Hikmet Özçetin

Tear function and ocular surface changes in keratoconus

PURPOSE To describe the ocular surface disorder in patients with keratoconus. DESIGN A prospective, case-controlled study. PARTICIPANTS Seventy-five eyes of 38 patients with keratoconus seen at Uludag University School of Medicine, Department of Ophthalmology, from March 2000 through April 2001, and 80 eyes of 40 normal control subjects were studied. INTERVENTION The subjects underwent routine ophthalmic examinations, corneal sensitivity measurements, Schirmer test, tear film breakup time (BUT), fluorescein and rose bengal staining of the ocular surface, and conjunctival impression cytology. MAIN OUTCOME MEASURES Patients and control subjects were compared for corneal sensitivity, tear function, ocular surface staining parameters, goblet cell density, and squamous metaplasia grade. The relation of these parameters to the severity of keratoconus progression was also investigated. RESULTS The mean corneal sensitivity was significantly lower in keratoconus patients compared with control subjects (P < 0.001). The BUT values were also significantly lower in the keratoconus group. Patients with keratoconus had significantly higher fluorescein and rose bengal staining scores (P < 0.001). Corneal sensitivity and tear function changes seemed to get worse with advanced stages of keratoconus. Impression cytology showed goblet cell loss and conjunctival squamous metaplasia, both of which again related to the extent of progression of keratoconus. CONCLUSIONS The ocular surface disease in keratoconus is characterized by disorder of tear quality, squamous metaplasia, and goblet cell loss, all of which seem to relate to the extent of keratoconus progression.

Transsclerally Fixated Intraocular Lenses in Children

BACKGROUND AND OBJECTIVE To evaluate the visual outcome and complications of transsclerally fixated intraocular lenses (IOLs) in children without sufficient capsular support. PATIENTS AND METHODS Twenty-one aphakic eyes of 18 children (13 boys and 5 girls) who underwent secondary transscleral IOL fixation were evaluated retrospectively. Ten eyes with aphakia after infantile cataract surgery, 7 aphakic eyes following traumatic cataract surgery, and 4 eyes after ectopia lentis surgery received secondary transscleral posterior chamber IOL fixation because of by insufficient posterior capsular support. Visual outcomes and postoperative complications were recorded. RESULTS After a mean follow up of 22.5 months (range, 12 to 36 months), visual improvement of more than 2 Snellen lines was observed in 9 eyes (42.8 %). Preoperative visual acuity could not be assessed in 7 eyes (33.3%) because of associated neurological and developmental disorders. One eye (4.7%) lost 2 Snellen lines of the best corrected visual acuity because of concurrent endophthalmitis and retinal detachment. Pupillary distortion, transient pupillary membrane, pupillary capture as well as strabismus and anterior uveitis, were the most common complications. Endophthalmitis and retinal detachment were the most severe postoperative complications. CONCLUSION Transsclerally fixated IOL implantation may be visually rewarding in well selected pediatric cases, but the potential complications would suggest extreme caution in its consideration. Until long-term studies are published, it is difficult to recommend implantation unless it is deemed impossible to provide adequate rehabilitation by other means such as contact lenses or aphakic spectacles.

Primary repair and intraocular lens implantation after perforating eye injury

Purpose: To evaluate the clinical outcome after primary treatment of lens injuries with corneal or corneoscleral trauma. Methods: Ten eyes of 10 patients were retrospectively evaluated. There were no foreign bodies in any eye. After primary repair, an anterior chamber maintainer (ACM) was introduced through the inferotemporal corneal quadrant. Sodium hyaluronate 1.4% (Healon GV®) was injected, and the anterior capsule was stained with trypan blue 0.1% vital stain (Vision Blue®) under the viscoelastic substance. After a capsulorhexis was created, the lens material was aspirated. The nucleus was delivered from the scleral tunnel, which was opened from the superior/superotemporal corneal quadrant. A conventional 21.0 diopter poly(methyl methacrylate) intraocular lens (IOL) with a 5.5 mm optic and overall diameter of 12.5 mm (Dr. Schmidth®, Hannan Kibbutz) was implanted through the scleral tunnel. The scleral tunnel was not sutured, and the corneal entry sites were closed with stromal hydration. Results: The final best spectacle‐corrected visual acuity (BSCVA) was better than 20/100 in all patients, and 6 patients had a BSCVA of 20/20. The IOL was in the capsular bag in all patients at the last follow‐up. The mean follow‐up was 12.3 months (range 7 to 25 months). The main visually limiting factors were corneal scar, irregular astigmatism, and traumatic maculopathy. Conclusions: Primary IOL implantation in carefully selected patients with penetrating corneoscleral lens injury may yield visually rewarding results. The use of a vital stain to increase the visibility of the injured anterior capsule and of a closed scleral tunnel system with an ACM increased the surgical safety.

Diclofenac Sodium for the Prevention of Surgically­ induced Miosis

In this study, the effectiveness of topical diclofenac sodium (VOLTAREN OPHTHA) has been investigated in the prevention of surgically-induced miosis during extracapsular cataract surgery with posterior chamber intraocular lens implantation. A double-blind method was used: 35 patients were treated preoperatively with 0.1% diclofenac sodium and routine midriatics and the control group of 30 patients with only midriatics. In the diclofenac treated group, the mean pupil diameters were larger than the control group. On statistical analysis, the difference between the results of two groups has been found to be significant ( P t -test. Diclofenac sodium seems to be a promising drug for the maintenance of mydriasis during intraocular lens implant surgery.

Oculocardiac reflex in a nonsedated laser in situ keratomileusis patient.

A healthy 21-year-old man had laser in situ keratomileusis (LASIK) in the right eye for a refractive error of -7.0 diopters. The electrocardiogram findings and heart rate were recorded before LASIK; during eye lid speculum insertion, vacuum application, corneal flap preparation, and excimer laser keratectomy; and after the procedure. The pre-LASIK heart rate was 90 pulses/min. Severe bradycardia of 40 beats/min developed during vacuum application, and the procedure was terminated. Severe bradycardia caused by an oculocardiac reflex may occur during LASIK, and patients should be closely monitored during the procedure.

Ultrasound biomicroscopic evaluation of anterior segment cysts as a risk factor for ocular hypertension and closure angle glaucoma

AIM To investigate the relationship between the ultrasound biomicroscopic (UBM) features of anterior-segment cysts (ASCs) and increased intraocular pressure (IOP) as a risk factor for closed-angle glaucoma (CAG). METHODS Totally 24 eyes with recently diagnosed ASCs were divided into two groups. First group with ASC and ocular normotension (n=13), second group with ASC and ocular hypertension (n=11). An ophthalmologic examination, including tonometry, slit-lamp biomicroscopy (SLBM), gonioscopy, fundoscopy, pentacam, and UBM, was performed. The features of the ASCs were compared with the IOP. RESULTS ASCs were accurately diagnosed and delineated in 24 eyes using UBM. IOP was elevated in those ASCs with a secondary aetiology (P=0.027), iridociliary location (P=0.006), deformed shape (P=0.013), increased size (P=0.001) and elongated pupillary aperture (P=0.009). However, the count (P=0.343) of ASCs, anterior chamber depth (ACD; P=0.22) and axial lenght (AL; P=0.31) were not associated with ocular hypertension. Correlations were found between the IOP and ASC size (r=-0.712; P=0.003), anterior chamber angle (ACA; r=-0.985; P<0.001), angle opening area (AOA; r=0.885; P<0.001), angulation of iris (r=-0.776, P<0.001), and affected iris quadrant (r =-0.655, P=0.002). CONCLUSION Ocular hypertension in some eyes with ASC might be associated with various mechanisms, including secondary aetiology, iridociliary location, deformed shape, increased size and elongated pupill, which can be determined by UBM.

The effect of anterior chamber maintainer on anterior chamber contamination.

Purpose To evaluate the effect of anterior chamber continuous infusion maintainer system on the contamination of anterior chamber in phacoemulsification surgery. Methods Clear corneal phacoemulsification surgery was performed in 132 eyes of 132 randomly selected patients with cataract who were divided into two groups of 66 eyes according to the use of an anterior chamber maintainer (ACM) system. The fluid specimens were taken from anterior chamber in the beginning and at the end of the surgery. They were transferred under anaerobic conditions and investigated by culturing onto blood agar and thiogluconate broth media. Differences between the two groups with respect to contamination of the specimens were investigated. Results The mean age of the group undergoing surgery without a maintainer system (Group A) was 63±10 years (min = 41, max = 80) versus 59±10 years (min = 33, max = 80) in the other group (Group B) in which the maintainer was used during surgery. In the postoperative specimen, Micrococcus species were isolated from one eye (1.5%) in Group A and S. pyogenes in one eye (1.5%) from Group B. Mean follow-up interval was 12±6 (min = 4, max = 28) months. Conclusions The use of ACM system in clear corneal phacoemulsification surgery carries no additional risks as far as contamination is concerned.

A Clinical Comparison of Dynamic Contour Tonometry Versus Goldmann Applanation Tonometry

BACKGROUND AND OBJECTIVE To compare the intraocular pressures (IOP) obtained with dynamic contour tonometry (DCT) and Goldmann applanation tonometry (GAT) and to determine the dependency of both devices on corneal structure. PATIENTS AND METHODS One hundred forty eyes of 70 patients were included. Cases with corneal pathologies, former glaucoma diagnosis, and systemic diseases were excluded. All eyes underwent measurements of central corneal thickness (CCT) and corneal curvature. IOP measurements were obtained with GAT and DCT. The agreement of measurements was statistically analyzed. RESULTS The correlation of IOP values obtained with DCT and GAT was statistically significant. The mean DCT values were 0.46 ± 2.55 mm Hg higher than those of GAT, but this difference was statistically insignificant. Bland-Altman plots showed reasonable inter-method agreement between DCT and GAT measurements. GAT readings were significantly affected by CCT, but DCT measurements were affected by age and corneal curvature. CONCLUSION DCT is a reliable method of assessing IOP and is less dependent on central corneal thickness. This new technology may be a promising step forward in the management of glaucoma. Further studies are required to validate these observations.

Refractive outcomes after arcuate keratotomy using the Terry astigmatome

Purpose: To investigate the refractive outcomes after arcuate keratotomy for astigmatism. Setting: Uludag University, Faculty of Medicine, Department of Ophthalmology, Bursa, Turkey. Method: Sixteen eyes of 11 patients with astigmatism had arcuate keratotomy using the Terry astigmatome. The mean age of the patients was 36 years ± 10 (SD). All patients received preoperative and postoperative ophthalmic examinations consisting of best spectacle‐corrected (BSCVA) and uncorrected (UCVA) visual acuities, corneal topography, and ultrasonic pachymetry. Surgery was performed using topical anesthesia of oxybuprocaine 0.1% eyedrops. The Terry astigmatome was selected by the mean paracentral (estimated incision area) corneal thickness. All patients received topical ofloxacin 0.3% and topical diclofenac 0.1% eyedrops postoperatively. Results: The mean corneal astigmatism was −4.0 ± 1.1 diopters (D) (range −2.2 to −6.0 D) preoperatively and –1.8 ± 0.8 D (range −0.6 to −3.0 D) postoperatively. The mean surgically induced corneal astigmatism was 2.5 ± 0.6 D. The mean UCVA (logMAR) was 0.74 ± 0.25 preoperatively and 0.18 ± 0.23 1 week postoperatively, and the mean BSCVA (logMAR) was 0.19 ± 0.24 and 0.19 ± 0.23, respectively. There were no intraoperative or postoperative complications. Conclusion: Arcuate keratotomy using the Terry astigmatome was a safe and reliable treatment for corneal astigmatism.

Comment on “Comparison of Anterior Segment Optical Coherence Tomography Bleb Grading, Moorfields Bleb Grading System, and Intraocular Pressure After Trabeculectomy”

To the Editor: We read with interest the article entitled “Comparison of Anterior Segment Optical Coherence Tomography Bleb Grading, Moorefields Bleb Grading System, and Intraocular Pressure After Trabeculectomy.” by Wen et al.1 We congratulate the authors for introducing this novel, simplified anterior segment optical coherence tomography (ASOCT) bleb classification, and its correlation with a widely used clinical system; Moorefields Bleb Grading System (MBGS)2 as well as intraocular pressure. We have found the technique very practical and correlation results with the clinical parameters are quite promising. However, in our opinion the characteristics of each AS-OCT bleb grade (0 to 3) may not be descriptive enough in the article. One need additional data to be able to describe; “Larger blebs with greater bleb height and width and with lower internal reflectivity were given lower grades.”1 As authors stated in the discussion; AS-OCT bleb grading system evaluated each grade in terms of bleb height and extent, which had a good correlation with MBGS bleb height and area. Nevertheless, we believe better described and quantified features of different bleb grades may contribute this classification with higher interobserver and intraobserver reproducibility. We have presented “Classification of Blebs With OCT” (poster presentation at the 8th Congress of the European Glaucoma Society, Berlin, 2008) with regard to bleb assessment including bleb height (BH0-3), bleb extent (BE0-3) and the scleral flap position relative to the bleb. This classification, as we refer “Bursa Bleb Classification” was also published in an inclusive glaucoma textbook in Turkish3 (by the author O.H.; book cover in Fig. 1). You can see a table from the mentioned textbook in Figure 2; further definition of “Bursa Bleb Classification” with images of different bleb types, as well as grading system examples. Despite being a primitive technique that was established with Stratus OCT in 2008, this classification has been assisting us substantially during postoperative bleb follow-up and provides crucial data for indicators of failure. Throughout the following years, developments in OCT technology has allowed us to better visualize bleb features and their association with bleb functionality. Hereby, we acknowledge that internal reflectivity pattern has recently become an appreciable indicator to demonstrate the bleb morphology. In the present article, the authors established higher AS-OCT bleb scores with an increase of MBGS central vascularity grade.1 On the basis of this outcome and our clinical experience, we are also in agreement that lower internal reflectivity is related to lower grades, and it should be one of the criteria at the classification. In conclusion, we would like to contribute this novel AS-OCT bleb classification system by offering to define each grade (0 to 3) by its own maximum height (H0-3), maximum extent (E0-3) and internal reflectivity scores (R0-3). This manner might contradict with its simplicity, but we believe it would promote its reproducibility and specificity. FIGURE 1. Book cover of the textbook “Glokom. Tani, Tedavisive Tipleri” (English translation: Glaucoma. Diagnoses, Treatment, and Types) by the author Hikmet Ozcetin, 2nd revised edition, Bursa: Nobel Medical Publishers. In Turkish. Figure 1 can be viewed in color online at www.glaucomajournal.com.