Central Haze Research Articles

Bilateral Corneal Endotheliitis Following Corneal Cross-linking with Riboflavin and Ultraviolet A.

This case report aims to document a case of bilateral endotheliitis occurring shortly after riboflavin-assisted cross-linking (CXL) in a young male patient with progressive keratoconus. The objective is to identify potential risk factors, treatment strategies, and outcomes while considering relevant literature on similar cases. A male in his late adolescence with bilateral progressive keratoconus underwent bilateral CXL using riboflavin and ultraviolet A light exposure. Postoperatively, the patient received moxifloxacin drops, prednisolone acetate drops, and artificial tears. Seven days later, the patient presented with decreased vision, photophobia, and corneal findings consistent with endotheliitis. Treatment with prednisolone acetate and moxifloxacin eye drops was initiated. Two months later, visual acuity deteriorated, but anterior slit-lamp findings improved, and the intraocular pressure measurement was high. Prednisolone acetate was tapered, whereas loteprednol etabonate gel, brimonidine eye drops, and cyclosporine eye drops were initiated. After 7 months, visual acuity improved, and endotheliitis resolved, although mild residual central haze persisted. This case highlights the occurrence of acute idiopathic endotheliitis following routine CXL and its successful management. Although limited cases have been reported, a standardized treatment protocol is lacking. In our patient, the utilization of loteprednol etabonate gel, cyclosporine eye drops, brimonidine eye drops, and regular follow-up examinations led to improved clinical findings and visual acuity. Further studies are warranted to establish optimal treatment approaches for similar cases of endotheliitis following CXL.

Peripheral sterile corneal infiltrate after cross linking in keratoconus: A case report

Aims/Purpose: The aim of our work is to describe the clinical aspect of sterile corneal infiltrates after cross linking and to evaluate the risk factors involved in their occurrence.Methods: We report the case of a young girl, followed for bilateral keratoconus having made a cross linking which was complicated by sterile catarrhal infiltrates.Results: This is a 15 years old girl, followed for allergic conjunctivitis with notion of self‐medication. The ophthalmological examination on admission found a visual acuity with correction counting fingers at 1 metre in oculus uterque (OU), some conjunctival papillae, minimal blepharitis, clear cornea, cortico‐nuclear cataract ocular tone was 10 mmHg in OU, normal fundus in OU. A corneal topography was performed showing signs of bilateral keratoconus classified as stage III according to the Krumeich classification. An emergency cross linking was indicated in OU starting with the OL, the patient was put on a topical antibiotic treatment, artificial tears with a daily control. At 4 days post‐op, the cornea had completely re‐epithelialized with the presence of a slight central haze and the appearance of 2 inferior stromal opacities of 1 mm/1 mm associated with a crescent infiltrate and 2 similar superior stromal opacities taking the fluorescent in front of the free edge. A corneal swab was taken for bacteriological, mycological and parasitological study and came back negative. The patient was initially put on ceftazidime and vancomycin based eye drops with a blepharitis treatment based on azyter collyrium lavage and artificial tear. The examination 48 h later showed persistence of stromal opacities without taking fluo. A local corticosteroid therapy was started with strict monitoring. The evolution was marked by an almost total regression of the stromal opacities and a disappearance of the central haze. The diagnosis of sterile infiltrate was made in view of the marked clinical improvement under local corticosteroid therapy and the absence of germs in the corneal sample.Conclusions: Evaluation of risk factors showed that epithelial injury may be the common pathway in pathogenesis, as no sterile infiltrate in Epi‐on CXL occurred, and postoperative NSAIDs use increased the risk of developing sterile infiltrates approximately fourfold.

Central corneal distortion after small-incision lenticule extraction.

A 33-year-old woman with a prior history of small-incision lenticule extraction (SMILE) presented with gradual deterioration of vision in her right eye since the surgery. She had undergone bilateral SMILE for myopic correction (-7.00 diopters [D] in the right eye and -6.00 D in the left eye) 3 weeks prior. SMILE was performed with a Zeiss VisuMax femtosecond laser system, with a cap thickness of 120 µm, a cap diameter of 7.50 mm, and a lenticule diameter of 6.50 mm. At the completion of the surgery, loose epithelium was noted at the SMILE incision bilaterally, and bandage contact lenses were placed in both eyes. On the first postoperative day, the patient's uncorrected distance visual acuity (UDVA) was 20/40 in both eyes. The bandage lenses were removed from both eyes, with the epithelium intact. At the first-week postoperative visit, her visual acuity was recorded as 20/30 in the right eye and 20/20 in the left eye. She noticed her vision in the right eye was not as sharp as that in her left eye. She denied experiencing any pain, redness, or ocular surface irritations. She was advised to return to the clinic for a 1-month postoperative visit and continue with aggressive lubrication in both eyes. However, a week later, the patient returned for an emergency visit, citing significant central visual distortion in the right eye and difficulty working on the computer. At this visit, her UDVA and corrected distance visual acuity (CDVA) was 20/50 in the right eye and 20/15 in the left eye at both near and far distances. A slitlamp examination revealed mild central changes in the right eye. She once again denied any pain, redness, or irritation. She was advised to continue with artificial tears and return to the office in 1 week for further observation of the central distortion in her right eye. Upon returning to the clinic at the third postoperative week, the patient still complained of central visual changes in the right eye, with a visual acuity of 20/70. Further slitlamp examination revealed a nonspecific central haze in the same eye, but there was no corneal staining or signs of epithelial defects. Anterior segment ocular coherence tomography (AS-OCT) and NIDEK topography were performed, showing the same central distortion in the right eye (Figures 1 and 2JOURNAL/jcrs/04.03/02158034-202311000-00016/figure1/v/2023-10-18T004638Z/r/image-tiffJOURNAL/jcrs/04.03/02158034-202311000-00016/figure2/v/2023-10-18T004638Z/r/image-tiff). Based on the examination and images provided, what is your working medical diagnosis? What other medical conditions are in your differential diagnosis? What medical and/or surgical interventions would you recommend, if any?

Stromal Rejection after Deep Anterior Lamellar Keratoplasty (DALK) - A Retrospective Study

Aim: To report and analyse the incidence of stromal rejction, which is a central island of flattening of the graft associated with thinning in patients who underwent DALK for keratoconus. Materials & Methods: Retrospective review of patients who underwent DALK for progressive keratoconus from 2010 to 2013 was done. Patients who completed 2 years of follow up were included. Slit lamp findings, corneal topography and central corneal thickness were analysed.122 eyes of 71 patients were analysed. Uncorrected visual acuity (UCVA) and best corrected visual acuity (BCVA) were analysed in each visit Results: Thirty one eyes of thirty one patients showed topographic evidence of Central Island of flattening which correlated with slit lamp finding of stromal haze of varying density. The pachymetry reading of the central cornea varied from 400 to 479µ and correlated with topographic finding of flattening. The average onset of central stromal haze was at 9 months post DALK. None of the patients had bilateral involvement. The central haze progressed over time and was associated with thinning of the cornea. The onset and progression of central flattening was associated with corresponding decrease in UCVA and BCVA. No epithelial defect was noted. Conclusion: 25.4% of keratoconus patients who underwent DALK developed a central island of flattening with associated decrease in the visual acuity. The central haze, flattening and thinning may be a chronic stromal rejection or progressive thinning of cornea associated with disease process of keratoconus.

Repeat Descemet Membrane Endothelial Keratoplasty: Secondary Grafts with Early Intervention Are Comparable with Fellow-Eye Primary Grafts

To evaluate the outcomes of secondary Descemet membrane endothelial keratoplasty (DMEK) after failed primary DMEK. Retrospective, interventional case series. Fifty-five DMEK recipients 42 to 89 years of age. An initial consecutive series of 1655 DMEK surgeries was reviewed to identify cases of secondary DMEK after failed primary DMEK (n = 55). A paired fellow-eye analysis was performed with a subgroup of 29 patients who underwent secondary DMEK in 1 eye and successful primary DMEK in the fellow eye. Corrected distance visual acuity (CDVA), central corneal thickness, and 1-year endothelial cell loss. The median follow-up after DMEK regraft was 18 months (range, 3-61 months). All 55 regrafts cleared, 8 (15%) had air reinjected to promote attachment, 1 eye (2%) with trabeculectomy and progressive synechiae demonstrated late endothelial failure, and no rejection episodes occurred (0%). In the paired analysis, the median duration of endothelial decompensation before the regraft was 21 days (range, 2-133 days). At 1, 3, 6, or 12 months, CDVA did not differ between the primary and secondary grafts in fellow eyes (mean difference, ≤2 Snellen letters; P > 0.05 at all examinations). At 1 year, the visual acuity was ≥20/20 in 61%, ≥20/25 in 81%, and ≥20/40 in 100% of the secondary grafts in the paired analysis, excluding 1 eye with retinal problems. Vision differed by ≤1 line between fellow eyes in all but the 1 patient with the longest time to regraft (133 days), who demonstrated central haze and irregular astigmatism from anterior stromal scarring during that period. At 1 year, CDVA associated with the scarring was 20/40 versus 20/20 for the fellow-eye primary graft. The central corneal thickness was comparable between fellow-eye primary and secondary grafts at 3, 6, and 12 months (mean difference at 1 year, 2 μm; P = 0.57). The 1-year endothelial cell loss was comparable in primary and secondary grafts (27% vs. 31%, respectively; P = 0.58). In patients who received prompt intervention to minimize the duration of central corneal decompensation, the visual outcomes with secondary DMEK matched the fellow-eye visual outcomes with primary DMEK.

Transepithelial Versus Epithelium-off Corneal Cross-linking for the Treatment of Progressive Keratoconus: A Randomized Controlled Trial

To compare the clinical effects and safety of transepithelial corneal cross-linking (CXL) to epithelium-off (epi-off) CXL in progressive keratoconus. Randomized clinical trial (noninferiority). Patients received either transepithelial CXL with Ricrolin TE (n= 35) or epi-off CXL with isotonic riboflavin (n= 26) in 1 academic treatment center, using a simple unrestricted randomization procedure. The main outcome measure was clinical stabilization of keratoconus after 1 year, defined as a maximal keratometry (Kmax) increase <1 diopter (D). Average Kmax was stable at all visits in the transepithelial group, while after epi-off CXL a significant flattening of 1.2-1.5 D was demonstrated from the 3-month follow-up onwards. The trend over time in Kmax flattening was significantly different between the groups (P= .022). Eight eyes (23%) in the transepithelial group showed a Kmax increase of >1 D after 1 year (range 1.3-5.4 D) vs none in the epi-off group (P= .017). There was significant different trend in corrected distance visual acuity (CDVA), with a more favorable outcome in the transepithelial group (P= .023). In the transepithelial group, no complications occurred and in the epi-off group, 4 eyes (15%) developed complications owing to healing problems (sterile infiltrate, herpes keratitis, central haze, and stromal scar). This study showed that although transepithelial CXL was a safe procedure without epithelial healing problems, 23% of cases showed a continued keratoconus progression after 1 year. Therefore, at this time, we do not recommend replacing epi-off CXL by transepithelial CXL for treatment of progressive keratoconus.

A Case of Schnyder Corneal Dystrophy with Crystals

To report a rare corneal dystrophy and its common findings to help aid others in proper and early diagnosis and management. A 56-year-old male patient presented with the concern of blurry vision in both eyes that has progressed over the last 10 years. Anterior segment examination revealed arcus with a central haze in both eyes and crystalline deposition in the right eye. A diagnosis of Schnyder corneal dystrophy was made based on clinical presentation. Schnyder corneal dystrophy is rare but has different presentations and may actually be misdiagnosed. The clinical signs change as the patient ages causing a decrease in vision, which may necessitate referral for phototherapeutic keratectomy, penetrating keratoplasty or deep anterior lamellar keratoplasty. The patient's systemic findings that correlate with the dystrophy need to be assessed and managed appropriately.

Surgical flap amputation for central flap necrosis after laser in situ keratomileusis

A 52-year-old man had uneventful bilateral myopic laser in situ keratomileusis (LASIK) with planned monovision. Three months later, the left eye was retreated to improve the near vision. On postoperative day 1, the uncorrected distance visual acuity (UDVA) was 0.95 and the patient reported mild ocular pain. Stage 2 diffuse lamellar keratitis was observed. Despite hourly prednisolone instillation, the UDVA decreased to 0.1 and central flap necrosis syndrome was diagnosed. The flap was lifted and stromal bed irrigation performed. One month later, the UDVA was 0.05 with a hyperopic shift of +3.25 diopters and the flap, which had central haze and several striae, was amputated. Four months later, the UDVA was 0.05 with residual irregular astigmatism. Customized transepithelial photorefractive keratectomy (PRK) was performed; there were no postoperative complications. Three months after PRK, the UDVA was 0.8 with no refractive defect.

Contact Lens-Induced Keratitis Resembling Central Toxic Keratopathy Syndrome

To document a case of contact lens-induced keratitis resembling central toxic keratopathy syndrome. A 23-year-old female developed an acute, central, stromal haze subsequent to soft contact lens overwear. Slit lamp examination revealed corrugated stromal "mud cracks," as seen in stage IV diffuse lamellar keratitis (DLK). This was accompanied by relative corneal thinning and flattening with a hyperopic shift of approximately 6 diopters. Eight weeks after discontinuing contact lens wear and after a 2-week tapering regimen of topical steroids, she had partial resolution of the central haze, partial increase in corneal thickness, steepness, and decrease in hyperopic shift. The authors present a case with a history of soft contact lens overwear and a clinical presentation notably similar to the central toxic keratopathy syndrome, which has recently been reported after laser refractive surgery.

Customized Topography-guided Photorefractive Keratectomy With the MEL-70 Platform and Mitomycin C to Correct Hyperopia After Radial Keratotomy

To evaluate topography-guided photorefractive keratectomy (PRK) for correcting hyperopia and astigmatism after radial keratotomy (RK). Prospective study of 12 consecutive patients (19 eyes) who were treated with topography-guided PRK with 0.02% mitomycin C using an Asclepion-Meditec MEL-70 excimer laser with a 9.5-mm ablation zone. All eyes were operated by the same surgeon and followed for 1 year. Thirteen eyes had complete epithelialization by day 7 and all eyes by day 10. At 1 year, uncorrected visual acuity was 20/25 or better in 42.1% of eyes and 20/40 or better in 68.4%. Preoperative mean spherical equivalent refraction was +3.80+/-2.47 diopters (D) and +0.24+/-2.36 D (P<.001) 1 year postoperative, with 47.4% of eyes being within +/-1.00 D and 73.7% within +/-2.00 D. Preoperative mean cylinder was -2.30+/-1.41 D and -0.62+/-0.73 D (P<.001) 1 year postoperative. At 1 year, 68.4% of eyes gained at least 1 line of best-spectacle corrected visual acuity, 36.8% gained more than 1 line, and only 2 eyes lost 1 line (one due to corneal haze). Three eyes developed central haze. Mean regression from 6 to 12 months in these 3 eyes was +1.83 D and in the remaining 16 eyes was -0.50 D. Topography-guided PRK with mitomycin C was safe and reasonably effective for the treatment of hyperopia after RK.