Are the effects of hemodialysis on ocular parameters similar during and after a hemodialysis session? / Os efeitos da hemodiálise sobre os parâmetros oculares são semelhantes durante e após a sessão de hemodiálise?

ABSTRACT Purpose: To evaluate the changes in several ocular parameters, including choroidal thickness, during and after hemodialysis. Methods: Twenty-seven eyes of 27 patients with chronic renal failure undergoing hemodialysis were included. The patients underwent an ophthalmic examination, including intraocular pressure, central corneal thickness, iridocorneal angle, subfoveal choroidal thickness, and blood pressure, just before a hemodialysis session, during the second hour of the session, and half an hour after the end of the session. Body weight was measured before and after the session, and ultrafiltration volume was noted after the session. Central corneal thickness, intraocular pressure, and subfoveal choroidal thickness were measured by optical coherence tomography. Results: In comparison with baseline levels, mean intraocular pressure and central corneal thickness increased significantly during the second hour of hemodialysis (p=0.001 and p=0.011, respectively) and showed no significant changes after hemodialysis (p=0.844 and p=0.246, respectively). Mean iridocorneal angle did not significantly change during the second hour of hemodialysis (p=0.101) and after hemodialysis (p=0.589). Mean subfoveal choroidal thickness was significantly lower during the second hour of hemodialysis (p<0.001) and after hemodialysis (p<0.001). Conclusions: Mean intraocular pressure and central corneal thickness increased and subfoveal choroidal thickness decreased during the second half of the hemodialysis session. During the second half of the session, intraocular pressure and central corneal thickness had a trend toward reduction, while subfoveal choroidal thickness had a relatively steady course. Because of possible fluctuations in the values, it would be reasonable to evaluate the changes not only from before to after hemodialysis but also during hemodialysis when analyzing the ocular effects of dialysis.

RESUMO Objetivo: Avaliar as alterações em vários parâmetros oculares, incluindo a espessura da coroide, durante e após a hemodiálise. Métodos: Foram incluídos 27 olhos de 27 pacientes portadores de insuficiência renal crônica e submetidos a hemodiálise. Todos foram submetidos ao exame oftalmológico, incluindo pressão intraocular, medida da espessura corneana central, ângulo iridocorneal e espessura da coroide subfoveal, além da medida da pressão arterial. A espessura corneana central, o ângulo iridocorneal e a espessura da coroide subfoveal foram medidos através da tomografia de coerência óptica. Os exames foram realizados logo antes, durante (na segunda hora) e meia hora após uma única sessão de hemodiálise. O peso corporal foi medido antes e depois da sessão, e os volumes de ultra filtração foram anotados após a sessão de hemodiálise. Resultados: Em comparação com os níveis basais, a pressão intraocular média e a espessura corneana central aumentaram significativamente na segunda hora de hemodiálise (p=0,001 e p=0,011, respectivamente), mas não houve diferença após a hemodiálise (p=0,844 para pressão intraocular e p=0,246 para espessura corneana central). O ângulo iridocorneal mostrou ligeira diminuição na segunda hora de hemodiálise (p=0,101) e após a sessão de hemodiálise (p=0,589), porém esta redução não foi estatisticamente significativa. Já a espessura da coroide subfoveal mostrou uma redução significativa tanto na segunda hora de hemodiálise (p<0,001) quanto após a sessão de hemodiálise (p<0,001). Conclusões: A pressão intraocular e a espessura corneana central aumentaram, enquanto a espessura da coroide subfoveal diminuiu na primeira metade da sessão de hemodiálise. Na segunda metade da sessão, a pressão intraocular e a espessura corneana central mostraram uma tendência de redução, enquanto a espessura da coroide subfoveal permaneceu estável. Ao analisar os efeitos oculares da hemodiálise, seria interessante avaliar as mudanças não só antes e depois da sessão, como também durante a hemodiálise, devido a possíveis flutuações dos valores.

Repeated bevacizumab injections versus mitomycin C in rotational conjunctival flap for prevention of pterygium recurrence.

Aims: To evaluate the efficacy of repeated bevacizumab injection in rotational conjunctival flap surgery versus rotational conjunctival flap with adjunctive mitomycin C (MMC) or rotational conjunctival flap alone. Materials and Methods: Ninety eyes of 90 patients who underwent primary pterygium surgery with rotational flap were evaluated. Patients were randomly assigned to undergo conjunctival rotational flap alone (Group A) or conjunctival rotational flap with either 0.02% MMC application (Group B) or adjunctive subconjunctival 2.5 mg/0.1 ml bevacizumab injection (Group C). Each group consisted of 30 eyes. Recurrence rates at 9 months were evaluated. Results: There were no statistically significant differences in mean size of the pterygium across the limbus in terms of length (P > 0.5). The recurrence rates at 9 months were 26.6% (n = 8) in Group A, 13.3% (n = 4) in Group B, and 10% (n = 3) in Group C. The recurrence rates in Group B and C were significantly lower than in Group A (P = 0.1806). The recurrence rates were similar in Group B and C (P > 0.05). Conclusions: Subconjunctival bevacizumab injection may decrease the recurrence rate of primary pterygium surgery with rotational conjunctival flap. Further studies with a larger population and longer follow‑up period are needed to supplement this study.

Corneal endothelium after deep anterior lamellar keratoplasty and penetrating keratoplasty for keratoconus: A four-year comparative study.

Purpose: To compare the status of corneal endothelium and central corneal thickness within the first four postoperative years after deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) in patients with keratoconus. Materials and Methods: Thirty-nine eyes (Group A) which had PK and 44 eyes (Group B) which had DALK for the treatment of keratoconus were included in this retrospective study. The endothelial cell density (ECD), the mean endothelial cell area and the coefficient of variation of cell area were assessed with a non-contact specular microscope, and the central corneal thickness (CCT) was measured with an ultrasound pachymeter. Results: Mean ECD loss rate at two years was 36.24% in Group A and 18.12% in Group B (P<0.001). Mean ECD loss rate at four years was 47.82% in Group A and 21.62% in Group B (P<0.001). Mean annual ECD loss rate was calculated 14.12% per year in Group A and 5.78% per year in Group B. In the PK group, increase in mean CCT was 15.60% in two years and 15.03% in four years, while in the DALK group, mean CCT increased by 8.05% in two years and 9.31% in four years. Conclusions: As the majority of ectatic disorders such as keratoconus occur in young people, long-term endothelial cell survival following treatment with keratoplasty is essential for the long-term visual ability. Our finding that corneal endothelial cell loss in the DALK group occurs at a slower rate than in the PK group suggests DALK as a safer alternative to PK in these selected patients.

Foldable iris-fixated phakic intraocular lens implantation for the correction of myopia: Two years of follow-up.

Purpose: To evaluate the safety, efficacy and potential risks of Artiflex foldable iris-fixated phakic intraocular lens (pIOL) implantation for the management of myopia. Materials and Methods: Seventy-eight eyes of 40 consecutive patients with a mean spherical refraction of –11.70 ± 3.77 diopters (D; range –5.50 to –17.5 D) were included in this prospective, noncomparative, interventional case series. Main parameters assessed were uncorrected visual acuity (UCVA), best-spectacle corrected visual acuity (BSCVA), corneal topography (Orbscan II, BauchandLomb, Rochester, NY, USA), manifest and cycloplegic refractive errors, endothelial cell density (ECD) and applanation tonometry. Results: After 2 years, BSCVA was 20/40 or better in 82% of the eyes and UCVA was 20/40 or better in 84% of the eyes. After 1 month, 1 year, and 2 years, 51.3% (37 of 72 eyes), 58.9% (46 of 78 eyes) and 76.0% (38 of 50 eyes) of eyes gained 1 line or more of BSCVA, respectively. Compared to preoperative values, the mean endothelial cell loss was 2.6% at 1 month, 4.9% at 1 year and 7.4% at 2 years. Pigmented or non-pigmented precipitates were observed in17 eyes (21.7%) which were treated with topical corticosteroids. At the second postoperative year, pigmented precipitates persisted in nine eyes. However, this was not associated with a loss of BSCVA. Conclusion: The implantation of Artiflex pIOL is an effective surgical option for the management of high myopia. The most common complication observed within 2 years of follow-up was accumulation of pigmented precipitates with no effect on the final BSCVA.

Intraocular lens exchange through a 3.2-mm corneal incision for opacified intraocular lenses.

Aim: The aim was to evaluate visual and refractive results and complications of intraocular lens (IOL) exchange through a 3.2 mm corneal incision for opacified IOLs. Materials and Methods: This retrospective study comprised 33 eyes of 32 patients with IOL opacification requiring an IOL exchange between July 2003 and March 2007. Exchange surgery was performed through a 3.2-mm temporal clear corneal incision followed by implantation of a new foldable hydrophobic IOL. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), topographical astigmatism, and refractive cylinder were evaluated. Surgically induced astigmatism (SIA) was calculated and complications were recorded. Results: Opacification was observed in 25 eyes (76%) with Aqua-Sense, 3 eyes (9%) with Hydroview, 3 eyes (9%) with MemoryLens IOLs, and 2 eyes (6%) with DgR. The mean follow-up period was 36.54 months. An uneventful IOL exchange was achieved in 18 eyes (55%). Zonular dehiscence occurred in 9 eyes (27%), and posterior capsule tear developed in 4 eyes (12%). The mean preoperative BSCVA (mean ± standard deviation, decimal scale) was 0.13 ± 0.08 (mean: 20/150, range 20/2000 to 20/60) and improved to 0.63 ± 0.18 (mean: 20/32, range 20/60 to 20/20, P < 0.001). The mean SIA was 0.70 D. Seven eyes (21%) had 0.5 D or lower SIA. Conclusion: IOL exchange is a technically challenging procedure with potential risks of reversing the advantages of a prior small-incision cataract surgery. The use of a small corneal incision for IOL exchange could preserve the advantages of modern phacoemulsification surgery with acceptable SIA related to the procedure.