Amniotic membrane properties and current practice of amniotic membrane use in ophthalmology in Slovenia.

Amniotic membrane (AM) is the innermost, multilayered part of the placenta. When harvested, processed and stored properly, its properties, stemming from AM biological composition, make it a useful tissue for ophthalmic surgery. AM was shown to have several beneficial effects: it promotes epithelization, has antimicrobial effects, decreases inflammation, fibrosis and neovascularization. Many case reports and case series as well as practical experience (e.g. reconstruction of conjunctival and corneal defects, treatment of corneal ulcers) demonstrated the beneficial effect of AM for different ophthalmological indications. The combination of the above mentioned beneficial effects and reasonable mechanical properties are also the reason why AM is used as a substrate for ex vivo expansion of epithelial progenitor cells. Recently, amnion-derived cells, which also have stem cell characteristics, have been proposed as potential contributors to cell-based treatment of ocular surface disease. However, the use of AM remains one of the least standardized methods in ophthalmic surgery. In this review, the various properties of AM and its current clinical use in ophthalmology in Slovenia are discussed.

Cortical potentials after electrical intraneural stimulation of the optic nerve during orbital enucleation.

BACKGROUND: The aim of this study was to present cortical potentials after electrical intraneural stimulation of the optic nerve during orbital enucleation due to malignant melanoma of the choroid or the ciliary body. These cortical potentials were related to cortical potentials after electrical epidural stimulation of the optic nerve, recorded during non-manipulative phases of neurosurgery for central skull base tumors. METHODS: Cortical potentials were recorded with surface occipital electrode (Oz) in six patients undergoing orbital enucleation under total intravenous anesthesia. Two thin needle stimulating electrodes were inserted inside the intraorbital part of the optic nerve. The electrical stimulus consisted of a rectangular current pulse of varying intensity (0.2-10.0 mA) and duration (0.1-0.3 ms); the stimulation rate was 2 Hz; the bandpass filter was 1-1,000 Hz; the analysis time was 50-300 ms. RESULTS: Cortical potentials could not be obtained or were inconsistently elicitable in three patients with longstanding history (>3 months) of severe visual deterioration, while they consisted of several positive and negative deflections in a patient with a short history of mild visual impairment. In two other patients, cortical potentials consisted of N20, P30 and N40 waves. DISCUSSION: Cortical potentials after electrical intraneural stimulation of the optic nerve could be recorded in patients with a short history of visual deterioration and without optic nerve atrophy and appear more heterogeneous than cortical potentials after electrical epidural stimulation of the optic nerve, recorded during non-manipulative phases of neurosurgery for central skull base tumors.

Morphological characteristics of conjunctival squamous papillomas in relation to human papillomavirus infection.

OBJECTIVE: To determine the prevalence of a broad spectrum of human papillomavirus (HPV) types in conjunctival papillomas and a possible difference in clinical and histopathological presentation of HPV-positive and HPV-negative papillomas. METHODS: Formalin-fixed, paraffin-embedded papilloma tissue specimens obtained from 25 patients were analysed using six different PCR-based methods targeting 87 HPV types from four different papillomavirus (PV) genera: α-PV, ß-PV, γ-PV and µ-PV, and in situ hybridisation for HPV-6/HPV-11. Slides were reviewed for pedunculated or sessile growth, the presence of goblet cells, keratinising or non-keratinising epithelium, elastosis, atypia and koilocytes. RESULTS: α-PV types HPV-6 and HPV-11 were detected in 19/25 (76%) conjunctival papilloma tissue specimens, 9 (47%) of which were also HPV-6/HPV-11 positive with in situ hybridisation. Six different ß-PV types-HPV-9, HPV-12, HPV-20, HPV-21, HPV-22, HPV-24-were additionally detected in four cases, all of which were also HPV-6/HPV-11 positive. No γ-PVs or µ-PVs were found in any of the tested tissues samples. Extralimbal location (p=0.021), presence of goblet cells (p=0.005), non-keratinising squamous epithelium (p=0.005), and absence of elastosis (p=0.005) were associated with the presence of HPV-6/HPV-11. CONCLUSIONS: We demonstrated that certain clinical and histological features are more frequently associated with HPV infection and that HPV genera other than α-PV are most probably not significant factors in conjunctival papilloma occurrence.

Transcanalicular diode laser-assisted dacryocystorhinostomy.

OBJECTIVE: We present a prospective, non-comparative case series study of 126 consecutive diode laser-assisted transcanalicular dacryocystorhinostomy (TCL-DCR) procedures on 122 patients. We analyzed success rate, procedure time and amount of laser energy needed for a 5 mm osteotomy. MATERIALS AND METHODS: One hundred and twenty-two patients with nasolacrimal duct obstruction were included in the study. The procedure was performed under general anesthesia, and the nasal mucosa was anesthetized. An endoscope was used for examination of the lacrimal pathways. The site of osteotomy was determined with transillumination of the lateral nasal wall. We achieved osteotomy by applying laser energy via an optic fiber. We used a 980 nm diode laser with power of 10 Watts. We inserted a bicanalicular silicone stent as the last step. Success of procedure was absence of epiphora (subjective), or patency of the lacrimal drainage system on irrigation (objective). RESULTS: We performed 126 successive endoscopic laser (EL-DCR) with bicanalicular intubation in 122 patients. The average procedure time was 12 min, and on average 245 Joules of laser energy was needed. The silicone stents were removed three to eight months after surgery. We observed absence of epiphora and a patent nasolacrimal duct on irrigation in 105 out of 126 treated eyes. Eighteen patients had epiphora despite a patent nasolacrimal duct on irrigation. This yields a success rate of 83.3%, with an average follow-up period of 12 months. CONCLUSIONS: The 980 nm EL-DCR with bicanalicular intubation is a new contribution to the field of lacrimal surgery. It is a minimally invasive quick procedure yielding a high success rate.

Trauma of the lacrimal drainage system: retrospective study of 32 patients.

AIM: To assess retrospectively the results and complications of surgical techniques applied in the treatment of patients with trauma of the lacrimal drainage system. METHODS: Out of 32 patients with lacrimal drainage system trauma included in the study, 25 were treated at the University Eye Clinic, Ljubljana Medical Center, Ljubljana, Slovenia, from 1999 to 2003, and 7 were referred for secondary repair from other health care institutions in the same time period. All patients with fresh injuries underwent surgery within 48 h. The patients were followed up to a year after surgery. We evaluated the function of the lacrimal drainage system by irrigation at the last follow-up visit. RESULTS: Patent lacrimal drainage system was achieved in all 25 patients with primary reconstruction of the injury. Restenosis of the canaliculus occurred in 4 out of 7 patients after secondary reconstruction. CONCLUSIONS: Early repair of the lacrimal drainage system eliminates complications in comparison with secondary repair. Repair of the lacrimal drainage system may be delayed for up to 48 h, if an experienced operating team is available.

Repetitive Er:YAG laser irradiation of human skin: a histological evaluation.

BACKGROUND AND OBJECTIVE: Deep coagulation of skin collagen by Er:YAG laser repetitive pulses has been predicted by previous theoretical models and later demonstrated on animal skin. The goal of this study was to determine the effect of repetitive Er:YAG laser pulses on human skin and its response to this treatment. STUDY DESIGN/MATERIALS AND METHODS: Lid skin of six female volunteers with blepharochalasis has been treated with laser at day 0, 7, and 21 before elective surgery-blepharoplasty. The treated skin was excised as part of the procedure and prepared for further histological examination. We used a 2,940 nm Er:YAG laser (Fidelis M320A by Fotona) with 'smooth' mode parameters: fluence from 0.50 to 2.00 J/cm2; six pulses per packet; 550 microsecond/pulse, 250 millisecond/packet; single pass, no overlapping; spot size 5 mm; repetition rate 20 Hz. RESULTS: We observed deep collagen denaturation at laser fluences of 1.25 J/cm2 and over; epidermal damage was proportional to fluence with total coagulation of the epidermal layer at fluences of 1.75 J/cm2 and over. At day 7 after laser treatment we observed a complete regeneration of the epidermal layer and a regeneration zone within the dermis with prominent infiltration of CD68+ monocytes/macrophages. At day 21 after laser treatment we observed collagen remodeling and (myo-)fibroblast proliferation at tissue depths of up to 240 microm. CONCLUSIONS: Repetitive Er:YAG laser irradiation is effective in deep denaturation and remodeling of human skin collagen in vivo, with less epidermal damage compared to standard Er:YAG laser skin resurfacing.