The effect of acetazolamide on the retinal and choroidal vasculature of the macula and the optic disc using OCT angiography

INTRODUCTION AND OBJECTIVES

To investigate the effect of acetazolamide (AZ) on the retinal and choroidal ocular microvasculature in the macula and radial peripapillary capillaries (RPC) of the optic disc with OCT Angiography (OCTA).

MATERIALS AND METHODS

Nine-month observational cross-sectional study. Forty-five eyes from 45 healthy participants who underwent cataract surgery were recruited. Macular retina and choriocapillaris vessel density (VD) and RPC VD in the optic disc area were compared before and 60min after 250mg acetazolamide per os. Intraocular pressure (IOP) and systemic blood pressure (BP) were also measured before each scan.

RESULTS

Mean age was 73.1±6.9 years. VDs in the superficial (SCP) and deep (DCP) capillary plexus of the retina and the choriocapillaris (CC) in the macular area showed no significant change (P>.5, for all parameters). VD in the RPC showed no significant change with AZ (P>.5, for all parameters). Foveal and parafoveal thickness increased from 248.98 (±23.89) to 250.33 (±23.74) and from 311.62 (±16.53) to 311.98 (±16.38) (P<.001 and P=.046), respectively. IOP decreased from 13.2 (±3.0) mmHg to 11.8 (±3.2) mmHg (P<.001), while systolic and diastolic BP decreased from 144.8 (±21.8) to 137.7 (±19.0) and from 80.0 (±12.7) to 76.2 (±11.7) (P=.021 and P=.030), respectively.

CONCLUSIONS

OCTA imaging did not reveal any significant changes in the VD of the optic disc or the retinal and choroidal VD in the macula with oral AZ one hour after its administration in otherwise healthy participants who underwent cataract surgery.

A hydrophilic interaction liquid chromatography - Tandem mass spectrometry method for the determination of phenylephrine in dried blood spots from preterm infants

A sensitive and accurate hydrophilic interaction liquid chromatography - tandem mass spectrometry method (HILIC-MS/MS) was developed and validated for the determination of phenylephrine concentration in Dried Blood Spot (DBS) samples from preterm infants, after ocular administration of an ophthalmic solution with phenylephrine. Sample preparation involved the extraction of the analyte from an 85 μL DBS sample with methanol - acetonitrile (50:50, v/v). Chromatographic separation was achieved on an ACQUITY UPLC BEH AMIDE column, under isocratic conditions within a 5 min run. Detection was achieved with a triple quadrupole MS applying electrospray ionization in positive mode. The method was fully validated and proved precise and accurate with in a linear range of 0.59-3.53 ng/ml in blood. The method was developed to provide insights on the level of exposure of infant population to phenylephrine after ocular administration.

Factors influencing corneal predescemetic endothelial keratoplasty (PDEK) graft creation: It's all in a bubble

AIM

To assess the effect of pneumatic (air) and fluidic (transport medium) injection to the type of bubble (I, II or mixed III) and the resultant dissection of corneal endothelial grafts PDEK or DMEK.

MATERIALS AND METHODS

All grafts were obtained from Dr Agrawal Hospital's Eye Bank. Air injection was the initial preferred mode of graft harvest. If pneumatic dissection was unsuccessful after 10 tries, fluidic dissection with transport medium was tried. SPSS 23.0 was used to statistically analyse the data.

RESULTS

40 consecutive donor corneas with a mean age of 46.5 and a mean endothelial count of 2980 were analysed. Air dissection lead to the harvest of 27 endothelial grafts and fluid dissection led to the creation of 7 endothelial grafts. Statistically significant difference was found the different bubble types and the type of injection (χ² chi square=10.02, 0=0.008).

CONCLUSION

In young donors pneumatic (air) graft dissection leads to PDEK in a high proportion. This percentage is reduced when transport medium is tried after unsuccessful air injection. Injection of transport medium increases the percentage of grafts harvested but also increases the ratio of Type II and III DMEK grafts created.

Low-dose tissue plasminogen activator in the management of anterior chamber fibrin formation

PURPOSE

To investigate the efficacy of tissue plasminogen activator (tPA) in the treatment of severe fibrinous anterior chamber reactions after intraocular surgery.

SETTING

Ophthalmology Department, AHEPA University Hospital, Thessaloniki, Greece.

METHODS

The study comprised routine surgical and postoperative cases selected in a nonrandomized fashion. Low-dose tPA infusion (0.2 mL of 125 microg/mL) was administered through a side-port in the anterior chamber in 25 patients with recent or long-standing fibrin formation after cataract extraction (n = 13), trabeculectomy (n = 5), combined procedure (n = 5), or penetrating keratoplasty (n = 2). Patients were treated 4 to 25 days postoperatively (mean 7 days).

RESULTS

Fibrin lysis was observed 2 to 12 hours after tPA infusion. No hemorrhage or other complications occurred, and no further treatment was necessary in any patient. Three cases of delayed partial fibrin lysis resolved with intense topical steroid treatment. There were no recurrences over the 3-month follow-up.

CONCLUSIONS

Low-dose tPA was an effective and safe method for the management of anterior chamber fibrin formation. Treatment was well tolerated and gave excellent results with no complications.