Rossen Mihaylov Hazarbassanov

Topographic patterns in refractive surgery candidates.

Purpose: To evaluate the prevalence of different topographic patterns in refractive surgery candidates and to estimate the extent of candidate rejection based on topography alone. Methods: We performed a retrospective evaluation of videokeratographies of previously unoperated refractive surgery candidates. The defined topographic patterns of their corneas and the indices computed by the videokeratographer software were registered. The data were evaluated by SPSS/PC statistical software. Results: One hundred candidate electronic topography records were evaluated. The candidates included 41 women and 59 men whose average age was 32 years (range 17.5–63.5). Their topographic patterns were: spherical (36/200 evaluated eyes), spherocylindrical (60), upper steep (32), lower steep (43), irregular astigmatism (9), decentered (3), suspected keratoconus (11), and probable keratoconus (6 eyes). Rejection from undergoing the procedure was based on topography alone in 27 of the 200 eyes. It was difficult to decide what to do with the 43 eyes with a lower steep pattern, and they were eventually rejected. Of the nine software-calculated indices, only one, “keratoconus index,” could distinguish between the spherocylindrical and the lower steep patterns. Conclusions: More than one-half of corneal topographies of refractive surgery candidates did not comply with the assumed “normal” spherical or spherocylindrical patterns. The possible continuum of keratoconus-suspected keratoconus–lower steep pattern raises the question of where to draw the line between reasonable and risky when considering corneal refractive surgery.

Minor salivary glands and labial mucous membrane graft in the treatment of severe symblepharon and dry eye in patients with Stevens–Johnson syndrome

Objective To evaluate minor salivary glands and labial mucous membrane graft in patients with severe symblepharon and dry eye secondary to Stevens–Johnson syndrome (SJS). Methods A prospective, non-comparative, interventional case series of 19 patients with severe symblepharon and dry eye secondary to SJS who underwent labial mucous membrane and minor salivary glands transplantation. A complete ophthalmic examination including the Schirmer I test was performed prior to and following surgery. All patients had a preoperative Schirmer I test value of zero. Results Nineteen patients with severe symblepharon and dry eye secondary to SJS were included in the study. There was a statistically significant improvement in the best spectacle-corrected visual acuity in eight patients (t test; p=0.0070). Values obtained in the Schirmer I test improved significantly in 14 eyes (73.7%) 6 months following surgery (χ2 test; p=0.0094). A statistically significant increase in tear production (Schirmer I test) was found in eyes that received more than 10 glands per graft compared with eyes that received fewer glands (χ2 test; p=0.0096). Corneal transparency improved significantly in 11 (72.2%) eyes and corneal neovascularisation improved significantly in five eyes (29.4%) (McNemar test; p=0.001 and p=0.0005). The symptoms questionnaire revealed improvement in foreign body sensation in 53.6% of the patients, in photophobia in 50.2% and in pain in 54.8% (Kruskal–Wallis test; p=0.0167). Conclusion Labial mucous membrane and minor salivary glands transplantation were found to constitute a good option for the treatment of severe symblepharon and dry eye secondary to SJS. This may be considered as a step prior to limbal stem cell and corneal transplantation in these patients.

Phototherapeutic Keratectomy for the Treatment of Corneal Opacities After Epidemic Keratoconjunctivitis

PURPOSE To assess visual results and compare methods of measuring central corneal thickness (CCT) and corneal opacity thickness (COT) in patients with corneal opacities induced by epidemic keratoconjunctivitis (EKC) and treated with phototherapeutic keratectomy (PTK) using low-dose mitomycin C (MMC). DESIGN Prospective consecutive case series. METHODS Patients with chronic adenoviral corneal opacity underwent transepithelial PTK with MMC 0.002% for 1 minute. The presence of photophobia, the best spectacle-corrected visual acuity (BSCVA), and the contrast sensitivity were evaluated. CCT measurements were obtained with ultrasound pachymeter (US), ultrasound biomicroscopy (UBM), Scheimpflug tomography (Pentacam Oculus), and optical coherence tomography (OCT Visante). COT measurements were obtained with UBM, Pentacam, and OCT. RESULTS Thirty-one eyes of 23 patients, comprising 15 women (65.2%) and 8 men (34.8%), mean age 41.8 years, were enrolled in the study. Duration of visual disturbance was 19.1 ± 14 months. The number of patients with photophobia was reduced from 100% to 29% after surgery. BSCVA improved 2 or more lines in 78% of the patients at 12 months. A hyperopic shift of 1.52 ± 0.91 diopters was achieved. Contrast sensitivity improved in both photopic and mesopic conditions. For each of the instruments, the CCT postoperative mean was significantly smaller than the preoperative measurement (P < .0001) and COT values were significantly reduced in comparison to the preoperative values (P < .001). CONCLUSION Improvements in photophobia, BSCVA, and contrast sensitivity were observed in patients treated using excimer laser PTK with low-dose MMC for subepithelial infiltrates.

Pentacam Scheimpflug Evaluation of Corneal Volume After LASIK

PURPOSE To assess the change in corneal volume and laser ablation volume over time after LASIK using a rotating Scheimpflug camera. METHODS Twenty-six patients (49 eyes) underwent LASIK. Pentacam Scheimpflug measurements were performed pre- and postoperatively at 1, 3, 7, 15, and 30 days. Central corneal thickness, total corneal volume (10-mm diameter), and partial corneal volumes (3, 5, and 7 mm) based on the apex of the cornea, were measured. Main outcome measures were differences between pre- and postoperative volume measurements of total and partial corneal regions, volume changes over time postoperatively, and comparison between laser ablation volume and corneal volume. RESULTS A strong linear relationship was noted between spherical equivalent refraction and laser ablation volume (r = -0.931, P < .0001). Furthermore, 30 days after LASIK, a strong linear relationship was noted between planned thickness and achieved thickness (r = 0.9457, P < .001). Corneal volumes for 3-, 5-, and 7-mm diameter regions significantly decreased over time postoperatively (one-way analysis of variance, P < .05). CONCLUSIONS Alterations in corneal volume correlated with laser ablation volume when the diameter of the region considered was 3, 5, or 7 mm from the corneal apex.

Effect of a light-emitting timer device on the blink rate of non-dry eye individuals and dry eye patients

Purpose To evaluate blink rate effects by a novel light-emitting diode (LED) timer device (PISC) on non-dry eye (DE) subjects and DE patients during a reading task on liquid crystal display (LCD) screens, in different environmental conditions. Methods This was a case–control study that included 15 DE patients and 15 non-DE subjects as controls. Participants had their blink rates measured while they read an electronic format text. These tasks were performed in four different conditions: with and without a LED timer device in two visits, and with and without air conditioning. All participants completed the Ocular Surface Disease Index and were examined by best spectacle-corrected visual acuity exam, biomicroscopy, Schirmer test 1, fluorescein staining and break-up time and lissamine green staining (Oxford scale grading). Results Outcomes between reading tasks conditions were compared independently for each group and blink rate frequency was higher in tasks with LED timer device, with and without air conditioning, for the DE group (p<0.0001), and with air conditioning for the control group (p<0.05). Conclusions An LED timer device increased blink frequency for DE and control groups. Further studies need to be carried out in order to evaluate long-term effects of this new device, as well as its assessment with different reading scenarios.

Late-onset laser in situ keratomileusis-related corneal ulcer--a case series.

Purpose: To report 4 cases of flap margin-related corneal ulcer that developed 5 years after laser in situ keratomileusis (LASIK) procedures. Methods: We retrospectively documented the clinical and laboratory characteristics of all patients between 2004 and 2008 who presented with LASIK-related corneal ulcer that appeared >5 years postoperatively. The 4 patients who had this condition were 25-, 33-, 61-, and 62-year-old males. Results: Two patients had cultures positive to Staphylococcus aureus and Streptococcus epidermidis. Two ulcers healed after standard fortified topical antibiotic regimen, 1 ulcer healed after treatment with moxifloxacin, and the fourth healed after treatment with lomefloxacin. All cases presented 5 years after the LASIK procedure. Conclusions: LASIK procedures can be associated with the risk of corneal infection even years later. The mechanism may be flap margin instability causing epithelial defense barrier disturbance.

Conjunctival epithelial cells cultivated ex vivo from patients with total limbal stem cell deficiency

Purpose Reconstruction of the ocular surface is challenging. As an alternative to mucosal and limbal epithelial, we study the feasibility of cultivated human conjunctival epithelial (HCjE) cells of patients with total limbal stem cell deficiency (LSCD). Methods We studied superior forniceal conjunctival biopsies harvested from 9 living donors with total LSCD of several etiologies who underwent surgery for ocular surface reconstruction. The conjunctival explants were cultivated on serum and growth factor supplemented DMEM/F12 under submerged conditions on denuded human amniotic membrane and tissue culture dishes. The area of cell growth was assessed. Cell morphology was analyzed by light microscopy, impression cytology, and transmission electron microscopy. Cultures were evaluated for epithelial cytokeratins (CK3, CK19), proliferation marker (Ki-67), and putative stem cells markers (ABCG2 and p63). Confocal immunofluorescence was also performed to assess CK3, CK19, Ki-67, ABCG2, and p63. Results The HCjE cells cultivated ex vivo were successfully expanded on denuded amniotic membrane but with a slower growth than in the tissue culture dish. Transmission electron microscopy showed stratified epithelium with microvilli, desmosomes, and hemidesmosomes. Impression cytology showed PAS+ cells that resembled goblet cells. Immunocytochemical analysis showed positivity for CK3, CK19, Ki-67, ABCG2, and p63. Confocal immunofluorescence was positive for CK3, CK19, Ki-67, ABCG2, and p63. Conclusions Our results showed that it is possible to cultivate HCjE cells ex vivo of patients with ocular surface diseases. This method is important for ocular surface reconstruction in patients with bilateral total LSCD.

Topical Osmoprotectant for the Management of Postrefractive Surgery-Induced Dry Eye Symptoms: A Randomised Controlled Double-Blind Trial

Background Dry eye disease (DED) is one of the most common complications following refractive surgery. Purpose Evaluate the efficacy of an osmoprotective eye drop (Optive®) for the management of induced DED in refractive surgery patients. Design Double-masked randomised controlled trial. Methods Twenty-two refractive surgery patients oriented to apply FreshTears (FT; n = 13) or Optive (Op; n = 9), topically, QID, for 3 months. Eye exams were performed before surgery (T0) and 1-month (T1) and 3-month (T3) follow-up and consisted of tear film osmolarity, Schirmer 1 test, tear film breakup time (TBUT), fluorescein staining, and ocular surface disease index (OSDI) and patient symptoms questionnaires. Main Outcome Measures Pain and osmolarity. Results Pain increased significantly for FT at T3 (p < 0.05). A reduction in osmolarity was observed at T1 and T3 for Op group (p < 0.01) and at T3 for FT group (p < 0.05). TBUT showed a decrease between T0 and T1 for FT (p < 0.05). Schirmer 1 values increased significantly for Op in T1. Conclusions Op was superior to FT in regard to pain, osmolarity, TBUT, and Schirmer 1. Osmoprotectant solutes, such as L-carnitine, could attenuate inflammation and secondary DED. Osmoprotective lubricants can be effectively applied for the prevention of refractive surgery-related dry eye symptoms and signs.

Evaluation of galectin-1 and galectin-3 as prospective biomarkers in keratoconus

Aims To evaluate the expression of β-galactoside-binding proteins galectin (Gal)-1 and Gal-3 in patients with keratoconus (KC) and postcorneal collagen cross-linking (CXL) treatment in vitro. Methods Tear fluid, cornea samples and conjunctival impression cytology specimens from control and KC patients were used to evaluate Gal-1 and Gal-3 expressions. Primary keratocytes were isolated by collagenase digestion from surgically removed corneas of five normal or KC human corneal buttons and cultured in Dulbecco’s modified eagle medium/Ham’s F12 medium supplemented with 2% fetal bovine serum. These cells were evaluated under two experimental conditions: control and submitted to the application of ultraviolet A light and riboflavin 0.1% (CXL) for 30 min. Results Patients with KC displayed increased levels of Gal-1 and Gal-3 in conjunctival epithelial cells compared with control. Furthermore, KC corneas were associated with intense expression of Gal-1 in the stroma, released by keratocytes. Ultrastructural analysis of keratocytes showed a marked increase of endogenous Gal-3 levels, but not Gal-1, in KC. In vitro, CXL induced significant release of Gal-1 in keratocyte supernatants (116±18 ng/mL, P<0.05) and decreased inflammatory biomarkers as interleukin (IL)-6, IL-8, matrix metalloproteinase (MMP)-2 and MMP-9. Gal-3 levels were not detected in the keratocyte supernatants. Conclusion Gal-1 and Gal-3 represent new interesting KC biomarkers as revealed by their different expression patterns in KC and control corneal samples. CXL has an immunosuppressive effect on keratocytes by reducing the release of cytokines and MMPs and increased expression of anti-inflammatory protein Gal-1.

Conjunctival impression cytology evaluation of patients with dry eye disease using scleral contact lenses

PURPOSE To evaluate conjunctival impression cytology and HLADR expression changes after wearing scleral contact lenses (ScCLs) for moderate to severe dry eye disease (DED). DESIGN Prospective interventional case series. METHODS Forty-one eyes from 25 patients with moderate to severe DED were evaluated for Esclera ScCL treatment. Best-corrected visual acuity (BCVA) and slit-lamp findings were assessed. Impression cytology specimens were obtained from DED patients at the baseline and after wearing ScCLs for 12 months. The impression cytology specimens were analyzed using morphological results score, and HLA-DR positive cells were detected and quantified. The values were compared to assess the IC changes after wearing ScCLs. RESULTS Forty-one eyes from 25 patients were fitted with ScCLs to manage DED. The underlying diseases were Stevens-Johnson syndrome (22 eyes), Sjogrens syndrome (11 eyes), graft-versus-host disease (2 eyes), dry eye after keratomileusis (2 eyes) and undifferentiated ocular surface disease (4 eyes). The HE-PAS impression cytology score did not differ significantly before and after wearing ScCLs for 12 months in DED patients (p>0.05). The percentage of eyes expressing the HLA-DR antigen in the temporal conjunctiva after wearing ScCL for 12 months significantly increased in patients with Sjogrens syndrome (11.11% to 66.66%; p=0.0498). In groups with Stevens Johnson syndrome and other ocular surface disorders, we did not observe statistically significant differences (p>0.05). CONCLUSIONS The ScCLs did not change the parameters used to evaluate inflammatory processes, which were measured using conjunctival impression cytology and HLA-DR expression, except in Sjogren syndrome, in which there was an unexpected increase in HLA expression.