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1.
Acta Clin Croat ; 60(3): 441-449, 2022 Feb.
Article in English | MEDLINE | ID: mdl-35282473

ABSTRACT

This study was designed to explore practical differences between visual acuity (VA) scores measured on Snellen chart versus ETDRS chart, to grade cataracts using LOCS III system, and to compare VA on both charts depending on cataract grade and type. Prospective evaluation of uncorrected and best-corrected visual acuity was carried out on the eye scheduled for cataract surgery preoperatively and postoperatively on the Snellen and ETDRS charts. The study was carried out at Department of Eye Diseases, Clinical Center of Serbia, during a two-year period. Inclusion criteria were met by 540 patients who underwent testing, surgery, data collection and analysis. The mean VA score was better on ETDRS than on Snellen chart. The mean difference was 6.05 letters or 1.21 lines. VA results correlated with all types of cataract regardless of the chart used, with the highest statistical significance (p<0.0001) for subcapsular cataract. The ETDRS chart was found to be more discriminative and precise than Snellen chart, especially for poor VA.


Subject(s)
Cataract , Vision Tests , Cataract/complications , Humans , Neurologic Examination , Vision Disorders , Vision Tests/methods , Visual Acuity
2.
BMJ Open ; 10(1): e031236, 2020 01 19.
Article in English | MEDLINE | ID: mdl-31959603

ABSTRACT

OBJECTIVE: Cross-cultural translation and validation of the Serbian version of the Retinopathy Treatment Satisfaction Questionnaire status version (RetTSQs). DESIGN: Cross-sectional study. SETTINGS: The study was conducted between June 2017 and June 2018 at tertiary care centre in Serbia, Belgrade. PARTICIPANTS: A total of 101 patients with diabetic retinopathy (DR) were included. All subjects were evaluated in two consecutive visits, the first during the initial contact to the clinic, while the second 4-6 weeks later. MAIN OUTCOME MEASURES: Validation of Serbian version of the RetTSQs was the major outcome. RESULTS: Cronbach alpha coefficient of the subscales ranged from 0.783 (positive scale) to 0.811 (negative scale) and for all domains it was excellent at α=0.829. The intraclass correlation coefficient was greater than 0.8 for all of the subscales. Univariable analyses revealed that age, gender, education, marital status and working status did not affect the RetTSQ scores, whereas participants with non-proliferative DR reported significantly higher treatment satisfaction (TS) than those with proliferative retinopathy (p=0.001). The group who received laser treatment scored significantly lower than the group without it (p=0.004) regardless of type of performed laser. Positive and statistically significant correlations were found between the RetTSQ score and most of the National Eye Institute Visual Functioning Questionnaire-25 subscales. CONCLUSION: Translated Serbian adaptation of the RetTSQs showed adequate psychometric characteristics as an acceptable, reliable and valid questionnaire. It was well understood by Serbian diabetic patients and it promises to be used in daily clinical work as an instrument for the assessment of TS for patients with DR.


Subject(s)
Cross-Cultural Comparison , Personal Satisfaction , Psychometrics/methods , Quality of Life , Retinal Diseases/psychology , Surveys and Questionnaires , Cross-Sectional Studies , Female , Humans , Incidence , Male , Middle Aged , Reproducibility of Results , Retinal Diseases/epidemiology , Retrospective Studies , Serbia/epidemiology
3.
Anal Bioanal Chem ; 411(22): 5755-5763, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31201462

ABSTRACT

A novel voltammetric method was developed for brimonidine (BRIM) determination in deproteinized aqueous humor, simplifying preparation of biological samples for analysis for stability studies. The differential pulse voltammetric (DPV) method using boron doped diamond electrode (BDDE), based on characteristic oxidation peaks, was proposed and successfully applied. The linearity range was within 5.0 × 10-6 to 5.0 × 10-5 M of brimonidine, and limit of detection and limit of quantitation were 1.94 × 10-6 M and 6.46 × 10-6 M, respectively. Intra-day and inter-day precision and accuracy were evaluated and all results were in accordance with validation ICH guidelines. The best short-term stability study results were obtained for a concentration level of 3.0 × 10-5 M expressed by deviation of + 1.86% between initial and post storage concentrations. A long-term stability study was performed for two concentrations of 3.0 × 10-5 M and 5.0 × 10-5 M and resulted in deviations of + 1.63% and + 3.56%, respectively. A freeze and thaw stability study indicated that samples might be frozen only once. The enhancement of DPV/BDDE method sensitivity gained by modification, for the analysis of immeasurable BRIM quantities in native, untreated aqueous humor, was reached for quantities of 6 or 12 nmol/0.1 mL aqueous humor with acceptable accuracy (up to + 7.5%). The nature of the process-the irreversible one electron oxidation voltammetric peak of BRIM-limited the sensitivity. Only electrochemical pre-treatment of the BDD electrode before each measurement significantly speeded up the whole procedure. The advantages of the proposed method are simplicity, short-time performance, and good specificity/selectivity, as well as satisfactory accuracy, and no chemical modification of BDDE was necessary.


Subject(s)
Adrenergic alpha-2 Receptor Agonists/metabolism , Aqueous Humor/metabolism , Brimonidine Tartrate/metabolism , Drug Stability , Humans
4.
J Ocul Pharmacol Ther ; 34(9): 642-646, 2018 11.
Article in English | MEDLINE | ID: mdl-30204548

ABSTRACT

PURPOSE: To test the hypothesis that the use of refrigerated fixed combination of dorzolamide 2% plus timolol 0.5% solution (COSOPT®) is associated with less ocular discomfort compared with the use of this solution kept at room temperature. METHODS: In this prospective comparative study, 30 primary open-angle patients and 30 healthy subjects filled in the questionnaire on symptoms (Ocular Surface Disease Index) and subjective stinging feeling scale (1-10), at the start of study and 30 days after continuous use of refrigerated fixed combination or placebo eye drops. Results were processed by applying the methods of descriptive (arithmetical mean, standard deviation) and analytical statistics for evaluation of significance of the difference (Student's t-test). RESULTS: Ocular discomfort parameters were significantly lower after the use of refrigerated fixed combination of dorzolamide 2% plus timolol 0.5% solution (t-test, P < 0.0001). Breakup time, Schirmer 1 test, and intraocular pressure values did not differ. CONCLUSIONS: The use of refrigerated fixed combination of dorzolamide 2% plus timolol 0.5% (COSOPT) solution is associated with less ocular discomfort than the use of the same fixed combination at room temperature.


Subject(s)
Antihypertensive Agents/pharmacology , Intraocular Pressure/drug effects , Ocular Hypertension/drug therapy , Ophthalmic Solutions/pharmacology , Sulfonamides/pharmacology , Thiophenes/pharmacology , Timolol/pharmacology , Antihypertensive Agents/administration & dosage , Drug Combinations , Humans , Ocular Hypertension/diagnosis , Ophthalmic Solutions/administration & dosage , Pilot Projects , Prospective Studies , Sulfonamides/administration & dosage , Thiophenes/administration & dosage , Timolol/administration & dosage
5.
Indian J Ophthalmol ; 64(2): 114-7, 2016 Feb.
Article in English | MEDLINE | ID: mdl-27050344

ABSTRACT

CONTEXT: In attempt to find an alternative way to determine conversion from ocular hypertension to primary open angle glaucoma (POAG) (besides visual field and optic disc changes), we analyzed intraocular pressure (IOP) pulse wave in spectral domain. AIMS: The aim of this study was to test the potential differences in spectral content of IOP pulse wave between ocular hypertension and POAG patients, which could indicate conversion. SETTINGS AND DESIGN: Cross-sectional study designed to test the differences in the spectral content of pressure pulse wave between nontreated ocular hypertensive and nontreated, freshly diagnosed POAG patients. METHODS: The total of 40 eyes of 40 subjects was included: 20 previously untreated ocular hypertensive patients, and 20 previously untreated POAG patients. Continuous IOP measuring gained by dynamic contour tonometry was submitted to fast Fourier transform signal analysis and further statistical data processing. Statistics Analysis Used: Ocular and systemic characteristics of the tested subjects were compared by analysis of variance appropriate for this study design. A P < 0.05 was considered to be statistically significant. RESULTS: Higher spectral components of the IOP pulse wave was discerned up to the fifth harmonic in both of the tested groups. No statistically significant differences were found in any of the tested harmonic amplitudes. CONCLUSIONS: There are no differences in the spectral content of IOP pulse wave between ocular hypertensive and primary open angle glaucoma patients which could be indicative for conversion.


Subject(s)
Glaucoma, Open-Angle/physiopathology , Intraocular Pressure/physiology , Ocular Hypertension/physiopathology , Pulse Wave Analysis , Aged , Blood Pressure/physiology , Cornea/physiopathology , Cross-Sectional Studies , Elasticity/physiology , Female , Fourier Analysis , Glaucoma, Open-Angle/diagnosis , Gonioscopy , Heart Rate/physiology , Humans , Male , Middle Aged , Ocular Hypertension/diagnosis , Tonometry, Ocular
6.
J Infect Dev Ctries ; 8(7): 925-8, 2014 Jul 14.
Article in English | MEDLINE | ID: mdl-25022307

ABSTRACT

Ophthalmomyiasis externa is the result of infestation of the conjunctiva by the larval form or maggots of flies from the order Diptera. If not recognized and managed appropriately, it can be complicated by the potentially fatal condition ophthalmomyiasis interna. Ophthalmomyiasis externa is mainly caused by the sheep bot fly (Oestrus ovis). We present the first case, to our knowledge, of ophthalmomyiasis externa in an elderly woman from Belgrade caused by Lucilia sericata Meigen--a green bottle fly.


Subject(s)
Conjunctival Diseases/etiology , Diptera/pathogenicity , Myiasis/etiology , Aged, 80 and over , Animals , Conjunctival Diseases/parasitology , Conjunctival Diseases/therapy , Female , Humans , Larva , Myiasis/parasitology , Myiasis/therapy , Serbia
7.
Hellenic J Cardiol ; 54(6): 435-40, 2013.
Article in English | MEDLINE | ID: mdl-24305579

ABSTRACT

INTRODUCTION: The aim of our study was to examine blood pressure (BP) changes in hypertensive and nonhypertensive patients after intravitreal bevacizumab injections and to assess whether intravitreal bevacizumab carries an associated vascular risk in patients with exudative ocular disease. We also aimed to estimate the influence of gender. METHODS: The study included 57 patients with age-related macular degeneration who received an intravitreal injection of 1.25 mg (0.1 mL) of bevacizumab. We analyzed systolic and diastolic BP values separately. Patients were divided into males and females, and into hypertensives and normotensives based on their BP values. BP was measured before bevacizumab administration, and 10 minutes, 1 hour, 2 days, 7 days and 6 weeks after the injection. RESULTS: Males had a statistically significant decline in systolic BP values 1 hour and 6 weeks after drug administration (p<0.05). The most notable significant decline in diastolic BP values was for males and for normotensive participants 1 hour after drug administration (p<0.05), while the most notable decline in diastolic BP values for females and for hypertensive participants was 7 days after drug administration, with statistical significance only for hypertensive patients (p<0.01). For males it was noticed that a statistically significant decline in diastolic BP persisted after 6 weeks (p<0.05). CONCLUSIONS: An intravitreal bevacizumab injection is safe as regards BP changes over 6 weeks post administration. Regular follow up for 6 weeks should be mandatory in order to promptly recognize individuals who have changes in BP values and include them in BP treatment in order to prevent complications.


Subject(s)
Angiogenesis Inhibitors/therapeutic use , Antibodies, Monoclonal, Humanized/therapeutic use , Blood Pressure/drug effects , Wet Macular Degeneration/drug therapy , Aged , Bevacizumab , Female , Humans , Intravitreal Injections , Male , Prospective Studies , Sex Factors , Treatment Outcome , Wet Macular Degeneration/physiopathology
8.
Ophthalmic Genet ; 34(1-2): 61-4, 2013.
Article in English | MEDLINE | ID: mdl-22697299

ABSTRACT

PURPOSE: Our aim is to report the co-existence of Duane's retraction syndrome and Wyburn-Mason syndrome, a rare condition characterized by arteriovenous malformations (AVMs) in the central nervous system and retina. METHODS: An 11-year-old boy was referred for evaluation of strabismus present since birth. On examination his uncorrected visual acuity was 6/6 in each eye, with small angle left eye esotropia in the primary position, ipsilateral face turn, abduction deficit, lid fissure narrowing in adduction and widening in abduction; plus typical features of left-sided type I Duane syndrome were present. The left fundus demonstrated localized, well-compensated, markedly convoluted, dilated and tortuous retinal vessels and venous congenital retinal macrovessel, which traverse the macular region. The right fundus was unremarkable. In order to elucidate if this retinal vascular malformation is associated with similar lesions in the orbit, paranasal sinuses and/or brain, magnetic resonance imaging (MRI) was performed, followed by digital subtraction angiography of the brain vessels. RESULTS: Clinical features of retinal disease (typical retinal vascular malformation) and brain imaging studies have led to the diagnosis of Wyburn-Mason syndrome. Digital subtraction angiography of the brain revealed an AVM of 30 mm maximal diameter in the left occipital lobe. CONCLUSIONS: Intracranial AVM might have affected the normal vascular development during the second month of gestation, causing involutional changes of the sixth nerve and resulted in Duane's syndrome by "steal phenomenon." Retinal AVM may point to concomitant intracranial AVMs, thus warranting neurological assessment. Patients with AVM of the retina should be examined early with brain and orbital neuroimaging to rule out cerebral AVMs.


Subject(s)
Arteriovenous Fistula/complications , Duane Retraction Syndrome/complications , Neurocutaneous Syndromes/complications , Angiography, Digital Subtraction , Arteriovenous Fistula/diagnosis , Arteriovenous Malformations/diagnosis , Child , Duane Retraction Syndrome/diagnosis , Humans , Intracranial Arteriovenous Malformations/diagnosis , Magnetic Resonance Imaging , Male , Neurocutaneous Syndromes/diagnosis , Retinal Artery/abnormalities , Retinal Vein/abnormalities , Visual Acuity/physiology
9.
Curr Eye Res ; 37(11): 1019-24, 2012 Nov.
Article in English | MEDLINE | ID: mdl-22730930

ABSTRACT

PURPOSE: To investigate the spectral content of intraocular pressure (IOP) pulse wave by advanced spectral signal processing of continuous IOP readings obtained by dynamic contour tonometry. PATIENTS AND METHODS: A non-interventional case-control study included 20 healthy subjects, 20 previously untreated primary open angle glaucoma patients, and 20 previously untreated normal tension glaucoma patients. The continuous IOP reading obtained by dynamic contour tonometry was submitted to Fast Fourier Transform signal analysis and further statistical data processing. RESULTS: The spectral components of the IOP pulse wave were discerned up to the fifth harmonic. Highly statistically significant difference was found between the control group and the primary open angle group, and between the primary open angle glaucoma group and the normal tension glaucoma group in the first, second and the third harmonic amplitude (p < 0.01). Glaucoma patients had significantly higher ocular pulse volume values. CONCLUSIONS: It is possible to determine spectral components of the IOP pulse wave up to the fifth harmonic by a spectral analysis of dynamic contour tonometry continuous readings. We found that high Ocular Pulse Amplitude values in primary open angle glaucoma group was associated with high harmonics amplitude, which indicates low rigidity of blood vessels.


Subject(s)
Glaucoma, Open-Angle/diagnosis , Intraocular Pressure/physiology , Tonometry, Ocular/methods , Female , Fourier Analysis , Glaucoma, Open-Angle/physiopathology , Humans , Male , Middle Aged , Pulsatile Flow , Reproducibility of Results
11.
Med Sci Monit ; 18(5): CR265-70, 2012 May.
Article in English | MEDLINE | ID: mdl-22534704

ABSTRACT

BACKGROUND: There has been only 1 study on postoperative pain after external dacryocystorhinostomy (DCR) that compared pain between 2 groups of patients; 1 group received local anesthesia and the other received general anesthesia. To further characterize the relationship between these 2 types of anesthesia and postoperative pain, we designed a study in which a single patient received these 2 different anesthesia modalities for a short interval on 2 different sides. MATERIAL/METHODS: There were 50 participants in this study. External DCR was performed on the same participant on both sides using local anesthesia on 1 side and general anesthesia on the other. Postoperative pain was measured using the visual analogue scale (VAS), and localization and timing of pain were reported by the participants. Postoperative nausea and vomiting (PONV) were documented if present. RESULTS: Pain levels were significantly higher with general anesthesia 3 hours post-surgery, and 6 hours post-surgery the pain remains higher following general anesthesia but is borderline insignificant (p=0.051). However, 12 hours post-surgery, there is no significant difference in the pain level (p=0.240). There was no significant difference in the localization of pain with local and general anesthesia. Postoperative nausea is significantly more frequent after general anesthesia, and vomiting only occurs with general anesthesia. Local anesthesia was preferred by 94% of the participants (47 out of 50). CONCLUSIONS: The vast majority of patients in our study who have undergone both GA and LA DCR would choose LA again, providing a compelling case for use of the LA technique.


Subject(s)
Anesthesia, General , Anesthesia, Local , Dacryocystorhinostomy , Pain, Postoperative , Patient Satisfaction , Adult , Humans , Prospective Studies
12.
Med Sci Monit ; 17(6): CR341-6, 2011 Jun.
Article in English | MEDLINE | ID: mdl-21629189

ABSTRACT

BACKGROUND: External dacryocystorhinostomy (DCR) is often performed under local anesthesia (LA) without adequate knowledge of the pain experienced by the patient. MATERIAL/METHODS: We subdivided our surgical technique into stages easily understood by the patients (introducing cotton tipped applicators, performing parabulbar injection, creating the incision, bone cracking (opening the ostium), manipulating the nose, intubating, closing the wound, and packing with gauze). A total of 50 patients ranging in age from 31 to 83 years of age (63.64±9.64) underwent external DCR. Each patient was asked 30 minutes after surgery to indicate the intensity of pain experienced at each stage of the surgery and during intramuscular (i.m.) injection of an antibiotic using a visual analog scale (VAS). RESULTS: Analysis of the VAS-based pain scores indicated 3 statistically equal occurrences of pain coinciding with the opening of the ostium, and receiving both parabulbar anesthetic and i.m. antibiotic injections. CONCLUSIONS: The level of pain experienced during the most unpleasant stage of external DCR (ostium opening) was similar to the pain experienced from an i.m. injection. Patients can be informed that pain during external DCR with local anesthesia is comparable to receiving an i.m. gluteal injection.


Subject(s)
Anesthesia, Local/adverse effects , Dacryocystorhinostomy/adverse effects , Pain/etiology , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Pain Measurement
13.
Curr Eye Res ; 35(12): 1099-104, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20929293

ABSTRACT

PURPOSE: Vascular dysregulation is deemed a significant risk factor in glaucoma occurrence and progression. Capillaroscopy of the blood vessels on the finger nail-fold is a method that can provide information regarding the state of the vascular system at the capillary level. The aim of this pilot study was to determine whether there are significant differences in the morphological characteristics of the peripheral blood vessels in normotensive glaucoma and primary open angle glaucoma. MATERIALS AND METHODS: An ophthalmological and capillaroscopic examination was conducted on 30 normotensive glaucoma patients and 30 primary open angle glaucoma patients. The capillaroscopic characteristics described were as follows: capillary row density, capillary diameter, number of spirally formed capillaries, permeability of the loop, and loop resistance. RESULTS: Statistically, significantly more intensively spiraled capillaries were found in normotensive glaucoma patients (χ(2) test, p < 0.05). CONCLUSIONS: Results confirm the thesis that vascular factors play a significant role in the pathogenesis of the glaucoma, especially in cases where the level of intraocular pressure cannot be deemed responsible for the present damage of the optical nerve. Despite the newer, technologically more developed methods for diagnostics and monitoring glaucoma, it is often not easy to establish the right diagnosis and determine further the course of the illness, since the role the intraocular pressure (IOP) plays compared to the role of vascular factors is unknown; hence, capillaroscopy as a complementary diagnostic procedure can be of help.


Subject(s)
Glaucoma, Neovascular/diagnosis , Glaucoma, Open-Angle/diagnosis , Intraocular Pressure/physiology , Microscopic Angioscopy/methods , Adult , Aged , Aged, 80 and over , Female , Glaucoma, Neovascular/physiopathology , Glaucoma, Open-Angle/physiopathology , Humans , Male , Middle Aged , Nails/blood supply , Optic Nerve/pathology , Pilot Projects
14.
Vojnosanit Pregl ; 63(9): 835-8, 2006 Sep.
Article in English | MEDLINE | ID: mdl-17039897

ABSTRACT

BACKGROUND: Congenital fibrosis of extraocular muscles (CFEOM) is a very rare congenital condition, characterized by variable amounts of restriction of the extraocular muscles, with or without ptosis. The aim of this report was to describe a severe, atypical, exposure-induced corneal stromal lysis in two patients. CASE REPORT: A mother and a daughter with a severe CFEOM were presented. The surgery of both extraocular muscles and ptosis led to a fair outcome in mother even 30 years after, and a very good outcome in daughter 4 years after the treatment. CONCLUSION: Though frequently challenging and dissapointing the outcome of surgery of both extraocular muscles and ptosis in CFEOM can be favorable even in rather severe cases. To the best of our knowledge, the atypical keratolysis we described has not been highlighted in the literature on CFEOM so far.


Subject(s)
Blepharoptosis/surgery , Oculomotor Muscles/pathology , Ophthalmoplegia/genetics , Strabismus/surgery , Adult , Blepharoptosis/etiology , Female , Fibrosis/congenital , Humans , Infant , Oculomotor Muscles/surgery , Ophthalmoplegia/complications , Ophthalmoplegia/surgery , Strabismus/etiology
15.
Ophthalmology ; 112(4): 694-704, 2005 Apr.
Article in English | MEDLINE | ID: mdl-15808264

ABSTRACT

OBJECTIVE: To investigate histopathologic alterations of eyelid biopsy specimens from patients with floppy eyelid syndrome (FES) with special regard to elastic fiber content and ultrastructure as well as to the expression of elastin-degrading enzymes to elucidate the pathogenesis of this disorder. DESIGN: Retrospective, interventional case series. PARTICIPANTS AND CONTROLS: Eleven consecutive patients with FES and 10 age-matched control patients with basal cell carcinoma of the eyelid. METHODS: Horizontal pentagonal eyelid resections of 16 upper lids were performed in 11 patients with FES. Full-thickness eyelid biopsy specimens from study and control patients were examined by light and transmission electron microscopy, semiquantitative morphometry, and immunohistochemistry using antibodies against matrix metalloproteinase (MMP)-2, MMP-7, MMP-9, and MMP-12 and neutrophil elastase. RESULTS: All patients treated with surgical horizontal eyelid shortening were asymptomatic at follow-up. Histopathologic analysis of the surgical specimens showed, apart from unspecific signs of chronic inflammation, a significant decrease in the amount of elastin within the tarsal plate and eyelid skin as compared with controls. Residual elastic fibers revealed an abnormal ultrastructure with a diminished elastin core. Immunohistochemistry demonstrated an increased immunoreactivity for elastolytic proteases, particularly MMP-7 and MMP-9, in areas of elastin depletion in FES specimens as compared with controls. CONCLUSIONS: The findings indicate that upregulation of elastolytic enzymes, most probably induced by repeated mechanical stress, participates in elastic fiber degradation and subsequent tarsal laxity and eyelash ptosis in FES.


Subject(s)
Eyelid Diseases/enzymology , Matrix Metalloproteinases/metabolism , Aged , Biopsy , Carcinoma, Basal Cell , Elastic Tissue/enzymology , Elastic Tissue/ultrastructure , Elastin/metabolism , Eyelid Diseases/pathology , Eyelid Neoplasms , Female , Humans , Immunoenzyme Techniques , Male , Matrix Metalloproteinase 12 , Matrix Metalloproteinase 2/metabolism , Matrix Metalloproteinase 7/metabolism , Matrix Metalloproteinase 9/metabolism , Metalloendopeptidases/metabolism , Middle Aged , Retrospective Studies , Syndrome
16.
Arch Ophthalmol ; 121(10): 1415-22, 2003 Oct.
Article in English | MEDLINE | ID: mdl-14557177

ABSTRACT

OBJECTIVE: To assess the alterations in human donor corneal tissue induced by Q-switched erbium (Er):YAG laser corneal trephination. METHODS: Thirty human corneoscleral donor buttons unsuitable for transplantation were placed in an artificial chamber on an automated rotation device. Corneas were trephined with a Q-switched Er:YAG laser (wavelength, 2.94 microm; pulse duration, 400 nanoseconds) along (donor and recipient) aluminum silicate (ceramic) open masks. A spot diameter of 0.65 mm, energy setting of 50 mJ/pulse, and repetition rate of 5 Hz were used. Corneal thermal damage and cut regularity were quantitatively assessed in 24 corneas processed for light microscopy and by transmission and scanning electron microscopy. RESULTS: The stromal thermal damage was the highest (mean [SD], 8.0 [2.7] microm) at a 150-microm cut depth and decreased downward. Cut regularity was very good and did not significantly differ between donors and recipients. Scanning electron microscopy confirmed that the cuts were highly regular; transmission electron microscopy revealed 2 distinctive subzones within the stromal thermal damage zone. CONCLUSIONS: Thermal damage induced by Q-switched Er:YAG nonmechanical corneal trephination was low, and the regularity of the cuts was very good. CLINICAL RELEVANCE: The Q-switched Er:YAG laser may have the potential to become an alternative to the excimer laser for nonmechanical penetrating keratoplasty.


Subject(s)
Cornea/surgery , Keratoplasty, Penetrating/methods , Laser Therapy/methods , Cornea/ultrastructure , Corneal Stroma/injuries , Corneal Stroma/ultrastructure , Endothelium, Corneal/injuries , Endothelium, Corneal/ultrastructure , Humans , Keratoplasty, Penetrating/instrumentation , Laser Therapy/adverse effects , Tissue Donors
17.
Graefes Arch Clin Exp Ophthalmol ; 241(8): 667-72, 2003 Aug.
Article in English | MEDLINE | ID: mdl-12883909

ABSTRACT

PURPOSE: To assess the degree of corneal diameter shrinkage induced by Q-switched mid-infrared laser corneal trephination for penetrating keratoplasty in an experimental model. METHODS: Corneal trephination was performed in 80 enucleated porcine eyes fixed in a holder centered on an automated globe rotation device, by Q-switched (2.94 microm) Er:YAG laser along open masks. Four types of masks were used to protect the underlying corneal tissue: metal masks (donor and recipient) and ceramic masks (donor and recipient). Two spot diameters (0.65 mm and 0.96 mm) were combined with two energy settings (40 mJ/pulse and 50 mJ/pulse) for each of the masks used. Repetition rate was fixed at 5 Hz. Diameters of donor buttons/recipient beds (horizontal and vertical) were measured immediately after the trephination and compared to the given mask size. RESULTS: Minimum corneal shrinkage was found in the recipient metal mask group (mean +/- SD=0.3+/-0.4%) with 50 mJ pulse energy and 0.65 mm spot diameter (in the horizontal diameter), while the maximum shrinkage (5.3+/-2.8%) was found in the donor metal mask group with 50 mJ pulse energy and 0.96 mm spot diameter. Corneal shrinkage was less pronounced in recipient beds than in donor buttons (P<0.01). The differences in shrinkage between the use of ceramic and metal masks were insignificant (P>0.05). Mean induced corneal diameter discrepancies between the donor button and the recipient bed (with metal and ceramic masks) were 2.5% and 2.5% in vertical diameter and 3.4% and 2.4% in horizontal diameter. CONCLUSIONS: The Q-switched Er:YAG laser experimental corneal trephination for penetrating keratoplasty may induce minor degrees of corneal diameter shrinkage in donor buttons and recipient openings. Oversizing of donor masks by 0.25-0.35 mm (i.e. 3-4% of graft size) may be a valid option to avoid refractive consequences.


Subject(s)
Cornea/pathology , Cornea/surgery , Keratoplasty, Penetrating , Laser Therapy , Trephining , Animals , Equipment Design , Eye Protective Devices , In Vitro Techniques , Swine , Tissue Donors , Trephining/instrumentation
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