Th ocular bilateral hypotensive effect after unilateral topical administration of medetomidine and 4 analogs was demonstrated in a dose-response study (0.5%-2%) in NZW rabbits (bilateral IOP-lowering efficacy: medetomidine>detomidine and MPV-1440>MPV-1441 and MPV-305BIII).

This project explores the use of a novel sustained release mucoadhesive micelle-based drug delivery system in combination with 0.005% latanoprost (LTP) on our partially open angle mouse model of glaucoma (AP-2β TMR-KO). We previously tested for LTP treatment in our model and found a reduction in intraocular pressure (IOP) 20 minutes following treatment. This information led us to investigate the long-term effect of LTP treatment and micelle loaded with LTP (MLTP) treatment in our model. We hypothesized that the MLTP treatment would be more effective in reducing IOP and preventing glaucomatous effects than LTP treatment alone in the AP-2β TMR-KO mice. The MLTP groups of animals (wildtype and mutant) were treated every 3 days, and this was compared with animals treated with LTP daily as well as animals treated every 3 days with LTP alone for comparison’s sake for 60 days. IOP measurements were taken every 3 days. Following long term LTP treatment alone, mutant mice showed a consistent decrease in their baseline IOPs with a significant reduction in baseline IOP at 35 days of treatment across all cohorts (P<0.0001). In comparison, mutants treated with MLTP exhibited an even greater reduction in baseline IOP following long term treatment. After the treatment period, mice were euthanized, and their eyes were enucleated, fixed, sectioned, and stained for retinal ganglion cells (RGCs) using Brn3a. Mutant mice exhibited a significant decrease in RGC cell number when compared to wildtype, and this loss was not rescued by treatment with LTP. However, mutants treated with MLTP demonstrated significant RGC cell protection compared to eyes of untreated mutants, as well as everyday LTP treated mutants. / Thesis / Master of Science (MSc) / An effective treatment strategy is required to prevent irreversible blindness caused from glaucoma. Unfortunately, compliance with current medications is extremely poor, as they require frequent administration due to their low ocular bioavailability and short-term effect. As such, this thesis aims to explore an alternative drug delivery approach in a partially open angle mouse model of glaucoma to prevent the worsening of glaucoma and ultimately improve patient compliance.

No description available.

A aferição da pressão intraocular (PIO) é essencial para o exame oftálmico. Objetivou-se estabelecer os valores da curva diária da PIO de porquinhos da índia de diferentes faixas etárias com tonômetro de rebote. A PIO foi aferida às 6, 12, 18 e 24 horas utilizando o tonômetro de rebote (Tonovet®). Os porquinhos da índia foram subdivididos em dois grupos com 10 animais no grupo I e 4 animais no grupo II, considerando as idades, designados por GI (animais entre 2 a 3 meses de idade) e GII (animais entre 2 a 3 anos de idade). Previamente, foram realizados teste da lágrima de Schirmer, prova da fluoresceína, biomicroscopia com lâmpada de fenda e oftalmoscopia indireta em todos animais. O valor médio da pressão intraocular foi de 12,0 ± 1,83 mmHg. Foram encontradas diferenças significativas entres as idades, sendo que os valores médios para o grupo I foram 11,63 ± 0,29 mmHg, e para o grupo II foram 12,82 ± 0,45mmHg (P= 0,0295). Não foram encontradas diferenças entre ambos os olhos (P= 0,7454). Não foram encontradas diferenças significativas nos valores da PIO relacionadas ao sexo (P= 0,1858). Os valores da PIO em porquinhos da índia tiveram alteração nas horas avaliadas. Com base nos resultados obtidos foi possível concluir que os valores da PIO em porquinhos da índia da sofrem alterações ao longo do dia. Os menores valores de pressão intraocular ocorreram às 18 horas. / The measuring of intraocular pressure (IOP) it is essential for the ophthalmic evaluation; the aim of this study was establish the values of the IOP diurnal curve of guinea pigs with different ages using the rebound tonometer (Tonovet®). The animals were divided according to the age in two groups, Group I (GI) constituted with 10 guinea pigs aged between 2 -3 moths, and Group II (GII), 4 animals with 2 -3 years of old. Previously the Schirmer tear test, fluorescein test, biomicroscopy with slit lamp, and direct optalmoscopy were performed on all animals. The men value of IOP was 12.0±0.34 mmHg. Statistical difference were found between ages (mean GI 11.64 ± 0.29 mmHg, and GII 12.83 ± 0.45mmHg), did not have statistical difference related with gender (P= 0.1858) or between eyes (P= 0.7454). In conclusion the guinea pigs had alteration of IOP true the day, the values of IOP are higher in the morning period, decrease true the day and at the night period haves an elevation again.

OBJETIVOS: 1) Avaliar os parâmetros de biomecânica ocular provenientes do Corvis ST (Oculus Corvis ST, Scheimpflug Technology; Wetzlar, Germany) obtidos de olhos saudáveis de uma população de pacientes brasileiros. 2) Correlacionar os parâmetros derivados do Corvis ST com a idade de pacientes jovens saudáveis. 3) Verificar se as técnicas de facoemulsificação (FC) e do laser de femtosegundo (LFS), empregadas na correção cirúrgica de catatara, influenciam os parâmetros de biomecânica ocular provenientes do Corvis ST. 4) Analisar as alterações da deformação da córnea observadas em um caso de ectasia pós LASIK com flap espesso. MÉTODOS: 1) Estudo clínico transversal conduzido em 90 pacientes (90 olhos saudáveis). Foram avaliados 11 parâmetros derivados do sistema de tonometria de não contato integrado com a câmera ultrarrápida de Scheimpflug (Oculus Corvis ST, Scheimpflug Technology; Wetzlar, Germany), a saber: deformidade de amplitude (DA); pressão intraocular; 1st A time; tempo de concavidade máxima; 2nd A time; 1st A Length (tempo da primeira aplanação); 2nd A Length (tempo da segunda aplanação); raio de curvatura de maior alcance; raio de curvatura normal; velocidade de entrada (Vin) e de saída (Vout). Estes parâmetros foram correlacionados com a espessura central corneana mensurada pela Tomografia de Córnea e Segmento Anterior (Pentacam® - Oculus, Wetzlar, Germany). 2) Estudo clínico observacional, retrospectivo, conduzido em 89 pacientes (89 olhos saudáveis). Os parâmetros derivados do Corvis ST foram correlacionados com a idade dos pacientes. 3) Estudo clínico prospectivo, envolvendo 151 olhos de 127 pacientes com diagnóstico de catarata nuclear. Setenta e cinco olhos de 65 pacientes foram submetidos à técnica do laser de femtosegundo (AlconLenSx, Aliso Viejo, USA) e 76 olhos de 62 pacientes à facoemulsificação convencional (Alcon Infinit, Fort Worth, USA). Foram avaliados os 11 parâmetros de biomecânica ocular derivados do Corvis ST antes (Pré) e após as cirurgias de catarata (D1, primeiro dia de pósoperatório). A densitometria do cristalino (scattering) foi realizada pelo PNS (Pentacam Nucleus Staging). 4) Avaliação com tomografia de coerência óptica de espessura dos flaps corneanos pós Lasik e análise dos parâmetros biomecânicos provenientes do Corvis ST em uma córnea com ectasia pós Lasik. RESULTADOS: 1) A média de idade dos pacientes foi de 35,80 ± 12,83 anos. A média do equivalente esférico foi de -3,29 ± 3,69 dioptrias. A média da espessura central corneana foi de 547,50 ± 32,00 ?m Os valores dos 11 parâmetros biomecânicos obtidos de olhos saudáveis, foram os seguintes: deformidade de amplitude 1,05 ± 0,08 mm; tempo de concavidade máxima 18,38 ± 0,93 ms; pressão intraocular 16,43 ± 2,15 mmHg; tempo da primeira aplanação (1st A time) 8,32 ± 0,33 ms; tempo da segunda aplanação 23,80 ± 0,44 ms; raio de curvatura de maior alcance 11,09 ± 2,06 mm; raio de curvatura normal 7,59 ± 0,67 mm; tempo da primeira aplanação (1st A Length) 2,07 ± 0,38 mm; tempo da segunda aplanação (2nd A Length) 2,37 ± 0,47 mm; velocidade de entrada (Vin) 0,21 ± 0,05 m/s e velocidade de saída (Vout) -0,33 ± 0,07 m/s. 2) A média de idade dos pacientes foi de 27,50 ± 6,30 anos. O tempo de concavidade máxima alcançada da córnea (HC-time) foi o único dos 11 parâmetros que apresentou correlação significativa com a idade (p=0,04, rs=0,18). 3) A média de idade dos pacientes dos grupos LFS (laser de femtosegundo) e FC (facoemulsificação convencional) foram, respectivamente, 67,6 ± 9,9 anos e 68,4 ± 11,8 anos. No grupo LFS, 9 dos 11 parâmetros foram estatisticamente significativos entre o Pré e D1; e no grupo FC, 7 dos 11 parâmetros foram estatisticamente significativos entre o Pré e D1. Entre os 11 parâmetros biomecânicos avaliados, somente o tempo de concavidade máxima da córnea (HC-time) foi significativamente diferente entre os dois grupos em D1 (p=0,0387). 4) Paciente do sexo feminino, 45 anos, submetida à Lasik em ambos os olhos. Com a utilização da tomografia de coerência óptica (OCT Rtvue, OptoVue, Fremont, CA,USA) foram identificados: um flap com espessura central de 392 ?m no OD e dois cortes, sendo um flap incompleto profundo e o outro mais fino superiormente, no OE. Os parâmetros derivados do Corvis ST como a deformidade de amplitude são diferentes em ambos os olhos. CONCLUSÕES: 1) Os valores de 8 dos 11 parâmetros derivados do Corvis ST foram influenciados pela espessura central da córnea, porém esta influência foi baixa. 2) Em olhos saudáveis de pacientes jovens foi obtida correlação significativa entre a idade e o tempo de concavidade máxima, que é o tempo do início de aplanação até a concavidade máxima alcançada da córnea. 3) O laser de femtosegundo para cirurgia de catarata e a técnica de facoemulsificação convencional induziram alterações nas propriedades biomecânicas da córnea no D1. Dos 11 parâmetros biomecânicos estudados apenas o tempo de concavidade máxima da córnea apresentou diferença significativa entre os grupos (LFS e FC) no D1. 4) A ectasia unilateral após LASIK pode ocorrer devido a flap espesso com falência biomecânica da córnea / PURPOSE: 1) To evaluate ocular biomechanical metrics given by the CorVis ST (Oculus, Inc., Berlin, Germany) in a population of healthy Brazilian patients. 2) To correlate parameters derived from corneal deformation resulting from non-contact tonometry integrated with an ultra-high-speed (UHS) Scheimpflug camera (Oculus Corvis ST, Scheimpflug Technology; Wetzlar, Germany) with age in normal eyes from young patients. 3) To evaluate the changes of corneal biomechanical after femtosecond laser - assisted cataract (FS) and to compare the parameters derived by Corvis ST between standard phacoemulsification (SP) and femtosecond laser - assisted in cataract surgery. 4) To report a case of post-LASIK corneal ectasia due to a thick flap, while the contralateral eye did not develop ectasia after an incomplete deep flap cut, followed by a thinner flap Lasik procedure. METHODS: 1) An observational and cross-sectional study involving 1 eye randomly selected from 90 healthy patients. Studied parameters (including deformation amplitude, first applanation time, highest concavity time, second applanation time, first applanation length, second applanation length, curvature radius highest concavity, curvature radius normal, velocity in, and velocity out) derived from the CorVis ST were correlated to central corneal thickness from the Pentacam (Oculus, Inc.). Differences between data on the basis of gender were evaluated. 2) Observational, retrospective study involving one eye randomly selected from study participants, totaling 89 healthy eyes. The Scheimpflug images were taken with an ultra-high-speed camera during each measurement by the Corvis ST. The deformation amplitude (DA) and other parameters (e.g., pachy apex, intraocular pressure, 1st A time, highest concavity-time, 2nd A time, 1st A Length, 2nd A Length, Wing-Dist, curvature radius highest concavity, curvature radius normal, Vin, Vout) measured by the corvis ST were correlated with age. 3) Prospective study: 151 eyes of 127 patients were underwent cataract surgery. 75 eyes of 65 patients were with femtosecond laser-assisted (FS)(Alcon Len Sx, Aliso Viejo,USA) and 76 eyes of 62 patients with standard phacoemulsification (SP) (Alcon Infinit, FortWorth, USA). 4) Case Report. RESULTS: 1) About the first study: Mean patient age was 35.80 ± 12.83 years (range: 21.07 to 78.84 years). Mean central corneal thickness was 547.50 ± 32.00 ?m (range: 490 to 647 ?m) and mean spherical equivalent refraction was -3.29 ± 3.69 diopters (range: -9.50 to +10.37 diopters). Mean deformation amplitude was 1.05 ± 0.08 mm (range: 0.91 to 1.26 mm). Highest concavity time was 18.38 ± 0.93 ms (range: 16.95 to 21.07 ms). Intraocular pressure was 16.43 ± 2.15 mm Hg (range: 11.50 to 21.0 mm Hg). First applanation time was 8.32 ± 0.33 ms (range: 7.53 to 9.12 ms) and second applanation time was 23.80 ± 0.44 ms (range: 22.76 to 24.95 ms). First applanation length (max) was 2.07 ± 0.38 mm (range: 1.20 to 3.10 mm) and second applanation length (max) was 2.37 ± 0.47 mm (range: 1.33 to 4.12 mm). Curvature radius highest concavity was 11.09 ± 2.06 mm (range: 7.58 to 15.98 mm) and curvature radius normal was 7.59 ± 0.67 mm (range: 6.82 to 11.02 mm). Velocity in was 0.21 ± 0.05 m/s (range: 0.16 to 0.72 m/s) and velocity out was -0.33 ± 0.07 m/s (range: - 0.72 to -0.20 m/s). Studied parameters were not associated with gender. 2) Mean patient age was 27.50 ± 6.30 years. The highest concavity-time was the only studied parameter statistically significantly correlated to age (i.e., p=0.04, rs=0.18). 3) In relation the surgery of cataract: In group of FS, 9 of 11 parameters derived from Corvis ST were statistically significant (ss). In group of SP, 7 of 11 parameters derived from Corvis ST were ss. Only the HC - time was statistically significant between two groups (FS;SP) with p = 0.0387. 4) Corneal OCT identified a deep meniscos-shaped Lasik flap, with a central thickness of a 392 ?m in the right eye, and a incomplete deep peripheral cut in the left eye with a thinner meniscos-shaped LASIK flap. CONCLUSIONS: 1) Eight of 11 ocular biomechanical metrics given by the CorVis ST were associated with central corneal thickness, but the influence of central corneal thickness on these measurements was low. 2) In healthy eyes, age and pressure or biomechanics as derived from the Corvis ST parameters were not associated with exception to highestconcavity-time, i.e., the time from starting until the highest concavity is reached. 3) The use of the femtosecond laser- assisted system for cataract surgery and standard phacoemulsification induzed changes of biomechanical properties of the cornea by Corvis ST. Only 1 of 11 parameters studied was different statistically in two groups. 4) Unilateral ectasia after LASIK may occur due to a thick flap which leads to biomechanical failure of the cornea

<p>Two different principles were studied. 1st - statistical analysis techniques were used to obtain medical results from a patient population. 2nd - the patient population was used to study the statistical analysis techniques. </p><p>Medical conclusions: latanoprost and timolol treatment showed a statistically significant and clinically useful mean IOP-reduction in a typical worldwide clinical trial population. Latanoprost reduced the IOP 1.6 mm Hg more than timolol. The IOP-reduction was maintained with timolol and slightly enforced with latanoprost up to 6 months of treatment. The mean IOP-reduction was maintained during 2 years of latanoprost treatment. The overall risk of withdrawal due to insufficient IOP-reduction with latanoprost was 8%. </p><p>The statistical methodological issues are of a general and reoccurring character in trial design of the IOP-reduction: should the statistical hypothesis testing be based on the mean intraocular pressure (IOP) or the proportion of patients who reach a specific IOP level, should the estimate of the IOP or IOP-reduction be based on single eyes, mean of bilaterally eligible and identically treated eyes or the difference between an eye with active treatment and a placebo treated contralateral eye, and is mean of replicated recordings useful? Statistical methodological conclusions: the most effective response variable varies with the selected patient population. Therefore, the trial design process should include a comparison of the variability, test power and required sample size for the possible response variables in a sample of the target population. At minimum a statistical consideration should be done.</p>

Two different principles were studied. 1st - statistical analysis techniques were used to obtain medical results from a patient population. 2nd - the patient population was used to study the statistical analysis techniques. Medical conclusions: latanoprost and timolol treatment showed a statistically significant and clinically useful mean IOP-reduction in a typical worldwide clinical trial population. Latanoprost reduced the IOP 1.6 mm Hg more than timolol. The IOP-reduction was maintained with timolol and slightly enforced with latanoprost up to 6 months of treatment. The mean IOP-reduction was maintained during 2 years of latanoprost treatment. The overall risk of withdrawal due to insufficient IOP-reduction with latanoprost was 8%. The statistical methodological issues are of a general and reoccurring character in trial design of the IOP-reduction: should the statistical hypothesis testing be based on the mean intraocular pressure (IOP) or the proportion of patients who reach a specific IOP level, should the estimate of the IOP or IOP-reduction be based on single eyes, mean of bilaterally eligible and identically treated eyes or the difference between an eye with active treatment and a placebo treated contralateral eye, and is mean of replicated recordings useful? Statistical methodological conclusions: the most effective response variable varies with the selected patient population. Therefore, the trial design process should include a comparison of the variability, test power and required sample size for the possible response variables in a sample of the target population. At minimum a statistical consideration should be done.

A aferição da pressão intraocular (PIO) é essencial para o exame oftálmico. Objetivou-se estabelecer os valores da curva diária da PIO de porquinhos da índia de diferentes faixas etárias com tonômetro de rebote. A PIO foi aferida às 6, 12, 18 e 24 horas utilizando o tonômetro de rebote (Tonovet®). Os porquinhos da índia foram subdivididos em dois grupos com 10 animais no grupo I e 4 animais no grupo II, considerando as idades, designados por GI (animais entre 2 a 3 meses de idade) e GII (animais entre 2 a 3 anos de idade). Previamente, foram realizados teste da lágrima de Schirmer, prova da fluoresceína, biomicroscopia com lâmpada de fenda e oftalmoscopia indireta em todos animais. O valor médio da pressão intraocular foi de 12,0 ± 1,83 mmHg. Foram encontradas diferenças significativas entres as idades, sendo que os valores médios para o grupo I foram 11,63 ± 0,29 mmHg, e para o grupo II foram 12,82 ± 0,45mmHg (P= 0,0295). Não foram encontradas diferenças entre ambos os olhos (P= 0,7454). Não foram encontradas diferenças significativas nos valores da PIO relacionadas ao sexo (P= 0,1858). Os valores da PIO em porquinhos da índia tiveram alteração nas horas avaliadas. Com base nos resultados obtidos foi possível concluir que os valores da PIO em porquinhos da índia da sofrem alterações ao longo do dia. Os menores valores de pressão intraocular ocorreram às 18 horas. / The measuring of intraocular pressure (IOP) it is essential for the ophthalmic evaluation; the aim of this study was establish the values of the IOP diurnal curve of guinea pigs with different ages using the rebound tonometer (Tonovet®). The animals were divided according to the age in two groups, Group I (GI) constituted with 10 guinea pigs aged between 2 -3 moths, and Group II (GII), 4 animals with 2 -3 years of old. Previously the Schirmer tear test, fluorescein test, biomicroscopy with slit lamp, and direct optalmoscopy were performed on all animals. The men value of IOP was 12.0±0.34 mmHg. Statistical difference were found between ages (mean GI 11.64 ± 0.29 mmHg, and GII 12.83 ± 0.45mmHg), did not have statistical difference related with gender (P= 0.1858) or between eyes (P= 0.7454). In conclusion the guinea pigs had alteration of IOP true the day, the values of IOP are higher in the morning period, decrease true the day and at the night period haves an elevation again.

A aferição da pressão intraocular (PIO) é importante para o diagnóstico e acompanhamento de doenças oculares. Métodos fidedignos para quantificar a PIO de maneira acurada têm sido buscados. Com o aparecimento de tonômetros portáteis, a avaliação da pressão intraocular em equinos tem se intensificado e os diferentes princípios de aferição têm sido comparados. Este estudo objetivou a comparação entre a tonometria de aplanação, realizada com o Tono-Pen Avia®, e tonometria de rebote, realizada com o Tonovet®, em equinos da raça Crioula. Além disso, a utilização, ou não, do cachimbo como método de contenção também foi comparada e submetida à análise estatística. Foram avaliados 30 cavalos com idades entre dois e 20 anos, machos ou fêmeas. Exame oftálmico prévio foi realizado com teste da lágrima de Schirmer, prova da fluoresceína, biomicroscopia com lâmpada de fenda e oftalmoscopia direta. A tonometria de aplanação foi realizada, no mínimo, 30 minutos após a tonometria de rebote. A pressão intraocular média do Tonovet® foi maior, 36,82 ± 5,91mmHg com cachimbo e 30,04 ± 3,19mmHg sem. A do Tono-Pen Avia® foi de 26,43 ± 5,48 mmHg com cachimbo e 23,10 ±4,01mmHg sem. Todos os resultados diferiram estatisticamente entre si. Quando comparados os sexos, o Tono-Pen Avia® não mostrou diferenças, enquanto o Tonovet® mostrou pressões maiores para cavalos castrados e garanhões, e menores para éguas (p<0,001) com a utilização do cachimbo. Não há correlação entre a idade dos cavalos e os valores de PIO, independente do aparelho (p > 0,05). Os valores da PIO com o Tonovet® foram maiores do que os obtidos com o Tono-Pen Avia®. A contenção dos animais com cachimbo eleva a pressão intraocular em equinos. / Intraocular pressure evaluation is important for diagnosis and control of ophthalmic diseases. Accurate methods to quantify intraocular pressure have been searched. With the development of handheld tonometers, equine intraocular pressure evaluation has been intensified and the different principles of measurement have been compared. The objective of this study was to compare the applanation tonometry, taken with the Tono- Pen Avia® and the rebound tonometry, taken with the Tonovet® in adult “crioulo” breed horses. The age, gender and the use of upper lip twitch as a restraint method was also surveyed and submitted to statistical analysis. Thirty horses, aged two to 20, male or female were evaluated. A previous ophthalmic examination was performed with Schirmer tear test, fluoresceine test, slit lamp biomicroscopy and direct ophthalmoscopy in all animals. Applanation tonometry was performed, at least, 30 minutes after rebound tonometry. Intraocular pressure mean values measured with the Tonovet® was higher, 36,82±5,91mmHg with the lip twitch and 30,04±3,19mmHg without. Tonopen Avia® mean values were 26,43±5,48mmHg with the lip twitch and 23,10±4,1mmHg without. All results was statistical different between themselves. When genders were compared the Tono-Pen Avia® revealed no difference, however the Tonovet® showed higher pressures for male horses (p‹0,001) with the use of lip twitch. There was no correlation between age and intraocular pressure in “crioulo” horses, regardless of the equipment tested (p›0,05). Intraocular pressure mean values measured with the Tonove®t were higher than those obtained with the Tono-Pen Avia®. The restraint of animals with upper lip twitch increases equine intraocular pressure.

Objetivo: medir a pressão intra-ocular (PIO) em pré-termos de muito baixo peso (PMBP) e correlacionar com a idade pós-concepção (IPC). Métodos: Estudo longitudinal incluindo 50 pré-termos. Local: Hospital de Clínicas de Porto Alegre. Período: entre novembro de 2008 e junho de 2010. Pacientes: PMBP definido como idade nascimento ≤ 1.500 g e idade gestacional ≤ 32 semanas. Intervenção: medidas semanais da PIO. Principais desfechos: variação da PIO de acordo com a idade pós-concepção (IPC definida como a idade gestacional ao nascimento mais a idade no momento do exame) nas semanas seguintes ao nascimento pré-termo. Análise estatística: modelos de efeitos mistos foram utilizados para determinar a variação da PIO em relação a IPC. Foram calculados as médias e os percentis 10 e 90 (P10 e P90) para os valores da PIO. Resultados: Cinqüenta PMBP com idade gestacional média de 29,7 ± 1,6 semanas e peso de nascimento de 1.127,7 ± 222,7 gramas foram avaliados. Não houve diferença significativa entre a PIO do olho direito e do olho esquerdo (p=0.177). A média da PIO em toda a coorte, considerando ambos os olhos, foi de 14,9 ± 4,5 mmHg, sendo que 13,5% das medidas isoladas da PIO foram superiores a 20 mmHg. A PIO reduziu em média 0,29 mmHg para cada aumento de uma semana da IPC (p=0.047 IC95%: -0,58 a -0,0035). A PIO média (P10-P90) reduziu de 16,3 mmHg (10,52-22,16) com 26,3 semanas de IPC para 13,1 mmHg (7,28-18,92) com 37,6 semanas de IPC. Conclusões: A PIO média em PMBP foi 14,9 ± 4,5 mmHg e apresentou correlação negativa em relação a idade pós-concepção. / Purpose: To measure intraocular pressure (IOP) in very low birth weight preterm infants and correlate it with the postconceptional age (PCA). Methods: Longitudinal study including 50 premature infants. Setting: Hospital de Clinicas de Porto Alegre, Brazil. Patients: Very low birth weight premature infants (defined as birth weight ≤1,500 g and gestational age ≤32 weeks). Intervention: Weekly measurements of the IOP. Main outcomes: The variation of IOP according to the postconceptional age (PCA defined as the gestational age at birth plus the age in weeks at the time of examination) in the weeks following preterm birth. Statistics: Mixed-effects models were used for the statistical analysis to determine IOP variation according to PCA. Means, 10th and 90th percentiles were calculated for IOP values. Results: Fifty preterm infants with a mean gestational age of 29.7 ± 1.6 weeks and mean birth weight of 1,127.7 ± 222.7 grams were evaluated. Mean IOP in the whole cohort considering both eyes was 14.9 ± 4.5 mmHg, and 13.5% of the IOP measurement values were greater than 20 mmHg. The analysis revealed a mean IOP reduction of 0.29 mmHg for each increase of PCA (p=0.047; 95% CI, -0.58 to -0.0035). Mean IOP (P10- P90) decreased from 16.3 mmHg (10.52-22.16) at 26.3 weeks PCA to 13.1 mmHg (7.28- 18.92) at 37.6 weeks PCA. Conclusions: Mean IOP in very low birth weight preterm infants was 14.9 ± 4.5 mmHg and was negatively correlated with PCA.