Daytime levels of melatonin in patients with age-related macular degeneration

PURPOSE

Melatonin (N-acetyl-5-methoxytryptamine) (MT) is a hormone that acts as an antioxidant. It is produced by the pineal gland and within the retina; its release is blocked by light entering the eye. We examined whether MT daytime levels differ between pseudophakic patients with age-related macular degeneration (ARMD) and pseudophakic subjects without any ocular pathology of the same age.

METHODS

A prospective, cross-sectional, observational study was performed. Pseudophakic patients of the same age group were included. Patients underwent complete ophthalmic examinations and blood sampling between 08:00 and 10:00 hr. MT daytime value in the serum was the main outcome measure.

RESULTS

Sixty-nine pseudophakic patients were included. Fifty patients with exudative and non-exudative ARMD were in the study group while 19 patients were controls. Patients with ARMD had significantly higher daytime levels of MT (P = 0.003). There were significant differences in MT daytime levels between the exudative and non-exudative forms (P = 0.009). MT values also correlated with the best-corrected visual acuity (r = -0.285, P = 0.019).

CONCLUSION

These data indicate that pseudophakic patients with ARMD produce more MT during the day compared to pseudophakic subjects without ARMD. This may be caused by the reduced visual acuity in patients with ARMD, whereby less light reaches the photoreceptors, allowing MT secretion to continue during the day. Because MT also acts as an antioxidant and daytime levels are higher in patients with ARMD, these results might be interpreted as a rescue factor.

[Long-term results of scleral buckling using a microsurgical approach]

BACKGROUND

The purpose of this study is to report the long-term results of a refined scleral buckling technique for the treatment of retinal detachments.

PATIENTS/MATERIALS AND METHODS

We retrospectively reviewed the charts of 152 consecutive cases (129 patients), operated in our clinic by one surgeon. Indirect ophthalmoscopy was used for the identification and treatment of retinal breaks. All other steps of the operation were performed under the operating microscope. The main outcome measures were the retinal redetachment rate, intraoperative and postoperative complication rates as well as the functional outcome.

RESULTS

Reattachment was achieved in 130 eyes (85.5 %) after the first procedure and in 151 eyes (99.3 %) after reoperation. No intraoperative complications occurred in our series. Eighty-one eyes (53.3 %) showed a significant improvement in visual acuity after surgery, whereas 16 eyes (10.5 %) showed a significant deterioration in visual acuity. At the last follow-up visit, 101 cases (66.4 %) showed a visual acuity of 0.5 or better, 68 cases (44.7 %) had a visual acuity of 0.8 or better and in 7 cases (4.6 %) the visual acuity was lower than 0.1.

CONCLUSIONS

Adding microsurgical techniques to scleral buckle surgery may help to minimise the incidence of intraoperative and postoperative complications resulting in a favourable functional outcome.

Quality of the threshold algorithm in age-related macular degeneration: Stratus versus Cirrus OCT

PURPOSE

Automatically generated measurements of the retinal volume or the central retinal thickness are based on correctly set threshold lines on the retinal surface and the retinal pigment epithelium. The purpose of this study was to compare the accuracy of threshold algorithm lines of Stratus optical coherence tomography (OCT) with those of Cirrus OCT.

METHODS

A consecutive series of patients at least 50 years of age with exudative age-related macular degeneration was included. Stratus OCT (retinal thickness program) and Cirrus OCT (macular cube 512 x 128) were performed by the same examiner, the sequence of the examinations was randomized. Two independent examiners evaluated the positioning of the threshold algorithm lines and performed a grading of the failures. Logistic regression analysis was applied for evaluation of the failure rate.

RESULTS

One hundred four patients were included. For the entire OCT examination (6 scans Stratus OCT, 128 scans Cirrus OCT) algorithm line failures were detected in 69.2% of the Stratus OCT and in 25% of the Cirrus OCT examinations, with the difference reaching statistical significance (P < 0.001). The median failure grade was 1 (0-6) for Stratus and 0 (0-5.15) for Cirrus OCT. Age, measurement sequence, and investigator did not influence the error rates.

CONCLUSIONS

With Cirrus OCT automatically performed and therefore objective measurements of central retinal thickness and retinal volume were provided correctly in 69.2% of the scans. Furthermore, this latest software version offers the possibility of manual correction of false positioned algorithm lines (ClinicalTrials.gov number, NCT00568191).

Correlation of different circulating endothelial progenitor cells to stages of diabetic retinopathy: first in vivo data

PURPOSE

To investigate vasculogenic circulating progenitor cells (CPCs), endothelial progenitor cells (EPCs), and mature EPCs in patients with type 1 diabetes mellitus (T1DM) with or without diabetic retinopathy (DR).

METHODS

A case-control study comparing 90 patients with T1DM with and without DR was performed. Patients were studied and staged for retinopathy according to the Early Treatment of Diabetic Retinopathy Study (ETDRS) classification. Ninety patients were included: 30 without DR (control [CO]), 30 with mild nonproliferative DR (mNPDR), 10 with moderate-severe NPDR (msNPDR), 10 with mild-moderate proliferative diabetic retinopathy (mmPDR), and 10 with high-risk PDR (hrPDR). CPCs (CD34/CD133), EPCs (CD34/CD133/CD309), and mature EPCs (CD34/CD133/CD309/CD31) were enumerated by flow cytometry.

RESULTS

EPCs were reduced in mNPDR (114 +/- 66; P < 0.001) and msNPDR (77 +/- 40; P = 0.042) compared with CO (244 +/- 115). In contrast, EPCs were unchanged in mmPDR (248 +/- 155) compared with CO. Strikingly, EPCs were augmented in hrPDR (389 +/- 124) compared with all other stages. Numbers of undifferentiated progenitor cells (CPCs) did not differ among CO, mmPDR, and hrPDR. Augmentation (3x) of mature EPCs in hrPDR (325 +/- 118; P < 0.001) compared with CO (100 +/- 49) but against all other stages of DR was observed. The percentage of mature EPCs/EPCs was augmented in an ETDRS classification-dependent manner.

CONCLUSIONS

In patients with T1DM with DR, EPCs undergo stage-related regulation. In nonproliferative retinopathy, a reduction of EPCs was observed, and in proliferative retinopathy, a dramatic increase of mature EPCs was observed.

Subretinal surgery and transplantation of autologous pigment epithelial cells in retinal angiomatous proliferation

PURPOSE

The aim of this study was to examine whether the presence of retinal angiomatous proliferation (RAP) is a prognostic factor in subretinal surgery with transplantation of a suspension of autologous retinal pigment epithelial (RPE) cells.

METHODS

Eyes that had been followed for at least 12 months after subretinal surgery were reviewed retrospectively and assigned to group 1 (presence of RAP) or group 2 (lesions without RAP). Main outcome measures were logMAR distance acuity and lesion size at 12 months.

RESULTS

A total of 68 eyes of 68 patients were included; 28 were assigned to group 1 and 40 to group 2. A total of 43% of patients were male and 57% were female. Their mean age was 77.8 years. Mean distance acuity was 1.02 logMAR at baseline and 1.06 logMAR at month 12. Mean lesion size was 27.9 mm(2) at baseline and 29.9 mm2 at month 12. The differences between the groups were not significant.

CONCLUSIONS

The presence of RAP did not significantly influence the outcome after subretinal surgery with transplantation of autologous RPE cells. Other than age, preoperative lesion size and distance acuity were the only predictive factors for postoperative results.

Derivation of sonograph quality parameters by the use of point spread function analysis

A measuring system evaluating a Point Spread Function generated in an ultrasonographic image by scanning a spherical target was developed. The target is moved in measuring bath filled by water over scanned volume via 3D computer controlled positioning system. A video signal obtained is converted to digital form and analyzed by original software to derive various objective parameters of the imager as follows: Focal areas in both the azimuth and the elevation directions, Ultrasound scanning lines visualisation, Manufacturer preloaded TGC, Width of the scanning plane, Side lobe levels and Amplification uniformity in the azimuth direction. The method was verified by testing 18 different equipments in 282 measurements. Samples of particular measurement results in form of graphical outputs are included. Medical and physiological impacts of this approach are discussed.

Blue light-filter intraocular lenses in vitrectomy combined with cataract surgery: results of a randomized controlled clinical trial

PURPOSE

To evaluate the effect of the blue light-filter intraocular lenses (IOLs) in vitrectomy combined with cataract surgery, focusing on the surgeon's ability to perform specific vitreoretinal procedures and on the patients' outcome.

DESIGN

Randomized clinical trial.

METHODS

Sixty patients, recruited from our outpatient department, were assigned randomly to receive an ultraviolet-filter IOL (clear IOL group) or a blue light-filter IOL (yellow IOL group) combined with a vitreoretinal procedure. Main outcome measures were intraoperative conditions for the surgeon and the functional outcome. Second outcome measures were complication rates and vitreoretinal diagnoses.

RESULTS

The questionnaire responses showed that the blue light-filter IOLs did not represent an impediment to vitreoretinal surgery (P>.05). No intraoperative complications were encountered in either group. Patients in both IOL groups showed comparable functional results with respect to visual acuity, contrast sensitivity, color vision, and glare effect (P>.05). The functional outcome was influenced significantly by the vitreoretinal diagnosis (P<.01).

CONCLUSIONS

With the possible advantage of macular protection and no intraoperative or functional disadvantage, the routine use of the blue light-filter IOL in combined surgery can be recommended.