Krzysztof Penkala

Publications of Krzysztof Penkala

• [Functional improvement of injured retina following the adjuvant stem cell-based therapy. Preliminary report].

  Authors: Anna Machalińska, Wojciech Lubiński, Krzysztof Penkala, Miłosz Kawa, Bartłomiej Baumert, Barbara Wiszniewska, Danuta Karczewicz, Bogusław Machaliński

  Klinika oczna. 01/2011; 113(4-6):117-21.

  The purpose of this study was to appraise the functional response of damaged retina to the stem cell-based therapy in mice. The majority of disorders leading to the irreversible vision loss in theThe purpose of this study was to appraise the functional response of damaged retina to the stem cell-based therapy in mice. The majority of disorders leading to the irreversible vision loss in the developed world is caused by retinal degeneration. Since, recent reports emphasized regenerative potential of bone marrow stem marrow stem/progenitor cells (SPCs), we investigated here the beneficial effect of intravenously administrated SPCs on regeneration of acutely injured retina. Selective chemical injury of murine retinas was induced by intravenous administration of sodium iodate (NalO3) in its toxic dose. Flash electroretinogram (ERG), was performed in different time points after infusion of bone marrow-derived and negative for linage antigens population of SPCs. Stem cell-based therapy resulted in gradual increase of b-wave amplitude in ERG recordings starting from the 3rd day after NalO3 administration, what confirmed the improvement of retinal function in long-term observation. Our preliminary findings revealed that the selected stem cell-based therapy employed in the adjuvant mode has been shown to be effective in supporting the retinal function recovery after acute retinal damage.

• Sodium iodate selectively injuries the posterior pole of the retina in a dose-dependent manner: morphological and electrophysiological study.

  Authors: Anna Machalińska, Wojciech Lubiński, Patrycja Kłos, Miłosz Kawa, Bartłomiej Baumert, Krzysztof Penkala, Ryszard Grzegrzółka, Danuta Karczewicz, Barbara Wiszniewska, Bogusław Machaliński

  Neurochemical research. 11/2010; 35(11):1819-27.

  Sequential morphological and functional features of retinal damage in mice exposed to different doses (40 vs. 20 mg/kg) of sodium iodate (NaIO(3)) were analyzed. Retinal morphology, apoptosis (TUNELSequential morphological and functional features of retinal damage in mice exposed to different doses (40 vs. 20 mg/kg) of sodium iodate (NaIO(3)) were analyzed. Retinal morphology, apoptosis (TUNEL assay), and function (electroretinography; ERG) were examined at several time points after NaIO(3) administration. The higher dose of NaIO(3) caused progressive degeneration of the whole retinal area and total suppression of scotopic and photopic ERG. In contrast, the lower dose induced much less severe degeneration in peripheral part of retina along with a moderate decline of b- and a-wave amplitudes in ERG, corroborating the presence of regions within retina that retain their function. The peak of photoreceptor apoptosis was found on the 3rd day, but the lower dose induced more intense reaction within the central retina than in its peripheral region. In conclusion, these results indicate that peripheral area of the retina reveals better resistance to NaIO(3) injury than its central part.

• A 43-year-old man with reduced visual acuity and normal fundus: occult macular dystrophy--case report.

  Authors: Wojciech Lubiński, Wojciech Gosławski, Krzysztof Penkala, Monika Drobek-Słowik, Danuta Karczewicz

  Documenta ophthalmologica. Advances in ophthalmology. 04/2008; 116(2):111-8.

  PURPOSE: Occult macular dystrophy (OMD) is an unusual, inherited macular dystrophy characterized by a slowly progressive decline of visual acuity with normal fundus and fluorescein angiography (FA).PURPOSE: Occult macular dystrophy (OMD) is an unusual, inherited macular dystrophy characterized by a slowly progressive decline of visual acuity with normal fundus and fluorescein angiography (FA). The authors present a 43-year-old man who was diagnosed as having OMD because of the results of electrophysiological, psychophysical, optical coherence tomography (OCT) tests. METHODS: Routine ophthalmological evaluation, FA, visual field tests, electroretinographic examinations (EOG, ERG, PERG and mfERG recordings according to ISCEV standards) and foveal thickness measurements (OCT) were performed. RESULTS: Funduscopic examinations, FA, full field ERG as well as PERG results were all normal. In both eyes, the abnormalities were observed in static perimetry (relative central scotomas), mfERG (significant reduction of P1 amplitude in the central retinas) and OCT (significantly thinner foveal thickness). CONCLUSIONS: A new case with OMD is added to preceding reports. The mfERG and OCT tests are important in detection of OMD patients. It can help in differential diagnosis of amblyopia, optic nerve diseases and non-organic visual disorders.

• [Computer fusion of the mfVEP and HVF images]

  Authors: Łukasz Santarek, Michał Zaleski, Wojciech Lubiński, Krzysztof Penkala

  Annales Academiae Medicae Stetinensis. 02/2007; 53 Suppl 1:62-5; discussion 65.

  INTRODUCTION: The purpose of this paper is to show a method of data fusion from two different tests: the multifocal visual evoked potentials (mfVEP) and humphrey visual field (HVF). Fusing theINTRODUCTION: The purpose of this paper is to show a method of data fusion from two different tests: the multifocal visual evoked potentials (mfVEP) and humphrey visual field (HVF). Fusing the results may lead to a better diagnosis of various diseases associated with changes of patient's field-of-view. MATERIAL AND METHODS: Two methods were used: mfVEP and HVF. MatLab environment was used for computer fusion of the images obtained in the mfVEP and HVF tests. RESULT: The two methods results' fusion was achieved during computer experiments. CONCLUSIONS: Achieved results will allow more precise and objective analysis of patient's field-of-view.

• [Improvement of the PERG parameters measurement accuracy in the continuous wavelet transform coefficients domain]

  Authors: Krzysztof Penkala, Marek Jaskuła, Wojciech Lubiński

  Annales Academiae Medicae Stetinensis. 01/2007; 53 Suppl 1:58-60; discussion 61.

  PURPOSE: To determine parameters of the pattern electroretinogram (PERG) waveforms in the continuous wavelet transform (CWT) coefficients domain important in more precise clinical assessment of thePURPOSE: To determine parameters of the pattern electroretinogram (PERG) waveforms in the continuous wavelet transform (CWT) coefficients domain important in more precise clinical assessment of the recordings. MATERIAL AND METHODS: 102 normal PERG recordings were studied in two age groups (< or = 50 years, > 50 years). Continuous wavelet transform analysis was performed using the MatLab 7.0 software. Various wavelets were used in the experiments. Mother wavelets selection was optimized with the criterion based on minimal scatter of the results for normal PERG waveforms. RESULTS: Comparison with traditional, time-domain based analysis showed that determining the PERG parameters in CWT domain was achieved with better accuracy. Normal values for the test showed much less scatter. It was shown on some clinical examples (glaucomatous patients) that the sensitivity of the test was improved. CONCLUSIONS: The CWT-based method of the PERG signal analysis is useful in clinical differentiation between normal and abnormal waveforms, particularly in objective early detection of glaucoma.

• Retinal dysfunction in eyes of patients with BRCA1 gene mutation.

  Authors: Wojciech Lubiński, Bohdan Górski, Zbigniew Szych, Krzysztof Penkala, Olgierd Palacz, Jan Lubiński

  Klinika oczna. 02/2005; 107(10-12):603-6.

  PURPOSE: To assess the retinal function in BRCA1 gene mutation carriers. MATERIAL AND METHODS: Thirty unaffected patients (60 eyes) with constitutional BRCA1 gene mutation were studied. Flash ERGPURPOSE: To assess the retinal function in BRCA1 gene mutation carriers. MATERIAL AND METHODS: Thirty unaffected patients (60 eyes) with constitutional BRCA1 gene mutation were studied. Flash ERG recordings were performed in accordance with the International Society for Clinical Electrophysiology of Vision (ISCEV) standards. RESULTS: In ERGs, in the maximal response, amplitude of a-wave (p<0.02) was reduced. In the cone single- flash response, the amplitude of a-wave (p<0.04) was also reduced. In the scotopic oscillatory potentials (OPs), we noted: increased amplitude of OP2 (p<0.0006), increased index of OP amplitude (01+02+03+04) (p<0.04), and increased latencies of OP1 (<0.05) and OP3 (p<0.004) and OP4 (p<0.03). CONCLUSIONS: Slight dysfunction of rods, cones and inner retinal layers is present in asymptomatic carriers of BRCA1 gene mutation.

• Supernormal electro-oculograms in patients with neurofibromatosis type 1.

  Authors: Wojciech Lubiński, Stanisław Zajaczek, Zbigniew Sych, Krzysztof Penkala, Olgierd Palacz, Jan Lubiński

  Hereditary cancer in clinical practice. 01/2004; 2(4):193-6.

  To asses the retinal pigment epithelium (RPE) function measured by EOG testing in patients with neurofibromatosis type 1 (NF-1). Our preliminary EOG results suggested dysfunction of the RPE inTo asses the retinal pigment epithelium (RPE) function measured by EOG testing in patients with neurofibromatosis type 1 (NF-1). Our preliminary EOG results suggested dysfunction of the RPE in individuals with NF-1. In order to confirm our initial results we performed EOG examination on a larger group of NF-1 patients. Studies were performed on 36 patients with clinically diagnosed NF-1 and compared to normal healthy controls. Standard EOG recordings were performed in accordance with the International Society for Clinical Electrophysiology of Vision (ISCEV) standards. In NF-1 patients the Arden indexes of the EOG test were significantly higher primarily due to the lower values of dark troughs. Supernormal EOGs (exceeding the value of the mean + 2 SD from the control group) were present in 58% of NF-1 patients. Dysfunction of the RPE is a characteristic feature of individuals with NF-1.

• Retinal function in the von Hippel-Lindau disease.

  Authors: Wojciech Lubiński, Karol Krzystolik, Cezary Cybulski, Zbigniew Szych, Krzysztof Penkala, Olgierd Palacz, Jan Lubiński

  Documenta ophthalmologica. Advances in ophthalmology. 05/2003; 106(3):271-80.

  PURPOSE: To assess the retinal function in patients with von Hippel-Lindau disease (VHL). PATIENTS: Studies were undertaken in 12 patients (17 eyes) with detected VHL gene mutation and 12 normalPURPOSE: To assess the retinal function in patients with von Hippel-Lindau disease (VHL). PATIENTS: Studies were undertaken in 12 patients (17 eyes) with detected VHL gene mutation and 12 normal healthy controls (17 eyes). METHODS: Pattern ERG (PERG), standard flash electroretinogram (ERG) recordings were performed in accordance with the International Society for Clinical Electrophysiology of Vision (ISCEV) standards. RESULTS: In VHL patients, electrophysiological statistically significant changes were found. In PERG examination, increased latency of P50 was found in the total VHL group (p < 0.02) and in the VHL subgroup with retinal angiomas (p < 0.04). In ERG examination, photopic b-wave latency was increased in the total VHL group (p < 0.03) and also in the VHL subgroup without retinal angiomas (p < 0.05). In OPs, latency increase of OP2, OP3 waves and reduced amplitude of OP3 wave in the total VHL group (OP2 latency, p < 0.05; OP3 latency, p < 0.01; OP3 amplitude, p < 0.03) and in the VHL subgroup with retinal angiomas (OP2 latency, p < 0.02; OP3 latency, p < .008; OP3 amplitude, p < 0.02) were obtained. CONCLUSIONS: It can be hypothesized that dysfunction of the inner retinal layer is present in individuals with VHL disease even in patients without retinal angiomas.

• Electroretinographic changes in the inner retinal layers of the retained eyes of patients with sporadic unilateral retinoblastoma.

  Authors: Wojciech Lubiński, Stanisław Zajaczek, Zbigniew Sych, Krzysztof Penkala, Olgierd Palacz, Jan Lubiński

  Ophthalmic genetics. 06/2002; 23(2):99-107.

  PURPOSE: Examination of retinal function as measured by flash electroretinogram (ERG) including oscillatory potentials (OPs) and pattern electroretinogram (PERG) in a series of patients withPURPOSE: Examination of retinal function as measured by flash electroretinogram (ERG) including oscillatory potentials (OPs) and pattern electroretinogram (PERG) in a series of patients with unilateral sporadic retinoblastoma. PATIENTS: Studies were undertaken in the retained eye (without clinical evidence of retinoblastoma) of 13 patients with sporadic unilateral retinoblastoma and in 13 healthy controls. METHODS: Standard flash ERG including scotopic OPs and PERG recordings were performed in accordance with the International Society for Clinical Electrophysiology of Vision (ISCEV) standards. RESULTS: Statistically significant differences between the studied and the control groups were observed with flash ERG (OP1 amplitude increase, p < 0.003; photopic flicker amplitude increase, p < 0.05) and PERG (P50 latency increase, p < 0.008). CONCLUSIONS: Inner retinal layer dysfunction may be a characteristic feature of individuals with unilateral sporadic retinoblastoma.

• Electroretinographic changes in eyes of patients with BRCA1 gene mutation.

  Authors: Wojciech Lubiński, Bogdan Górski, Zbigniew Szych, Krzysztof Penkala, Olgierd Palacz, Jan Lubiński

  Ophthalmic research. 35(3):164-9.

  AIM: To assess the retinal function in BRCA1 gene mutation carriers and to evaluate the clinical significance of its potential alterations. PATIENTS AND METHODS: Flash electroretinogram (ERG) wasAIM: To assess the retinal function in BRCA1 gene mutation carriers and to evaluate the clinical significance of its potential alterations. PATIENTS AND METHODS: Flash electroretinogram (ERG) was studied in 15 unaffected patients (30 eyes) with constitutional BRCA1 gene mutation. Routine ophthalmological examination was additionally performed in the oldest, unaffected 15 patients and in 15 breast cancer patients being carriers of BRCA1 mutation. RESULTS: In ERGs, in the maximal response, a-wave (p < 0.03) and b-wave (p < 0.05) amplitudes were reduced. In the cone single-flash response, the amplitude of a-wave (p < 0.007) was also reduced. In the oscillatory potentials (OPs), increased amplitude of OP2 (p < 0.03), and increased latencies of OP3 (p < 0.0009) and OP4 (p < 0.03) were obtained. BRCA1 carriers even at old age or after treatment of breast cancer have not presented increased frequency of abnormalities detectable by routine ophthalmological examination. CONCLUSION: It can be hypothesized that dysfunction of rods, cones and inner retinal layers is present in asymptomatic carriers of BRCA1 gene mutation; however, this does not have clinical consequences.

• Electro-oculographic and electroretinographic studies in HNPCC gene mutation carriers.

  Authors: Wojciech Lubiński, Grzegorz Kurzawski, Joanna Suchy, Zbigniew Szych, Krzysztof Penkala, Olgierd Palacz, Rodney J Scott, Jan Lubiński

  Ophthalmic research. 35(5):281-94.

  PURPOSE: To assess retinal function in HNPCC gene mutation carriers. PATIENTS: 19 carriers (38 eyes) of HNPCC genes and controls. METHODS: Electro-oculogram, standard flash electroretinogram andPURPOSE: To assess retinal function in HNPCC gene mutation carriers. PATIENTS: 19 carriers (38 eyes) of HNPCC genes and controls. METHODS: Electro-oculogram, standard flash electroretinogram and pattern electroretinogram (PERG) recordings were performed. RESULTS: In the total group of HNPCC gene mutation carriers examined by oscillatory potentials, reduced amplitude (p < 0.0004) and increased latency (p < 0.04) of the O3 wave and increased latency (p < 0.02) of the O4 wave were found. In the subgroup of carriers with hMLH1 gene mutation, reduced amplitudes of the O3 (p < 0.0005) and O4 (p < 0.04) waves were identified. In the total group of HNPCC gene mutation carriers examined by PERG, reduced amplitudes of the P50 (p < 0.003), N95 (p < 0.02) and abnormal N95/P50 ratio (p < 0.02) were revealed. In the subgroup of hMLH1 gene mutation carriers, reduced amplitude of the P50 (p < 0.04) and abnormal N95/P50 ratio (p < 0.02) were observed, whereas in the hMSH2 gene mutation carrier subgroup, reduced amplitude (p < 0.03), shortened latency of the P50 wave (p < 0.02) and reduced amplitude of the N95 wave (p < 0.03) were found. CONCLUSION: Constitutional dysfunction of the inner retina appears to be a characteristic feature of HNPCC gene mutation carriers.