[Chloroquine retinopathy]

BACKGROUND

Chloroquine (CQ) and hydroxychloroquine (HCQ) can induce retinopathy. The risk of this severe, irreversible ophthalmological complication significantly increases with duration of treatment (> 5 years) and dosage of medication (for CQ > 2.3 mg/kg/day and HCQ > 5.0 mg/kg/day). Other important risk factors are renal failure, concomitant tamoxifen use and pre-existing retinopathy or maculopathy.

CASE DESCRIPTION

We describe a 46-year old woman with chronic discoid lupus erythematosus who developed bull's-eye maculopathy as a consequence of treatment with CQ in varying doses of 100-300 mg/day for five years. Treatment with CQ was subsequently discontinued.

CONCLUSION

All patients treated with CQ or HCQ should be referred to the ophthalmologist for baseline testing within 1 year after starting treatment. If there are no risk factors, patients who are treated with CQ or HCQ should undergo annual ophthalmological testing from 1 year, respectively 5 years after start of treatment. The risk factors need to be rechecked at each outpatient check-up because these factors can affect the required frequency of ophthalmological check-ups.

Outcomes of severe uveitic glaucoma treated with Baerveldt implant: can blindness be prevented?

PURPOSE

To evaluate long-term outcomes on efficacy and safety of severe uveitic glaucoma treated with a Baerveldt glaucoma implant (BGI).

METHODS

A retrospective study of 47 eyes of 47 patients with uveitic glaucoma treated by a BGI between September 2002 and September 2015. Main outcome measures were intraocular pressure (IOP), number of glaucoma medications, course of the uveitis, visual acuity (VA) and complications.

RESULTS

Mean IOP dropped from 30.6 ± 8.1 mmHg with 3.6 ± 1.1 glaucoma medications at baseline to 10.6 ± 4.3 mmHg with 1.0 ± 1.3 glaucoma medications after a mean follow-up of 63.6 ± 43.1 months. In the majority of cases, IOP remained stable during follow-up. However, especially in several patients with viral uveitis, episodes with IOP peaks were observed during a flare-up despite a functioning implant. These peaks remained below preoperative levels. During follow-up, 16 patients (34%) experienced a clinically significant VA loss, mainly because of late-stage glaucoma or hypotony maculopathy. Early postoperative complications were transient choroidal effusion (n = 5), shallow/flat anterior chamber (n = 4), hyphaema (n = 2) and suprachoroidal haemorrhage (n = 1). The most important late postoperative complication was hypotony maculopathy (n = 5), three of these in juvenile idiopathic arthritis (JIA) patients.

CONCLUSION

The BGI is an effective and safe treatment for patients with refractive secondary glaucoma due to uveitis. In a majority of patients, VA remains stable and a low and stable IOP is maintained over time with an acceptable number of complications. In particular, patients with viral uveitis and glaucoma should be closely monitored for IOP peaks that may occur during episodes of a flare-up of uveitis, whereas at the other end of the spectrum, patients with JIA seem much more prone to hypotony maculopathy.

Corneal endothelial cell loss after Baerveldt glaucoma drainage device implantation in the anterior chamber

Purpose

To investigate central and peripheral corneal endothelial cell density (ECD) in relation to Baerveldt (BV) glaucoma drainage device (GDD) tube corneal (TC) distance.

Methods

Prospective study of all patients scheduled for glaucoma tube surgery with 36 months follow‐up. A BV GDD was inserted into the anterior chamber (AC). Anterior segment optical coherence tomography (AS‐OCT) scans were made to determine the TC distance. Central and peripheral ECD was measured, preoperatively and at 3, 6, 12, 24 and 36 months postoperatively.

Results

Fifty‐three eyes were included [primary open‐angle glaucoma, (n = 13); secondary glaucoma, (n = 30); and primary angle‐closure glaucoma, (n = 10)]. Central ECD significantly decreased during follow‐up, with a mean decrease of 4.54% per year (p < 0.001), and 6.57% in the peripheral quadrant closest to the BV GDD tube (PQC, p < 0.001). In the PQC, a yearly decrease of 1.57% was shown after transiridial tube placement versus 7.43% after placement ‘free’ into the AC (p = 0.006). Endothelial cell (EC) loss was related to TC distance (mean 1.69 mm), with a central loss of 6.20% and 7.25% in the PQC per year with shorter TC distances, versus a central loss of 4.11% and 5.77% in the PQC per year with longer TC distances (outside mean ± 2SD, p < 0.001). A difference in EC loss by glaucoma subtype was not identified.

Conclusion

The TC distance is of significant influence on corneal ECD, a shorter TC distance causing more severe EC loss, especially in the PQC. Transiridial placement of the BV GDD tube seems safer than placement ‘free’ into the AC.

Horseshoe crab, Tachypleus gigas (Müller, 1785) spawning population at Balok Beach, Kuantan, Pahang, Malaysia

Local and regional decline of Asian horseshoe crabs has spurred a study on its spawning population at Balok Beach, Kuantan, Pahang, Malaysia. This location was identified as spawning site due to the occurrence of horseshoe crab spawning pairs and nests. Size-frequency, length-weight relationships, sex ratio and epibiont infestation of Tachypleus gigas were studied. Instar stage was estimated based on prosomal width. Condition of the horseshoe crab carapace was reported. Visual search technique of horseshoe crab was conducted during high tide of new and full moons. Prosomal, opisthosomal and telson length and weight of each horseshoe crab were measured. Largest female was recorded with mean prosomal length and width of 154.4 and 246.9 mm, respectively. About 69.8% of the males belonged to size group of 151-200 mm and 53.3% of females were grouped into 201-250 mm. All individuals were of fourteenth to sixteenth instar stages. Sex ratio varied from 0.313 to 2.5 and attributed to commercial harvest and monsoon season. Sand sediment of study site showed 93% of fine sands with grain size ranged from 120 to 250 microm. Acorn and pedunculate barnacle, conical and flat slipper shells were found on the carapace of the specimens. Most males had damaged eyes and carapaces while females with broken telsons. Body damages of about 19.9% on the specimens were likely due to nearby fishing activities. Lack of satellite male indicated low spawning population. The finding of this study showed that the species is extremely threatened by human activities and coastal development.

Reproducibility of anterior chamber angle measurements with anterior segment optical coherence tomography

PURPOSE

To study the reproducibility and variability of iridocorneal angle (ICA) measurements by using anterior segment optical coherence tomography (AS-OCT) by expert and nonexpert observers.

METHODS

Twenty-three healthy volunteers (nonexperts with a basic knowledge of ophthalmology) acquired five consecutive AS-OCT images in the enhanced anterior segment single mode in the 180° to 0° meridian of the right eyes of their peers. Two experts and the 23 nonexperts analyzed the images. The ICA software tool was used to determine the angle opening distance (AOD) and the trabecular iris surface area (TISA) at 500 and 750 μm. A random intercept model was fitted to evaluate the variability of acquiring an image. For both the experts and the nonexperts, inter- and intraobserver variability of analyzing an AS-OCT image was determined with the coefficient of variation (CV). Reproducibility was qualified by using the intraclass correlation coefficient (ICC).

RESULTS

There was no statistically significant difference in the variability of acquiring an image. The range of intraobserver variability in image analysis was from 9.4% to 12.5% in the experts and from 4.2% to 17.4% in the nonexperts. Interobserver variability was 10.7% in the experts and 10.2% in the nonexperts. The reproducibility was high, 0.875 and 0.942 in the experts and 0.906 in the nonexperts.

CONCLUSIONS

The overall reproducibility of the ICA measurements with the AS-OCT is good in open angles. Inter- and intraobserver variability showed similar mean values of reproducibility between the experts and nonexperts. The wide range of intraobserver variation in the nonexperts suggests that this group should undergo extensive instruction before routinely analyzing AS-OCT images.

Baerveldt implant for secondary glaucoma due to iris melanoma

BACKGROUND

Proton beam therapy (PBT) is effective in the treatment of iris melanoma. Reported complications after PBT are radiation-induced cataract and raised intraocular pressure (IOP). Filtering glaucoma surgery has generally been avoided because of fears of seeding.

CASE REPORT

A 37-year-old man presented with a self-discovered, pigmented lesion on his right iris. Four years later, the pigmented lesion was diagnosed as an iris melanoma, because of documented growth. The patient was treated with PBT but developed secondary glaucoma one month later. The IOP could not be controlled despite maximal medical therapy and selective laser trabeculoplasty (SLT). Finally, Baerveldt implant surgery was performed, resulting in an IOP lowering to 10 mmHg and stabilization of the glaucomatous visual field loss.

CONCLUSION

Our case demonstrates that Baerveldt implant surgery is a reasonable therapy for glaucoma following successful radiotherapy of iris melanoma.