ophthalmic consultation in childhood. It is most often caused by persisting of Hasner's membrane. However, congenital malformations of the lacrimal drainage system can also occur in rare cases. In the area of the proximal lacrimal drainage system, supernumerary lacrimal puncta and canaliculi can arise as well as diverticula, fistula, and atresia. The distal lacrimal drainage system can be affected by fistulas, amniotoceles, and cysts. Association of lacrimal malformations with congenital systemic diseases is reported in about 10% of cases. Depending on the severity of the symptoms, surgical rehabilitation can be performed, and endoscopic procedures and modern lacrimal drainage intubation systems may be employed.

Concrements of the Lacrimal Apparatus. / Konkremente des Tränenapparates.

Concrements of the lacrimal apparatus, known as dacryoliths, can occur at different localizations and can cause a variety of symptoms. A common clinical sign is chronic inflammation, possibly exhibiting acute exacerbation. Based on a literature review and descriptive clinical cases with histopathological correlations, this contribution summarises the most important information concerning epidemiology, aetiopathogenesis, composition, histology, and therapy of lacrimal concrements. Furthermore, factors known to affect lacrimal lithogenesis are addressed. Concrements of the lacrimal gland cause a swelling at the lateral canthus. With only mild pain, this manifests as circumscribed conjunctival hyperaemia. Histologically, the gland tissue is characterised by acute-erosive to chronic inflammation. The concrements consist of amorphic material. Inflammatory infiltration is dominated by neutrophil granulocytes. Canalicular concrements are highly correlated with chronic canaliculitis. Besides epiphora, patients present with purulent discharge at the affected canaliculus. Actinomyces are frequently found inside these deposits and form drusen-like formations. The surrounding tissue reacts with plasma-cellular and granulocytic inflammation. Dacryoliths (concrements of the lacrimal sac) are associated with dacryocystitis, whereby acute and chronic types are common. Stones can be found in up to 18% of patients undergoing dacryocystorhinostomy or dacryoendoscopy. Preoperative diagnostic testing is challenging, as many lacrimal sac stones cannot be reliably visualised by diagnostic procedures. Recurring episodes of epiphora, mucopurulent discharge, and dacryocystitis are common indicators of dacryoliths. Lacrimal syringing is often possible and shows that total blockage is not present. Histology of the lacrimal mucosa reveals lymphocytic infiltration and submucosal fibrosis. The immediate vicinity of the dacryoliths shows acute inflammation. Therapy consists of stone extraction and improving lacrimal drainage, as the latter is recognised as the main risk factor for dacryolith formation.

Congenital Anomalies in Lacrimal Drainage. / Angeborene Fehlbildungen der ableitenden Tränenwege.

Congenital dacryostenosis is the most common reason for ophthalmic consultation in childhood. It is most often caused by persisting of Hasner's membrane. However, congenital malformations of the lacrimal drainage system can also occur in rare cases. In the area of the proximal lacrimal drainage system, supernumerary lacrimal puncta and canaliculi can arise as well as diverticula, fistula, and atresia. The distal lacrimal drainage system can be affected by fistulas, amniotoceles, and cysts. Association of lacrimal malformations with congenital systemic diseases is reported in about 10% of cases. Depending on the severity of the symptoms, surgical rehabilitation can be performed, and endoscopic procedures and modern lacrimal drainage intubation systems may be employed.

[Deep periocular trauma with affection of the lacrimal ducts during Caesarean section]. / Tiefes periokuläres Trauma mit Tränenwegsbeteiligung durch Kaiserschnittentbindung.

Periocular injuries during a caesarean section are extremely rare. The case report of a five hour old newborn addresses the trauma management concerning diagnostics, therapy, and post-operative care of a deep periocular soft tissue injury. The pattern of injury consisted of full thickness wounds of the medial and lateral lid margins, opening of the superior conjunctival fornix, and penetration of Tenon's capsule. The reconstruction was performed layer by layer while an autostable monocanaliculonasal lacrimal intubation was inserted.

[Primary Reconstruction of Lacrimal Ducts after Trauma - Bicanaliculonasal Intubation Using Autostable Tubes]. / Primäre Rekonstruktion der ableitenden Tränenwege nach Trauma ­ bikanalikulonasale Schienung mit autostabilen Silikonverweilsonden.

Trauma of the medial canthal region can affect all parts of the lacrimal ducts. Depending on the patient's age, there may be different mechanisms of injury. Surgical reconstruction using two autostable ("self-retaining") monocanaliculonasal lacrimal tubes is demonstrated by two case reports. Here, a 6 years old girl attacked by a dog (Rottweiler) showed severe periocular soft tissue damage with deep involvement of the lacrimal ducts. The child's inferior canaliculus was lacerated. Furthermore, the common canaliculus was dissected from the lacrimal sac. Deep soft tissue damage consisted of blunt and sharp injuries down to the cheek and nose. After lacrimal intubation with two autostable monocanaliculonasal tubes, the soft tissue was reconstructed by direct canalicular suturing and stepwise closure of each layer. One of the lacrimal tubes was fixated at the lid by additional sutures, in order to avoid stent prolapse. Beside slight medial depression of inferior lid, there were no signs of functional disturbance of the lacrimal ducts. The follow-up was 18 months. The second case report presents a 43 years old man. He accidentally cut himself with a butcher's knife. He suffered a deep wound of his medial canthal region. The patient presented with proximal (located near the lacrimal sac) laceration of both canaliculi. The medial canthal ligament as well as the orbicularis muscle had been cut. Using two autostable monocanaliculonasal lacrimal tubes, the lacrimal ducts were stented and reconstructed with sutures. During the follow-up of 6 months, no epiphora or mucopurulent lacrimal discharge occurred. In lacrimal trauma, different parts of the lacrimal ducts may be affected at the same time. Identification of the injured structures with respect to the kind of injury, localisation and the extent of damage is crucial. Stepwise wound closure in respect to the topographic anatomy is mandatory. Here, lid and lacrimal ducts must be respected as one functional unit. Simultaneous use of autostable monocanaliculonasal lacrimal tubes in both canaliculi can be applied for trauma reconstruction of the lacrimal ducts in children and adults.

[Lacrimal Duct Obstruction in Adults]. / Tränenwegsstenosen im Erwachsenenalter.

The tearing eye (epiphora) is the guiding symptome of nasolacrimal duct obstruction. Depending on the localization of stenosis, mucopurulent lacrimal discharge occurs additionally. These symptoms induce alterations of the optical system and can cause severe complications such as acute phlegmonous dacryocystitis. The grade of suffering in these patients is very high. For the diagnosis, patient's history, ocular surface conditions and inspection (macro-/microscopically) as well as palpation of the lacrimal region are essential examinations. Moreover, functional and anatomical tests enable a classification of nasolacrimal duct obstruction regarding grade of stenosis (incomplete vs. complete), type (functional vs. mechanical), and localization (pre-, intra-, postsaccal). ENT consultation prior to lacrimal surgery is obligate. Through this, a purposeful therapeutic intervention is warranted. Surgical methods consist of minimally invasive transcanalicular procedures or anastomosing surgeries. Dependent on the clinical findings, these treatment options can be applied in a patient centered therapeutic concept.

[Disorders of the Lacrimal Apparatus, Part 2: Basics of Therapy]. / Erkrankungen des Tränenapparats, Teil 2: Grundlagen der Therapie.

The tearing eye (epiphora) is deemed to be the leading symptome of efferent tear duct stenosis. Nevertheless, epiphora might be caused by ocular surface pathologies or even intraocular diseases. A distinguished anamnesis and sufficient clinical examination is most meaningful for the differential diagnostic distinction. Therapy is based on pathologic changes. In case of ocular surface disease, a suitable tear substitution and antiinflammatory approach is mandatory. Multifarious triggers have to be considered as well. Addressing tear film distribution, suitable oculoplastic surgery is required. Efferent tear duct stenosis necessitates surgical treatment as the level of suffering is often very high and acute exacerbations may develop. Besides recanalization, anastomosing techniques represent the available therapeutic principles. Possible surgical approaches offer a great variety and many influencing factors navigate therapy decisions. This part of the review comments on the most important therapeutic approaches for lacrimal apparatus diseases.

[Disorders of the Lacrimal Apparatus, Part 1: Anatomy, Physiology, Diagnostics]. / Erkrankungen des Tränenapparats, Teil 1: Anatomie, Physiologie und Diagnostik.

The lacrimal apparatus is a part of the ocular adnexa preserving ocular surface homoeostasis and therefore enabling sufficiant visual functioning. Tear producting tissues, eyelids and efferent tear ducts operate as one functional unit. Pathologic changes consist of inflammatory diseases, congenital disorders, degenerations and neoplasia. Common to all these conditions is a potential impairment of the ocular integrity as well as a substantial degree of suffering for the affected patients. This review reflects basics of the anatomy, physiology, and diagnostics of the lacrimal apparatus.

[Primary Reconstruction of Lacrimal Ducts after Trauma - Bicanaliculonasal Intubation Using Autostable Tubes]. / Primäre Rekonstruktion der ableitenden Tränenwege nach Trauma ­ bikanalikulonasale Schienung mit autostabilen Silikonverweilsonden.

Trauma of the medial canthal region can affect all parts of the lacrimal ducts. Depending on the patient's age, there may be different mechanisms of injury. Surgical reconstruction using two autostable ("self-retaining") monocanaliculonasal lacrimal tubes is demonstrated by two case reports. Here, a 6 years old girl attacked by a dog (Rottweiler) showed severe periocular soft tissue damage with deep involvement of the lacrimal ducts. The child's inferior canaliculus was lacerated. Furthermore, the common canaliculus was dissected from the lacrimal sac. Deep soft tissue damage consisted of blunt and sharp injuries down to the cheek and nose. After lacrimal intubation with two autostable monocanaliculonasal tubes, the soft tissue was reconstructed by direct canalicular suturing and stepwise closure of each layer. One of the lacrimal tubes was fixated at the lid by additional sutures, in order to avoid stent prolapse. Beside slight medial depression of inferior lid, there were no signs of functional disturbance of the lacrimal ducts. The follow-up was 18 months. The second case report presents a 43 years old man. He accidentally cut himself with a butcher's knife. He suffered a deep wound of his medial canthal region. The patient presented with proximal (located near the lacrimal sac) laceration of both canaliculi. The medial canthal ligament as well as the orbicularis muscle had been cut. Using two autostable monocanaliculonasal lacrimal tubes, the lacrimal ducts were stented and reconstructed with sutures. During the follow-up of 6 months, no epiphora or mucopurulent lacrimal discharge occurred. In lacrimal trauma, different parts of the lacrimal ducts may be affected at the same time. Identification of the injured structures with respect to the kind of injury, localisation and the extent of damage is crucial. Stepwise wound closure in respect to the topographic anatomy is mandatory. Here, lid and lacrimal ducts must be respected as one functional unit. Simultaneous use of autostable monocanaliculonasal lacrimal tubes in both canaliculi can be applied for trauma reconstruction of the lacrimal ducts in children and adults.

[Lacrimal Stenosis after Chemical and Thermal Ocular Burns]. / Tränenwegstenosen durch Verätzungen und Verbrennungen.

BACKGROUND: Chemical or thermal burns of the ocular surface are an urgent ophthalmologic emergency. Consecutive epiphora causes a high level of suffering for affected patients. METHOD: Based on a review of current literature, and our own longstanding experiences, recommendations are given on the treatment of secondary lacrimal duct obstruction due to ocular surface damage after chemical or thermal burns. RESULTS: An initial evaluation of the tissue damage is crucial. Necrotic tissue should be removed. The patency of the lacrimal passage has to be proved in respect. In case of primary involvement of the lacrimal ducts, treatment is necessary. Here, recanalization can be achieved by using conical probes or lacrimal cannulas. Lacrimal intubation has to be performed. Scar formation should be completed if a secondary reconstruction is required. CONCLUSION: Lacrimal stenosis after chemical or thermal burns of the ocular surface is a rare complication. Initial surgical intervention should be performed if primary lacrimal involvement can be ensured. If possible, surgical reconstruction should not be performed prior to 6 months after the trauma.

[Dacryoendoscopic Surgery-Factors Influencing Postoperative Results]. / Dakryoendoskopische Tränenwegschirurgie ­ Einflussfaktoren auf das postoperative Ergebnis.

BACKGROUND: Dacryoendoscopy (DE) is an established method in lacrimal surgery. Long-term follow-up-analyses of this surgery are of great interest. Here, factors influencing postoperative success rates should be considered to elect suitable patients. METHODS: In this retrospective study, patients having had dacryoendoscopic surgery were included. Using a questionnaire, a prospective follow-up analysis was made. Pre- and intraoperative factors were correlated with treatment success, which was defined as improved epiphora, absence of a second lacrimal surgery and no signs of chronic dacryocystitis (secretion, pain at the lacrimal sac). Additionally, we asked for patient's satisfaction with the postoperative result (categorized in "very good", "good", "poor", and "bad"). RESULTS: Overall, 215 DE of 182 patients (130 women, 52 men) were studied. Mean patient age was 58 ± 17 years (range: 18 to 91 years). Follow-up was 31 to 77 months (median: 55 months). Treatment success after this time was 59.1%, in which neither patient's age nor sex showed significant influences. In comparison to complete stenosis, incomplete obstruction could be treated successfully twice as often (p = 0.02). Patients suffering from ectatic lacrimal sacs had a risk of 1.9 for failing therapy (p = 0.01). A trend concerning worse cure rates could be observed in patients with postsaccal localization of stenosis (p = 0.2) and an age of older than 49 years (p = 0.1). Surgical results evaluated by the patients were "very good" in 32.1% and "good" in 30.2%. CONCLUSION: Dacryoendoscopy with its minimally invasive approach is suitable as a first-step procedure in lacrimal surgery. The absence of a scar and the quick recovery are vitally important for the patients. Medically important is that the topographic anatomy is preserved by using dacryoendoscopy, so other surgical techniques can be performed later without limitations, if necessary. Patients with incomplete obstructions and a localization of stenosis, being pre- to intrasaccal, profit from this treatment method in particular.

Sclerocorneal graft and sequential removal of melted cornea after severe corneal burn with perforation.

Corneal burn grade IV usually leads to blindness. Several different surgical techniques remain challenging owing to the extensive tissue damage. Here, we introduce a novel technique with a 15 mm corneoscleral and limbal homologous graft combined with sequential autologous corneal removal ab interno, with a vitrectomy probe to save the anterior chamber angle. In vivo anatomy with optical coherence tomography is the surgical key. A large 15 mm sclerocorneal graft is sutured on top of the remainder of the destroyed cornea and sclera after removal of the epithelium and conjunctiva, with anterior synechiolysis if necessary, peripheral iridectomy and conjunctivoplasty. The recipient central corneal stroma is not removed, primarily to protect the anterior chamber angle. After three weeks, the collagenolytic central recipient corneal stroma can be removed with a small 23 g vitrectomy probe, respecting the lens and scleral spur. The corneoscleral graft remains clear under systemic and local immunosuppression. Intraocular pressure is well controlled because the anterior chamber angle is respected. Recurrent corneal erosions need close follow-up. Therapeutic soft contact lenses can support topical therapy. In cases of sclercorneal graft decompensation or rejection after 3-5 years, a new sclerocorneal graft (with limbal donation) seems to be superior to perforating keratoplasty without limbal stem cell transplantation. Repeated sclerocorneal grafts after severe corneal burn with limbal transplantation and maintenance of the complete anterior angle structure are a successful option for preventing blindness and achieving good visual acuity. Clin. Anat. 31:39-42, 2018. © 2017 Wiley Periodicals, Inc.

Anatomic landmarks in lacrimal surgery from an ophthalmologist's point of view: Clinical findings of external dacryocystorhinostomy and dacryoendoscopy.

Epiphora is a common clinical symptom of nasolacrimal duct obstruction. However, it is present in several pathologies and can lead to decreased quality of life for patients. A careful clinical examination including a detailed patient's history and diagnostic tests such as the fluorescein dye disappearance test and diagnostic syringing of the lacrimal duct are essential. Depending on the time of presentation (congenital, primary, or secondary acquired), grade (subtotal or total) and location of the stenosis, different surgical approaches can be considered. These are subdivided into minimally invasive (transcanalicular) and anastomosing (dacryocystorhinostomy) procedures. Furthermore, the anatomical landmarks and the site of surgical intervention differentiate the surgical techniques into endoscopic or transcutaneous. Modern intubation techniques offer a large spectrum of therapeutic possibilities enabling patient care to be customized and individualized. Knowledge of the topographical anatomy is crucial for achieving greater success and a lower complication rate. Clin. Anat. 30:1034-1042, 2017. © 2017 Wiley Periodicals, Inc.

A Case Series of Dacryoendoscopy in Childhood: A Diagnostic and Therapeutic Alternative for Complex Congenital Nasolacrimal Duct Obstruction Even in the First Year of Life.

INTRODUCTION: Congenital nasolacrimal duct obstruction (CNLDO) is the most common cause of epiphora in infancy. Spontaneous resolution occurs in the majority of the cases by 1 year of age. Nevertheless, obstruction has a negative impact on the outcome of conservative or surgical therapy, especially in cases of complex CNLDO. When the condition persists beyond several months, early intervention with dacryoendoscopy (DE) around the age of 1 year could yield good results. The objective of the study is to analyze the success rate and effectiveness of early DE for complex CNLDO in the first year of life. METHODS: A retrospective, non-comparative case series is presented. DE was performed under general anesthesia in patients between the age of 1 and 12 months with severe recurrent acute or chronic dacryocystitis. The medical histories, intraoperative and postoperative results after 3 months as well as via parents' interviews were analyzed to investigate the success rate. RESULTS: A total of 18 consecutive DE in 16 patients between the age of 1 and 12 months (mean 7.3 ± 3.4 months) were studied. Nine lacrimal ducts were diagnosed with persistent chronic dacryocystitis refractory to probing/syringing. The remaining 9 presented recurrent acute dacryocystitis. Diagnostic DE was performed in 18 cases. A therapeutic DE was conducted in 15 lacrimal ducts (83.3%) with simultaneous correction of the associated stenosiswith the tip of the endoscope. A visual controlled opening of the stenosis was impossible in 3 cases due to a too narrow presaccal anatomy (n = 1), an osseous duct stenosis (n = 1), and a bulging membrane of Hasner into the inferior nasal meatus (n = 1). Postoperative findings were classified into four categories: poor, fair, good and excellent. Good results were documented in 16.7% (n = 3) and excellent results in 77.7% (n = 14). The bony obstruction was treated with dacryocystorhinostomy. A minimum follow-up of 3 months was considered for final clinical analysis. Ten patients' parents (12 surgeries) were interviewed by telephone (mean follow-up 24.8 months). No recurrence of stenosis and no further postoperative complications were observed. CONCLUSION: DE is a diagnostic and therapeutic option for complex CNLDO in patients before the age of 1 year. The outcome of DE in the 3 months follow-up is highly indicative of positive final results in terms of patency of the lacrimal duct.

[Comparative clinical study of two dexamethasone phosphate-containing ophthalmics]. / Klinische Studie zum Nachweis der Vergleichbarkeit von zwei Dexamethasonphosphat-haltigen Ophthalmika.

For the drug application of the already known active ingredient dexamethasone dihydrogen phosphate disodium salt (CAS 2392-39-4) for ocular use clinical data on the efficacy and safety were required by the drug regulatory agency. The comparison of the pharmaceutical properties had already shown that no differences in clinical use had to be expected. The results of a double-blind, randomised, comparative clinical study on 210 patients prove that no differences between test and comparator product could be observed. This case shows that the demand for clinical trials to proof therapeutic equivalence should be done with a sense of proportion related to the specific situation.

Changes in the lens epithelium with respect to cataractogenesis: light microscopic and Scheimpflug densitometric analysis of the cataractous and the clear lens of diabetics and non-diabetics.

BACKGROUND: We compared the human lens documented, using the Scheimpflug densitometry, with the light microscopic changes in the epithelium of the anterior central lens in patients with age-related cataract and diabetes mellitus type II and verified the findings on the control tissue of the clear eye lens. We wanted to determine the relevance of the lens epithelium in cataract formation in type II diabetics compared to non-diabetics. MATERIALS AND METHODS: One hundred fifty central lens capsules (138 cataract and 12 clear lenses) of type II diabetics (n=77, 45 female, 32 male) and non-diabetics (n=73, 41 female, 32 male) were examined by light microscope, regarding defined histomorphological parameters. Further criteria were duration of diabetes, diabetic retinopathy, cataract (PENTACAM, scheimpflug densitometric definition), protein content in the aqueous humour (laser flare meter 500 KOWA, tyndallometry), different blood parameters and glucose content in the aqueous humour. RESULTS: The mean cell density in the cataractous lens in type II diabetics was 3,951+/-528 cells/mm(2) and in non-diabetics 4,329+/-580 cells/mm(2) (P<0.001); in the clear lens it corresponded to 4,593+/-409 cells/mm(2) (type II diabetics) and 4,894+/-333 cells/mm(2) (non-diabetics, P=0.207). The cell density of the cataractous lens in type II diabetics (P=0.005) and in non-diabetics (P=0.035) is smaller than that of the clear lens. The cell area of the lens epithelium in the cataractous diabetic lens is larger (P<0.001) and the nucleus-plasma ratio is lower (P<0.001) than those of the clear non-diabetic lens. The increase in damage of the lens epithelium correlates with the decrease of cell density (P< 0.001), the increase of nucleus area and volume (P< 0.001), and the decrease of nucleus-plasma ratio (P< 0.001). Risk factors for the decrease of cell density are advanced age (P=0.015), type II diabetes (P=0.01), increase in glucose content in the aqueous humour (P=0.014), increase in blood sugar (P=0.003) and increase in glycosylated haemoglobin (P=0.039). CONCLUSIONS: The lens epithelium is primarily damaged in type II diabetics who develop age-related cataract. This might play an important role in cataract formation.