Custom anterior segment optical coherence tomography indices for detection of corneal ectasia.

INTRODUCTION: Corneal thinning and changes in the corneal thickness profile are major symptoms of corneal ectasia. The anterior seg-ment optical coherence tomography is currently widely used, and the development of additional indices may lead to improvements in the diagnostics of keratoconus. AIM: To determine the diagnostic value of newly developed custom anterior segment OCT indices in diagnosing corneal ectasia. PATIENTS AND METHODS: Two sets of patients were included in the current study - healthy controls in the first and patients with corneal ectasia in the second, 80 eyes per group of 43 patients each. The groups were age- and sex-matched. Each patient underwent a standard ophthalmological examination (visual acuity, tonometry, slit lamp examination, fundus biomicroscopy), a corneal topography with OCULUS Keratograph 5M, and an anterior segment optical coherence tomography with RTVue-100. Besides the indices automatically generated by the software of the device, we measured the following custom parameters: partial corneal area (PCA), partial chamber area (PCA), and an index that reflects the relation between the two (CpC). All measurements were performed in two axial pachymetric scans, one vertical and one horizontal using the built-in software. RESULTS: A statistically significant difference was found between the two groups (p<0.001, confidence Interval 95%) for all the proposed indices in both the vertical and the horizontal scans. The ROC analysis showed promising results for differentiation between the groups with the area under the curve (AUC) in the range from 0.892 for the vertical partial anterior chamber area to 0.984 for the vertical CpC index. CONCLUSIONS: The proposed indices can be used to differentiate between normal and ectatic corneas.

Confocal Microscopy of Filtering Blebs after Trabeculectomy.

INTRODUCTION: Filtration surgery is the most effective method of lowering intraocular pressure (IOP) in patients with insufficient medical control. It consists in facilitating the drainage of the intraocular fluid (IOF) from the anterior chamber to the subconjunctival space and subsequent lowering of IOP. The formation of filtration blebs (FB) and the processes of scarring occurring in the conjunctiva are of particular importance in glaucoma surgery. In many cases, the appearance of FB does not match the IOP values, and what causes the failure after trabeculectomy often remains unclear. Often, over time, there is a change in the structure of the FB, as fibrous tissue grows, which prevents the IOF drainage. Laser scanning in vivo confocal microscopy is a non-invasive study allowing the production of layered images at the microstructural level with high resolution of both the cornea and other structures of the anterior ocular surface. AIM: To evaluate the morphological structure and function of filtering blebs after trabeculectomy using in vivo confocal microscopy taking into account the type of implant and when the surgery was performed. MATERIALS AND METHODS: The study included 33 patients, 46 eyes with glaucoma. Twenty-six of the eyes had primary open-angle glaucoma (POAG), 18 eyes had pseudoexfoliative glaucoma and 2 eyes had juvenile glaucoma. All patients underwent trabeculectomy with fornix-based flap, and three of the eyes underwent retrabeculectomy. Mitomicyn C (MMC) was administered intraoperatively to all patients. The study of the filtering bleb was performed by in vivo confocal microscopy (CFM) (Heidelberg Retina Tomograph II (HRT II) /Rostock Cornea Module/ (Heidelberg Engineering GmbH, Heidelberg, Germany), the period from trabeculectomy and examination being from 1 year to 22 years. An Express implant was placed in 14 eyes, Ologen implant in 7 eyes, and 25 eyes had no implant placed. In the analysis of the morphological structure of the filtering blebs, three indicators were evaluated: the type of epithelium, the type of stroma, and blood vessels. RESULTS: Statistical significance was established with regard to the function and morphological structure of the filtering bleb (p=0.009). Blebs with fine collagen mesh and dense collagen mesh demonstrate good function. In the case of blebs with insufficient function, those with a dense collagen network and hyper-reflective tissue predominated and there were no blebs with a fine collagen network, and in non-functioning blebs most common were those with a pronounced collagen network and hyper-reflective tissue. With regard to vascularization, we found that the functioning blebs in the shortest postoperative period were dominated by those with one blood vessel (stage 1) and there was no stage 3, with weak tortuosity, while in non-functioning blebs in the late postoperative period, there was moderate to severe vascularization and tortuosity (p=0.037), (p=0.043), (p=0.047), (p=0.021). The type of implant affects the tortuosity of the blood vessels of the filtering bleb (p=0.026). The blebs with Express implants show a slight tortuosity, followed by the blebs with Ologen implants. The highest percentage of highly kinked blood vessels occurred in blebs without an implant. CONCLUSIONS: In vivo confocal microscopy is an innovative method which allows visualization of the internal structure of the filtering blebs at a cellular level, giving us a new insight into the ongoing healing processes, premising the function of the filtering blebs after glaucoma surgery.

Distribution of glaucomas by type, stage of development and therapy.

AIM: To establish the distribution of glaucomas by type and stage of development and analyze their treatment on the basis of free examinations of glaucoma patients. PATIENTS AND METHODS: Three hundred and two consecutive glaucoma patients (91 males and 211 females, mean age 66.5+/-11.6 years, mean duration of disease 4.4 years) were investigated. Each patient underwent examination of the intraocular pressure (IOP), anterior eye segment, fundus oculi, and recommendations about further treatment were given. RESULTS: Females were 70% of the investigated subjects (the ratio of men to women was 1:2.3). Sixty-seven patients (22%) had a family history of glaucoma. Fifty-one (17%) of the glaucoma patients had diabetes mellitus, and 174 (58%)--arterial hypertension. Pseudoexfoliations on the pupillary margin and on anterior lens capsule were observed in 51 patients (17%). The distribution of glaucomas by type was as follows: primary open-angle glaucoma (POAG)--209 patients, pseudoexfoliation glaucoma (PEG)--50 patients, normal-tension glaucoma (NTG)--15 patients, closed-angle glaucoma (CAG)--9 patients, pigmentary glaucoma--6 patients, juvenile glaucoma--1 patient, congenital glaucoma--1 patient, secondary glaucoma--11 patients. According to the stage of the disease the investigated eyes were distributed as follows: early stage of glaucoma--41%, evolution stage--20%, progressive stage--19%, terminal stage--8%. Ten percent of the eyes presented with ocular hypertension and were suspect for glaucoma, while 2% were without glaucoma. Prostaglandin analogues were the most frequently used antiglaucoma topical drugs (45%), followed by beta-blockers (35%). The therapeutic approach was changed for 104 glaucoma patients (34%). CONCLUSION: The primary open-angle glaucoma has the highest frequency in our sample approximately 70% of the cases of glaucomas; pseudoexfoliation glaucoma has a relatively low frequency--17% and the low pressure glaucoma has a surprisingly low relative percentage in the sample. Therapy was changed in more than a third of the examined glaucoma patients--change in the drug therapy or referring patients for antiglaucoma surgery.