Swept Source Optical Coherence Tomography Analysis of a Selected Eye’s Anterior Segment Parameters in Patients with Pseudoexfoliation Syndrome

Background: Pseudoexfoliation syndrome (PEX) is a systemic, age-related disorder characterized by the production and accumulation of pseudoexfoliation material. To date, detailed characteristics have not been published regarding the iridocorneal angle and cornea in patients with pseudoexfoliation syndrome determined through swept source optical coherence tomography (SS-OCT). Methods: A total of 150 eyes of patients with pseudoexfoliation syndrome (ages 69–86 years) and 166 eyes in a control group (ages 54–79 years) were analyzed. Results: The central corneal thickness in the PEX group was 549.56 μm and was slightly (insignificantly) higher than that of the control group (540.56 µm). The anterior chamber of the eye was visibly shallower in patients with PEX syndrome than in those of the control group (2.49 mm vs. 3.07 mm; p < 0.001). The Fourier analysis parameters of the cornea showed multiple differences between the PEX and control groups. With respect to iris area, the parameters showed statistically significant differences between the PEX and control groups in all four quadrants of the eye. No statistical significance was found in the PEX group for the iridocorneal angle parameters, or corneal and lens parameters depending on gender and age. Conclusions: PEX syndrome is characterized by a significant impact on the anterior eye segment, including higher anterior and posterior keratometric values, lower anterior chamber depth, higher iris thickness, and narrower angle parameters. The characteristic anterior eye segment features of PEX syndrome can be detected using SS-OCT, which could potentially assist clinicians in properly managing the disease.

Changes in Iridocorneal Angle Configuration and Intraocular Pressure during Smartphone Use under Room Light

Purpose: To investigate changes in intraocular pressure (IOP) and iridocorneal angle (ICA) configuration during smartphone use under room light. Methods: We included healthy adults aged 19-35 years with no ophthalmological abnormalities. All read text on a smartphone for 6 minutes under room light. IOP was measured via rebound tonometry at baseline and at 2, 4, and 6 minutes. ICA images were obtained via anterior segment optical coherence tomography after each IOP measurement. After 6 minutes, participants stopped reading text and rested for 2 minutes. IOP was then measured again. Results: The IOP significantly increased at 2, 4, and 6 minutes of reading compared to baseline (p < 0.001) but recovered to baseline after 2 minutes of rest (p = 1.000). The anterior chamber depth decreased significantly, and the anterior chamber angle width increased after 6 minutes of smartphone reading (both p < 0.05). Conclusions: IOP increased when reading smartphone text under room light but the ICA did not change. Prolonged smartphone reading is inappropriate for a patient at risk of glaucoma or glaucoma progression. Such patients should be cautioned.

The mechanism of intraocular pressure rise after keratoplasty

Purpose: To determine the pathomechanism of increased intraocular pressure after penetrating and lamellar keratoplasty based on clinical observation and literature data. Materials and methods: Morphometric analysis of the anterior segment of the eye using spectroscopic optical coherence tomography, gonioscopy and biomicroscopy. Results: Pre- and postoperative spectroscopic optical coherence tomography scans in patients after keratoplasty reveal deformation of the peripheral cornea, narrowing of the iridocorneal angle, presence of anterior synechiae and various types of pupillary block. Conclusions: The mechanism of elevated intraocular pressure after corneal grafting is complex and depends on pre-, intra- and postoperative factors, such as anatomy changes of the iridocorneal angle, presence of anterior synechiae, as well as anterior and posterior pupillary block. Spectroscopic optical coherence tomography plays an important role in diagnosis and further treatment management.

Evaluation the Acute Effects of Hyperbaric Oxygen Therapy on Eye Anterior Segment Morphology and on İntraocular Pressure

Purpose: In this study the acute effects of 1 session of hyperbaric oxygen therapy on eye anterior segment morphology and on intraocular pressure was evaluated.Materials and methods: 30 patients taking hyperbaric oxygen therapy for different indications were included in this prospective study. Only the right eye per patient was included in the study. The refractive errors were measured with autorefractometry, intraocular pressures were measured with pneumatic tonometry; anterior segment parameters pachymetry, keratometry, anterior chamber depth and iridocorneal angle values were measured with corneal topography prior to and 24 hours after 1 session of hyperbaric oxygen therapy.Results: In this study 30 eyes from a total of 30 patients were evaluated; 19 men (% 64) and 11 women (% 36). Median age was 44.33 ±16.12 (Age range 18-80 years). Mean intraocular pressure was 13.7 ±4,16 mmHg (milimetermercuries), mean central corneal thickness was 531.9 ±28.24 μm, mean anterior chamber depth was 3.30 ±0.375 mm, mean iridocorneal angle value was 35.3± 6.61 degrees before hyperbaric oxygen therapy. The mean intraocular pressure was 12.66±4,54 mmHg, mean central corneal thickness was 529.43± 26.68 μm, mean anterior chamber depth was 3.28±0.372 mm, mean iridocorneal angle value was 34.5±6.42 degrees after HBOT. A statistically significant decrease in these values were recorded. No statistically significant changes were found in spheric equivalent and keratometry values of the patients before and after HBOT.Conclusions: After one session of HBOT a decrease in intraocular pressure, central corneal thickness, anterior chamber depth and iridocorneal angles of patients were observed; keratometry and spheric equivalent values remained unchanged. More studies are needed in order to use the effects of HBOT on anterior segment morphology and on intraocular pressure for situations like glaucoma, corneal edema etc.

Changes in Anterior Chamber Angle and Pupillary Diameter after Implantation of a New Posterior Chamber Phakic Intraocular Lens

Purpose: To evaluate the effect of the Eyecryl posterior chamber phakic intraocular lens (pIOL) on iridocorneal angle (ICA) parameters, anterior chamber depth (ACD), and pupillary size.Methods: The medical files of myopic patients who had implantation of the Eyecryl posterior chamber pIOL were reviewed retrospectively. Trabecular-iris space area at 500 and 750μm (TISA500, TISA750), angle opening distances at 500 and 750μm (AOD500, AOD750), anterior chamber depth (ACD), iridocorneal angle (ICA), and pupil diameter under different illumination conditions were analyzed preoperatively, and at 1 and 3 months postoperatively.Results: Ninety-three eyes of 48 patients were included in the study. The mean age of patients was 31.63 ±4.95 years (range, 21-54). The mean ICA decreased from 49.97° ± 6.33 before surgery to 30.75° ± 5.86 and 30.79° ± 5.74 at 1 and 3 months after surgery, respectively. The mean ACD was reduced from 3.23 ± 0.22 mm before surgery to 2.55 ± 0.34 mm and 2.46 ± 0.28 mm at 1 and 3 months after surgery, respectively. TISA500, TISA750, AOD500, and AOD750 were also reduced significantly after surgery. The mean pupil size under photopic, mesopic and scotopic illuminations decreased insignificantly by 1 month and continued to decrease significantly by 3 months after surgery.Conclusion: The implantation of the Eyecryl posterior chamber pIOL in myopic patients caused significant changes in anterior chamber parameters including ICA, ACD, TISA 500, TISA 750, AOD 500, AOD 750, and the pupil diameter under different illumination conditions.

Swept Source Optical Coherence Tomography Analysis of the Selected Eye’s Anterior Segment Parameters

Background: The present study determined the mean reference values of the anterior segment parameters of the selected eye using swept source optical coherence tomography (SS-OCT) in healthy Caucasian participants. Methods: A total of 166 volunteers (age 54–79 years), women (n = 92) and men (n = 74), were analyzed. One eye of each subject was randomly selected for anterior segment imaging. The anterior segment of the eye was scanned with CASIA2. The analyzed anterior segment parameters were divided into three groups, namely parameters of the cornea, lens, and angle. Results: The OCT (e.g., Ks, Kf, pKf, pKs, and central corneal thickness) and Fourier parameters of the cornea were significantly different between females and males. The iridocorneal angle was the smallest in the upper quadrant for all distance from the apex of the angle (250, 500, and 750 µm). Conclusions: Therefore, SS-OCT enables the analysis of parameters of the cornea, anterior chamber, lens, and iridocorneal angle, highlighting its clinical utility. Sex-specific differences in the analyzed parameters should be taken into account during the diagnosis of corneal diseases. The configuration of the filtration angle is an important marker during glaucoma diagnosis and drainage implant surgery. Measurements with CASIA 2is characterized by very good repeatability.